High-damping rubber composition

Abstract

To provide a high-damping rubber composition capable of achieving a low dynamic-to-static modulus ratio and improving durability.SOLUTION: A rubber composition contains: an ethylenic rubbery polymer (A) in which the iodine value is 10-250 Ig / 100 g, the content of an ethylene structure is 3 mass% or more, the content of an aromatic vinyl monomer block is less than 10 mass%, and the content of a conjugated diene monomer unit is 2 mass% or more; and a rubbery polymer (B). When the total amount of a rubber component containing the ethylenic rubbery polymer (A) and the rubbery polymer (B) is 100 pts. mass, the amount of the ethylenic rubbery polymer (A) is 10 pts. mass or more and 90 pts. mass or less. When the total amount of the rubber component containing the ethylenic rubbery polymer (A) and the rubbery polymer (B) is 100 pts. mass, the amount of the rubbery polymer (B) is 10 pts. mass or more and 90 pts. mass or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a high-damping rubber composition that serves as the basis for a high-damping member that can reduce or absorb the transmission of vibration energy. [Background technology]

[0002] High-damping materials that mitigate or absorb the transmission of vibration energy are used in a wide range of fields, including buildings and bridges, industrial machinery, aircraft, automobiles, railroad cars, computers and their peripherals, household electrical appliances, and even automobile tires. Rubber-like polymers are generally used as the base polymer for high-damping materials that have functions such as seismic isolation, vibration control, vibration damping, and vibration isolation.

[0003] In the technical field of vibration-proof rubber, requirements include durability, heat resistance, suppression of increases in the loss factor tanδ, and low dynamic magnification (reducing the value of dynamic magnification [dynamic spring constant (Kd) / static spring constant (Ks)]).

[0004] Patent Document 1 listed below describes a technology for reducing the dynamic magnification and improving the durability of vibration-proof rubber by compounding 2 to 10 parts by weight of a specific composite zinc white with 100 parts by weight of a rubber component containing 5 to 30 parts by weight of styrene-butadiene rubber. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-89918 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the technical field of high-damping rubber, it is said to be particularly difficult to achieve both damping performance and durability, and there is a demand for achieving both of these properties at a high level.

[0007] The present invention has been made in view of the above problems, and an object of the present invention is to provide a high-damping rubber composition that can achieve a low dynamic magnification and improve durability. [Means for solving the problem]

[0008] As a result of extensive research into solving the problems of the prior art described above, the present inventors have found that the above object can be achieved by using a specific rubber-like polymer.

[0009] That is, the present invention is as follows. [1] an ethylene-based rubbery polymer (A) having an iodine value of 10 to 250 Ig / 100g, an ethylene structure content of 3% by mass or more, an aromatic vinyl monomer block content of less than 10% by mass, and a conjugated diene monomer unit content of 2% by mass or more; a rubbery polymer (B); Including, the amount of the ethylene-based rubbery polymer (A) is 10 parts by mass or more and 90 parts by mass or less, when the total amount of the rubber component including the ethylene-based rubbery polymer (A) and the rubbery polymer (B) is 100 parts by mass, The rubber composition, wherein the amount of the rubbery polymer (B) is 10 parts by mass or more and 90 parts by mass or less, when the total amount of the rubber component containing the ethylene-based rubbery polymer (A) and the rubbery polymer (B) is 100 parts by mass. [2] The rubber composition according to [1], wherein the rubber-like polymer (B) is at least one selected from the group consisting of natural rubber, polybutadiene, polyisoprene rubber, and ethylene-α-olefin-non-conjugated polyene copolymer. [3] The rubber composition according to [1] or [2], further comprising an inorganic filler (C), wherein the amount of the inorganic filler (C) is 30 parts by mass or more and 120 parts by mass or less, relative to 100 parts by mass of the total amount of the rubber component comprising the ethylene-based rubber-like polymer (A) and the rubber-like polymer (B). [4] The solubility parameter (SP value) of the ethylene rubber polymer (A) is 16.8 (MPa). 1 / 2 Above 17.5 (MPa) 1 / 2 The rubber composition according to any one of [1] to [3] below: [5] The rubber composition according to any one of [1] to [4], wherein the ethylene-based rubbery polymer (A) contains a nitrogen atom. [6] The rubber composition according to any one of [1] to [5], wherein the modification rate of the ethylene-based rubbery polymer (A) is 40% by mass or more. [7] A vulcanized rubber which is a vulcanizate of the rubber composition according to any one of [1] to [6]. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a high-damping rubber composition that is excellent in tensile strength, durability, etc. while satisfying the properties required of high-damping rubber, such as low dynamic magnification. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to the following embodiment. The present invention can be practiced by appropriately modifying it within the scope of its gist.

[0012] [Rubber composition] The high-damping rubber composition of this embodiment comprises an ethylene-based rubbery polymer (A) having an iodine value of 10 to 250 Ig / 100g, an ethylene structure content of 3% by mass or more, an aromatic vinyl monomer block content of less than 10% by mass, and a conjugated diene monomer unit content of 2% by mass or more, and a rubbery polymer (B), wherein the amount of the ethylene-based rubbery polymer (A) is 10 parts by mass or more and 90 parts by mass or less, when the total amount of the rubber component including the ethylene-based rubbery polymer (A) and the rubbery polymer (B ....

[0013] The rubber composition of this embodiment is preferably used as a vulcanizate. The vulcanizate can be obtained, for example, by mixing the ethylene-based rubbery polymer (A) and the rubbery polymer (B) of this embodiment with an inorganic filler (C) such as silica or carbon black, a silane coupling agent, a rubber softener, wax, a vulcanizing agent, a vulcanization accelerator, and a vulcanization aid to form a rubber composition, and then heating and vulcanizing the rubber composition. Each component will be described in detail below.

[0014] [Ethylene-based rubber polymer (A)] The ethylene-based rubbery polymer of this embodiment is preferably obtained by copolymerizing at least a conjugated diene monomer and then hydrogenating a portion of the conjugated diene monomer units, or by copolymerizing at least ethylene and a conjugated diene monomer, thereby obtaining a rubbery polymer containing an ethylene structure and conjugated diene monomer units.

[0015] The ethylene-based rubber polymer may also contain aromatic vinyl monomer units as needed. In this case, the ethylene-based rubber polymer can be obtained by copolymerizing at least a conjugated diene monomer and an aromatic vinyl monomer and then hydrogenating a portion of the conjugated diene monomer units, or by copolymerizing at least ethylene, a conjugated diene monomer, and an aromatic vinyl monomer. Furthermore, the ethylene-based rubber polymer may further contain other monomer units.

[0016] In this embodiment, the term "monomer" refers to a compound before polymerization, and the term "monomer unit" refers to a structural unit that constitutes a polymer. The term "ethylene structure" includes both those generated by hydrogenating a portion of the double bond portion of a conjugated diene monomer unit and ethylene monomer units when ethylene is used as a monomer.

[0017] As a method of polymerizing a conjugated diene monomer and then hydrogenating it, as described in WO96 / 05250, JP2000-053706, WO2003 / 085010, WO2019 / 151126, WO2019 / 151127, WO2002 / 002663, and WO2015 / 006179, a method is preferred in which a conjugated diene monomer is polymerized by anionic polymerization using various additives and under various conditions, and if necessary, copolymerized with other monomers, and then hydrogenated.

[0018] The conjugated diene monomer is not particularly limited, but examples thereof include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene. Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of industrial availability. 1,3-butadiene is most preferred. These may be used alone or in combination of two or more.

[0019] The aromatic vinyl monomer is not particularly limited, but examples thereof include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and diphenylethylene. Among these, styrene is preferred from the viewpoint of industrial availability. These may be used alone or in combination of two or more. By including a structural unit based on such an aromatic vinyl monomer, the tensile strength and durability of a high-damping member tend to be further improved.

[0020] The other monomers are not particularly limited, but examples thereof include non-conjugated polyene compound monomers such as ethylidene norbornene, dicyclopentadiene, vinyl norbornene, and divinylbenzene; and cyclic non-conjugated polyene compound monomers such as dicyclopentadiene, vinyl norbornene, and ethylidene norbornene. The use of such other monomers tends to further improve the balance between tensile strength and durability when used in a high-damping rubber composition. These may be used alone or in combination of two or more.

[0021] As a method for copolymerizing at least ethylene and a conjugated diene monomer, the methods described in WO2019 / 078083, WO2019 / 171679, and WO2019 / 142501 are preferred. A method in which ethylene, a conjugated diene monomer, and, if necessary, other monomers are added by coordination polymerization under various additives and conditions is preferred. The conjugated diene monomer is the same as the conjugated diene monomer examples described above.

[0022] The iodine value of the ethylene-based rubbery polymer of this embodiment is 10 or more, preferably 15 or more, more preferably 30 or more, even more preferably 50 or more, and even more preferably 70 or more. An iodine value of 10 or more improves ease of crosslinking and the balance between tensile strength, durability, and heat resistance when made into a high-damping rubber composition. On the other hand, the iodine value of the rubbery polymer is 250 or less, preferably 170 or less, more preferably 140 or less, even more preferably 110 or less, and most preferably 80 or less. An iodine value of 250 or less improves tensile strength when made into a high-damping rubber composition.

[0023] The iodine value can be measured according to the method described in "JIS K 0070: 1992." The iodine value is a value that expresses the amount of halogen that reacts with 100 g of a target substance, converted into the number of grams of iodine, so the unit of the iodine value is "Ig / 100 g."

[0024] The iodine value of the ethylene-based rubbery polymer of this embodiment can be adjusted by the amount of double bonds contained in the conjugated diene monomer units. In the method for producing a rubbery polymer described below, for example, when a conjugated diene monomer and an aromatic vinyl monomer are copolymerized, the iodine value tends to be lower as the content of the conjugated diene monomer is lower, and when the conjugated diene monomer is hydrogenated, the iodine value tends to be lower as the hydrogenation rate is higher.

[0025] The content of ethylene structures contained in the ethylene-based rubbery polymer of this embodiment is 3% by mass or more, preferably 5% by mass or more. When the ethylene structure is 3% by mass or more, the tensile strength is excellent. Furthermore, the content of ethylene structures is preferably 90% by mass or less, more preferably 80% by mass or less. When the ethylene structure content is 90% by mass or less, the rubber elasticity tends to be further improved.

[0026] Ethylene-based rubbery polymers may be produced by hydrogenating a diene copolymer having an aromatic moiety and a conjugated diene moiety to convert some of the double bonds in the conjugated diene moiety into ethylene moieties, or by random copolymerization of an aromatic vinyl compound, a conjugated diene compound, and ethylene. Among these, from the viewpoint of production costs, it is preferable to obtain rubbery polymers by subjecting a diene copolymer to a hydrogenation reaction. The content of ethylene moieties in the hydrogenated product of a diene copolymer can be controlled to 3% by mass or more of ethylene structures by controlling the amount of ethylene added or the conjugated diene compound and its hydrogenation rate.

[0027] In this embodiment, a structural unit based on an aromatic vinyl compound may also be referred to as an "aromatic portion," a structural unit based on a conjugated diene compound may also be referred to as a "conjugated diene portion," and an ethylene structure may also be referred to as an "ethylene portion."

[0028] The content of the aromatic vinyl monomer block contained in the ethylene-based rubbery polymer of this embodiment is less than 10% by mass, preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less. By having the aromatic vinyl monomer block content of less than 10% by mass, damping performance is further improved when the polymer is used as a high-damping rubber composition. The lower limit of the aromatic vinyl monomer block content is not limited, but can be set to 1% by mass or more.

[0029] In this embodiment, the term "aromatic vinyl monomer block" refers to a structure in which eight or more aromatic vinyl monomer units are linked together. From the viewpoint of damping performance when made into a high-damping rubber material, it is preferable that the rubbery polymer of this embodiment has few or no such aromatic vinyl monomer blocks.

[0030] The method for measuring the aromatic vinyl monomer block is not particularly limited, but for example, when the rubbery polymer is a butadiene-styrene copolymer, the polymer can be decomposed by the Kolthoff method (the method described in I. M. Kolthoff, et al., J. Polym. Sci. 1, 429 (1946)) and the amount of polystyrene insoluble in methanol can be analyzed. As another method, it can be measured by a known method such as measuring the chain of styrene units using NMR, as described in WO2014-133097.

[0031] The content of conjugated diene monomer units in the ethylene-based rubbery polymer of this embodiment is 2% by mass or more, preferably 3% by mass or more, and more preferably 6% by mass or more. The double bonds in the conjugated diene monomer units can become crosslinkable unsaturated groups. The content of conjugated diene monomer units in the ethylene-based rubbery polymer is closely related to the iodine value. A conjugated diene monomer unit content of 2% by mass or more results in ease of crosslinking and excellent tensile strength and durability when formed into a high-damping rubber composition. Furthermore, the content of conjugated diene monomer units is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. A conjugated diene monomer unit content of 50% by mass or less tends to result in an excellent balance between tensile strength, damping performance, and durability when formed into a high-damping rubber composition.

[0032] The ethylene-based rubbery polymer of this embodiment preferably contains an aromatic vinyl monomer unit. The content of the aromatic vinyl monomer unit is preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 9% by mass or more. When the content of the aromatic vinyl monomer unit is 5% by mass or more, the tensile strength tends to be excellent when made into a high-damping rubber composition. Furthermore, the content of the aromatic vinyl monomer unit is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. When the content of the aromatic vinyl monomer unit is 40% by mass or less, the tensile strength tends to be further improved when made into a high-damping rubber composition.

[0033] From the viewpoint of damping characteristics and durability when made into a high-damping rubber composition, the 1,2-vinyl bond content in the conjugated diene monomer units in the ethylene-based rubbery polymer of this embodiment is preferably 10 mol % or more, more preferably 20 mass % or more, and even more preferably 30 mass % or more. From the viewpoint of damping characteristics and durability when made into a high-damping rubber composition, the 1,2-vinyl bond content in the conjugated diene monomer units is preferably 60 mol % or less, more preferably 50 mass % or less, and even more preferably 40 mass % or less.

[0034] When the total amount of the rubber component including the ethylene-based rubbery polymer (A) and the rubbery polymer (B) is taken as 100 parts by mass, the content of the ethylene-based rubbery polymer is 10 parts by mass or more, preferably 20 parts by mass or more, and more preferably 30 parts by mass or more. By having a rubbery polymer content of 10 parts by mass or more, a high-damping rubber composition will have excellent tensile strength and durability. Furthermore, from the viewpoint of improving the damping performance and durability when made into a high-damping rubber composition, the content of the rubbery polymer is 90 parts by mass or less, preferably 70 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less.

[0035] Unless otherwise specified, the values ​​expressed in "parts by mass" below are values ​​when the total amount of the ethylene-based rubbery polymer and the rubber component containing the rubbery polymer is 100 parts by mass.

[0036] The solubility parameter (hereinafter referred to as SP value) of the ethylene-based rubber polymer of this embodiment is 16.8 (MPa). 1 / 2 Above 17.5 (MPa) 1 / 2 When the SP value of the ethylene-based rubber-like polymer is within the above range, the ethylene-based rubber-like polymer and the natural rubber (SP value: 17.19 (MPa)) 1 / 2) or ethylene-α-olefin-non-conjugated polyene copolymer, and when the inorganic filler is vulcanized, it disperses uniformly, reducing friction between the inorganic fillers and tending to improve durability.

[0037] Furthermore, from the viewpoint of improving crack resistance when made into a high damping rubber composition, the SP value of the rubber-like polymer is 17.0 (MPa). 1 / 2 Above 17.2 (MPa) 1 / 2 The SP value of the rubber-like polymer is more preferably 17.0 (MPa). 1 / 2 By doing so, the rubber becomes compatible with natural rubber or ethylene-α-olefin-non-conjugated polyene copolymer, eliminating the interface, and when a high-damping rubber composition is made, stress concentration is suppressed and crack resistance tends to improve.

[0038] The SP value of the ethylene-based rubber polymer is expressed as follows: (SP value)=((molar cohesive energy) / (molar volume)) 1 / 2 It is calculated from the formula. When an ethylene-based rubber-like polymer is composed of two or more different types of monomers, the molar cohesive energy is additive. Therefore, the molar cohesive energy of an ethylene-based rubber-like polymer is calculated as the average value of the molar cohesive energy based on the content (mol%) of each component (average value apportioned according to the content). As with the molar cohesive energy, the molar volume is also additive, and the molar volume of an ethylene-based rubber-like polymer is calculated as the average value of the molar volume based on the content (mol%) of each component (average value apportioned according to the content).

[0039] The two or more different types of components are not particularly limited, and examples thereof include conjugated diene compound monomer units and aromatic vinyl hydrocarbon monomer units incorporated in the following bonding modes: unhydrogenated 1,2-bonds, hydrogenated 1,2-bonds, unhydrogenated 3,4-bonds, hydrogenated 3,4-bonds, unhydrogenated 1,4-bonds, and hydrogenated 1,4-bonds. The amount of each of the conjugated diene compound monomer units incorporated in each bonding mode can be measured by NMR or the like.

[0040] The molar volumes and molar cohesive energies of conjugated diene compound monomer units, aromatic vinyl hydrocarbon monomer units, and other monomer units incorporated in the bonding patterns of unhydrogenated 1,2-bonds, hydrogenated 1,2-bonds, unhydrogenated 3,4-bonds, hydrogenated 3,4-bonds, unhydrogenated 1,4-bonds, and hydrogenated 1,4-bonds are determined according to the method (Bicerano method) described in J. Bicerano, Prediction of Polymer Properties, 3rd Ed. Marcel Dekker, 2002.

[0041] The SP value can be controlled within the above range by controlling the amount of 1,2-vinyl bonds in the conjugated diene monomer units, the amount of aromatic vinyl compound, and the hydrogenation rate. 1 / 2 Above 17.5 (MPa) 1 / 2 The following methods can make it possible to set the SP value within the above range, for example, by setting the amount of aromatic vinyl compound to 5 to 30 mass %, the amount of 1,2-bonds in conjugated diene monomer units to 20 to 50 mass %, or the hydrogenation rate to 40 to 90 mol %.

[0042] The glass transition temperature of the ethylene-based rubbery polymer of this embodiment is preferably −35° C. or lower, more preferably −45° C. or lower, and even more preferably −50° C. or lower. The glass transition temperature of the ethylene-based rubbery polymer can be controlled within the above range by adjusting the amount of aromatic vinyl compound, the amount of 1,2-bonds, and the hydrogenation rate. When the glass transition temperature of the ethylene-based rubbery polymer is within the above range, it tends to have excellent damping performance when made into a high-damping rubber composition.

[0043] The glass transition temperature can be controlled within the above range by controlling the amount of 1,2-vinyl bonds in the conjugated diene monomer units and the amount of aromatic vinyl compounds. Specifically, the glass transition temperature can be lowered by reducing the amount of aromatic vinyl compounds and the amount of 1,2-vinyl bonds. A method for controlling the glass transition temperature to -35°C or lower is, for example, to set the amount of aromatic vinyl to 5 to 30% by mass and the amount of 1,2-vinyl bonds in the conjugated diene monomer units to 20 to 50% by mass, thereby making it possible to control the glass transition temperature within the above range.

[0044] The glass transition temperature is determined by recording a DSC curve while increasing the temperature within a predetermined temperature range in accordance with ISO 22768:2006, and the peak top (inflection point) of the DSC differential curve is taken as the glass transition temperature. Specifically, it can be measured by the method described in the examples below.

[0045] The lower limit of the glass transition temperature of the rubbery polymer is not particularly limited, but is preferably −90° C. or higher, more preferably −80° C. or higher, and even more preferably −70° C. or higher.

[0046] The ethylene-based rubber-like polymer of this embodiment preferably contains nitrogen atoms from the viewpoint of improving the balance between tensile strength, damping characteristics, and durability when made into a high-damping rubber composition. The nitrogen atoms can be introduced using a modifier. This tends to further improve the dispersibility of the inorganic filler, which is a reinforcing material for the high-damping rubber composition.

[0047] From the viewpoint of dispersibility of the inorganic filler that is a reinforcing material of the high-damping rubber composition, the ethylene-based rubber-like polymer of this embodiment preferably has a modification rate of 40% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. The upper limit of the modification rate is not particularly limited, but from the viewpoint of reducing the viscosity of the compound after kneading and improving processability, it is preferably 98% or less, more preferably 95% or less, and even more preferably 90% or less.

[0048] In this specification, the "modification ratio" represents the mass ratio of the polymer having a nitrogen atom-containing functional group to the total amount of the ethylene-based rubber-like polymer. The nitrogen atom may be introduced into the ethylene-based rubber-like polymer of this embodiment at any position, such as the polymerization initiation terminal, the molecular chain (including grafts), or the polymerization terminal of the ethylene-based rubber-like polymer.

[0049] When the ethylene-based rubbery polymer of the present embodiment is produced by polymerizing a conjugated diene monomer and then hydrogenating it, a method of introducing the polymer using a coupling agent containing a tin atom or a nitrogen atom is preferred in terms of polymerization productivity, a high modification rate, and damping performance when made into a high-damping rubber composition.

[0050] As the nitrogen atom-containing coupling agent, in terms of polymerization productivity and a high modification rate, an isocyanate compound, an isothiocyanate compound, an isocyanuric acid derivative, a nitrogen group-containing carbonyl compound, a nitrogen group-containing vinyl compound, a nitrogen group-containing epoxy compound, a nitrogen group-containing alkoxysilane compound, and the like are preferred.

[0051] Furthermore, from the viewpoint of improving processability when forming a high-damping rubber composition, the coupling agent preferably has a higher number of branches. The number of branches is not particularly limited, but from the viewpoint of improving processability, 3 branches or more is preferred, and 4 branches or more is more preferred. The upper limit of the number of branches is not particularly limited, but from the viewpoint of productivity, 30 branches or less is preferred.

[0052] As these nitrogen atom-containing coupling agents, nitrogen group-containing alkoxysilane compounds are more preferred in terms of polymerization productivity of ethylene-based rubber polymers, high modification rate, and damping performance when made into a high-damping rubber composition.

[0053] The nitrogen group-containing alkoxysilane compound is not particularly limited, and examples thereof include 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(5-trimethoxysilylpentyl)-1-aza-2-silacycloheptane, 2,2-dimethoxy-1-(3-di 2-Methoxy,2-methyl-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silacyclopentane, 2-methoxy,2-methyl-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-ethoxy,2-ethyl-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-methoxy,2-methyl-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, 2-ethoxy 2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silacyclopentane, tris(3-trimethoxysilylpropyl)amine, tris(3-methyldimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-methyldiethoxysilylpropyl)amine, tris(trimethoxysilylmethyl)amine, tris(2-trimethoxysilylethyl)amine, tris(4-trimethoxysilylbutyl)amine, tetrakis[3-(2,2-dimethoxy-1-aza -2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, and N1-(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N1-methyl-N3-(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N3-(3-(trimethoxysilyl)propyl)-1,3-propanediamine.

[0054] When the ethylene-based rubbery polymer of the embodiment is produced by copolymerizing ethylene and a conjugated diene monomer, it preferably contains tin atoms, nitrogen atoms, or silicon atoms in terms of damping performance when made into a high-damping rubber composition. In terms of productivity of the ethylene-based rubbery polymer, it is preferred to introduce a coupling agent containing tin atoms, nitrogen atoms, or silicon atoms when the polymerization reaction reaches 100%.

[0055] Examples of coupling agents containing tin atoms, nitrogen atoms, or silicon atoms include tin-containing compounds such as bis(1-octadecylmaleate)dioctyltin, isocyanate compounds such as 4,4-diphenylmethane diisocyanate, and alkoxysilane compounds such as glycidylpropyltrimethoxysilane.

[0056] The weight-average molecular weight of the ethylene-based rubbery polymer is preferably 150,000 or more, more preferably 200,000 or more, from the viewpoint of the shape stability of a molded article of the rubber composition and the tensile strength and durability of a crosslinked article using the rubber composition, while from the viewpoint of the processability when the rubber composition is made into a crosslinkable composition, it is preferably 1,000,000 or less, more preferably 500,000 or less, and even more preferably 400,000 or less.

[0057] The molecular weight distribution (=weight average molecular weight / number average molecular weight) of the ethylene-based rubbery polymer is preferably 2.0 or less, more preferably 1.8 or less, and even more preferably 1.6 or less, from the viewpoint of durability when the rubber composition is used as a high-damping rubber composition. On the other hand, from the viewpoint of processability when the rubber composition is made into a crosslinking composition, the molecular weight distribution of the ethylene-based rubbery polymer is preferably 1.05 or more, more preferably 1.2 or more, and even more preferably 1.4 or more.

[0058] The weight average molecular weight and molecular weight distribution can be calculated from the polystyrene-equivalent molecular weight measured by GC (gel permeation chromatography).

[0059] If necessary, a deactivator, neutralizer, etc. may be added at the end of the polymerization process of an ethylene-based rubber polymer. Examples of deactivators include, but are not limited to, water; and alcohols such as methanol, ethanol, and isopropanol. The end of the polymerization process here refers to a state in which 95% or more of the added monomers have been consumed in the polymerization.

[0060] Examples of neutralizing agents include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and versatic acid (a highly branched carboxylic acid mixture having 9 to 11 carbon atoms, mainly 10 carbon atoms); aqueous solutions of inorganic acids; and carbon dioxide gas.

[0061] It is preferable to add a rubber stabilizer at the final stage of the polymerization process of the ethylene rubber polymer in order to prevent gel formation and ensure processing stability.

[0062] The rubber stabilizer is not limited to the following and known stabilizers can be used, but preferred are antioxidants such as 2,6-di-tert-butyl-4-hydroxytoluene (hereinafter also referred to as "BHT"), n-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenol) propionate, and 2-methyl-4,6-bis[(octylthio)methyl]phenol.

[0063] A rubber softener can be added as needed, for example, at the final stage of the polymerization process of an ethylene-based rubber-like polymer, in order to improve the productivity of the polymer and the processability when an inorganic filler or the like is compounded during the production of a high-damping rubber composition.

[0064] The rubber softener is not particularly limited, but examples thereof include extender oil, liquid rubber, resin, etc. From the viewpoints of processability, productivity, and economy, extender oil is preferred.

[0065] Examples of extender oils include aromatic extender oils, naphthenic extender oils, and paraffinic extender oils.

[0066] Examples of aromatic extender oils include Diana Process Oil AC-12, AC460, AH-16, and AH-58 manufactured by Idemitsu Kosan Co., Ltd.; Mobilsol K, Mobilsol 22, and Mobilsol 130 manufactured by Exxon Mobil Corporation; Kyoseki Process X50, X100, and X140 manufactured by Nikko Kyoseki Co., Ltd.; Resox No. 3 and Deutrex 729 UK manufactured by Shell Chemical Company, Ltd.; Komorex 200, 300, 500, and 700 manufactured by Nippon Oil Corporation (formerly Nippon Oil Corporation); Esso Process Oil 110 and 120 manufactured by Exxon Mobil Corporation; and Mitsubishi 34 Heavy Process Oil, Mitsubishi 44 Heavy Process Oil, Mitsubishi 38 Heavy Process Oil, and Mitsubishi 39 Heavy Process Oil manufactured by Nippon Oil Corporation (formerly Mitsubishi Oil Company).

[0067] Examples of naphthenic extender oils include Diana Process Oil NS-24, NS-100, NM-26, NM-280, and NP-24 manufactured by Idemitsu Kosan Co., Ltd., Naplex 38 manufactured by Exxon Mobil Corporation, Fukkol FLEX #1060N, #1150N, #1400N, #2040N, and #2050N manufactured by Fuji Kosan Co., Ltd., Kyoseki Process R25, R50, R200, and R1000 manufactured by Nikko Kyoseki Co., Ltd., and Shellflex manufactured by Shell Chemical Co., Ltd. Examples include 371JY, 371N, 451, N-40, 22, 22R, 32R, 100R, 100S, 100SA, 220RS, 220S, 260, 320R, 680, Morex No. 2 process oil manufactured by Nippon Oil Corporation (formerly Nippon Oil Corporation), Esso Process Oil L-2 and 765 manufactured by ExxonMobil, and Mitsubishi 20 Light process oil manufactured by Nippon Oil Corporation (formerly Mitsubishi Oil Corporation).

[0068] Examples of paraffinic extender oils include Diana Process Oil PW-90, PW-380, PS-32, PS-90, and PS-430 manufactured by Idemitsu Kosan Co., Ltd.; Fukkol Process P-100, P-200, P-300, P400, and P-500 manufactured by Fuji Kosan Co., Ltd.; Kyoseki Process P-200, P-300, and P-500, Kyoseki EPT750, Kyoseki 1000, and Kyoseki Process S90 manufactured by Nikko Kyoseki Co., Ltd.; Rubrex 26, Rubrex 100, and Rubrex 460 manufactured by Shell Chemical Co., Ltd.; Esso Process Oil 815, Esso 845, and Esso B-1 manufactured by Exxon Mobil; and Naplex 32 manufactured by Exxon Mobil. Mitsubishi 10 Light Process Oil manufactured by Nippon Oil Corporation (formerly Mitsubishi Oil Co., Ltd.) can also be mentioned.

[0069] The method of adding a rubber softener to a conjugated diene polymer is not limited to the following, but a preferred method is to add a rubber softener to a polymer solution, mix, and remove the solvent from the resulting polymer solution containing the rubber softener.

[0070] The content of the extender oil in the rubber composition of this embodiment is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and most preferably 5% by mass or less, from the viewpoint of deterioration over time when made into a high-damping rubber composition.

[0071] The ethylene-based rubbery polymer of this embodiment can be obtained by removing the solvent from the polymer solution using known methods, such as a method of separating the solvent by steam stripping or the like, filtering the polymer, and then dehydrating and drying it to obtain the polymer, a method of concentrating the polymer in a flashing tank and then devolatilizing it using a vent extruder or the like, and a method of directly devolatilizing it using a drum dryer or the like.

[0072] (rubber softener) The high-damping rubber composition of this embodiment may contain a rubber softener to improve processability. Suitable rubber softeners include, for example, mineral oil-based rubber softeners, and liquid or low-molecular-weight synthetic softeners and resins.

[0073] Examples of the mineral oil-based rubber softener include aromatic extender oils, naphthenic extender oils, and paraffin extender oils.

[0074] Preferred resins include, but are not limited to, aromatic petroleum resins, coumarone-indene resins, terpene resins, rosin derivatives (including tung oil resins), tall oil, tall oil derivatives, rosin ester resins, natural and synthetic terpene resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, mixed aliphatic-aromatic hydrocarbon resins, coumarin-indene resins, phenolic resins, p-tert-butylphenol-acetylene resins, phenol-formaldehyde resins, xylene-formaldehyde resins, monoolefin oligomers, diolefin oligomers, aromatic hydrocarbon resins, aromatic petroleum resins, hydrogenated aromatic hydrocarbon resins, cycloaliphatic hydrocarbon resins, hydrogenated hydrocarbon resins, hydrocarbon resins, hydrogenated tung oil resins, hydrogenated oil resins, and esters of hydrogenated oil resins with monofunctional or polyfunctional alcohols.

[0075] These resins may be used alone or in combination of two or more. When hydrogenating, all of the unsaturated groups may be hydrogenated, or some may remain.

[0076] The effect of adding the resin is to improve the processability of a rubber composition containing the conjugated diene polymer and a filler, etc., and also tends to improve the tensile strength of a vulcanized product.

[0077] The amount of rubber softener, such as extender oil, liquid rubber, or resin, added is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, per 100 parts by mass of the total amount of the ethylene-based rubbery polymer and the rubber component containing the rubbery polymer. By adding an amount within this range, durability and crack resistance tend to be excellent. Furthermore, from the viewpoint of suppressing bleed-out and preventing stickiness on the surface of the rubber composition, the amount is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 40 parts by mass or less.

[0078] [Rubber polymer (B)] The high-damping rubber composition of this embodiment contains a rubbery polymer (B). Examples of the rubbery polymer include natural rubber (NR), ethylene-α-olefin-non-conjugated polyene copolymer, styrene-butadiene rubber (SBR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), or hydrogenated products thereof, isoprene rubber (IR), etc.

[0079] Particularly preferred rubber polymers include natural rubber (NR) and ethylene-α-olefin-non-conjugated polyene copolymers.

[0080] The natural rubber is not particularly limited, but examples thereof include smoked sheets RSS3 to 5, SMR, and epoxidized natural rubber, which contain a large amount of high molecular weight components and have excellent breaking strength.

[0081] When the total amount of the rubber component containing the ethylene-based rubbery polymer (A) and the rubbery polymer (B) is taken as 100 parts by mass, the content of the rubbery polymer is 10 parts by mass or more, preferably 30 parts by mass or more, more preferably 50 parts by mass or more, and even more preferably 60 parts by mass or more. By having the content of the rubbery polymer within the above range, the tensile strength and durability of a high-damping rubber composition are further improved. Furthermore, from the viewpoint of improving the damping performance of a high-damping rubber composition, the content of the rubbery polymer is 90 parts by mass or less. It is preferably 80 parts by mass or less, more preferably 70 parts by mass or less.

[0082] [Inorganic filler] The rubber composition of this embodiment preferably contains an inorganic filler. From the viewpoint of improving tensile strength and durability when made into a high-damping rubber composition, the content of the inorganic filler is preferably 30 parts by mass or more, more preferably 60 parts by mass or more, and even more preferably 75 parts by mass or more, per 100 parts by mass of the total amount of the rubber components including the ethylene-based rubbery polymer (A) and the rubbery polymer (B). Furthermore, from the viewpoint of improving damping performance when made into a high-damping rubber composition, the content of the inorganic filler is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 90 parts by mass or less.

[0083] The inorganic filler is not particularly limited and any known filler can be used, but silica-based inorganic fillers or carbon black are preferred.

[0084] Examples of silica-based inorganic fillers include, but are not limited to, inorganic fibrous materials such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber. Commercially available silica-based inorganic fillers include, for example, "Ultrasil 7000GR" manufactured by Evonik Degussa. Other examples include silica-based inorganic fillers with hydrophobic surfaces and mixtures of silica-based inorganic fillers with non-silica-based inorganic fillers. Among these, silica and glass fiber are preferred from the viewpoints of strength and abrasion resistance, and silica is more preferred. Examples of silica include dry silica, wet silica, and synthetic silicate silica. Among these, wet silica is even more preferred from the viewpoints of improving tensile strength and durability.

[0085] In order to obtain practically satisfactory durability and tensile strength in a high-damping rubber composition, the nitrogen adsorption specific surface area determined by the BET adsorption method of the silica-based inorganic filler is 100 m 2 / g or more 300m 2 / g or less, and 170m 2 / g or more 250m 2 / g or less. If necessary, a relatively small specific surface area (for example, a specific surface area of ​​200 m 2 / g or less) and those with a relatively large specific surface area (e.g., 200m 2 / g or more of a silica-based inorganic filler) can be used in combination, which allows for a high level of balance between good tensile strength and durability.

[0086] The carbon black is not particularly limited, and for example, carbon black of various classes such as SRF, FEF, HAF, ISAF, SAF, etc. Among these, from the viewpoint of extrusion moldability and rolling resistance characteristics, carbon black having a nitrogen adsorption specific surface area of ​​50 m 2 / g or more, and a dibutyl phthalate (DBP) oil absorption of 80 mL / 100 g or more is preferred.

[0087] The high-damping rubber composition of the present embodiment may contain a metal oxide or a metal hydroxide in addition to the silica-based inorganic filler and carbon black.

[0088] Metal oxides refer to solid particles whose main constituent unit is the chemical formula MxOy (M represents a metal atom, and x and y each independently represent an integer of 1 to 6), and examples thereof include alumina, titanium oxide, magnesium oxide, and zinc oxide. Mixtures of metal oxides and inorganic fillers other than metal oxides can also be used. Metal hydroxides are not particularly limited, and examples include aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

[0089] (Silane coupling agent) The high-damping rubber composition of this embodiment may contain a silane coupling agent. The silane coupling agent has groups that have affinity or bonding properties for both the rubber component and the silica-based inorganic filler, and functions to strengthen the interaction between them. Generally, a compound having a sulfur bond, an alkoxysilyl group, and a silanol group in one molecule is used.

[0090] Examples of the silane coupling agent include, but are not limited to, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, ethoxy(3-mercaptopropyl)bis(3,6,9,12,15-pentaoxaoctacosan-1-yloxy)silane [Si363 manufactured by Evonik Degussa], and NXT-Z30, NXT-Z45, NXT-Z60, and NXT Silane manufactured by Momentive. Silane coupling agents containing mercapto groups, such as bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide, bis(3-triethoxysilylpropyl)trisulfide, bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide silane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide tetrasulfide, 3-triethoxysilylpropyl benzoyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis(3-diethoxymethylsilylpropyl)tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, dimethoxymethylsilylpropyl benzothiazolyl tetrasulfide, and the like.

[0091] Among these, from the viewpoint of high reinforcing effect, mercapto group-containing silane coupling agents such as bis-[3-(triethoxysilyl)-propyl]-disulfide, ethoxy(3-mercaptopropyl)bis(3,6,9,12,15-pentaoxaoctacosan-1-yloxy)silane [Si363 manufactured by Evonik Degussa], and NXT-Z30, NXT-Z45, NXTZ60, and NXT silane manufactured by Momentive, and bis-[3-(triethoxysilyl)-propyl]-tetrasulfide are preferred. These silane coupling agents can be used alone or in combination of two or more.

[0092] The amount of the silane coupling agent is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 1 part by mass or more, per 100 parts by mass of the rubber component including the ethylene-based rubbery polymer (A) and the rubbery polymer (B), from the viewpoint of further enhancing the effect of intensifying the interaction between the rubber component and the silica-based inorganic filler. Also, from the viewpoint of improving processability, the amount of the silane coupling agent is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

[0093] (Kneading method) The method for mixing the constituent materials of the high damping rubber composition of this embodiment, such as the ethylene-based rubbery polymer and the rubber component containing the rubbery polymer, the silica-based inorganic filler, carbon black and other fillers, and additives such as a silane coupling agent and a rubber softener, is not limited to the following, but examples include a melt-kneading method using a general mixer such as an open roll, a Banbury mixer, a kneader, a single-screw extruder, a twin-screw extruder or a multi-screw extruder, and a method in which the components are dissolved and mixed and then the solvent is removed by heating.

[0094] Among these, melt-kneading methods using a roll, a Banbury mixer, a kneader, or an extruder are preferred from the viewpoints of productivity and good kneading ability. Furthermore, it is also possible to use a method in which the constituent materials of the high-damping rubber composition of the present embodiment are kneaded all at once, or a method in which the materials are mixed in separate batches.

[0095] The high-damping rubber composition of the present embodiment may be a vulcanized composition obtained by vulcanizing the rubber composition with a vulcanizing agent, which may include, but is not limited to, radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur compounds.

[0096] The sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, polymeric polysulfur compounds, and the like.

[0097] From the viewpoint of improving breaking strength through a reinforcing effect, the content of the vulcanizing agent is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 1 part by mass or more, per 100 parts by mass of the total amount of the rubber component including the ethylene-based rubbery polymer (A) and the rubbery polymer (B). From the viewpoint of improving flexibility and elongation at break, the content of the vulcanizing agent is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less.

[0098] As the vulcanization method, a conventionally known method can be applied, and the vulcanization temperature is not particularly limited, but from the viewpoint of shortening the vulcanization time and increasing production efficiency, it is preferably 120°C or higher, more preferably 140°C or higher, and even more preferably 150°C or higher. Also, from the viewpoint of suppressing thermal degradation during vulcanization, it is preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 160°C or lower.

[0099] In vulcanization, a vulcanization accelerator may be used as needed.

[0100] As the vulcanization accelerator, a conventionally known material can be used, and examples thereof include, but are not limited to, sulfenamide compounds, guanidine compounds, thiuram compounds, aldehyde-amine compounds, aldehyde-ammonia compounds, thiazole compounds, thiourea compounds, and dithiocarbamate compounds.

[0101] The vulcanization aid may include, but is not limited to, zinc oxide and stearic acid.

[0102] The content of the vulcanization accelerator is preferably 0.01 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 15 parts by mass or less, per 100 parts by mass of the total amount of the rubber component including the ethylene-based rubber-like polymer (A) and the rubber-like polymer (B).

[0103] The high-damping rubber composition of this embodiment may contain various additives other than those described above, such as softeners, fillers, heat stabilizers, antistatic agents, weather stabilizers, antioxidants, colorants, and lubricants, within the scope that does not impair the object of this embodiment.

[0104] As the other softening agent, known softening agents can be used. Specific examples of the other filler include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate.

[0105] Known materials can be used for the heat stabilizer, antistatic agent, weather stabilizer, antioxidant, colorant, and lubricant.

[0106] [High-damping vulcanized rubber] The rubber composition of this embodiment is suitably used as a high-damping rubber composition, that is, the high-damping vulcanized rubber of this embodiment is made using the rubber composition of this embodiment.

[0107] The high-damping vulcanized rubber of this embodiment has excellent damping characteristics and sufficient durability, so it can be suitably used as a vibration-damping material, although it is not limited to the following. In particular, it can be suitably used as a high-damping rubber material that requires high durability, such as vibration-damping rubber for engine mounts and seismic isolation rubber. [Example]

[0108] Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples, but the present embodiment is not limited to the following examples and comparative examples.

[0109] Various physical properties in the examples and comparative examples were measured by the methods shown below.

[0110] (Weight average molecular weight (Mw) of rubber-like polymer) The chromatogram was measured using a GPC measurement device with three connected columns packed with polystyrene gel, and the weight-average molecular weight (Mw) was determined based on a calibration curve using standard polystyrene. Specific measurement conditions are shown below. 20 μL of the following measurement solution was injected into the GPC measurement device and the measurement was performed. (Measurement conditions) Device: Tosoh Corporation, product name "HLC-8320GPC" Eluent: 5mmol / L triethylamine in tetrahydrofuran (THF) Guard column: Tosoh Corporation's product name "TSKguardcolumn SuperH-H" Separation column: Tosoh Corporation product names "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000" connected in this order. Oven temperature: 40°C Flow rate: 0.6mL / min Detector: RI detector (Tosoh Corporation, product name "HLC8020") Measurement solution: 10 mg of sample dissolved in 20 mL of THF

[0111] (Mooney Viscosity of Rubber Polymers and Rubber Compositions) The Mooney viscosity was measured using a Mooney viscometer (product name "VR1132" manufactured by Ueshima Seisakusho Co., Ltd.) with an L-shaped rotor in accordance with ISO 289. Specifically, the sample was first preheated at 100°C for 1 minute, and then the rotor was rotated at 2 rpm. The torque after 4 minutes was measured and used as the Mooney viscosity at 100°C (ML(1+4)).

[0112] (Modification rate of rubber polymer) The modification rate of the rubbery polymer was measured by the column adsorption GPC method, utilizing the property of the modified rubbery polymer to be adsorbed onto a column, as follows. The amount of adsorption onto the silica-based column was measured by subtracting the chromatogram of a sample solution containing the sample and low-molecular-weight internal standard polystyrene measured using a column packed with polystyrene-based gel from the chromatogram measured using a column packed with silica-based gel, and the modification rate was calculated.

[0113] The GPC measurement conditions using a polystyrene column are as follows: 20 μL of the measurement solution below was injected into the GPC measurement device and the measurement was carried out. (GPC measurement conditions using a polystyrene column) Device: Tosoh Corporation, product name "HLC-8320GPC" Eluent: THF containing 5mmol / L triethylamine Guard column: Tosoh Corporation's product name "TSKguardcolumn SuperH-H" Column: Tosoh Corporation product names "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000" connected in this order Oven temperature: 40°C Flow rate: 0.6mL / min Detector: RI detector (Tosoh HLC8020) Measurement solution: 10 mg of sample and 5 mg of standard polystyrene were dissolved in 20 mL of THF to prepare a sample solution.

[0114] The conditions for GPC measurement using a silica column are as follows: 50 μL of the measurement solution below was injected into the GPC measurement device and measurement was carried out. (GPC measurement conditions using a silica column) Device: Tosoh Corporation, product name "HLC-8320GPC" Eluent:THF Guard column: GL Sciences product name "DIOL 4.6 x 12.5 mm 5 micron" Separation column: Agilent Technologies' Zorbax PSM-1000S, PSM-300S, and PSM-60S columns connected in this order Oven temperature: 40℃, Flow rate: 0.5mL / min Detector: RI detector (Tosoh HLC8020)

[0115] Calculation method for modification rate: The total peak area of ​​the chromatogram using a polystyrene column was set to 100, the peak area of ​​the sample was set to P1, the peak area of ​​the standard polystyrene was set to P2, and the total peak area of ​​the chromatogram using a silica column was set to 100, the peak area of ​​the sample was set to P3, and the peak area of ​​the standard polystyrene was set to P4. The modification rate (%) was calculated using the following formula. Denaturation rate (%) = [1-(P2 x P3) / (P1 x P4)] x 100 (However, P1+P2=P3+P4=100)

[0116] (Bound styrene content of rubber polymer) 100 mg of sample was dissolved in 100 mL of chloroform to prepare a measurement sample. The amount of bound styrene (mass%) relative to 100 mass% of the rubber-like polymer sample was measured based on the amount of absorption of ultraviolet light by the phenyl group of styrene (near 254 nm). The measurement device used was a Shimadzu UV-2450 spectrophotometer.

[0117] (Microstructure of butadiene part of rubber polymer (1,2-vinyl bond content)) 50 mg of sample was dissolved in 10 mL of carbon disulfide to prepare a measurement sample. Using a solution cell, the infrared spectrum was measured from 600 to 1000 cm -1 The absorbance at a predetermined wave number was measured in the range of 100 Hz to 100 Hz, and the microstructure of the butadiene moiety, i.e., the 1,2-vinyl bond content (mol%) was determined according to the calculation formula of Hampton's method (method described in R.R. Hampton, Analytical Chemistry 21, 923 (1949)). The measuring device used was a Fourier transform infrared spectrophotometer "FT-IR230" manufactured by JASCO Corporation.

[0118] (Hydrogenation rate, ethylene structure, and conjugated diene monomer unit of rubber-like polymer) 1 The integrated value of the unsaturated bond portion of the polymer before hydrogenation was obtained by H-NMR measurement. Next, a large amount of methanol was added to the reaction solution after the hydrogenation reaction, and the hydrogenated conjugated diene polymer was precipitated and recovered. Next, the hydrogenated conjugated diene polymer was extracted with acetone, and the hydrogenated conjugated diene polymer was vacuum dried. This was 1 The hydrogenation rate, ethylene structure, and conjugated diene monomer units were measured using the sample for H-NMR measurement. 1 The conditions for H-NMR measurement are as follows: (Measurement conditions) Measuring equipment: JNM-LA400 (JEOL) Solvent: deuterated chloroform Measurement sample: Samples taken before and after hydrogenation of polymer Sample concentration: 50mg / mL Observation frequency: 400MHz Chemical shift standard: TMS (tetramethylsilane) Pulse delay: 2.904 seconds Number of scans: 64 Pulse width: 45° Measurement temperature: 26℃

[0119] (styrene block content of rubber polymer) A chain consisting of eight or more styrene structural units was defined as a styrene block, and the content of the styrene block in the rubbery block polymer was calculated as follows: From the 400 MHz 1H-NMR spectrum measured using deuterated chloroform as a solvent, the integral ratio of each chemical shift range (X) below was calculated, and the content of the styrene block in the rubbery block polymer was calculated. (X) Aromatic vinyl compounds with 8 or more chains: 6.00≦S<6.68

[0120] (Iodine value of rubber polymer) The iodine value of the rubbery polymer was calculated according to the method described in "JIS K 0070:1992".

[0121] (SP value of rubber polymer) SP value (MPa 1 / 2 ) is ((molar cohesive energy) / (molar volume)) 1 / 2 It was calculated from the formula. Here, when a rubber-like polymer is composed of two or more different types of monomers, the molar cohesive energy is additive, and the molar cohesive energy of the polymer is calculated as the average value of the molar cohesive energies of each monomer (average value apportioned according to the content) from the content (mol%) of each monomer and the molar cohesive energy of the homopolymer of that monomer. As with the molar cohesive energy, the molar volume is also additive, and the molar volume of the polymer is calculated as the average value of the molar volumes of each monomer (average value apportioned according to the content) from the content (mol%) of each monomer and the molar volume of the homopolymer of that monomer. The molar cohesive energy and molar volume of the homopolymer composed of each monomer are listed in Table 1.

[0122] [Table 1]

[0123] (Glass transition temperature (Tg) of rubbery polymer) Using a rubbery polymer as a sample, a DSC curve was recorded in accordance with ISO 22768:2006 using a differential scanning calorimeter "DSC3200S" manufactured by Mac Science, while heating from -100°C at 20°C / min under a helium flow of 50 mL / min, and the peak top (inflection point) of the DSC differential curve was taken as the glass transition temperature.

[0124] (Production Example 1) Rubber-like polymer (A) before hydrogenation A 40 L temperature-controllable autoclave equipped with a stirrer and a jacket was used as a reactor, and 2,160 g of 1,3-butadiene, 300 g of styrene, 21,000 g of cyclohexane, and 30 mmol of tetrahydrofuran (THF) and 4.9 mmol of 2,2-bis(2-oxolanyl)propane as polar substances were placed in the reactor, and the internal temperature of the reactor was maintained at 42° C. 33.2 mmol of n-butyllithium was fed as a polymerization initiator to the reactor. After the polymerization reaction started, the temperature inside the reactor began to rise due to heat generated by the polymerization, and after the monomer conversion in the reactor reached 98%, 540 g of 1,3-butadiene was added and reacted. The final temperature inside the reactor reached 76°C. Two minutes after the reaction temperature reached its peak, 6.6 mmol of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (compound 1) was added to the reactor, and the coupling reaction was carried out for 20 minutes. 6.0 mmol of methanol was added to this polymer solution as a reaction terminator to obtain a rubbery polymer solution (A-1). A portion of the conjugated diene polymer solution was withdrawn and the solvent was removed in a dryer to obtain the rubbery polymer (A) before hydrogenation. The analysis results are shown in Table 2.

[0125] (Production Example 2) Rubber-like polymer (B) before hydrogenation A 40 L temperature-controllable autoclave equipped with a stirrer and a jacket was used as a reactor, and 2,100 g of 1,3-butadiene, 780 g of styrene, 21,000 g of cyclohexane, and 30 mmol of tetrahydrofuran (THF) and 18.3 mmol of 2,2-bis(2-oxolanyl)propane as polar substances were placed in the reactor, and the internal temperature of the reactor was maintained at 42° C. 26.2 mmol of n-butyllithium was fed as a polymerization initiator to the reactor. After the polymerization reaction started, the temperature inside the reactor began to rise due to heat generated by the polymerization, and after the monomer conversion in the reactor reached 98%, 120 g of 1,3-butadiene was added and reacted. The final temperature inside the reactor reached 78°C. Two minutes after the reaction temperature reached its peak, 5.2 mmol of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (compound 1) was added to the reactor, and the coupling reaction was carried out for 20 minutes. 4.7 mmol of methanol was added to this polymer solution as a reaction terminator to obtain a rubbery polymer solution (B-1). A portion of the conjugated diene polymer solution was withdrawn and the solvent was removed in a dryer to obtain the rubbery polymer (B) before hydrogenation. The analysis results are shown in Table 2.

[0126] (Production Example 3) Hydrogenation catalyst (TC1) Two liters of dried and purified cyclohexane was placed in a nitrogen-purged reactor, and 40 mmol of bis(η5-cyclopentadienyl)titanium di-(p-tolyl) and 150 g of 1,2-polybutadiene (1,2-vinyl bond content approximately 85%) with a molecular weight of approximately 1,000 were dissolved therein. A cyclohexane solution containing 60 mmol of n-butyllithium was then added to the reactor, and the mixture was allowed to react at room temperature for 5 minutes. 40 mmol of n-butanol was immediately added and stirred to obtain the hydrogenation catalyst (TC1). The resulting catalyst was stored at room temperature.

[0127] (Production Example 4) Rubber-like polymer (AH1) The hydrogenation catalyst (TC1) was added to the rubbery polymer solution (A-1) before hydrogenation obtained in Production Example 1 in an amount of 35 ppm (Ti standard) per 100 parts by mass of the rubbery polymer before hydrogenation, and the hydrogenation reaction was carried out for 50 minutes at a hydrogen pressure of 0.8 MPa and an average temperature of 85°C. 12.6 g of n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and 3.0 g of 4,6-bis(octylthiomethyl)-o-cresol were added as antioxidants to the resulting rubbery polymer solution, and the rubber composition solution was then added dropwise to warm water to remove the solvent. The mixture was then dried in a dryer to obtain rubbery polymer (AH1).

[0128] (Production Example 5) Rubber-like polymer (AH2) A rubbery polymer (AH2) was obtained in the same manner as in Production Example 4, except that the amount of the hydrogenation catalyst (TC1) added was changed to 45 ppm on a Ti basis per 100 parts by mass of the rubbery polymer before hydrogenation.

[0129] (Production Example 6) Rubber-like polymer (AH3) A rubbery polymer (AH3) was obtained in the same manner as in Production Example 4, except that the amount of the hydrogenation catalyst (TC1) added was changed to 60 ppm on a Ti basis per 100 parts by mass of the rubbery polymer before hydrogenation.

[0130] (Production Example 7) Rubber-like polymer (AH4) A rubbery polymer (AH4) was obtained in the same manner as in Production Example 4, except that the amount of the hydrogenation catalyst (TC1) added was changed to 70 ppm on a Ti basis per 100 parts by mass of the rubbery polymer before hydrogenation.

[0131] (Production Example 8) Rubber-like polymer (AH5) A rubbery polymer (AH5) was obtained in the same manner as in Production Example 4, except that the amount of the hydrogenation catalyst (TC1) added was changed to 80 ppm on a Ti basis per 100 parts by mass of the rubbery polymer before hydrogenation.

[0132] (Production Example 9) Rubber-like polymer (BH1) The hydrogenation catalyst (TC1) was added to the rubbery polymer solution (B-1) before hydrogenation obtained in Production Example 2 in an amount of 90 ppm (Ti standard) per 100 parts by mass of the rubbery polymer before hydrogenation, and the hydrogenation reaction was carried out for 50 minutes at a hydrogen pressure of 0.8 MPa and an average temperature of 85°C. 12.6 g of n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and 3.0 g of 4,6-bis(octylthiomethyl)-o-cresol were added as antioxidants to the resulting rubbery polymer solution, and the rubber composition solution was then added dropwise to warm water to remove the solvent. The mixture was then dried in a dryer to obtain rubbery polymer (BH1).

[0133] (Production Example 10) Rubber-like polymer (BH2) A rubbery polymer (BH2) was obtained in the same manner as in Production Example 9, except that the amount of the hydrogenation catalyst (TC1) added was changed to 70 ppm on a Ti basis per 100 parts by mass of the rubbery polymer before hydrogenation.

[0134] [Table 2]

[0135] [Preparation of rubber composition] Using an internal mixer (0.3 L capacity) equipped with a temperature control device, the raw rubber (rubber-like polymer, natural rubber, high-cis polybutadiene), filler (silica, carbon black), silane coupling agent, process oil, zinc oxide, and stearic acid were kneaded in the first stage at a filling rate of 65% and a rotor rotation speed of 30 to 50 rpm, according to the formulation shown in Table 3. During this process, the temperature of the internal mixer was controlled, and each rubber composition (compound) was obtained at a discharge temperature of 155 to 160°C. Next, in the second stage of mixing, the compound obtained above was cooled to room temperature, and then an antioxidant was added. The compound was then mixed again to improve dispersion of the inorganic filler. Again, the temperature of the mixer was controlled to 155-160°C before discharge. After cooling, the compound was mixed in the third stage of mixing using an open roll set at 70°C, where sulfur and a vulcanization accelerator were added and mixed. The mixture was then molded and vulcanized in a vulcanization press at 160°C for 25 minutes. The properties of the resulting vulcanized rubber are shown in Tables 4 and 5.

[0136] The product names used for each component in Table 3 are as follows: Extender oil (product name "Process R800" manufactured by ENEOS Corporation) Silica (product name "Ultrasil 7000GR" manufactured by Evonik Degussa) with a nitrogen adsorption specific surface area of ​​170 m 2 / g) Carbon black (product name "Seat KH (N339)" manufactured by Tokai Carbon Co., Ltd.) Silane coupling agent (Evonik Degussa brand name "Si75", bis(triethoxysilylpropyl) disulfide) Antioxidant (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) · Vulcanization accelerator NS (N-tert-butyl-2-benzothiazylsulfenamide) Vulcanization accelerator TT (tetramethylthiuram disulfide)

[0137] [Table 3]

[0138] [Table 4]

[0139] [Table 5]

[0140] The product names used for each component in Tables 4 and 5 are as follows: BR (UBEPOL (registered trademark) BR150) ·NR(RSS No.3)

[0141] [Evaluation of characteristics] (tensile strength) The breaking strength was measured in accordance with the tensile test method of JIS K6251. The results of Comparative Examples 1 and 3 were indexed with 100. A larger index indicates better breaking strength.

[0142] (stretch) The elongation at break of the crosslinked rubber composition after vulcanization was measured in accordance with the tensile test method of JIS K6251. The results of Comparative Examples 1 and 3 were indexed as 100. A larger index indicates better elongation at break.

[0143] (crack resistance) Trouser-shaped test specimens were prepared as test specimens, and a tear test was carried out in accordance with JIS K-6252 to measure the maximum tear strength until the test specimen broke. The evaluations of Comparative Examples 1 and 3 were indexed, with the evaluations being 100. A larger index indicates better crack resistance.

[0144] (Dynamic magnification and loss factor) Measurements were made in accordance with JIS-K-6385 and JIS-K-6394. Using a rubber vibration isolation tester, the loss factor (tanδ) was measured at 15 Hz and an amplitude of 1%, and the dynamic modulus of elasticity (Kd) was measured at 100 Hz and an amplitude of 0.1%. The ratio of the dynamic modulus of elasticity to the static modulus of elasticity (Ks) was taken as the dynamic magnification factor. The results of Comparative Examples 1 and 3 were indexed, with 100 being used as the dynamic magnification factor. The dynamic magnification factor is a measure of soundproofing performance, and a smaller index indicates better soundproofing performance. The loss factor (tan δ) is a measure of vibration-damping performance, and the larger the index, the better the vibration-damping performance.

[0145] (durability) Using a Goodrich heat generation tester, the strain (reduction in the height of the original sample (%)) after repeated compression 100,000 times at 100°C with a stroke of 5.71 mm was measured. The results of Comparative Examples 1 and 3 were indexed, with the results being 100. A smaller index indicates better durability.

[0146] (Compression set) According to JIS-K-6301, the distortion after 22 hours at 100°C was measured and indexed, with the results of Comparative Examples 1 and 3 being set to 100. Compression set is used as a measure of static durability, with a smaller index indicating better durability.

[0147] Tables 4 and 5 show that the vulcanized rubbers of the present invention obtained in Examples 1 to 8 are all superior in tensile strength, elongation, and crack resistance compared to the vulcanized rubbers obtained in Comparative Examples 1 and 3. Furthermore, the vulcanized rubbers obtained in Examples 1 to 8 are rubber compositions that are superior in vibration-damping properties such as loss factor and dynamic magnification, and are also superior in durability such as compression set compared to the vulcanized rubbers obtained in Comparative Examples 1 and 3. It is also clear that the compression set of Comparative Example 2, which used a rubber-like polymer (AH5) with an iodine value of 0, was unfavorable. [Industrial Applicability]

[0148] The high-damping rubber composition according to the present invention has good performance as a high-damping rubber, such as processability, tensile strength, durability, heat resistance, and soundproofing performance, and by making use of these characteristics, the rubber composition is suitable for vibration-proof rubber used in various parts of automobiles such as passenger cars, trucks, buses, construction vehicles, and light trucks, as well as railway vehicles; seismic isolation rubber installed in buildings and the like to absorb the energy of earthquakes; and vibration-damping rubber that converts the sound, vibration, and impact of transportation equipment and mechanical facilities, including office automation equipment and electronic devices in personal computers, into thermal energy to absorb the sound, vibration, and impact.

Claims

1. A vibration-damping material comprising a rubber composition, The rubber composition an ethylene-based rubbery polymer (A) having an iodine value of 10 to 250 Ig / 100g, an ethylene structure content of 3% by mass or more, an aromatic vinyl monomer block content of less than 10% by mass, and a conjugated diene monomer unit content of 2% by mass or more; a rubbery polymer (B); Including, the amount of the ethylene-based rubbery polymer (A) is 10 parts by mass or more and 90 parts by mass or less, when the total amount of the rubber component including the ethylene-based rubbery polymer (A) and the rubbery polymer (B) is 100 parts by mass, the amount of the rubbery polymer (B) is 10 parts by mass or more and 90 parts by mass or less, when the total amount of the rubber component including the ethylene-based rubbery polymer (A) and the rubbery polymer (B) is 100 parts by mass; The modification rate of the ethylene-based rubber polymer (A) is 40% by mass or more. Anti-vibration material.

2. The vibration-damping material described in claim 1, wherein the vibration-damping material is vibration-damping rubber for engine mounts.

3. The vibration-damping material described in claim 1, wherein the vibration-damping material is seismic isolation rubber.

4. The vibration-damping material according to any one of claims 1 to 3, wherein the rubber-like polymer (B) is at least one selected from the group consisting of natural rubber, polybutadiene, polyisoprene rubber, and ethylene-α-olefin-non-conjugated polyene copolymer.

5. A vibration-damping material described in any one of claims 1 to 4, wherein the rubber composition further contains an inorganic filler (C), and the amount of the inorganic filler (C) is 30 parts by mass or more and 120 parts by mass or less, when the total amount of the rubber components including the ethylene-based rubber-like polymer (A) and the rubber-like polymer (B) is 100 parts by mass.

6. The solubility parameter (SP value) of the ethylene rubber polymer (A) is 16.8 (MPa). 1 / 2 More than 17.5 (MPa) 1 / 2 The vibration-damping material according to any one of claims 1 to 5, wherein:

7. 7. The vibration-proof material according to claim 1, wherein the ethylene-based rubber-like polymer (A) contains a nitrogen atom.

8. A vibration-damping material described in any one of claims 1 to 7, wherein the rubber composition is vulcanized.

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