JP2006090388A - Vibration absorbing rubber device and vibration absorbing rubber composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration absorbing rubber device suitable as an automobile engine mount, having improved vibration absorbing performance and mechanical strength. <P>SOLUTION: The vibration absorbing rubber device as a liquid sealed mount 10 comprises a vibration source side mounting member 11 attached to the side of a vibration source such as an engine, a body side mounting member 12, a liquid sealed chamber 20 encircled by an elastic member 13 of a rubber material and a diaphragm 15 attached to the body side mounting member 12, a partition member 14 for partitioning the liquid sealed chamber 20 into a main liquid chamber 16 and a sub liquid chamber 17, and an orifice passage 161 for communicating the main liquid chamber 16 with the sub liquid chamber 17. The rubber material consists of a samarium complex containing samarium and substitutional cyclopentadienyl groups and a polybutadiene rubber obtained by the polymerization reaction of 1,3-butadiene using a catalyst composition of toluene soluble aluminoxan. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an anti-vibration rubber device and the like, and more particularly to an anti-vibration rubber device and the like using a rubber material having a low dynamic magnification.

  Conventionally, anti-vibration rubbers used for automobile strut mounts, suspension bushings, engine mounts and the like are required to have anti-vibration performance and fatigue resistance to reduce engine vibration and noise. From the viewpoint of anti-vibration performance, the smaller the spring constant (dynamic spring constant) in the vibration state, the better. The larger the static spring constant indicating the support rigidity, the better. It can be said that the vibration-proof rubber having a smaller dynamic magnification (dynamic spring constant / static spring constant) which is the ratio of

  Specific examples of such anti-vibration rubber include, for example, a rubber composition improved in creep characteristics by blending carbon black with natural rubber (NR) excellent in low vibration transmission performance (see Patent Document 1), polybutadiene By blending an unsaturated fatty acid amide with rubber (BR) and blending a rubber composition (see Patent Document 2) that has an effect of reducing friction in addition to vibration proof performance, natural rubber and end-modified polybutadiene rubber are blended. A rubber composition with improved vibration characteristics (see Patent Document 3) has been reported.

JP 08-269236 A JP 09-302148 A Japanese Patent Application Laid-Open No. 08-073658

By the way, such an anti-vibration rubber for automobiles is usually used in a state where a certain load is applied. In particular, vibration-proof rubbers such as engine mounts are required to have mechanical strength that can withstand long-time use in addition to vibration-proof performance.
However, conventional anti-vibration rubber for automobiles using natural rubber (NR) or polybutadiene rubber (BR) is often insufficient in terms of mechanical strength, and further improvement is required.

  The present invention has been made in order to solve the problem of such a vibration-proof rubber for automobiles. That is, an object of the present invention is to provide an anti-vibration rubber device excellent in anti-vibration performance and mechanical strength and an anti-vibration rubber composition used for the anti-vibration rubber device.

Therefore, as a result of intensive studies, the present inventor has found that a polybutadiene polymerized by using a recently reported metallocene rare earth metal complex as a polymerization catalyst (Japanese Patent No. 3422733, etc.) has a microstructure with an extremely high 1,4-cis bond amount. Focusing on the fact that the anti-vibration rubber material has been studied, it has been found that an anti-vibration rubber device having excellent dynamic characteristics can be obtained, and the present invention has been completed based on this finding.
That is, according to the present invention, the vibration source side attachment member attached to the vibration source side, the vehicle body side attachment member attached to the vehicle body side, the vibration source side attachment member and the vehicle body side attachment member are connected and provided integrally. An anti-vibration rubber device comprising a conjugated diene rubber obtained by a polymerization reaction of a conjugated diene using a catalyst composition comprising a metallocene type rare earth metal complex and a cocatalyst. Provided.

  An anti-vibration rubber device to which the present invention is applied is applied to, for example, an engine mount for automobiles, and in particular, a diaphragm surrounded by a diaphragm and an elastic member attached to a vehicle body side mounting member so as to face the elastic member. A liquid sealing chamber comprising a space; a partition member that divides the liquid sealing chamber into a main liquid chamber on the elastic member side and a sub liquid chamber on the diaphragm side; and an orifice passage that communicates the main liquid chamber and the sub liquid chamber. It is preferable to be applied to a liquid ring mount provided with.

  Next, according to the present invention, an anti-vibration rubber composition containing a conjugated diene rubber obtained by a polymerization reaction of a conjugated diene using a catalyst composition comprising a metallocene rare earth metal complex and a cocatalyst is provided.

The conjugated diene rubber constituting the vibration-proof rubber composition to which the present invention is applied is preferably obtained by a polymerization reaction with 1,3-butadiene.
Furthermore, the microstructure of the conjugated diene rubber has a 1,4-cis bond of 95 mol% or more, and the molecular weight distribution of the conjugated diene rubber is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). (Mw / Mn) is preferably 2.0 or less.

  Further, as a polymerization catalyst for obtaining a conjugated diene rubber constituting the vibration-proof rubber composition to which the present invention is applied, the metallocene-type rare earth metal complex is a samarium complex containing samarium and a substituted cyclopentadienyl group. The cocatalyst is preferably an ionic compound and / or an aluminoxane.

  Moreover, it is preferable that the vibration-proof rubber composition to which the present invention is applied further contains 5 to 100 parts by weight of a reinforcing agent with respect to 100 parts by weight of the conjugated diene rubber. Among the reinforcing agents, carbon black is preferable, and carbon black having a particle surface area of 50 g / kg or less in terms of iodine adsorption is preferable.

  According to the present invention, an anti-vibration rubber device having excellent anti-vibration performance and mechanical strength can be obtained.

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described using an example of a liquid seal mount which is one form of a vibration-proof rubber device. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.
FIG. 1 is a diagram illustrating a vibration isolator to which the present embodiment is applied. FIG. 1 shows a liquid ring mount 10 which is one form of a vibration isolator. A liquid ring mount 10 shown in FIG. 1 includes a vibration source side attachment member 11 attached to an engine (not shown) which is a vibration source, a vehicle body side attachment member 12 attached to the vehicle body side, and a vibration source side attachment. The member 11 and the vehicle body side attachment member 12 are connected, and the elastic member 13 provided integrally with these is provided.

  The shape of the vibration source side mounting member 11 has an axial shape extending toward the inside of the vehicle body side mounting member 12 in parallel with the main vibration input direction X. The vibration source side attachment member 11 is fitted to a mount side boss 101 formed at one end of the engine attachment bracket 100 and attached by a nut 111. An engine-side boss 102 is formed at the other end of the engine mounting bracket 100, and is attached to an engine (not shown) with bolts or the like. Further, in the middle portion of the engine mounting bracket 100, an upper pressing portion 104a in which the engine mounting bracket 100 is bent downward to provide a horizontal portion, a lower pressing portion 104b that protrudes toward the elastic member 13, and an elastic member 13, a pressing portion 104 having a front pressing portion 104c opposite to the pressing portion 104 is integrally formed.

  The elastic member 13 has an inner surface that is in close contact with the surface of the vibration source side mounting member 11, a conical portion 131 that is formed in a substantially conical shape, and is integrally formed with the conical portion 131, and is formed on the surface of the vehicle body side mounting member 12. And a cylindrical portion 132 formed in a cylindrical shape having an outer surface to be in close contact with. The elastic member 13 is formed of a rubber-like elastic material made of conjugated diene rubber. The elastic material will be described later.

  The vehicle body side attachment member 12 includes a flange 121 that forms a vehicle body attachment surface, and a cylindrical portion 122 that is formed continuously below the flange 121 and that is in close contact with the outer surface of the cylindrical portion 132 of the elastic member 13. Although not shown, the flange 121 is formed with a mounting hole for mounting to the vehicle body side with a bolt or the like. Further, a collision stopper 125 is provided at a part of the flange 121 facing the pressing portion 104 of the engine mounting bracket 100. The collision stopper 125 is pressed so as to form a predetermined gap between the upper pressing portion 104a in the pressing portion 104 of the engine mounting bracket 100, the lower pressing portion 104b, and the front pressing portion 104c. It enters into the abutting part 104. An elastic coating layer 135 covered with a rubber material constituting the elastic member 13 is formed integrally with the elastic member 13 at a contact portion between the collision stopper 125 and the pressing portion 104.

  A lower part of the cylindrical portion 122 of the vehicle body side mounting member 12 is provided with a partition member 14 provided horizontally inside, and an upper partition mounting portion 123 having a larger diameter than the cylindrical portion 122 is provided integrally with the cylindrical portion 122. Yes. Further, a diaphragm 15 is provided inside, and a lower partition mounting portion 124 is provided which is fitted with the upper partition mounting portion 123 and integrated by caulking and whose lower portion has a smaller diameter than the upper partition mounting portion 123.

  As shown in FIG. 1, inside the cylindrical portion 132 of the elastic member 13, a lower partition mounting portion 124 that is integrated with the inner surface of the cylindrical portion 122 of the vehicle body side mounting member 12 and is attached to the lower portion of the cylindrical portion 122. A liquid sealing chamber 20 is formed which is a closed space surrounded by a diaphragm 15 and an elastic member 13 fixed inside. Further, the liquid sealing chamber 20 is fixed in the main liquid chamber 16 partitioned by the partition member 14 provided in the upper partition mounting portion 123 and the inner surface of the elastic member 13, and in the partition member 14 and the lower partition mounting portion 124. The auxiliary liquid chamber 17 is partitioned by the diaphragm 15. The main liquid chamber 16 and the sub liquid chamber 17 are communicated with each other by an orifice passage 161 formed between the partition member 14 and the peripheral edge portion 151 of the diaphragm 15. The orifice passage 161 communicates with the main liquid chamber 16 at an inlet 162 formed in the partition member 14 and communicates with the sub liquid chamber 17 at an outlet 163 formed in the elastic member 13.

  As shown in FIG. 1, the liquid seal mount 10 to which this exemplary embodiment is applied has a thin wall portion 134 in which a part of the inner wall of the conical portion 131 of the elastic member 13 is thinner than the other portions of the elastic member 13. A recess 133 is formed on the inner surface of the elastic member 13. The recess 133 is formed continuously on the inner surfaces of the conical part 131 and the cylindrical part 132. Although not shown, the recess 133 is provided on the inner surface of the elastic member 13 so as to form a pair of identical shapes at axially symmetric positions.

  Furthermore, the liquid seal mount 10 to which the present embodiment is applied has the liquid in the liquid seal chamber 20 at the predetermined frequency in the middle and high frequency range at the end protruding into the main liquid chamber 16 of the vibration source side mounting member 11. In order to cause liquid column resonance, a disk-shaped medium-frequency device 19 is attached and supported.

  Next, the operation of the liquid seal mount 10 to which this exemplary embodiment is applied will be described. In FIG. 1, when the liquid ring mount 10 has a vibration input in the middle frequency range of about 40 Hz to 500 Hz through the vibration source side mounting member 11, an elastic member formed integrally with the vibration source side mounting member 11. Thirteen thin-walled portions 134 cause membrane resonance, and become a minimum value at a preset specific frequency. Here, the membrane resonance is caused when the thin portion 134 of the elastic member 13 is elastically deformed into a spring shape due to the liquid flow in the liquid sealing chamber 20 constituted by the main liquid chamber 16 and the sub liquid chamber 17. Resonance phenomenon as an elastic membrane. A plurality of thin portions 134 may be provided on the inner surface of the elastic member 13 and each may be provided in the same shape at a symmetrical position. In addition, a plurality of thin portions 134 may be provided on the inner surface of the elastic member 13 and each may be provided in a different shape at a symmetrical position. Further, the thin-walled portion 134 can absorb vibration by membrane resonance with respect to vibration input in a specific middle circumference region by adjusting the size and depth of the recess 133 and changing the film thickness and area. it can.

  Further, when the liquid seal mount 10 receives vibration input in a high frequency range of about 500 Hz to 1000 Hz through the vibration source side mounting member 11, the medium frequency device 19 provided at the end of the vibration source side mounting member 11. And the orifice gap 18 formed between the inner surface of the conical portion 131 of the elastic member 13 and the liquid column resonance occurs, the value becomes a minimum value at a specific frequency. As a result, two local minimum values are formed in the medium frequency range from the medium frequency range of about 40 Hz to 500 Hz to the high frequency range of about 500 Hz to 1000 Hz, and the low dynamics with significantly reduced dynamic spring characteristics in a wide range of vibration wavelength range. A spring is realized.

Next, the rubber material will be described.
The elastic member 13 in the liquid ring mount 10 to which the present embodiment is applied includes a conjugated diene rubber (hereinafter, metallocene) obtained by a polymerization reaction of a conjugated diene using a catalyst composition comprising a metallocene rare earth metal complex and a cocatalyst. It may be described as rubber.)
That is, the metallocene rubber used in the present embodiment is a metallocene rare earth metal complex having a substituted cyclopentadienyl group such as a pentamethylcyclopentadienyl group as a ligand on a rare earth metal such as samarium (Sm). Hereinafter, it may be referred to as a metallocene rare earth catalyst), and a conjugated diene compound as a monomer is polymerized by a catalyst composition that combines an ionic compound and / or an aluminoxane as a co-catalyst ( Japanese Patent No. 3422733, Japanese Patent Application Laid-Open No. 2004-27103, Japanese Patent Application Laid-Open No. 2004-238637).

Specific examples of such metallocene rare earth metal complexes include, for example, bispentamethylcyclopentadienylbistetrahydrofuran samarium, methylbispentamethylcyclopentadienyltetrahydrofuran samarium, chlorobispentamethylcyclopentadienyltetrahydrofuran samarium, iodo Samarium complexes such as bispentamethylcyclopentadienyltetrahydrofuran samarium and dimethylaluminum (μ-dimethyl) bis (pentamethylcyclopentadienyl) samarium are preferred. The cocatalyst is preferably an aluminoxane.
In addition, about the polymerization catalyst composition used for superposition | polymerization of a conjugated diene monomer in order to obtain such a metallocene rubber used in this Embodiment, patent 34222733 gazette ((0009) column-(0024) column), This is described in detail in JP-A-2004-27103 and JP-A-2004-238637.

  The conjugated diene used as a monomer for obtaining the metallocene rubber is not particularly limited. For example, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 1,3-pentadiene (piperylene), Examples include 2-ethyl-1,3-butadiene, 2,3-dimethylbutadiene, 2-methylpentadiene, 4-methylpentadiene, 2,4-hexadiene, and among these, 1,3-butadiene is preferable. . These conjugated diene monomer components may be used alone or in combination of two or more.

  A metallocene rubber obtained by a polymerization reaction of a conjugated diene using such a metallocene rare earth catalyst is conventionally obtained by a Ziegler-Natta type coordination polymerization catalyst having cobalt (Co), nickel (Ni) or the like as a central metal. Compared with synthetic rubber, it is particularly characterized in that the amount of 1,4-cis bonds in the microstructure is extremely high and the molecular weight distribution is narrow.

The amount of 1,4-cis bond in the microstructure of the metallocene rubber is usually 80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more, and particularly preferably 98 mol% or more.
Here, the microstructure of the metallocene rubber is measured using proton NMR ( ¹ H-NMR) and carbon ¹³ NMR ( ¹³ C-NMR). That is, for example, when the conjugated diene monomer is 1,3-butadiene, the peak obtained from ¹ H-NMR and ¹³ C-NMR [ ¹ HNMR: δ 4.8-5.0 (of 1,2-vinyl bond) = _CH 2), 5.2-5.8 (1,4- bond -CH = and 1,2-vinyl bond of ^{-CH =), 13 CNMR: δ27.4} (1,4- cis bonds), 32.7 (1,4-trans bond), 127.7-131.8 (1,4-bond), 113.8-114.8 and 143.3-144.7 (1,2-vinyl bond) ] Is calculated from the integration ratio.

  The molecular weight distribution of the metallocene rubber is such that the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually 2.0 or less, preferably 1.80 or less, more preferably 1.60 or less, more preferably 1.40 or less, and particularly preferably 1.30 or less. Here, the weight average molecular weight (Mw), the number average molecular weight (Mn), and the molecular weight distribution (Mw / Mn) of the metallocene rubber are determined as numerical values in terms of standard polystyrene by gel permeation chromatography (GPC).

  In order to obtain the rubber material used in the present embodiment, the polymerization method of the conjugated diene monomer using a catalyst composition comprising a metallocene rare earth metal complex and a cocatalyst is not particularly limited, and in the presence or absence of a solvent. Any of these may be used. The solvent is not particularly limited as long as it is inert in the polymerization reaction and has sufficient solubility with respect to the conjugated diene monomer and the catalyst composition. For example, saturated aliphatic hydrocarbons such as butane, pentane, hexane and heptane; saturated alicyclic hydrocarbons such as cyclopentane and cyclohexane; monoolefins such as 1-butene and 2-butene; aromatics such as benzene and toluene Hydrocarbons: Halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, trichloroethylene, perchlorethylene, 1,2-dichloroethane, chlorobenzene, bromobenzene, chlorotoluene, etc. Among these, toluene is preferable. Two or more solvents may be used in combination.

  Moreover, superposition | polymerization temperature is the range of -100 degreeC-100 degreeC, for example, Preferably, it is the range of -50 degreeC-80 degreeC. The polymerization time is, for example, about 1 minute to 12 hours, preferably about 5 minutes to 5 hours. The conditions for the polymerization reaction are appropriately selected according to the kind of the conjugated diene monomer and the kind of the catalyst composition, and are not particularly limited.

Next, the anti-vibration rubber composition will be described.
As described above, the vibration-proof rubber composition to which the present embodiment is applied is a conjugated diene rubber (metallocene) obtained by a polymerization reaction of a conjugated diene using a catalyst composition comprising a metallocene rare earth metal complex and a promoter. Rubber).

(Other ingredients)
The anti-vibration rubber composition to which the present embodiment is applied contains various reinforcing agents, vulcanizing agents, vulcanization accelerators, plasticizers, anti-aging agents, and the like as necessary together with the metallocene rubber described above. be able to.
Examples of the various reinforcing agents include carbon black, silica, calcium carbonate, magnesium carbonate, clay, talc, and calcium silicate. Among these, carbon black is preferable, and carbon black having a particle surface area of 50 g / kg or less in terms of iodine adsorption is particularly preferable. The blending amount of carbon black is not particularly limited, but is usually 5 to 100 parts by weight, preferably 10 to 60 parts by weight with respect to 100 parts by weight of the metallocene rubber.

  Examples of vulcanizing agents include sulfur vulcanizing agents and organic peroxides. Examples of the sulfur-based vulcanizing agent include sulfur such as powdered sulfur and precipitated sulfur; organic sulfur compounds such as 4,4'-dithiomorpholine, tetramethylthiuram disulfide, tetraethylthiuram disulfide, and polymer polysulfide.

  When a sulfur vulcanizing agent is used, a vulcanization accelerator and a vulcanization acceleration aid are usually used in combination. Examples of the vulcanization accelerator include sulfur-containing accelerators such as thiuram, sulfenamide, thiazole, dithiocarbamate, and thiourea; nitrogen-containing aldehyde / ammonia, aldehyde / amine, and guanidine Examples include accelerators.

  Of the vulcanization accelerators, thiuram accelerators are preferred. Specific examples of the thiuram accelerator include, for example, tetramethylthiuram disulfide (TT) (TMTD), tetramethylthiuram monosulfide (TS) (TMTM), tetraethylthiuram disulfide (TET) (TETD), tetrabutylthiuram disulfide ( TBT) (TBTD), dipentamethylene thiuram hexasulfide (TRA) (DPTT), tetrabenzyl thiuram disulfide and the like. Examples of the vulcanization acceleration aid include zinc white and magnesium oxide. The usage-amount of a vulcanization accelerator and a vulcanization acceleration adjuvant is not specifically limited, It determines suitably according to the kind etc. of sulfur vulcanization agent.

  Examples of the organic peroxide include dialkyl peroxides, diacyl peroxides, and peroxyesters. Dialkyl peroxides include dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) -3-hexyne, 2,5-dimethyl-2, Examples include 5-di (t-butylperoxy) hexane and 1,3-bis (t-butylperoxyisopropyl) benzene. Examples of the diacyl peroxide include benzoyl peroxide and isobutyryl peroxide. Examples of peroxyesters include 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyisopropyl carbonate, and the like.

  When using an organic peroxide, a crosslinking aid is usually used in combination. Examples of the crosslinking aid include triallyl cyanurate and trimethylolpropane trimethacrylate. The amount of the crosslinking aid used is not particularly limited and can be appropriately determined according to the type of the crosslinking agent.

  The blending amount of these vulcanizing agents is not particularly limited, but is usually 0.1 to 10 parts by weight, preferably 0.3 to 7 parts by weight, based on 100 parts by weight of the metallocene rubber. Preferably, it is 0.5 to 5 parts by weight.

  A bismaleimide compound may be blended with the anti-vibration rubber composition to which the present embodiment is applied in order to improve the adhesion between the metal member constituting the anti-vibration rubber device and the rubber material. Examples of the bismaleimide compound include N, N ′-(m-phenylene) bismaleimide, N, N ′-(p-phenylene) bismaleimide, N, N ′-(o-phenylene) bismaleimide, N, N′-. (1,3-naphthylene) bismaleimide, N, N ′-(1,4-naphthylene) bismaleimide, N, N ′-(1,5-naphthylene) bismaleimide, N, N ′-(3,3 ′ -Dimethyl-4,4'-biphenylene) bismaleimide, N, N '-(3,3'-dichloro-4,4'-biphenylene) bismaleimide and the like.

  When a bismaleimide compound is used, for example, oximes such as p-quinonedioxime, p, p'-dibenzoylquinonedioxime, tetrachloro-p-benzoquinone; Morpholine compounds such as morpholine, N-ethylmorpholine, morpholine and the like can be used in combination.

  In addition, process oils such as aromatic oils, naphthenic oils, and paraffinic oils; plasticizers such as dioctyl phthalate; waxes such as paraffin wax and carnauba wax; various agents such as stabilizers and colorants It can be used by appropriately blending as necessary.

Moreover, it is preferable to mix | blend an anti-aging agent with the vibration-proof rubber composition to which this Embodiment is applied, in order to improve the heat resistance of the vibration-proof rubber used for a long time in a high temperature atmosphere. Anti-aging agents include, for example, amine-ketones such as poly- (2,2,4-trimethyl-1,2-dihydroquinone); N-phenyl-N′-isopropyl-p-phenylenediamine, N-phenyl Amines such as -N '-(3-methacryloyloxy-2-hydroxypropyl) -p-phenylenediamine; phenols such as 2,2'-methylenebis (4-ethyl-6-t-butylphenol); 2-mercapto Examples include benzimidazole.
The blending amount of the antioxidant is not particularly limited, but is usually 0.1 to 10 parts by weight, preferably 0.3 to 7 parts by weight, more preferably 100 parts by weight of the metallocene rubber. 0.5 parts by weight to 5 parts by weight.

  In the vibration-proof rubber composition to which the present embodiment is applied, in addition to the metallocene rubber described above, other rubbers can be mixed and used as necessary. Examples of other rubbers include natural rubber, polyisoprene rubber, high cis-polybutadiene rubber polymerized using a Ziegler-Natta polymerization catalyst, low cis-polybutadiene rubber polymerized using a lithium polymerization catalyst, and SBR. (Emulsion polymerization SBR (random), solution polymerization SBR (random, styrene tapered)), acrylonitrile-butadiene copolymer rubber (NBR), hydrogenated acrylonitrile-butadiene copolymer rubber (HNBR), ethylene-α-olefin copolymer rubber (EPR, EPDM) and the like.

(Method for producing anti-vibration rubber composition)
The method for producing the vibration-insulating rubber composition to which the present embodiment is applied is not particularly limited. Usually, a conjugated diene rubber, a predetermined vulcanizing agent, and other compounding agents are mixed with a mixer such as a roll or a Banbury mixer. Are kneaded and mixed, molded into a predetermined shape by a conventionally known molding method such as injection molding or extrusion molding, and vulcanized by a predetermined method. The vulcanization temperature is not particularly limited, but is usually 100 ° C to 200 ° C, preferably 130 ° C to 190 ° C, and more preferably 140 ° C to 180 ° C. The vulcanization time is appropriately changed depending on the vulcanization method, temperature, shape and the like, and is not particularly limited, but is usually 1 minute or more and 5 hours or less. In addition, you may perform secondary vulcanization | cure as needed. The vulcanization method can be appropriately selected from methods usually used for rubber vulcanization, such as press heating, steam heating, oven heating, and hot air heating.

  As described above, the vibration-proof rubber composition to which the present embodiment is applied is a conjugated diene rubber (metallocene) obtained by a polymerization reaction of a conjugated diene using a catalyst composition comprising a metallocene rare earth metal complex and a promoter. Rubber). The anti-vibration rubber composition containing such a metallocene rubber has excellent vibration and noise prevention characteristics as compared with polybutadiene rubber (BR) and natural rubber (NR) obtained with a Ziegler-Natta type polymerization catalyst. Has the required mechanical strength. For this reason, body mount, cab mount, member mount, strut bar cushion, center bearing support, torsional damper, steering rubber coupling, tension rod bush, lower ring bush, arm bush, bump strapper, FF engine, etc. It can be used as a constituent member of various anti-vibration rubbers for automobiles such as roll stoppers and muffler hangers.

Hereinafter, the present embodiment will be described in more detail based on examples. Note that this embodiment is not limited to the examples. In the examples and comparative examples, all parts and% are based on weight unless otherwise specified.
1. Normal state physical properties About a test piece prepared by heating a rubber composition having the composition shown in Table 1 at 160 ° C. for 12 minutes to form a vulcanized sheet and punching it into a No. 3 dumbbell type (JIS K6251). 100% tensile stress (unit: MPa), tensile strength (unit: MPa), elongation (unit:%), and tear strength (unit: MPa) were measured. The hardness Hs was measured according to the method described in JIS K6253 spring type durometer hardness test.
2. Dynamic characteristics The rubber composition having the composition shown in Table 1 was heated at 160 ° C. for 20 minutes to prepare a cylindrical specimen having a diameter of 50 mm and a height of 50 mm. The static spring constant (Ks ( (Unit: N / mm)) and dynamic spring constant (Kd (unit: N / mm 100 Hz)) were measured to determine the dynamic magnification (Kd / Ks 100 Hz). Further, tan δ (15 Hz) was also obtained.
The static spring constant (Ks) was calculated by compressing the cylindrical test piece in the axial direction of the cylinder by 3 mm and reading the load at the time of distortion of 1 mm and 2 mm from the load spring diagram of the second round.
The dynamic spring constant (Kd) is obtained by compressing the above cylindrical test piece by 1.5 mm in the axial direction of the cylinder, and with an amplitude of ± 0.05 mm at a frequency of 100 Hz from the bottom centered on the 1.5 mm compression position Then, the dynamic load was measured with a load cell attached above the test piece and calculated according to JIS K6394. The dynamic magnification (Kd / Ks) is a ratio between the static spring constant (Ks) and the dynamic spring constant (Kd).

3. Processability test A rubber composition having the composition shown in Table 1 was roll kneaded at 40 ° C to 80 ° C and evaluated for bagging, earring and perforation according to the following criteria.
(Bugging)
(Double-circle): It can knead | mix well, without producing bagging.
○: Some bagging occurs but kneading is possible.
Δ: Bagging occurs and kneading takes time.
X: Bagging occurs and kneading is quite difficult.

(Ear cut)
A: No ear cutting occurs.
○: Slightly cut ears occur.
Δ: The ear is considerably cut
X: Numerous ear cuts occur, and kneading is quite difficult.

(pierced)
A: There is no perforation.
○: Slight perforation occurs.
Δ: Perforation is considerably generated.
X: Many perforations occur and kneading is quite difficult.

(Example 1, Comparative Examples 1 to 4)
According to the polymerization conditions described in Japanese Patent No. 3422733 (0029), bispentamethylcyclopentadienylbistetrahydrofuran samarium [(Cp ^* ) ₂ Sm (THF) ₂ ] (Cp ^* : pentamethyl) as a metallocene rare earth metal complex 1,3-butadiene is polymerized using a catalyst composition containing a cyclopentadienyl ligand) and toluene-soluble aluminoxane as a co-catalyst, and the amount of 1,4-cis bonds is 99.0 mol% or more, Polybutadiene rubber having a weight average molecular weight (Mw) of 590,000, a number average molecular weight (Mn) of 300,000, a ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / Mn) of 1.96 (prototype BR) )
Next, using the prototype BR thus obtained, a composition having the composition shown in Table 1 was prepared, and normal physical properties, dynamic properties, and workability were measured. The results are shown in Table 1. At the same time, polybutadiene rubber (BR-1, BR-2, BR-3) polymerized using a polymerization catalyst other than the metallocene rare earth metal complex and natural rubber (NR) are blended in the same manner as in the prototype BR. A normal composition, dynamic characteristics and processability were measured. The results are shown in Table 1.

However, the polybutadiene rubbers (BR-1, BR-2, BR-3) in Table 1 are as follows.
BR-1: Nipol BR1220 manufactured by Nippon Zeon Co., Ltd.
BR-2: JSR BR730 manufactured by JSR Corporation
BR-3: UBEPOL-BR150L manufactured by Ube Industries, Ltd.
Moreover, TT and NS are as follows.
TT: Vulcanization accelerator Tetramethylthiuram disulfide NS: Vulcanization accelerator N-tert-butyl-2-benzothiazolylsulfenamide

  From the results shown in Table 1, rubber composition containing polybutadiene rubber (trial BR) obtained by polymerization reaction using a catalyst composition comprising 1,3-butadiene and a metallocene rare earth metal complex and a cocatalyst (implemented BR) It can be seen that Example 1) is a rubber material having a high mechanical strength and a large measured value of 100% tensile stress (unit: MPa) and tensile strength (unit: MPa) in normal state physical properties. Furthermore, the dynamic magnification (Kd / Ks), which is the ratio between the static spring constant (Ks) and the dynamic spring constant (Kd), is 1.18, which is the smallest, and it is understood that the dynamic characteristics are also excellent. Therefore, a rubber composition (Example 1) containing polybutadiene rubber (trial BR) obtained by a polymerization reaction using a catalyst composition comprising 1,3-butadiene and a metallocene rare earth metal complex and a cocatalyst is used. Thus, it can be seen that a vibration-proof rubber material excellent in vibration-proof performance and mechanical strength can be obtained.

On the other hand, rubber compositions (Comparative Example 1 / BR-1, Comparative Example 2 / BR-2, Comparative Example 3 / BR-3) containing polybutadiene rubber polymerized using a polymerization catalyst other than a metallocene-type rare earth metal complex are: It can be seen that the rubber material has low mechanical strength and low measured values of 100% tensile stress (unit: MPa) and tensile strength (unit: MPa) in normal state physical properties. Furthermore, the dynamic magnification (Kd / Ks), which is the ratio between the static spring constant (Ks) and the dynamic spring constant (Kd), is 1.4 or more in all cases, indicating that the dynamic characteristics are insufficient.
In addition, the rubber composition containing natural rubber (Comparative Example 4) is a rubber having a high mechanical strength and a large measured value of 100% tensile stress (unit: MPa) and tensile strength (unit: MPa) in normal properties. Although it is a material, the dynamic magnification (Kd / Ks), which is the ratio between the static spring constant (Ks) and the dynamic spring constant (Kd), is 3.25, which is the largest. It can be seen that the balance with the dynamic characteristics is insufficient.

It is a figure explaining the vibration isolator to which this Embodiment is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid seal mount, 11 ... Vibration source side attachment member, 12 ... Vehicle body side attachment member, 13 ... Elastic member, 14 ... Partition member, 15 ... Diaphragm, 16 ... Main liquid seal chamber, 17 ... Sub liquid seal chamber, 18 ... Orifice gap, 19 ... Medium frequency device, 20 ... Liquid seal chamber, 100 ... Engine mounting bracket, 101 ... Mount side boss, 102 ... Engine side boss, 104 ... Pressing part, 104a ... Upper pressing part, 104b ... Lower Side pressing portion, 104c ... front pressing portion, 111 ... nut, 121 ... flange, 122 ... cylindrical portion, 123 ... upper partition mounting portion, 124 ... lower partition mounting portion, 125 ... collision stopper, 131 ... conical portion, 132: cylindrical portion, 134: thin-walled portion, 133: recessed portion, 135 ... elastic coating layer, 151 ... peripheral edge portion, 161 ... orifice passage, 162 ... entrance 163 ... exit

Claims (9)

A vibration source side attachment member attached to the vibration source side;
A vehicle body side mounting member attached to the vehicle body side;
An elastic member integrally provided by connecting the vibration source side mounting member and the vehicle body side mounting member;
An anti-vibration rubber device, wherein the elastic member is composed of a conjugated diene rubber obtained by a polymerization reaction of a conjugated diene using a catalyst composition comprising a metallocene rare earth metal complex and a promoter.   The apparatus further includes a diaphragm attached to the vehicle body side attachment member so as to face the elastic member, and a liquid sealed chamber including a closed space surrounded by the elastic member, and the liquid sealed chamber is a main liquid chamber on the elastic member side. 2. A vibration isolator according to claim 1, further comprising: a partition member partitioned into a sub liquid chamber on the diaphragm side and an orifice passage communicating the main liquid chamber and the sub liquid chamber. Rubber device.   An anti-vibration rubber composition comprising a conjugated diene rubber obtained by a polymerization reaction of a conjugated diene using a catalyst composition comprising a metallocene-type rare earth metal complex and a cocatalyst.   The anti-vibration rubber composition according to claim 3, wherein the conjugated diene is 1,3-butadiene.   The microstructure of the conjugated diene rubber has a 1,4-cis bond of 95 mol% or more, and the molecular weight distribution of the conjugated diene rubber is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). The anti-vibration rubber composition according to claim 3, wherein (Mw / Mn) is 2.0 or less.   The anti-vibration rubber composition according to claim 3, wherein the metallocene rare earth metal complex is a samarium complex containing samarium and a substituted cyclopentadienyl group.   The vibration-insulating rubber composition according to claim 3, wherein the promoter is an ionic compound and / or an aluminoxane.   The vibration-insulating rubber composition according to claim 3, further comprising 5 to 100 parts by weight of a reinforcing agent with respect to 100 parts by weight of the conjugated diene rubber.   The anti-vibration rubber composition according to claim 8, wherein the reinforcing agent is carbon black having a particle surface area of 50 g / kg or less in terms of iodine adsorption.

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