JP4929694B2 - Rubber composition, crosslinked rubber, and rubber molded product - Google Patents

Description

  The present invention relates to a rubber composition, a crosslinked rubber, and a rubber molded article, and more particularly relates to a rubber composition having excellent processability, a crosslinked rubber obtained using the rubber composition, and a rubber molded article.

  Ethylene / α-olefin / conjugated diene copolymer rubber and ethylene / α-olefin copolymer rubber are automotive rubber materials, rubber materials for building materials, rubber belts / rubber roller materials, rubber materials for vibration isolation, and thermoplastic elastomer modifiers. Used in a wide range of applications such as tubes, hoses, and general rubber products.

  On the other hand, various improved vulcanizates of ethylene / α-olefin / non-conjugated diene copolymer rubber have been proposed as vibration-proof rubbers used for automobiles (see Patent Documents 1 to 3).

  For example, Patent Document 1 discloses an intrinsic viscosity [η] measured in xylene at 70 ° C. for the purpose of providing a rubber composition having excellent roll processability and good fatigue resistance after vulcanization. A high molecular weight copolymer composed of an ethylene / α-olefin / non-conjugated diene copolymer having a viscosity of 3 dl / g or more, and an intrinsic viscosity [η] measured in xylene at 70 ° C. of 0.7-1 dl / g A rubber composition containing a low molecular weight copolymer composed of an ethylene / α-olefin / non-conjugated diene copolymer and having a bimodal molecular weight distribution is disclosed.

Patent Document 2 aims to provide a rubber composition for heat-resistant and vibration-proof rubber having excellent heat aging resistance and capable of advantageously enhancing both dynamic fatigue resistance and sag resistance. Is a heat-resistant and vibration-proof rubber using an ethylene / propylene / diene terpolymer having a polymer viscosity (ML _{1 + 4} : 121 ° C.) of 120 or more and a peroxide and a coagent (crosslinking aid). A rubber composition is disclosed.

  Patent Document 3 discloses that ethylene / α having an intrinsic viscosity [η] measured in xylene at 70 ° C. of 3 dl / g or more for the purpose of providing a vulcanized rubber having improved durability and dynamic fatigue resistance. A vulcanized rubber containing a liquid diene polymer obtained by hydrogenating 70% or more of double bonds to an olefin / non-conjugated diene copolymer rubber is disclosed.

Furthermore, a rubber composition (for example, see Patent Document 4) in which a crosslinked product obtained by crosslinking a functional group-containing (co) polymer with a metal component is blended with an ethylene / α-olefin copolymer rubber, or ethylene / α -A rubber composition (for example, refer to Patent Document 5) in which a functional group-containing (co) polymer and a silica-based filler are blended with an olefin copolymer rubber is disclosed. However, even rubber molded products produced using these rubber compositions can be said to have room for further improvement in terms of vibration resistance and heat resistance. Moreover, about these rubber compositions, processability may not necessarily be enough, and the further improvement needs to be aimed at.
JP-A-7-173336 JP 7-268147 A Japanese Utility Model Publication No. 7-292177 JP 2004-67831 A JP 2004-83622 A

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to provide a rubber composition having excellent processability and a crosslinked rubber obtained using the rubber composition. It is to provide a rubber molded product.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that ethylene / α-olefin / non-conjugated polyene copolymer and / or ethylene / α-olefin copolymer having a high molecular weight and little branching, and water It has been found that the above-mentioned problems can be achieved by blending the additive diene polymer, and the present invention has been completed.

  That is, according to the present invention, the following rubber composition, crosslinked rubber, and rubber molded product are provided.

[1] (A) Ethylene · α having an intrinsic viscosity [η] of 5.0 to 10 dl / g and a branching index (g) represented by [η] / [η] _blank of 0.80 or more -Rubber composition containing an olefin copolymer and / or an ethylene / α-olefin / non-conjugated polyene copolymer and (B) a hydrogenated diene polymer having a weight average molecular weight of 200,000 to 600,000 . .
(However, [η] is the intrinsic viscosity determined by measuring in accordance with JIS K7367-3 at a measurement temperature of 135 ° C. using decalin, and [η] _blank is the ethylene viscosity of the intrinsic viscosity [η]. A straight chain having the same weight average molecular weight (determined by GPC method using standard polystyrene) as the α-olefin copolymer or ethylene / α-olefin / non-conjugated polyene copolymer, and having an ethylene content of 70 mol% (Intrinsic viscosity of ethylene / propylene copolymer)

  [2] Total content of (A) ethylene / α-olefin copolymer and / or ethylene / α-olefin / non-conjugated polyene copolymer, and content of (B) hydrogenated diene polymer The rubber composition according to [1], wherein a mass ratio of (A) / (B) = 30/70 to 99/1.

[3] The area of the low molecular weight region having a molecular weight of less than 1 × 10 ⁵ in the GPC chromatogram of the (A) ethylene / α-olefin copolymer and / or ethylene / α-olefin / non-conjugated polyene copolymer. The rubber composition according to [1] or [2], which is a copolymer having a ratio of 4% or less.

  [4] The hydrogenated diene polymer (B) is a hydrogenated styrene-butadiene rubber, a hydrogenated butadiene rubber, a hydrogenated acrylonitrile rubber, a hydrogenated ethylene / α-olefin / diene copolymer rubber, a hydrogenated styrene / The rubber composition according to any one of [1] to [3], which is at least one selected from the group consisting of a butadiene block copolymer and a hydrogenated styrene / butadiene / isoprene block copolymer.

  [5] The rubber composition according to any one of [1] to [4], wherein the (B) hydrogenated diene polymer is a modified copolymer having a functional group in its molecular chain.

  [6] The functional group is at least one selected from the group consisting of a carboxyl group, an alkoxysilyl group, an epoxy group, an amino group, a hydroxyl group, a sulfone group, an oxazoline group, an isocyanate group, a thiol group, and a halogen. 5].

  [7] For a total of 100 parts by mass of the (A) ethylene / α-olefin copolymer and / or the ethylene / α-olefin / non-conjugated polyene copolymer and the (B) hydrogenated diene polymer. (C) The rubber composition according to any one of [1] to [6], further containing 1 to 100 parts by mass of a filler.

  [8] The filler (C) is at least one selected from the group consisting of silica, carbon black, glass fiber, mica, potassium titanate whisker, talc, clay, barium sulfate, glass flake, and fluororesin. [7] The rubber composition according to [7].

  [9] A crosslinked rubber obtained by crosslinking the rubber composition according to any one of [1] to [8] with a crosslinking agent.

  [10] A rubber molded product comprising the crosslinked rubber according to [9].

  The rubber composition of the present invention has excellent processability. Further, the crosslinked rubber of the present invention has excellent processability, and can produce a rubber molded product excellent in various properties such as vibration proofing and heat resistance.

  The rubber molded product of the present invention can exhibit excellent properties such as vibration proofing and heat resistance.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

1. Rubber composition In one embodiment of the rubber composition of the present invention, (A) the intrinsic viscosity [η] is 5.0 to 10 dl / g , and the branching index (g) represented by [η] / [η] _blank ) Is 0.80 or more, (A1) an ethylene / α-olefin copolymer and / or (A2) an ethylene / α-olefin / non-conjugated polyene copolymer (hereinafter also simply referred to as “component (A)”). ) And (B) a hydrogenated diene polymer having a weight average molecular weight of 200,000 to 600,000 (hereinafter, also simply referred to as “component (B)”). The details will be described below.

((A) ethylene / α-olefin copolymer and / or ethylene / α-olefin / non-conjugated polyene copolymer)
The component (A) contained in the rubber composition of the present embodiment includes (A1) an ethylene / α-olefin copolymer (hereinafter also simply referred to as “(A1) component”) and / or (A2) ethylene · It is an α-olefin / non-conjugated polyene copolymer (hereinafter also simply referred to as “component (A2)”).

The “intrinsic viscosity [η]” referred to in the present specification is an intrinsic viscosity obtained by measuring in accordance with JIS K7367-3 using decalin at a measurement temperature of 135 ° C. Further, the “branch index (g)” referred to in this specification is a value represented by [η] / [η] _blank , and [η] is the above-described intrinsic viscosity. [Η] _blank has the same weight average molecular weight (standard polystyrene equivalent molecular weight by GPC method) as the ethylene / α-olefin copolymer or ethylene / α-olefin / non-conjugated diene copolymer measured for [η]. And the intrinsic viscosity of a linear ethylene / propylene copolymer having an ethylene content of 70 mol%. The GPC measurement method is a value obtained by measurement under conditions of a temperature of 135 ° C., an O-dichlorobenzene solvent, and a flow rate of 1 ml / min.

The intrinsic viscosity [η] usually increases corresponding to the molecular weight, but when comparing polymers having the same molecular weight, the linear polymer shows the largest [η], and the more the polymer is branched, the more [η ] Becomes smaller. Therefore, the ratio of [η] to the intrinsic viscosity [η] _blank ([η] / [η] _blank ) of the linear copolymer having the same weight average molecular weight is 1 at the maximum, and the degree of branching is 0. This indicates that the copolymer is a linear copolymer, and the smaller this ratio ([η] / [η] _blank ), the greater the degree of branching of the copolymer.

[Η] of the component (A) is 5.0 to 10 dl / g and the branching index (g) is 0.80 or more, that is, the molecular weight is high and the number of branches is small. When the rubber composition of this embodiment containing is crosslinked, a crosslinked rubber having an excellent balance of heat resistance and vibration-proofing properties can be obtained.

  [Η] of the component (A) is 4.0 dl / g or more, preferably 4.5 dl / g or more, more preferably 5.0 dl / g or more from the viewpoint of improving the strength and the static / dynamic ratio. On the other hand, if [η] of the component (A) is too large, that is, if the molecular weight is too high, it becomes difficult to produce and process the copolymer. Therefore, [η] of the component (A) is preferably 11 dl / g or less, and more preferably 10 dl / g or less.

  The branching index (g) of the component (A) is 0.70 or more, preferably 0.75 or more, and more preferably 0.80 or more from the viewpoint of improving the static / dynamic ratio. The upper limit of the branching index (g) of the component (A) is 1 as described above.

It is preferable that the low molecular weight component of the component (A) is extremely small. Specifically, in the GPC chromatogram of the component (A), the area ratio of the low molecular weight region having a molecular weight of less than 1 × 10 ^{5 to the} entire component (A) is preferably 4% or less, and preferably 3% or less. More preferably. That is, in the chromatogram showing the molecular weight distribution of the component (A) obtained by GPC measurement, the molecular weight relative to the integral value of the molecular weight distribution curve of the entire component (A) (corresponding to the peak area of the entire component (A) on the chromatogram). The ratio of the integral value (corresponding to the area of the molecular weight less than 1 × 10 ⁵ on the chromatogram) of the portion less than 1 × 10 ⁵ (low molecular weight region) is preferably 4% or less, and 3% or less. More preferably it is. If the proportion of this low molecular weight region exceeds 5%, that is, if the amount of low molecular weight components is excessive, the static / dynamic ratio tends to increase and the vibration-proof characteristics tend to deteriorate.

  The weight average molecular weight (Mw) of the component (A) is preferably 800,000 to 3,000,000, and more preferably 1,000,000 to 2,000,000. The number average molecular weight (Mn) of the component (A) is preferably 300,000 to 1,200,000, and more preferably 400,000 to 1,000,000. The Q value (Mw / Mn) indicating the molecular weight distribution is preferably 1.7 to 3.5, and more preferably 1.7 to 3.0.

((A1) ethylene / α-olefin copolymer)
The α-olefin in the (A1) ethylene / α-olefin copolymer used as the component (A) is preferably an α-olefin having 3 to 20 carbon atoms. Preferable examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and 1-decene. Of these, propylene, 1-butene, 1-hexene and 1-octene are preferable, and propylene is more preferable. These α-olefins can be used singly or in combination of two or more. The ethylene component content is preferably 50 to 80% by mass and more preferably 54 to 75% by mass in the total monomer components. When the ethylene component content is within the above range, good vibration isolation is exhibited. When the ethylene component content is more than 80% by mass, the temperature dependency tends to deteriorate. On the other hand, when the ethylene component content is less than 50% by mass, problems such as deterioration in strength and heat resistance, reduction in productivity of copolymer rubber, and cost increase tend to occur.

((A2) ethylene / α-olefin / non-conjugated polyene copolymer)
Examples of the α-olefin in the (A2) ethylene / α-olefin / non-conjugated polyene copolymer used as the component (A) include the same as the α-olefin in the ethylene / α-olefin copolymer described above. The same thing is preferable. The ethylene component content is preferably 50 to 80% by mass, particularly preferably 54 to 75% by mass, based on all monomer components. When the ethylene component content is within the above range, the rubber-like properties and low-temperature characteristics of the vulcanized rubber tend to be appropriate. When the ethylene component content exceeds 80% by mass, the compression set at low temperatures of the vulcanized rubber tends to deteriorate. On the other hand, when the ethylene component content is less than 50% by mass, defects such as a decrease in productivity of the copolymer rubber and an increase in cost tend to occur.

  As the non-conjugated polyene in the component (A2), for example, 5-ethylidene-2-norbornene, dicyclopentadiene, 5-propylidene-2-norbornene, 5-vinyl-2-norbornene, 2,5-norbornadiene, 1,4 -Cyclic polyene such as cyclohexadiene, 1,4-cyclooctadiene, 1,5-cyclooctadiene; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene, 5,7-dimethyl-1,6- Octadiene, 7-methyl-1,7-nonadiene, 8-methyl-1,7-nonadiene, 8-methyl-1,8-decadiene, 9- Til-1,8-decadiene, 4-ethylidene-1,6-octadiene, 7-methyl-4-ethylidene-1,6-octadiene, 7-methyl-4-ethylidene-1,6-nonadiene, 7-ethyl- 6 to 15 carbon atoms such as 4-ethylidene-1,6-nonadiene, 6,7-dimethyl-4-ethylidene-1,6-octadiene, 6,7-dimethyl-4-ethylidene-1,6-nonadiene, etc. Chain polyene having an internal unsaturated bond; 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, 1,11- Examples include α, ω-dienes such as dodecadiene, 1,12-tridecadiene, and 1,13-tetradecadiene. Of these, 5-ethylidene-2-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, 7-methyl-1,6-octadiene and 5-methyl-1,4-hexadiene are preferable, and 5-ethylidene-2 is preferable. -Norbornene is more preferred. These non-conjugated polyenes can be used singly or in combination of two or more.

  The non-conjugated polyene is preferably contained in the copolymer so that the copolymer has an iodine value of preferably 0 to 40, more preferably 0 to 30. This iodine value is a measure of the content of the non-conjugated polyene component. When the iodine value is more than 40, gelation tends to occur during kneading, and troubles such as generation of bumps (state in which convex portions are observed instead of smooth surfaces) in extrusion and other molding processes. It tends to occur easily.

(Production method of component (A))
The component (A) can be produced by a method such as a gas phase polymerization method, a solution polymerization method, or a slurry polymerization method. These polymerization methods can be carried out either batchwise or continuously. In the solution polymerization method or slurry polymerization method, an inert hydrocarbon is usually used as a reaction medium. Examples of such inert hydrocarbon solvents include aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, n-decane, and n-dodecane; cyclohexane, methylcyclohexane, and the like. Alicyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene, xylene and the like. These inert hydrocarbon solvents can be used singly or in combination of two or more. Moreover, a raw material monomer can also be utilized as a hydrocarbon solvent.

  (A) As a polymerization catalyst used when manufacturing a component, the olefin polymerization catalyst which consists of the compound of the transition metal selected from V, Ti, Zr, and Hf, and an organometallic compound can be mentioned, for example. . In addition, the said transition metal compound and organometallic compound can each be used individually by 1 type or in combination of 2 or more types. As a particularly preferred example of such an olefin polymerization catalyst, a metallocene compound comprising a metallocene compound and an ionic compound that reacts with an organoaluminum compound or a metallocene compound to form an ionic complex, or a vanadium compound and an organoaluminum A Ziegler-Natta catalyst comprising a compound can be mentioned. In the production of the component (A), hydrogen gas may be used as a molecular weight regulator. The amount of hydrogen gas used also varies depending on the polymerization conditions such as catalyst type, catalyst amount, polymerization temperature, polymerization pressure, and the like, and the polymerization process such as polymerization scale, stirring state, and charging method. For example, in solution polymerization using a Ziegler-Natta catalyst, the amount of the Ziegler-Natta catalyst used (catalytic amount) is usually 0.01 to 20 ppm, preferably 0.1, based on all monomer components. -10 ppm.

((B) Hydrogenated diene polymer)
The component (B) contained in the rubber composition of the present embodiment is a hydrogenated diene polymer having a weight average molecular weight of 200,000 to 600,000 . This component (B) is a so-called hydrogenated product obtained by hydrogenating a predetermined polymer before hydrogenation. There are no particular limitations on the type and structure of the pre-hydrogenated polymer, and it may be a homopolymer or a copolymer. Specific examples of the component (B) include hydrogenated styrene-butadiene rubber (hydrogenated SBR), hydrogenated butadiene rubber (hydrogenated BR), hydrogenated acrylonitrile rubber (hydrogenated NBR), hydrogenated ethylene, α-olefin, Examples thereof include at least one selected from the group consisting of a diene copolymer rubber (hydrogenated EPDM), a hydrogenated styrene / butadiene block copolymer, and a hydrogenated styrene / butadiene / isoprene block copolymer. Among them, it is preferable to use a hydrogenated polymer that can be cross-linked with an organic peroxide as the component (B) because good processability, excellent vibration proofing properties, and heat resistance can be exhibited. Preferred examples of hydrogenated polymers that can be crosslinked with organic peroxides include hydrogenated SBR, hydrogenated BR, and hydrogenated NBR.

  Specific examples of component (B) (B1) hydrogenated styrene / butadiene block copolymer (hereinafter also simply referred to as “component (B1)”), (B2) hydrogenated styrene / butadiene / isoprene block copolymer ( Hereinafter, simply referred to as “component (B2)” can be easily produced by a known method. For example, a pre-hydrogenation polymer is produced by the method disclosed in JP-A-2-36244, that is, a method of living anion polymerization of a conjugated diene compound and a vinyl aromatic compound, and then the pre-hydrogenation polymer. Can be produced by a method such as hydrogenation in the presence of a catalyst.

  In the living anionic polymerization, an initiator such as an organic lithium compound or an organic sodium compound is usually used. Examples of the organic lithium compound include alkyllithiums such as n-butyllithium, sec-butyllithium, and t-butyllithium. Moreover, as a solvent used at the time of superposition | polymerization, hydrocarbon solvents, such as hexane, heptane, methylcyclopentane, cyclohexane, benzene, toluene, xylene, 2-methylbutene-1, 2-methylbutene-2, are used. The living anion polymerization method may be a batch method or a continuous method, and the polymerization temperature is usually in the range of 0 to 120 ° C.

  In living anionic polymerization, ether, tertiary amine, alkali metal (sodium, potassium, etc.) alkoxide, phenoxide, sulfonate, etc. are used in combination, and the type, amount used, etc. are appropriately selected. The ratio of the number of conjugated diene units having an olefinically unsaturated bond in the side chain in the hydrogenated block copolymer to the number of all conjugated diene units can be easily controlled.

  Furthermore, the molecular weight of the polymer can be increased by adding a polyfunctional coupling agent or crosslinking agent to effect coupling reaction or crosslinking immediately before the end of the living anionic polymerization.

  As coupling agents, divinylbenzene, 1,2,4-trivinylbenzene, epoxidized 1,2-polybutadiene, epoxidized soybean oil, epoxidized linseed oil, benzene-1,2,4-triisocyanate, Shu Diethyl acetate, diethyl malonate, diethyl adipate, dioctyl adipate, dimethyl phthalate, diethyl phthalate, diethyl terephthalate, diethyl carbonate, 1,1,2,2-tetrachloroethane, 1,4-bis (trichloromethyl) Examples include benzene, trichlorosilane, methyltrichlorosilane, butyltrichlorosilane, tetrachlorosilane, (dichloromethyl) trichlorosilane, hexachlorodisilane, tetraethoxysilane, tetrachlorotin, and 1,3-dichloro-2-propanone. Of these, divinylbenzene, epoxidized 1,2-polybutadiene, trichlorosilane, methyltrichlorosilane, and tetrachlorosilane are preferred.

  Examples of the crosslinking agent include divinylbenzene, adipic acid diester, epoxidized liquid butadiene, epoxidized soybean oil, epoxidized linseed oil, tolylene diisocyanate, diphenylmethane diisocyanate, 1,2,4-benzene triisocyanate, and the like. .

The pre-hydrogenation polymer obtained as described above is reacted, for example, in a hydrocarbon solvent in the presence of a hydrogenation catalyst at a hydrogen pressure of 1 to 100 kg / cm ² and a temperature in the range of −10 to 150 ° C. Then, the desired component (B1) and component (B2) can be obtained.

  As a hydrogenation catalyst, a metal element selected from periodic table Ib, IVb, Vb, VIb, VIIb, and Group VIII elements such as Ti, V, Co, Ni, Zr, Ru, Rh, Pd, Hf, Re, and Pt. Including compounds are used. Examples of the compound include metallocene compounds containing elements such as Ti, Zr, Hf, Co, Ni, Pd, Pt, Ru, Rh, and Re, metals such as Pd, Ni, Pt, Rh, and Ru, carbon, silica, A supported heterogeneous catalyst supported on a support such as alumina or diatomaceous earth, a homogeneous Ziegler catalyst comprising a combination of an organic salt or an acetylacetone salt of an element such as Ni or Co, and a reducing agent such as organoaluminum, Ru, Examples include organometallic compounds or complexes such as Rh, fullerenes occluded with hydrogen, and carbon nanotubes. These hydrogenation catalysts can be used singly or in combination of two or more. Of these, a metallocene compound containing one or more elements selected from the group consisting of Ti, Zr, Hf, Co, and Ni, which can be hydrogenated in a homogeneous system in an inert organic solvent, and Ti A metallocene compound containing one or more elements selected from the group consisting of Zr and Hf is preferred. Further, a hydrogenation catalyst obtained by reacting an inexpensive and industrially useful titanocene compound with alkyl lithium is also preferred.

  After hydrogenation, the hydrogenated diene polymer produced from the reaction solution is isolated by removing the catalyst residue as necessary, or by adding a phenol-based or amine-based antioxidant. do it. Isolation of the hydrogenated diene polymer is performed, for example, by adding acetone, alcohol or the like to the reaction solution to precipitate, or by pouring the reaction solution into hot water with stirring and then removing the solvent by distillation. be able to.

  In addition, as the component (B1) and the component (B2), the following commercially available products can be used. For example, Kuraray's trade name “Septon” (preferred grades for hydrogenated styrene / butadiene / isoprene block copolymers are 4044, 4055, 4077, etc., and hydrogenated styrene / butadiene block copolymers are 8007. , 8004, 8006, etc.), trade name “Tough Tech” manufactured by Asahi Kasei Co., Ltd. (preferred grades are H1052, H1031, H1041, H1051, H1062, H1943, H1913, H1043, H1075, JT- Such as 90P), etc., such as “Dynalon” manufactured by JSR (preferred grades for hydrogenated styrene / butadiene block copolymers are 8600, 8900, etc.). (Hydrogenated styrene / butadiene Preferred grade as click copolymer can be used G1650, G1651, G1652, a G1657 and the like) and the like.

  The vinyl bond content of the polymer before hydrogenation is preferably 30 to 55%, more preferably 32 to 48%, and particularly preferably 35 to 45%. If the vinyl bond content of the pre-hydrogenated polymer is less than 30%, the low temperature characteristics tend to deteriorate. On the other hand, if it exceeds 55%, the static / dynamic ratio is lowered without sufficient crosslinking, and the vibration-proof property tends to be lowered. The “vinyl bond” in this specification includes both 1,2-vinyl bonds and 3,4-vinyl bonds.

  The weight average molecular weight (Mw) of the component (B) is preferably 200,000 to 1,700,000, more preferably 200,000 to 1,000,000, and particularly preferably 200,000 to 600,000. If the weight average molecular weight (Mw) is less than 200,000, the workability and vibration proofing tend to be lowered. On the other hand, if it exceeds 1.7 million, the workability tends to deteriorate. Further, the Q value (Mw / Mn) indicating the molecular weight distribution of the component (B) is preferably 1.5 or less, more preferably 1.0 to 1.3, and further preferably 1.0 to 1. 2 is particularly preferred. When the Q value is more than 1.5, the static / dynamic ratio tends to decrease.

(Hydrogenation)
The hydrogenation rate of the component (B) is not particularly limited, but is preferably 80 to 100%, more preferably 85 to 100%, and particularly preferably 90 to 100%. When the hydrogenation rate is less than 80%, heat resistance and heat aging resistance tend to decrease.

  There are no particular limitations on the hydrogenation method and reaction conditions. Usually, it is carried out in the presence of a hydrogenation catalyst at 20 to 150 ° C. under hydrogen pressure of 0.1 to 10 MPa. The hydrogenation rate can be arbitrarily selected by changing the amount of the hydrogenation catalyst, the hydrogen pressure during the hydrogenation reaction, the reaction time, and the like. As the hydrogenation catalyst, a compound containing any one of group metals of the periodic table Ib, IVb, Vb, VIb, VIIb, and VIII can be used. For example, a compound containing Ti, V, Co, Ni, Zr, Ru, Rh, Pd, Hf, Re, and Pt atoms can be used as the hydrogenation catalyst. More specific hydrogenation catalysts include metallocene compounds such as Ti, Zr, Hf, Co, Ni, Pd, Pt, Ru, Rh, and Re; metals such as Pd, Ni, Pt, Rh, and Ru Supported heterogeneous catalyst in which is supported on a carrier such as carbon, silica, alumina, diatomaceous earth, etc .; a homogeneous Ziegler combining a metal element organic salt such as Ni or Co or an acetylacetone salt and a reducing agent such as organic aluminum Type catalysts; organometallic compounds or complexes such as Ru and Rh; fullerenes and carbon nanotubes in which hydrogen is occluded.

  Of these, metallocene compounds containing any one of Ti, Zr, Hf, Co, and Ni are preferable in that they can be hydrogenated in a homogeneous system in an inert organic solvent. Furthermore, a metallocene compound containing any of Ti, Zr, and Hf is preferable. In particular, a hydrogenation catalyst obtained by reacting a titanocene compound with an alkyl lithium is preferable because it is an inexpensive and industrially useful catalyst. Specific examples include, for example, JP-A-1-275605, JP-A-5-271326, JP-A-5-271325, JP-A-5-222115, JP-A-11-292924, and JP-A-11-292924. JP 2000-37632 A, JP 59-133203 A, JP 63-5401 A, JP 62-218403 A, JP 7-90017 A, JP 43-19960 A, Mention may be made of the hydrogenation catalyst described in JP-B 47-40473. In addition, these hydrogenation catalysts can be used individually by 1 type or in combination of 2 or more types.

(Functional group)
The component (B) is preferably a modified copolymer having a functional group in its molecular chain. When a modified polymer is used as the component (B), the dispersibility of the filler in the rubber composition can be improved by interacting with the filler, particularly when mixed with a filler such as silica described later. For this reason, it is possible to improve the vibration isolation characteristics by improving the static / dynamic ratio, and to improve the physical properties at high temperatures, in particular, elongation at high temperatures, elongation fatigue properties, heat resistance, and the like.

  When the component (B) is a modified copolymer, the functional group introduced into the molecular chain is a carboxyl group, an alkoxysilyl group, an epoxy group, an amino group, a hydroxyl group, a sulfone group, an oxazoline group, an isocyanate group, It is preferably a thiol group or a halogen (one or more of fluorine, chlorine, bromine and iodine). Of these, a carboxyl group, an amino group, and a hydroxyl group are more preferable. The functional group introduced into one molecular chain may be only one type or two or more types. The carboxyl group includes not only a normal carboxyl group (—COOH) but also a group that generates a carboxyl group by hydrolysis. Examples of the “carboxyl group by hydrolysis” include an ester group, an amide group and the like in addition to the anhydrous carboxyl group represented by the following formula (1).

  There is no particular limitation on the method for introducing the functional group into the hydrogenated diene polymer. For example, (1) a method of introducing by polymerization using a polymerization initiator having a functional group, (2) a method of introducing by reacting an unsaturated monomer having a functional group, and (3) ( Examples thereof include a method of introducing a polymerization terminator having a functional group at the active site of the (co) polymer by reacting it. In addition, each of the above methods may be performed alone, or a plurality of methods may be combined.

  In the case where the component (B) is a modified copolymer, the number of functional groups contained in one molecular chain is preferably 0.5 to 2.0, and 1.0 to 2.0. More preferably, it is particularly preferably 1.5 to 2.0. If the number is less than 0.5, the effect when the functional group is introduced tends to be insufficient.

The “number of functional groups contained in one molecular chain” in this specification, ie, “functional group content (= functional group (number) / polymer (single molecular chain))” is described in Analy. Chem. It is a value quantified according to the amine titration method described in 564 (1952). That is, a polymer solution is prepared by dissolving the purified polymer in an organic solvent, and HClO ₄ / CH ₃ COOH is dropped until the color of the polymer solution changes from purple to light blue using methyl violet as an indicator. The functional group content can be calculated from the dropping amount of HClO ₄ / CH ₃ COOH.

(Rubber composition)
The mass ratio ((A) / (B)) of the component (A) (the sum of (A1) and (A2)) and the component (B) contained in the rubber composition of the present embodiment is 30/70. It is preferably ˜99 / 1, more preferably 40/60 to 90/10, and particularly preferably 50/50 to 80/20. When the value of (A) / (B) is within the above range, it becomes possible to maintain good workability and maintain and improve the static / dynamic ratio and to exhibit excellent vibration isolation characteristics. When the value of (A) / (B) is less than 30/70, sufficient anti-vibration characteristics tend to be hardly exhibited. On the other hand, if the value of (A) / (B) is more than 99/1, excellent anti-vibration properties are easily exhibited, but the workability tends to be lowered.

((C) filler)
The rubber composition of the present embodiment preferably further contains (C) filler (hereinafter also simply referred to as “component (C)”). By containing the component (C), the strength can be improved. Preferred fillers include silica, carbon black, glass fiber, glass powder, glass beads, mica, calcium carbonate, potassium titanate whisker, talc, clay, barium sulfate, glass flake, fluororesin and the like. Of these, silica, carbon black, glass fiber, mica, potassium titanate whisker, talc, clay, barium sulfate, glass flake, and fluororesin are preferable. Further, silica and carbon black are preferable, silica is more preferably contained, and both silica and carbon black are particularly preferably contained.

  Silica is preferred from the standpoint of static ratio. Carbon black is preferable from the viewpoint of the strength of the rubber composition and the crosslinked rubber. There are various types of silica such as wet method white carbon, dry method white carbon, colloidal silica and the like, and any of them can be used. Of these, wet-type white carbon containing hydrous silicic acid as a main component is preferable. There are various types of carbon black such as furnace black, acetylene black, thermal black, channel black, graphite, etc., any of which can be used. Of these, furnace black is preferable, and more specifically, SRF, GPF, FEF, HAF, ISAF, SAF, MT, and the like are more preferable.

Further, the nitrogen adsorption specific surface area of carbon black measured by the BET method in accordance with ASTM D3037-81 is not particularly limited, but in order to sufficiently improve the tensile strength and the like of the crosslinked rubber, it is 5 to 200 m ² / g. is preferably, more preferably from 50 to 150 m ² / g, particularly preferably 80~130m ² / g. The DBP adsorption amount of carbon black is not particularly limited, but is preferably 5 to 300 ml / 100 g, more preferably 50 to 200 ml / 100 g in order to sufficiently improve the strength and the like of the crosslinked rubber. 80 to 160 ml / 100 g is particularly preferable.

  Although the compounding quantity of (C) component changes with uses, it is preferable that it is 1-100 mass parts with respect to a total of 100 mass parts of (A) component and (B) component, and is 10-70 mass parts. It is further more preferable and it is especially preferable that it is 10-60 mass parts. When the blending amount of the component (C) is less than 1 part by mass, the effect of improving the strength by adding the filler tends to be hardly exhibited. On the other hand, when it exceeds 100 parts by mass, the viscosity of the rubber composition is excessively increased, and kneading and molding tend to be difficult.

(Other ingredients)
The rubber composition of the present embodiment may contain a rubber component other than the component (A) and the component (B) as long as the object of the present invention is not impaired. Examples of such a rubber component include styrene / butadiene rubber, butadiene rubber, acrylonitrile rubber, isoprene rubber, and natural rubber. However, when a large amount of natural rubber is blended, the heat resistance of the rubber composition may decrease. Therefore, when natural rubber is contained, the content is preferably 15 parts by mass or less with respect to 100 parts by mass in total of the component (A) and the component (B).

  Moreover, the rubber composition of this embodiment can contain an amine compound as long as the object of the present invention is not impaired. By containing such an amine compound, for example, when the component (C) is contained, the wettability of the component (C) can be improved. That is, it is preferable because the dispersibility of the component (C) in the rubber composition can be improved, and durability and vibration isolation performance can be improved. In addition, an amine compound can be used individually by 1 type or in combination of 2 or more types.

  As long as the amine compound contains an amino group, the structure thereof is not particularly limited, and any of a primary amine, a secondary amine, and a tertiary amine may be used. The number of amino groups is not particularly limited, and may be monoamine, diamine, triamine, tetraamine, or polyamine. Furthermore, the number of carbon atoms of the amine compound is not particularly limited, and is usually 1 to 20, preferably 1 to 15, more preferably 3 to 15, and more preferably 3 to 10. Moreover, you may contain functional groups other than an amino group like alkanolamine. Specific examples of the amine compound include 2-ethylhexylamine and triethanolamine.

  There is no limitation in particular also about content of an amine compound, It can be set as various ranges as needed. The content of the amine compound is usually 20 parts by mass or less with respect to a total of 100 parts by mass of the component (A) and the component (B), preferably greater than 0 and 15 parts by mass, More preferably, it is more preferably 0.01 to 10 parts by mass, particularly preferably 0.01 to 8 parts by mass, most preferably 0.01 to 5 parts by mass. preferable.

  Furthermore, various additives can be appropriately added to the rubber composition of the present embodiment as needed within a range not impairing the object of the present invention. Examples of such additives include rubber extending oils and fillers.

  As the extending oil for rubber, a paraffinic process oil, an aromatic process oil, a naphthenic process oil, or the like, which is a petroleum-based blended oil, can be used. Of these, paraffinic process oil is preferred. The blending amount of the rubber extender oil is the sum of the component (A) and the component (B) (when other rubber components are included, the sum of the components (A), (B), and other rubber components) 100 It is preferable to set it as 150 mass parts or less with respect to a mass part, and it is still more preferable to set it as 100 mass parts or less. Moreover, this rubber extending oil may be previously contained in the rubber component.

  As the filler, an appropriate amount of talc, clay, calcium carbonate, magnesium carbonate or the like can be blended.

(Method for producing rubber composition)
The rubber composition of this embodiment can be produced by mixing the component (A) and the component (B). In addition, when (A) component is a modified polymer and (C) component is further contained, it is preferable to heat-mix (A) component and (C) component. By mixing with heating, an interaction is caused between the functional group of the component (A) and the component (C), and the dispersibility of the component (C) in the resulting rubber composition can be improved. There are no particular limitations on the conditions when the components (A) and (C) are heated and mixed, and various conditions may be used as necessary. The heating temperature is preferably 150 to 220 ° C, more preferably 150 to 200 ° C. The mixing time is preferably 10 minutes or less, and more preferably 1 to 5 minutes. By setting this range, the interaction between the functional group of the component (A) and the component (C) proceeds favorably, improving the static / kinetic ratio, and at the same time the physical properties at high temperatures, particularly the elongation and elongation at high temperatures. This is preferable because fatigue can be improved. Moreover, as a mixing method, the method etc. which mix using a Banbury mixer, a mixing roll, etc. can be mentioned. At this stage, other components may be added and mixed as necessary.

2. Crosslinked Rubber, Rubber Molded Article One embodiment of the crosslinked rubber of the present invention is obtained by crosslinking the above rubber composition with a crosslinking agent. For this reason, the crosslinked rubber of this embodiment has excellent processability, and has an excellent balance between strength and vibration-proof characteristics. Moreover, one Embodiment of the rubber molded product of this invention consists of the said crosslinked rubber. For this reason, the rubber molded product of this embodiment is excellent in the balance between strength and vibration-proof characteristics. Details of these will be described below.

  As a crosslinking agent, an organic peroxide type crosslinking agent and a sulfur type crosslinking agent can be mentioned, It is preferable that at least 1 type of these is included, and it is still more preferable that both are included. Examples of the organic peroxide-based crosslinking agent include dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, di-tert-butyl peroxide, di-tert-butyloxy-3,3,5-trimethylcyclohexane, tert-butyl A hydroperoxide etc. can be mentioned. Of these, dicumyl peroxide, di-tert-butyl peroxide, and di-tert-butyl peroxy-3,3,5-trimethylcyclohexane are preferable. Examples of the sulfur-based crosslinking agent include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, selenium dimethyldithiocarbamate and the like. Of these, sulfur is preferred.

  The amount of the organic peroxide crosslinking agent used is the sum of the component (A) and the component (B) (if other rubber components are included, the components (A), (B), and other rubber components The total amount is preferably 0.1 to 15 parts by mass, more preferably 0.2 to 10 parts by mass with respect to 100 parts by mass. Moreover, the usage-amount of a sulfur type crosslinking agent is the sum total of (A) component and (B) component (when other rubber components are included, the total of (A) component, (B) component, and another rubber component. ) It is preferable to set it as 0.1-10 mass parts with respect to 100 mass parts, and it is still more preferable to set it as 0.1-6 mass parts. In addition, when using a sulfur type crosslinking agent, a crosslinking accelerator and a crosslinking adjuvant are used together as needed.

  Examples of the crosslinking accelerator include N-cyclohexyl-2-benzothiazole-sulfenamide, N-oxydiethylene-2-benzothiazole-sulfenamide, N, N-diisopropyl-2-benzothiazole sulfenamide, 2-mercapto Benzothiazole, 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- (2,6-diethyl-4-morpholinothio) benzothiazole, dibenzothiazyl-disulfide, diphenylguanidine, triphenylguanidine, diorthotolyl Guanidine, orthotolyl biguanide, diphenylguanidine phthalate, acetaldehyde-aniline reactant, butyraldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde ammonia, 2-mercaptoimidazo , Thiocarbanilide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorthotolylthiourea, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide, dimethyldithiocarbamine Zinc oxide, zinc diethylthiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, tellurium diethyldithiocarbamate, zinc dibutylxanthate, etc. Can be mentioned.

  The amount of crosslinking accelerator used is the total of component (A) and component (B) (when other rubber components are included, the total of component (A), component (B), and other rubber components) 100 mass It is preferable to set it as 0.1-20 mass parts with respect to a part, and it is still more preferable to set it as 0.2-10 mass parts.

  Examples of the crosslinking aid include metal oxides such as magnesium oxide and zinc oxide. Of these, zinc oxide is preferable. The amount of crosslinking accelerator used is the total of component (A) and component (B) (when other rubber components are included, the total of component (A), component (B), and other rubber components) 100 mass It is preferable to set it as 1-20 mass parts with respect to a part, and it is still more preferable to set it as 3-10 mass parts.

  In addition, when an organic peroxide crosslinking agent is used, a crosslinking aid such as quinone dioxime such as sulfur or p-quinonedioxime, polyethylene glycol dimethacrylate, diallyl phthalate, triallyl cyanurate, divinylbenzene, etc. May be used as The amount of the crosslinking aid used is the sum of the component (A) and the component (B) (when other rubber components are included, the sum of the components (A), (B) and other rubber components) 100 It is preferable to set it as 0.1-20 mass parts with respect to a mass part, and it is still more preferable to set it as 0.1-10 mass parts.

  When manufacturing a foam, a foaming agent is mix | blended. Examples of the foaming agent include sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, ammonium nitrite, N, N′-dimethyl N, N′-dinitrone terephthalamide, N, N′-dinitrosopentamethylenetetramine, azo Dicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, azodiaminonene, barium azodicarboxylate, benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, P, P′-oxybis (benzenesulfonyl hydrazide), diphenylsulfone-3, Mention may be made of 3′-disulfonylhydrazide, calcium azide, 4,4′-diphenyldisulfonyl azidobaratoluene malonyl azide. The amount of foaming agent used is 100 parts by mass of the total of component (A) and component (B) (if other rubber components are included, the total of component (A), component (B), and other rubber components) The content is preferably 0.5 to 30 parts by mass, and more preferably 1 to 15 parts by mass. Further, if necessary, a foaming aid may be used together with the foaming agent.

  After the compounded rubber composition obtained by blending a rubber composition with a crosslinking agent or the like is molded into a desired shape by an extruder or a mold, a heating device such as a high-frequency heating device, an air oven, PCM, or LCM is used. If it is used and crosslinked, a rubber molded product made of a crosslinked rubber can be obtained. Moreover, you may manufacture the rubber molded product which consists of crosslinked rubber by the method of shape | molding and bridge | crosslinking in a metal mold | die using a well-known vulcanizer. The production conditions for rubber molded products vary greatly depending on the crosslinking method, blending, application and the like. As typical crosslinking conditions in the case of press crosslinking, for example, the heating temperature is preferably 140 to 200 ° C., and the heating time is preferably about 1 to 60 minutes.

The static / kinetic ratio of the crosslinked rubber of the present embodiment obtained as described above is preferably 1.0 to 1.4, and more preferably 1.0 to 1.3. The “static ratio” referred to in the present specification is based on JIS K6394, using a block-shaped test piece, at a temperature of 25 ° C., 70 Hz, dynamic strain 1%, 0.1 Hz, dynamic It is a value calculated by the following equation (2) by measuring the dynamic modulus of elasticity at a static strain of 10%.
Static ratio = (dynamic elastic modulus at 70 Hz) / (dynamic elastic modulus at 0.1 Hz) (2)

  The closer the static ratio is to 1, the better the anti-vibration characteristics. By crosslinking the rubber composition of the present embodiment, a crosslinked rubber having a static / kinetic ratio in the above-described preferable range can be easily obtained.

  The rubber composition of the present embodiment and the crosslinked rubber obtained by crosslinking the rubber composition are excellent in strength and vibration-proofing properties and have sufficient heat resistance, as a matter of course for general rubber applications. It is expected to be. Therefore, the rubber molded product made of the crosslinked rubber of the present embodiment can be suitably used as a vibration-proof material. In particular, it can be suitably used as an anti-vibration material in an environment having a high temperature atmosphere, such as an anti-vibration rubber for engine mounts.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. In the following examples, 5-ethylidene-2-norbornene (ENB) was used as the non-conjugated polyene. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

  [Intrinsic viscosity [η]]: In accordance with JIS K7367-3, decalin (decahydronaphthalene) was used as a solvent at a measurement temperature of 135 ° C. and an Ubbelohde viscometer No. The solution viscosity was measured by 0B to determine the intrinsic viscosity.

[Branching index (g)]: calculated by the following formula (3).
Branch index (g) = [η] / [η] _blank (3)
(However, [η] _blank has the same weight average molecular weight as the component (A) used (determined by the GPC method using standard polystyrene) and has an ethylene content of 70 mol%. (It is the intrinsic viscosity of the polymer)

  [Ethylene content, ENB content]: Determined as mass% by infrared absorption spectroscopy.

[Mn, Mw, Q value]: GPC measurement is performed under the following conditions. Number average molecular weight (Mn), weight average molecular weight (Mw), and Q value (Mw / Mn) were determined. The calibration curve was prepared by a conventional method using standard polystyrene manufactured by Tosoh Corporation. The measurement data was processed using “CIRRUS” manufactured by Polymer Laboratories.
GPC measuring device: “PL-GPC220 type” manufactured by Polymer Laboratory
Column: “PLgel 10 μm MiXED-B” manufactured by Polymer Laboratory Co., Ltd., 3 connected Sample volume: 500 μl (polymer concentration: 1.0 mg / ml)
Flow rate: 1 ml / min
Temperature: 135 ° C
Solvent: o-dichlorobenzene

[Area ratio of molecular weight less than 1 × 10 ⁵ ]: From the standard polystyrene equivalent GPC chromatogram of component (A) measured under the above GPC measurement conditions, the area ratio of low molecular weight components having a molecular weight of less than 1 × 10 ⁵ Calculation was performed using “CIRRUS” manufactured by Laboratory.

  [Vinyl bond content (of pre-hydrogenated polymer)]: Using infrared analysis, the contents of 1,2-vinyl bonds and 3,4-vinyl bonds were calculated by the Hampton method.

[Functional group content]: Analy. Chem. Quantified in accordance with the amine titration method described in 564 (1952). That is, a polymer solution was prepared by dissolving the purified polymer in an organic solvent, and HClO ₄ / CH ₃ COOH was added dropwise using methyl violet as an indicator until the color of the polymer solution changed from purple to light blue. The functional group content was calculated from the drop amount of HClO ₄ / CH ₃ COOH. The functional group content is represented by the following formula (4).
Functional group content = functional group (pieces) / polymer (single molecular chain) (4)

[Hydrogenation rate]: Carbon tetrachloride solution was used as a solvent, and calculation was performed from a 270 MHz, ¹ H-NMR spectrum.

[Workability (roll winding property)]: Using a 6-inch roll, the roll rotation number was observed at the front / rear = 22 rpm / 20 rpm, nip 2 mm, temperature control 50 ° C. The workability (roll winding property) was evaluated according to the criteria shown in FIG.
○: Good (wraps tightly and does not stick)
×: Impossible (does not wind or adheres)

[Tensile Stress, Tensile Breaking Strength (T _B ), Tensile Breaking Elongation (E _B )]: In accordance with JIS K6251, No. 3 type test piece obtained from a vulcanized rubber sheet, measuring temperature 23 ° C., tensile speed Tensile stress, tensile breaking strength (T _B ), and tensile breaking elongation (E _B ) were measured under the condition of 500 mm / min. The raw rubber strength was measured under the same conditions by taking a test piece from a raw rubber press sheet.

  [Hardness (Durometer A)]: The spring hardness (durometer A hardness) of the test piece was measured in accordance with JIS K6253.

  [Dynamic elastic modulus]: Based on JIS K6394, using a block-shaped test piece, the dynamic elastic modulus at 70 Hz was measured under the conditions of dynamic strain of 1% and temperature of 25 ° C. Similarly, the dynamic elastic modulus at 0.1 Hz was measured under the conditions of a dynamic strain of 10% and a temperature of 25 ° C. In the measurement, a viscoelasticity measuring device (trade name “ARESS”) manufactured by Rheometric Co., Ltd. was used.

[Static motion ratio]: The static motion ratio was calculated by the following equation (5).
Static ratio = (dynamic elastic modulus at 70 Hz) / (dynamic elastic modulus at 0.1 Hz) (5)

  [Compression set (CS)]: Measured under conditions of 120 ° C. and 70 hours in accordance with JIS K6262.

(EP (1) (oil-extended rubber))
Intrinsic viscosity [η] is 7.0 dl / g, ethylene content is 68%, ENB content is 4.2%, Q value is 2.8, Mn is 493,000, Mw is 135.7 million, and branching index An ethylene / α-olefin / ENB copolymer (polymer) having (g) of 0.87 was used. In this hexane solution of polymer, 30 parts of oil (softener, trade name “Diana Process PW90”, manufactured by Idemitsu Kosan Co., Ltd.) as a plasticizing material is added to 75 parts of the polymer, stirred, and steam stripped. A composition was obtained. The obtained composition was dried to obtain an oil-extended rubber (EP (1)).

(EP (2))
EPDM (trade name “EP27”) manufactured by JSR Corporation was used as “EP (2)”. Table 1 shows various physical property values of this EP (2).

(Hydrogenated diene polymer (1))
To a reaction vessel with an internal volume of 50 liters purged with nitrogen, 28 kg of cyclohexane, 56 g of tetrahydrofuran, 1.11 g of n-butyllithium, 1.08 g of piperidine and 1400 g of 1,3-butadiene are added, and adiabatic polymerization is carried out from 50 ° C. It was. After completion of the polymerization, 0.8 g of N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane was added to the system and reacted for 60 minutes, and introduced into the active site of the diene polymer obtained by the adiabatic polymerization. . Next, hydrogen gas was supplied at a pressure of 0.4 MPa-Gauge, stirred for 20 minutes, and reacted with unreacted polymer terminal lithium to obtain lithium hydride. The reaction solution was set to 90 ° C., hydrogen gas was set to a pressure of 0.4 MPa-Gauge, and a hydrogenation reaction was performed using a catalyst mainly composed of titanocene dichloride. When the absorption of hydrogen was completed, the reaction solution was returned to room temperature and normal pressure and extracted from the reaction vessel. The extracted reaction solution was stirred into water and the solvent was removed by steam stripping to obtain a hydrogenated diene polymer (1). The molecular characteristics of the obtained hydrogenated diene polymer (1) were measured. As a result, the vinyl bond content in the polybutadiene chain was 34.4%, Mw was 237,000, Mn was 20.8, Q value was 1 The functional group content was 1.2 / polymer, and the hydrogenation rate was 98.4%.

(Hydrogenated diene polymer (2))
28 kg of cyclohexane, 42 g of tetrahydrofuran, 2.54 g of n-butyllithium and 4000 g of 1,3-butadiene were added to a reaction vessel having an internal volume of 50 liters purged with nitrogen, and adiabatic polymerization was carried out from 50 ° C. After the completion of the polymerization, hydrogen gas was supplied at a pressure of 0.4 MPa-Gauge and stirred for 20 minutes to react with unreacted polymer terminal lithium to obtain lithium hydride. A hydrogen gas supply pressure was set to 0.7 MPa-Gauge, a reaction solution was set to 90 ° C., and a hydrogenation reaction was performed using a catalyst mainly composed of titanocene dichloride. When the absorption of hydrogen was completed, the reaction solution was returned to room temperature and normal pressure and extracted from the reaction vessel. The extracted reaction solution was stirred into water and the solvent was removed by steam stripping to obtain a hydrogenated diene polymer (2). When the molecular characteristics of the hydrogenated diene polymer (2) obtained were measured, the vinyl bond content in the polybutadiene chain was 35.4%, Mw was 267,000, Mn was 25.4, Q value was 1 0.05 and the hydrogenation rate was 93.9%. Table 2 shows the measurement results of various molecular properties of the hydrogenated diene polymers (1) and (2).

Example 1
EP (1) 105 parts, hydrogenated diene polymer (1) 25 parts, zinc white 5 parts, stearic acid 0.5 parts, silica 30 parts, coupling agent 3 parts, SRF carbon 5 parts, and softener 5 The mixture was kneaded at 150 ° C. for 5 minutes using a plastmill with a capacity of 250 ml to obtain a mixture. A blended rubber composition was obtained by adding 5 parts of a crosslinking agent and 0.2 part of a crosslinking aid to the obtained mixture and kneading with a 6-inch open roll at 50 to 70 ° C. for 5 minutes. . In addition, as various compounding components, those shown in the following (1) to (9) were used.

(1) Zinc flower: Trade name "Zinc oxide 2 types" (manufactured by Hakusui Chemical Co., Ltd.)
(2) Stearic acid: Trade name “Lunac S30” (manufactured by Kao Corporation)
(3) Silica: Trade name “Nipsil ER” (manufactured by Tosoh Silica)
(4) Coupling agent: Trade name “TSL8370” (manufactured by GE Toshiba Silicone)
(5) SRF carbon: Trade name “SEAST S” (manufactured by Tokai Carbon Co., Ltd.)
(6) Softener: Trade name “Diana Process PW90” (manufactured by Idemitsu Kosan Co., Ltd.)
(7) Crosslinking agent: Trade name “Park Mill D-40” (manufactured by NOF Corporation)
(8) Crosslinking aid: Trade name “Sulfur” (manufactured by Tsurumi Chemical Co., Ltd.)

The obtained compounded rubber composition was heated using a press molding machine at 170 ° C. under a pressing pressure of 150 kgf / cm ² for 20 minutes to prepare a test piece (vulcanized rubber sheet) having a thickness of 2 mm. Evaluation of the workability (roll winding property) of the produced test piece was “Δ”, the tensile stress was 1.4 MPa (100% modulus) and 6.3 MPa (300% modulus), and the tensile strength at break (T _B ) was 16. .4MPa, tensile elongation at break (E _B) 440% hardness (Duro a) 55, compression set (CS) was 19%.

  Moreover, the block-shaped test piece for a viscoelasticity test was produced by heating the obtained compounded rubber composition for 20 minutes. The produced block-shaped specimens had a dynamic modulus of elasticity of 1.831 MPa (70 Hz) and 1.46 MPa (0.1 Hz), and a static / kinetic ratio of 1.25.

(Examples 2-5, Comparative Examples 1-5)
A compounded rubber composition, a test piece (vulcanized rubber sheet), and a block-shaped test piece were prepared in the same manner as in Example 1 except that the formulation shown in Table 3 was used. Table 3 shows various physical property values of the prepared test piece (vulcanized rubber sheet) and the block-shaped test piece.

(Discussion)
As is clear from the results shown in Table 3, the rubber compositions of Examples 1 to 5 have the same or better processability (roll wrapping property) than the rubber compositions of Comparative Examples 1 to 5. I understand. In particular, it is clear that the workability is improved by blending a hydrogenated diene polymer (compare the evaluation results of “workability” in Examples 1 to 5 and Comparative Example 1).

  In addition, by making the blending ratio of EP (1) as the component (A) and the hydrogenated diene polymer as the component (B) within a predetermined range, the workability is further improved and the resulting crosslinking is obtained. It is clear that the static-motion ratio of rubber is reduced and excellent vibration-proof properties are exhibited (comparing the evaluation results of “workability” and the value of “static-static ratio” in Examples 1 to 3).

  Furthermore, when the modified polymer is used as the component (B), it is clear that the heat resistance of the resulting crosslinked rubber is improved (“Compression permanent” in Examples 1 and 4 and Examples 2 and 5). Comparing the values of “distortion (CS)”).

  Rubber molded articles obtained using the rubber composition of the present invention include, for example, vibration-insulating rubbers such as engine mounts and muffler hangers; various hoses such as diaphragms, rolls, radiator hoses, air hoses and hose covers; Suitable for seals such as packings, gaskets, weather strips, O-rings and oil seals; belts, linings, dust boots, and the like.

Claims (10)

(A) An ethylene / α-olefin copolymer having an intrinsic viscosity [η] of 5.0 to 10 dl / g and a branching index (g) represented by [η] / [η] _blank of 0.80 or more. A polymer and / or an ethylene / α-olefin / non-conjugated polyene copolymer;
(B) a hydrogenated diene polymer having a weight average molecular weight of 200,000 to 600,000 ,
Containing a rubber composition.
(However, [η] is the intrinsic viscosity determined by measuring in accordance with JIS K7367-3 at a measurement temperature of 135 ° C. using decalin, and [η] _blank is the ethylene viscosity of the intrinsic viscosity [η]. A straight chain having the same weight average molecular weight (determined by GPC method using standard polystyrene) as the α-olefin copolymer or ethylene / α-olefin / non-conjugated polyene copolymer, and having an ethylene content of 70 mol% (Intrinsic viscosity of ethylene / propylene copolymer) The total content of (A) ethylene / α-olefin copolymer and / or ethylene / α-olefin / non-conjugated polyene copolymer;
The mass ratio of the content of the (B) hydrogenated diene polymer is
The rubber composition according to claim 1, wherein (A) / (B) = 30/70 to 99/1. (A) the ethylene / α-olefin copolymer and / or the ethylene / α-olefin / non-conjugated polyene copolymer,
3. The rubber composition according to claim 1, wherein the rubber composition is a copolymer in which the area ratio of a low molecular weight region having a molecular weight of less than 1 × 10 ⁵ is 4% or less in the GPC chromatogram.   The (B) hydrogenated diene polymer comprises hydrogenated styrene-butadiene rubber, hydrogenated butadiene rubber, hydrogenated acrylonitrile rubber, hydrogenated ethylene / α-olefin / diene copolymer rubber, hydrogenated styrene / butadiene block. The rubber composition according to any one of claims 1 to 3, wherein the rubber composition is at least one selected from the group consisting of a polymer and a hydrogenated styrene / butadiene / isoprene block copolymer.   The rubber composition according to any one of claims 1 to 4, wherein the (B) hydrogenated diene polymer is a modified copolymer having a functional group in its molecular chain.   The functional group is at least one selected from the group consisting of a carboxyl group, an alkoxysilyl group, an epoxy group, an amino group, a hydroxyl group, a sulfone group, an oxazoline group, an isocyanate group, a thiol group, and a halogen. Rubber composition. For a total of 100 parts by mass of the (A) ethylene / α-olefin copolymer and / or the ethylene / α-olefin / non-conjugated polyene copolymer and the (B) hydrogenated diene polymer,
(C) The rubber composition according to any one of claims 1 to 6, further comprising 1 to 100 parts by mass of a filler.   The filler (C) is at least one selected from the group consisting of silica, carbon black, glass fiber, mica, potassium titanate whisker, talc, clay, barium sulfate, glass flakes, and fluororesin. The rubber composition as described.   A crosslinked rubber obtained by crosslinking the rubber composition according to claim 1 with a crosslinking agent.   A rubber molded article comprising the crosslinked rubber according to claim 9.