JP3366493B2 - Ethylene / α-olefin / non-conjugated polyene copolymer rubber composition and vulcanized rubber comprising the composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vulcanized rubber excellent in weather resistance, ozone resistance and heat aging resistance without impairing the excellent mechanical properties, wear resistance and dynamic fatigue resistance of diene rubber. The present invention relates to an ethylene / α-olefin / non-conjugated polyene copolymer rubber composition and a vulcanized rubber comprising the composition.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Ethylene / propylene / diene rubber (EPDM) is a rubber having excellent weather resistance, ozone resistance, and heat aging resistance, and is used as a rubber for automobile parts such as weather stripping, door glass run channel, radiator hose, etc. It is often used in the part where the physical force is applied.

On the other hand, most of the parts such as tires and anti-vibration rubber which require mechanical strength against dynamic fatigue are N
Diene rubbers such as R, SBR and BR, or blends thereof are used.

By the way, with the recent improvement in the quality of automobiles, improvement in heat aging resistance and weather resistance of automobile parts is desired. However, although EPDM has excellent weather resistance, ozone resistance, and heat aging resistance, EPDM cannot be used alone in tires, anti-vibration rubbers, etc. because of poor dynamic fatigue resistance.

Therefore, in order to utilize the advantages of these materials by blending EPDM with diene rubber, EPD has been conventionally used.
Although many studies have been conducted on blends of M with a diene rubber, a blend of EPDM and a diene rubber having excellent co-vulcanizability has not been obtained and it has not reached the level of practical use.

The existing technology relating to the blending of EPDM and diene rubber in the above research is described by Yasuhiro Oda and Masashi Aoshima in “The Rubber Association of Japan, 51, 685 (197).
8) ”, and as a method of this blending,
(1) Polysulfide vulcanization, (2) Peroxide vulcanization, (3)
The application of pre-vulcanized EPDM, (4) application of high iodine number EPDM, (5) application of halogenated EPDM, (6) use of accelerator having a long-chain alkyl group, etc. are inquired.

According to the above description, EPDM having an intrinsic viscosity of 3.0 dl / g or more, a propylene content of 35% or less and a high iodine value measured in xylene at 70 ° C. is good.

However, these descriptions refer to EPDM
Although it shows the direction of improving the co-vulcanizability with the diene rubber of the above, there is no description of quality items necessary for actual products, especially when dynamic strength is required. With such a method, the characteristics targeted by the present invention cannot be obtained at all.

The purpose of blending EPDM with a diene rubber is to provide excellent heat aging resistance and weather resistance without practically reducing the excellent wear resistance, dynamic fatigue resistance and crack growth resistance of the diene rubber. Is to give. Therefore, the EPD that is the blending partner of the diene rubber
It is necessary to impart dynamic fatigue resistance to M as well.

"Rubber Chemistry Technology, 44
Vol. 10, October 1971, p. 1043 ", mentions a vibration damping rubber material as an example in which dynamic fatigue resistance is most required. If high molecular weight EPDM having high Mooney viscosity is used as a vibration damping rubber material, It is described that a vulcanized rubber having excellent dynamic fatigue resistance can be obtained.

However, the use of high molecular weight EPDM is considered by all persons skilled in the art, and the point that requires the most research and development is the covulcanizability with diene rubber, which was a drawback of damaged EPDM. Is to improve.

As a method for improving the co-vulcanizability of EPDM with a diene rubber, a method of copolymerizing ethylene and propylene with another diene having a high vulcanization rate in place of ethylidene norbornene which has been used until now. Being tried.

However, with the diene used in the method that has been attempted in the past, the EPDM obtained is still insufficient in co-vulcanizability with the diene rubber. Therefore, the development of ethylene / α-olefin / non-conjugated polyene copolymer rubber with a vulcanization speed similar to that of diene rubber, and further impair the excellent mechanical properties, wear resistance and dynamic fatigue resistance of diene rubber. Ethylene / α that can provide vulcanized rubber with excellent weather resistance, ozone resistance, and heat aging resistance
Development of an olefin / non-conjugated polyene copolymer rubber composition and a vulcanized rubber comprising the composition is desired.

[0014]

It is an object of the present invention to solve the problems associated with the prior art as described above and to impair the excellent mechanical properties, wear resistance and dynamic fatigue resistance of diene rubber. Provided are an ethylene / α-olefin / non-conjugated polyene copolymer rubber composition capable of supplying a vulcanized rubber excellent in weather resistance, ozone resistance and heat aging resistance, and a vulcanized rubber comprising the composition. It is an object.

[0015]

SUMMARY OF THE INVENTION An ethylene / α-olefin / non-conjugated polyene copolymer rubber composition according to the present invention comprises ethylene and
Random copolymer rubber (A) comprising an α-olefin having 3 to 20 carbon atoms and at least one branched polyene compound represented by the following general formula [I], and a diene rubber (B) (nitrile The random copolymer rubber (A) has a molar ratio of (i) ethylene and an α-olefin having 3 to 20 carbon atoms (ethylene / α-olefin) of 40/60.
To 95/5, (ii) iodine value is in the range of 1 to 50, (iii) intrinsic viscosity [η] measured in 135 ° C. decalin.
Is in the range represented by 0.8 <[η] <5.0 dl / g.

[0016]

[Chemical 2]

[In the formula [I], n is an integer of 1 to 5,
R ¹ is an alkyl group having 1 to 5 carbon atoms, and R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. The vulcanized rubber according to the present invention is characterized by being vulcanized with the above-mentioned ethylene / α-olefin / non-conjugated polyene copolymer rubber composition according to the present invention.

[0018]

Detailed Description of the Invention Ethylene / α according to the present invention
The olefin / non-conjugated polyene copolymer composition and the vulcanized rubber comprising the composition will be specifically described.

Ethylene / α-olefins according to the present invention
The non-conjugated polyene copolymer rubber composition includes a random copolymer rubber (A) and a diene rubber (B) (excluding nitrile rubber ).
And it is configured from Ku) and. Random copolymer rubber (A) The ethylene copolymer rubber (A) used in the present invention is
Ethylene and an α-olefin having 3 to 20 carbon atoms,
It consists of a branched polyene compound.

Specific examples of such α-olefins having 3 to 20 carbon atoms include propylene, 1-butene,
1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-
Pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene,
1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like can be mentioned. Among them, propylene, 1-butene, 1-hexene and 1-octene are preferably used.

These α-olefins can be used alone or in combination of two or more kinds. The branched polyene compound is represented by the following general formula [I].

[0022]

[Chemical 3]

In the formula [I], n is an integer of 1 to 5 and R
¹ is an alkyl group having 1 to 5 carbon atoms, and R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

As the alkyl group having 1 to 5 carbon atoms,
Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, i-pentyl group, etc. Is mentioned.

Examples of such branched polyene compounds (hereinafter, also referred to as branched polyene compound [I]) include the compounds specifically exemplified in the following (1) to (24). Among them, (5), (6), (9),
Branched chain polyene compounds (11), (14), (19) and (20) are preferably used. (1) 4-ethylidene-1,6-octadiene (2) 7-methyl-4-ethylidene-1,6-octadiene (3) 7-methyl-4-ethylidene-1,6-nonadiene (4) 7-ethyl -4-Ethylidene-1,6-nonadiene (5) 6,7-dimethyl-4-Ethylidene-1,6-octadiene (6) 6,7-Dimethyl-4-ethylidene-1,6-nonadiene (7) 4 -Ethylidene-1,6-decadiene (8) 7-methyl-4-ethylidene-1,6-decadiene (9) 7-methyl-6-propyl-4-ethylidene-1,6-octadiene (10) 4-ethylidene -1,7- Nonadiene (11) 8-methyl-4-ethylidene-1,7-nonadiene (EM
N) (12) 4-ethylidene-1,7-undecadiene (13) 8-methyl-4-ethylidene-1,7-undecadiene (14) 7,8-dimethyl-4-ethylidene-1,7-nonadiene (15 ) 7,8-Dimethyl-4-ethylidene-1,7-decadiene (16) 7,8-Dimethyl-4-ethylidene-1,7-undecadiene (17) 8-Methyl-7-ethyl-4-ethylidene-1 , 7- Undecadiene (18) 7,8-Diethyl-4-ethylidene-1,7-decadiene (19) 9-Methyl-4-ethylidene-1,8-decadiene (20) 8,9-Dimethyl-4-ethylidene -1,8-decadiene (21) 10-methyl-4-ethylidene-1,9-undecadiene (22) 9,10-dimethyl-4-ethylidene-1,9-undecadiene (23) 11-methyl-4-ethylidene -1,10-Dodecadiene (24) 10,11-Dimethyl-4-ethylidene-1,10-dodecadiene These can be used alone or in combination of two or more kinds.

The above branched polyene compound [I] is
It may be a mixture of trans isomer and cis isomer, and may be trans isomer alone or cis isomer alone. Such a branched chain polyene compound can be prepared by the method described in the specification of Japanese Patent Application No. 6-154952 filed by the applicant of the present application.

That is, it can be produced by reacting a compound having a conjugated diene represented by the following [Ia] with ethylene in the presence of a catalyst composed of a transition metal compound and an organoaluminum compound.

[0028]

[Chemical 4]

(In the formula [Ia], n, R ¹ , R ² and R
³ is n in the general formula [I] described above,
Same as R ¹ , R ² and R ³ . ) In the random copolymer rubber (A) used in the present invention, structural units derived from the above-mentioned monomers of ethylene, α-olefin and branched polyene compound are randomly arranged and bonded. However, the main chain has a substantially linear structure while having a branched structure derived from the branched polyene compound.

The fact that this copolymer rubber has a substantially linear structure and does not substantially contain a gelled crosslinked polymer means that this copolymer rubber dissolves in an organic solvent and substantially contains insoluble components. It can be confirmed by not including it. For example, when measuring the intrinsic viscosity [η], it can be confirmed by completely dissolving the copolymer rubber in decalin at 135 ° C.

Further, in such a random copolymer rubber (A), the constitutional unit derived from the branched polyene compound has a structure substantially represented by the following formula [II].

[0032]

[Chemical 5]

[In the formula [II], n, R ¹ , R ² and R ³
Are n, R ¹ in the above general formula [I],
Same as R ² and R ³ . The constitutional unit derived from the branched polyene compound has the above structure, which means that ¹³ C-
This can be confirmed by measuring the NMR spectrum.

The random copolymer rubber (A) used in the present invention has the following composition and properties. (I) This random copolymer rubber has a molar ratio of ethylene and an α-olefin having 3 to 20 carbon atoms (ethylene /
α-olefin) is 40/60 to 95/5, preferably 50/50 to 80/20, and more preferably 60/40.
The range is from ~ 78/22.

When the random copolymer rubber (A) in which the molar ratio of ethylene and the α-olefin having 3 to 20 carbon atoms is within the above range is used, rubber elasticity is not impaired even at low temperature. A rubber composition capable of providing a vulcanized rubber product having excellent mechanical strength characteristics is obtained.

(Ii) This random copolymer rubber (A)
Has an iodine value of 1 to 50, preferably 5 to 40, and more preferably 10 to 30. The random copolymer rubber (A) having an iodine value in the above range has a high vulcanization rate, excellent co-vulcanizability with a diene rubber, and excellent heat aging resistance.

(Iii) This random copolymer rubber (A)
Is the intrinsic viscosity [η] measured in decalin at 135 ° C.
Usually 0.2 to 10 dl / g, preferably 0.8 <[η]
It is in the range represented by <5.0 dl / g.

The random copolymer rubber (A) having an intrinsic viscosity [η] in the above range has good blendability with a diene rubber and excellent covulcanizability with a diene rubber. There is. Moreover, when the random copolymer rubber (A) having such an intrinsic viscosity [η] is used, a rubber composition having excellent processability can be obtained.

In the present invention, the random copolymer rubber (A) is 20 to 80 relative to 100 parts by weight of the total amount of the random copolymer rubber (A) and the diene rubber (B).
It is used in a proportion of parts by weight, preferably 25 to 75 parts by weight, more preferably 30 to 70 parts by weight. When the random copolymer rubber (A) is used in the above proportion, it does not impair the excellent mechanical strength characteristics under the dynamic use conditions inherently possessed by the diene rubber, and has weather resistance and heat resistance. A rubber composition capable of providing a vulcanized rubber excellent in heat resistance is obtained.

Random copolymer rubber (A) as described above
Can be obtained by copolymerizing ethylene, an α-olefin having 3 to 20 carbon atoms, and a branched polyene compound represented by the above general formula [I] in the presence of a catalyst.

As such a catalyst, a Ziegler type catalyst composed of a transition metal compound such as vanadium (V), zirconium (Zr) and titanium (Ti) and an organic aluminum compound (organic aluminum oxy compound) can be used.

In the present invention, [a] a catalyst comprising a soluble vanadium compound and an organoaluminum compound, or [b] a metallocene compound of a transition metal selected from Group IVB of the periodic table, an organoaluminum oxy compound or an ionized ionic compound. A catalyst composed of a compound is particularly preferably used.

In the present invention, the above catalyst [a] (catalyst comprising a soluble vanadium compound and an organoaluminum compound) or catalyst [b] (a metallocene compound of a transition metal selected from Group IV of the periodic table and an organic compound) is used. In the presence of a catalyst consisting of an aluminum oxy compound or an ionized ionic compound), ethylene and α having 3 to 20 carbon atoms are present.
-The olefin and the branched polyene compound are usually copolymerized in the liquid phase.

At this time, a hydrocarbon solvent is generally used, but an α-olefin such as propylene may be used as a solvent. As such a hydrocarbon solvent, specifically, pentane, hexane, heptane, octane, decane, dodecane, aliphatic hydrocarbons such as kerosene and halogen derivatives thereof, cyclohexane, methylcyclopentane,
Alicyclic hydrocarbons such as methylcyclohexane and halogen derivatives thereof, aromatic hydrocarbons such as benzene, toluene and xylene, and halogen derivatives such as chlorobenzene are used.

These solvents may be used in combination.
The copolymerization of ethylene, an α-olefin having 3 to 20 carbon atoms and a branched polyene compound may be carried out by either a batch method or a continuous method. When carrying out the copolymerization by a continuous method, the above catalyst is used in the following concentrations.

In the present invention, when the catalyst [a], that is, the catalyst composed of the soluble vanadium compound and the organic aluminum compound is used, the concentration of the soluble vanadium compound in the polymerization system is usually 0.01 to 5 Mmol / liter (polymerization volume), preferably 0.05 to 3 mmol / liter. It is desirable that the soluble vanadium compound is supplied at a concentration of 10 times or less, preferably 1 to 7 times, and more preferably 1 to 5 times the concentration of the soluble vanadium compound present in the polymerization system.

The organoaluminum compound has a ratio of aluminum atom to vanadium atom in the polymerization system (A
1 / V), and is supplied in an amount of 2 or more, preferably 2 to 50, more preferably 3 to 20.

The catalyst [a] comprising a soluble vanadium compound and an organoaluminum compound is usually diluted with the above-mentioned hydrocarbon solvent and / or liquid α-olefin having 3 to 20 carbon atoms and a branched polyene compound. Supplied. At this time, the soluble vanadium compound is desirably diluted to the above-mentioned concentration, and the organoaluminum compound is diluted to a concentration of, for example, 50 in the polymerization system.
It is desirable that the concentration be adjusted to an arbitrary concentration equal to or less than twice the amount and be supplied into the polymerization system.

When a catalyst [b] comprising a metallocene compound and an organoaluminumoxy compound or an ionized ionic compound (also referred to as an ionic ionized compound or an ionic compound) is used in the present invention, a polymerization system is used. The concentration of the metallocene compound within the range of 0.
0.0005 to 0.1 mmol / liter (polymerization volume),
It is preferably 0.0001 to 0.05 mmol / liter.

Further, the organoaluminum oxy compound is
The ratio of aluminum atom to metallocene compound in the polymerization system (Al / transition metal) is supplied in an amount of 1 to 10,000, preferably 10 to 5,000.

In the case of an ionized ionic compound, the molar ratio of the ionized ionic compound to the metallocene compound in the polymerization system (ionized ionic compound / metallocene compound) is 0.5 to 20, preferably 1 to 10. Supplied.

When an organoaluminum compound is used, it is generally used in an amount of about 0 to 5 mmol / liter (polymerization degree product), preferably about 0 to 2 mmol / liter.

In the present invention, when ethylene, an α-olefin having 3 to 20 carbon atoms and a branched polyene compound are copolymerized in the presence of a catalyst [a] consisting of a soluble vanadium compound and an organoaluminum compound. Has
In the copolymerization reaction, the temperature is usually -50 ° C to 100 ° C, preferably -30 ° C to 80 ° C, more preferably -20 ° C to
At 60 ° C, the pressure is 50 kg / cm ² or less, preferably 2
It is carried out under the conditions of 0 kg / cm ² or less. However, the pressure is not zero.

In the present invention, ethylene, an α-olefin having 3 to 20 carbon atoms and a branched chain polyene compound are present in the presence of a catalyst [b] comprising a metallocene compound and an organoaluminum oxy compound or an ionizable ionic compound. In the case of copolymerizing and, the temperature of the copolymerization reaction is usually -20 ° C to 150 ° C, preferably 0 ° C to 12 ° C.
0 ° C., more preferably 0 ° C. to 100 ° C., pressure 80
It is carried out under the conditions of not more than kg / cm ² , preferably not more than 50 kg / cm ² . However, the pressure is not zero.

The reaction time (average residence time when the copolymerization is carried out by a continuous method) varies depending on conditions such as catalyst concentration and polymerization temperature, but is usually 5 minutes to 5 hours, preferably 10 minutes. ~ 3 hours.

In the present invention, ethylene and 3 to 2 carbon atoms are used.
Α-olefins and branched polyene compounds of 0 are
It is supplied to the polymerization system in such an amount that the above-mentioned random copolymer rubber having the specific composition is obtained. Further, in the copolymerization, a molecular weight modifier such as hydrogen can be used.

Ethylene and carbon atoms of 3 as described above
Copolymerization of .about.20 .alpha.-olefin and a branched chain polyene compound usually gives a random copolymer rubber as a polymerization liquid containing the same. This polymerization liquid is processed by a conventional method to obtain a random copolymer rubber.

The method for preparing the random copolymer rubber (A) [unsaturated ethylene copolymer] as described above is described in detail in Japanese Patent Application No. 7-69986 filed by the applicant of the present application. Has been done.

Diene rubber (B) Diene rubber (B) constituting the ethylene / α-olefin / non-conjugated polyene copolymer rubber composition according to the present invention
(Excluding nitrile rubber. The same applies to the following.) , Specifically, natural rubber (NR), isoprene rubber (IR),
Butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR) and the like can be used. Above all, isoprene-based rubber having a good balance of mechanical strength, that is, natural rubber (NR) and isoprene rubber (IR) are preferably used.

These diene rubbers can be used alone or in combination. In the present invention, the diene rubber (B) is based on 100 parts by weight of the total amount of the random copolymer rubber (A) and the diene rubber (B).
It is used in a proportion of 20 to 80 parts by weight, preferably 25 to 75 parts by weight, more preferably 30 to 70 parts by weight.

Rubber Composition and Vulcanized Rubber Thereof The ethylene / α-olefin / non-conjugated polyene copolymer rubber composition according to the present invention comprises the above-mentioned random copolymer rubber (A) and diene rubber (B). Besides, SRF,
GPF, FEF, HAF, ISAF, SAF, FT, M
Carbon black such as T, rubber reinforcing agent such as finely divided silicic acid, and light calcium carbonate, heavy calcium carbonate,
Fillers such as talc and clay may be blended.

The types and blending amounts of these rubber reinforcing agents and fillers can be appropriately selected according to the application, but these blending amounts are usually the above-mentioned random copolymer rubber (A).
The maximum amount is 300 parts by weight, preferably 200 parts by weight, based on 100 parts by weight of the total amount of the diene rubber (B).

The rubber composition according to the present invention can be used as it is unvulcanized, but it can exhibit its properties most when used as a vulcanized rubber. That is, the random copolymer rubber (A) constituting the rubber composition according to the present invention has a function of improving properties such as weather resistance and ozone resistance of the vulcanized rubber, and the diene rubber (B). Has a function of improving properties such as strength of the vulcanized rubber. Therefore, from the rubber composition according to the present invention, mechanical strength properties,
A vulcanized rubber having excellent weather resistance, ozone resistance and dynamic fatigue resistance can be obtained.

In producing a vulcanized rubber from the rubber composition according to the present invention, depending on the intended use of the vulcanized rubber and the performance based thereon, in addition to the above components (A) and (B), rubber reinforcement Types and amounts of vulcanizing agents, fillers, softeners, vulcanizing agents, vulcanization accelerators, vulcanization aids, etc. The process to be performed is appropriately selected.

As the above-mentioned softening agent, a softening agent usually used for rubber is used. Of these, petroleum-based softeners are preferably used, and process oils are particularly preferably used. The compounding amount of the softening agent is 150 parts by weight at maximum, preferably 100 parts by weight, based on 100 parts by weight of the total amount of the components (A) and (B).

In the production of the vulcanized rubber according to the present invention, conventionally known sulfur or sulfur compounds are used as a vulcanizing agent. The sulfur and sulfur compounds are used in a proportion of 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the total amount of the components (A) and (B).

When a sulfur compound is used as a vulcanizing agent when producing a vulcanized rubber from the rubber composition according to the present invention, it is preferable to use a vulcanization accelerator together. A conventionally known vulcanization accelerator can be used as the vulcanization accelerator.

The vulcanization accelerator is used in a proportion of 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the total amount of the above components (A) and (B). . The unvulcanized compounded rubber is prepared by the following method. That is, using a mixer such as a Banbury mixer, the random copolymer rubber (A) and the nitrile rubber (B), and further a softening agent are kneaded at a temperature of 80 to 150 ° C. for 3 to 10 minutes, and then an open roll is used. Using a roll such as the above, a vulcanizing agent and, if necessary, a vulcanization accelerator or a vulcanization aid are additionally mixed, and the roll temperature is 40 to 60 ° C.
After kneading for 30 minutes, the kneaded product is extruded to prepare a ribbon-shaped or sheet-shaped compounded rubber.

The compounded rubber thus prepared is molded into an intended shape by an extruder, calender roll, or press. Simultaneously with molding or by introducing the molded product into a vulcanization tank, the compounded rubber at 120 to 270 ° C. Heat at a temperature for 1 to 30 minutes to obtain a vulcanized rubber. When performing such vulcanization, a mold may or may not be used. When a mold is not used, the molding and vulcanization steps are usually carried out continuously.

The ethylene / α-olefin / non-conjugated polyene copolymer rubber according to the present invention obtained by blending the above-mentioned random copolymer rubber (A) and diene rubber (B) in the above-mentioned ratio. The composition is rubber-alloyed, and the vulcanized rubber product obtained from such a rubber composition has a dynamic fatigue resistance which is a defect of the existing EPDM and a heat aging resistance which is a defect of a diene rubber. , Weather resistance and ozone resistance are greatly improved.

[0071]

The ethylene / α-olefin / non-conjugated polyene copolymer rubber composition according to the present invention comprises ethylene, an α-olefin having 3 to 20 carbon atoms and the above-mentioned branched polyene compound. Since it is composed of a random copolymer rubber (A) having a molar ratio of ethylene and α-olefin, an iodine value and an intrinsic viscosity [η] within a specific range, and a diene rubber (B), the diene rubber has excellent properties. It is possible to provide a vulcanized rubber excellent in weather resistance, ozone resistance and heat aging resistance without impairing the mechanical strength characteristics, wear resistance and dynamic fatigue resistance.

Since the vulcanized rubber according to the present invention is obtained by vulcanizing the rubber composition according to the present invention, mechanical strength characteristics,
It has excellent wear resistance, dynamic fatigue resistance, weather resistance, ozone resistance and heat aging resistance.

Therefore, ethylene / α-according to the present invention
The olefin / non-conjugated polyene copolymer rubber composition and the vulcanized rubber are automobiles that are required to have excellent dynamic fatigue resistance, heat resistance and weather resistance, such as anti-vibration rubber, tire sidewalls and tire treads. It is suitable for applications such as parts.

The present invention will be described below with reference to examples.
The present invention is not limited to these examples. The evaluation tests in Examples and Comparative Examples were performed according to the following methods.

[1] Physical Property Test of Unvulcanized Rubber Physical property test of unvulcanized rubber was carried out in accordance with JIS K 6300, using a CLASTLASTMETER Model 3 manufactured by Japan Synthetic Rubber Co., Ltd. The change in torque was measured at 150 ° C., and t ₉₀ [min] was determined and used as the vulcanization rate. The shorter t ₉₀ is, the faster the vulcanization rate is.

[2] Co-vulcanization degree The co-vulcanization degree was calculated by the following formula. Co-vulcanization degree [%] = {T _B (blend) / [T _B (EPDM) × a
+ T _B (NR) × b]} × 100 In the above formula, T _B (blend) represents the actual tensile strength of the blend material, and T _B (EPDM) is the ethylene / propylene / diene rubber (EPDM). T _B (NR) represents the tensile strength of natural rubber (NR) and a is the ethylene / propylene / diene rubber (EP).
Represents the weight fraction of DM), b represents the weight fraction of natural rubber (NR), and a + b = 1.

[3] Tensile test A vulcanized rubber sheet is punched out and JIS K 6301 (198
Prepared No. 3 dumbbell test piece described in 9 years)
Then, the test piece was used to comply with JIS K 6301 Clause 3
According to the specified method, the measurement temperature is 25 ° C., the pulling speed is 500.
Tensile test was performed under the condition of mm / min and 100% module
Russ (M₁₀₀ ), 200% modulus (M ₂₀₀), 30
0% modulus (M₃₀₀ ), Tensile stress at break (T_B),
And tensile elongation at break (E_B) Was measured. 80 ℃ again
In the above tensile test,
The tensile stress at break T_B , And tensile elongation at break
E_B Was measured.

[4] Hardness Test In the hardness test, the spring hardness H _S (JIS A hardness) was measured according to JIS K 6301 (1989). For the test piece that was heat treated at 80 ° C for 1 hour,
The hardness test described above was performed to determine the spring hardness H _S (JIS
A hardness) was measured.

[5] Aging test According to the air heating aging test specified in JIS K 6301, a tensile test and a hardness test were performed on the test piece before and after the heat treatment, and the stress (T _B ) at the tensile breaking point and the tensile breaking point were measured. measured point elongation (E _B) and JIS a hardness (H _S), the rate of change of the tensile stress at break _{(T B) [a C (} T B)],
The difference [AH] between the rate of change in elongation at break (E _B ) [A _C (E _B )] and the JIS A hardness (H _S ) was determined. The test conditions are as follows. Test temperature: 100 ° C Test time (heat treatment time): 96 hours

[6] Crack Growth Test (DeMatcher Bending Test) In the crack growth test, resistance to crack growth was examined by a DeMatcher tester according to ASTM D813. That is, the number of times of bending until a crack was generated and the number of times of bending until the test piece was completely cut was measured (measurement temperature 40 ° C.,
Rotation speed 300 rpm).

[7] Elongation Fatigue Test (Monsanto Fatigue Test) A vulcanized rubber sheet was punched out to prepare a No. 1 type dumbbell test piece described in JIS K 6301, and 2 mm was placed at the center in the longitudinal direction of this test piece. I made a scratch. The elongation rate of each of the 20 test pieces thus obtained was 40%,
80% and 120%, measurement temperature 40 ℃, rotation speed 30
Elongation fatigue was carried out under the condition of 0 rpm, and the average value of stress at the time of the dumbbell rupture and the average value of the number of times at the rupture were measured.

[0082]

[Reference Example 1] [Preparation of catalyst] Anhydrous cobalt (II) chloride 4 was placed in a 50 ml flask containing a stirrer stirrer under an argon atmosphere.
3 mg (0.33 mmol), 1,2-bis (diphenylphosphino) ethane 263 mg (0.66 mmol) and anhydrous decane 23 ml were added, and the mixture was stirred at 25 ° C. for 2 hours.

Then, at 25 ° C., 17 ml of a triethylaluminum / toluene solution having a concentration of 1 mol / liter (17 mmol of triethylaluminum) was added and the mixture was stirred for 2 hours to prepare a catalyst.

[Synthesis of 4-ethylidene-8-methyl-1,7-nonadiene (EMN)]

[0085]

[Chemical 6]

In a 300 ml stainless steel (SUS316) autoclave, under an argon atmosphere, 7-methyl-3-
Methylene-1,6-octadiene (β-myrcene) 100g
(734 mmol) and the whole amount of the catalyst prepared as above were added and the mixture was sealed.

Then, an ethylene cylinder was directly connected to the autoclave, ethylene was introduced, and the inside of the autoclave was cooled to 3
The pressure was increased to 5 kg / cm ² . Then heat to 95 ° C,
Add ethylene consumed intermittently 5 times, total 1
Reaction was carried out for 5 hours.

After completion of the reaction, the autoclave was cooled and then opened, and the obtained reaction mixture was poured into 100 ml of water to separate an organic layer and an aqueous layer. The separated organic layer,
After removing low-boiling substances with an evaporator, 20-stage precision vacuum distillation was performed.

83 g of the target product, EMN, was obtained (yield 69%, β-myrcene conversion 90%). As a reaction byproduct, 16 g of 5,9-dimethyl-1,4,8-decatriene was used.
Produced (yield 13%).

4-Ethylidene-8-methyl-obtained above
The analysis results of 1,7-nonadiene (EMN) are shown below. (1) Boiling point: 103 to 105 ° C./30 mmHg (2) GC-MS (gas chromatography-mass spectrometry):
m / z 164 (M ⁺ molecular ion peak), 149, 1
23, 93, 79, 41, 27 (Gas chromatography measurement condition: column: J & W Scientific Co., capillary column DB-1701 0.25 mm × 30
m Vaporization temperature: 250 ° C. Column temperature: After holding at 60 ° C. for 5 minutes, up to 200 ° C. 10
(3) Infrared absorption spectrum (neat) Absorption peaks: 3080 cm ^-1 , 2975 cm ^-1 , 292
^{5cm -1, 2825cm -1, 1670cm -1} , 1640
^{cm -1, 1440cm -1, 1380cm -1} , 1235c
^{m -1, 1110cm -1, 910cm -1} , 830cm -1 (4) 1 H-NMR spectrum (solvent: CDCl ₃₎ shows an absorption peak below.

[0091]

[Table 1]

[Preparation of Random Copolymer Rubber] Ethylene and propylene and the above 4-ethylidene-8-methyl-1,7-nonadiene (EMN) were placed in a 15-liter capacity polymerization vessel equipped with a stirring blade. The copolymerization reaction of was carried out continuously.

That is, first, 2 liters of dehydrated and purified hexane and bis (1,
0.2 liters per hour of a hexane solution of 3-dimethylcyclopentadienyl) zirconium dichloride (concentration 0.05 mmol / liter) and 0.2 liters of a hexane solution of triisobutylaluminium (concentration 20 mmol / liter). , A hexane slurry solution of methylalumoxane (3 mg atom / liter in terms of aluminum atoms) / liter, and a hexane solution of EMN (concentration 0.12 liter / liter) / hour.
6 liters were continuously supplied.

Further, 180 liters / hour of ethylene, 620 liters / hour of propylene and hydrogen were continuously fed into the polymerization vessel from the upper portion of the polymerization vessel so that the concentration of the gas phase portion was 0.004 mol%. This copolymerization reaction is 5
Performed at 0 ° C.

Then, a small amount of methanol was added to the polymerization solution extracted from the lower part of the polymerization vessel to stop the polymerization reaction,
After the copolymer was separated from the solvent by steam strip treatment, the temperature was reduced to 100 ° C. and the pressure was reduced to 100 mmHg.
It was dried for 4 hours.

With the above operation, ethylene / propylene / E
An MN copolymer rubber was obtained. The obtained ethylene / propylene / EMN copolymer rubber (EMN-EPT1) is
The molar ratio of ethylene and propylene (ethylene / propylene) is 71/29, the iodine value is 9, and 135
Intrinsic viscosity [η] measured in decalin at 2.77 dl
/ G.

[0097]

[Reference Examples 2-4] The same operation as in Reference Example 1 was carried out to obtain ethylene / α-olefin / EMN copolymer rubbers (EMN-EPT2-4) shown in Table 2.

[0098]

[Table 2]

[0099]

Example 1 [Production of Vulcanized Rubber] As the random copolymer rubber (A), the above-mentioned ethylene / propylene / 4-ethylidene-8-methyl-
1,7-Nonadiene copolymer rubber (EMN-EPT1)
And RSS # 1 (N) commercially available as a diene rubber (B)
R) and blend ratio (NR / EMN-EPT1) 30 /
70 was compounded according to Table 3 to obtain an unvulcanized compounded rubber.

In this compounding, in addition to the above-mentioned copolymer rubber (EMN-EPT1) and NR, zinc flower 1
No., stearic acid, FEF carbon black [Product name
Asahi # 60HG, manufactured by Asahi Carbon Co., Ltd.], paraffin oil [Product name: Sunsen 4240, Japan Sun Oil Co., Ltd.]
Manufactured], anti-aging agent [trade name: Nocrac 810-NA,
Ouchi Shinko Chemical Co., Ltd.] was added and kneaded with a Banbury mixer with a capacity of 1.7 liters (manufactured by Kobe Steel, Ltd.). This kneading was performed at a filling rate of 70%.

Then, a vulcanization accelerator [NOCSELER CZ, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.] and sulfur were added to the obtained kneaded product to obtain 8 inch rolls (front roll / rear roll). :
(65 ° C / 65 ° C) was kneaded to obtain a compounded rubber.

[0102]

[Table 3]

The compounded rubber obtained as described above was subjected to the above-mentioned physical property test of unvulcanized rubber, and t ₉₀ [min]
(Time required for 90% vulcanization) was determined. The results are shown in Table 4.

Further, the compounded rubber obtained as described above was put out into a sheet, and heated at 160 ° C. for t ₉₀ (min) +2 minutes to obtain a vulcanized sheet having a thickness of 2 mm.
Were prepared, and the above-mentioned co-vulcanization degree test, tensile test, hardness test, aging test, crack growth test and elongation fatigue test were conducted. The results are shown in Table 4.

[0105]

Example 2 Example 1 was repeated except that EMN-EPT2 was used instead of EMN-EPT1. The results are shown in Table 4.

[0106]

[Example 3] The same procedure as in Example 1 was carried out except that EMN-EPT3 was used instead of EMN-EPT1. The results are shown in Table 4.

[0107]

Example 4 Example 1 was repeated except that EMN-EPT4 was used instead of EMN-EPT1. The results are shown in Table 4.

[0108]

Comparative Example 1 In Example 1, except that ENB-EPT shown in Table 2 was used instead of EMN-EPT1.
The same procedure as in Example 1 was performed. The results are shown in Table 4.

[0109]

[Table 4]

Front page continuation (72) Inventor Toshiyuki Tsutsui, 6-1-2 Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Mitsui Petrochemical Industry Co., Ltd. Wood 6-1-2 1-2 Mitsui Petrochemical Co., Ltd. (56) Reference JP-A-8-311266 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 9/00 -9/10 C08L 23/00-23/36 C08F 210/18 C08F 236/22

Claims (3)

(57) [Claims] 1. A random copolymer rubber (A) comprising ethylene, an α-olefin having 3 to 20 carbon atoms, and at least one branched polyene compound represented by the following general formula [I], and The random copolymer rubber (A) comprises a diene rubber (B) (excluding nitrile rubber), and the random copolymer rubber (A) comprises (i) a molar ratio of ethylene and an α-olefin having 3 to 20 carbon atoms (ethylene / α- Olefin) is 40/60
To 95/5, (ii) iodine value is in the range of 1 to 50, (iii) intrinsic viscosity [η] measured in 135 ° C. decalin.
Is in the range represented by 0.8 <[η] <5.0 dl / g. Ethylene / α-olefin / non-conjugated polyene copolymer rubber composition; [In the formula [I], n is an integer of 1 to 5, R ¹ is an alkyl group having 1 to 5 carbon atoms, and R ² and R ³ are each independently a hydrogen atom or the number of carbon atoms. 1 to 5 alkyl groups]. 2. The total amount of the random copolymer rubber (A) and the diene rubber (B) (excluding nitrile rubber) is 10
The content of the random copolymer rubber (A) is 20 to 80 parts by weight and the content of the diene rubber (B) is 20 to 80 parts by weight with respect to 0 parts by weight. Item 1. The ethylene / α-olefin / non-conjugated polyene copolymer rubber composition according to Item 1. 3. The ethylene / α- according to claim 1 or 2.
A vulcanized rubber obtained by vulcanizing an olefin / non-conjugated polyene copolymer rubber composition.