JPH09169878A - Ethylene copolymer rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ethylene copolymer rubber composition having good processability and an excellent balance between strengths and low-temperature properties. SOLUTION: This rubber composition contains a copolymer rubber (A) comprising ethylene (a), a 6-20C α-olefin (b) and a nonconjugated diene and having an (a) to (b) molar ratio of 50/50 to 95/5, a nonconjugated diene content in terms of an iodine value of 5-50, an Mw to Mn ratio of 3-10, and a Mooney viscosity (ML1+4 , 100 deg.C) of 10-100 and a copolymer rubber (B) comprising ethylene (a), a 6-12C α-olefin (b) and optionally propylene and/or a nonconjugated diene (c) and having an [(a)+(c)] to (b) molar ratio of 87/13 to 97/3, an (a) to (c) molar ratio of 50/50 to 99/1, a nonconjugated diene content in terms of an iodine value of 0-20, an Mw to Mn ratio of 3-10, a Mooney viscosity of 30-400, and an ethylene content and a Mooney viscosity both higher than those of component (A).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ethylene-based copolymer rubber composition, and more specifically, it has good workability and excellent balance between strength and low-temperature characteristics, and has a seal rubber part for automobiles, various hose parts, The present invention relates to an ethylene copolymer rubber composition suitable for heat resistant belts and the like.

[0002]

2. Description of the Related Art Ethylene-α-olefin-non-conjugated diene copolymer rubbers are excellent in heat resistance, ozone resistance, weather resistance and the like, and are widely used in various products including automobile hoses and seal members. Widely used in the field. When particularly high strength is required in such a field, it is generally adopted to reduce the α-olefin content in the copolymer, but there is a problem that the low temperature characteristics of the copolymer are remarkably lowered. there were. Further, by using a higher α-olefin as the α-olefin, the problem of low temperature characteristics is solved to some extent, but it is still insufficient. On the other hand, JP-B-59-30179 discloses that the molar ratio of ethylene to α-olefin having 3 to 10 carbon atoms is 50/50.
Ethylene-α-olefin-which is above 82/18
Non-conjugated diene copolymer rubber A, ethylene and carbon number 4 to 1
The molar ratio with the α-olefin of 0 is 82/18 to 95/5.
It has been disclosed that the rubber composition for vulcanization comprising the ethylene-α-olefin-non-conjugated diene copolymer rubber B, which is, is excellent in strength and low temperature characteristics, but is not necessarily sufficient in terms of processability. I can't say. In addition, ethylene-α-
Regarding the olefin-non-conjugated diene copolymer rubber composition, attempts to combine a specific low molecular weight component and a high molecular weight component have been made, for example, in JP-A-61-278540, JP-A-63-37149 and JP-A-3. -146531
However, these compositions are still unsatisfactory in terms of overall workability, strength, low-temperature characteristics, and the like. That is, ethylene-
In the α-olefin-non-conjugated diene copolymer rubber composition, there are many factors that influence the characteristics, and since these factors correlate in a complicated manner, from the viewpoint of balance of processability, strength, low temperature characteristics and the like, In reality, it is extremely difficult to select and combine appropriate factors.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ethylene copolymer rubber composition which has good processability and is excellent in the balance between strength and low temperature characteristics.

[0004]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above problems in the prior art, the inventors of the present invention contain two specific ethylene-α-olefin-nonconjugated diene copolymer rubbers. The inventors have found that a rubber composition can solve the problems, and completed the present invention. That is, the present invention comprises (A) (a) ethylene, (b) α-olefin and (c) non-conjugated diene, the α-olefin has 6 to 20 carbon atoms, and the ethylene / α-olefin molar ratio is 50. /
50-95 / 5, the content of non-conjugated diene is 5 in iodine value
˜50, ratio (Mw / Mn) of polystyrene-equivalent weight average molecular weight (Mw) and polystyrene-equivalent number average molecular weight (Mn) by gel permeation chromatography (hereinafter referred to as “GPC”) is 3 to 10, Mooney viscosity A copolymer rubber having (ML _{1 + 4} , 100 ° C.) of 10 to 100, and (B) (a) ethylene and (b) α-olefin as an essential component, and optionally (c) propylene and / or (d) ) Further containing a non-conjugated diene, the α-olefin has a carbon number of 6 to 12, (ethylene and propylene) / α
-Olefin molar ratio is 87/13 to 97/3, ethylene / propylene molar ratio when containing propylene is 5
0/50 to 99/1, the content of the non-conjugated diene is 0 to 20 in iodine value, the polystyrene reduced weight average molecular weight (Mw) and the polystyrene reduced number average molecular weight (Mn) by GPC.
Ratio (Mw / Mn) of 3 to 10, Mooney viscosity (ML
_{1 + 4} , 100 ° C.) is 30 to 400, and (A)
An ethylene-based copolymer rubber composition containing a copolymer rubber having a higher ethylene content and a higher Mooney viscosity than the components
It is the gist.

Hereinafter, the present invention will be described in detail. (A) Copolymer rubber (A) Copolymer rubber composed of (a) ethylene, (b) α-olefin and (c) non-conjugated diene (hereinafter, simply referred to as “(A) copolymer rubber”). 6 carbons in
Examples of the α-olefin of 20 (hereinafter referred to as “α-olefin (a)”) include, for example, 1-hexene and 3
-Methyl-1-pentene, 4-methyl-1-pentene,
1-heptene, 3-ethyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-undecene, 1-
Tetradecene, 1-hexadecene, 1-octadecene,
1-Eicosene and the like can be mentioned, and 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene are preferably used. These α-olefins (a) are
They can be used alone or in combination of two or more. The ethylene / α-olefin (a) molar ratio in the (A) copolymer rubber is 50/50 to 95/5, and preferably 60/40 to 93/7. In this case, if the ethylene / α-olefin (a) molar ratio is less than 50/50, the strength of the vulcanized rubber is poor, while if it exceeds 95/5,
The vulcanized rubber has a poor compression set at low temperatures. Examples of the non-conjugated diene in the (A) copolymer rubber include 1,4
-Hexadiene, 1,6-octadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene,
2-methyl-1,5-hexadiene, 6-methyl-1,
5-hexadiene, 7-methyl-1,6-octadiene, cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, etc. Among them, 5-ethylidene-2-norbornene is particularly preferable. These non-conjugated dienes can be used alone or in combination of two or more. The content of the non-conjugated diene in the copolymer rubber (A) is an iodine value of 5 to 50, preferably 10 to 3.
5 In this case, when the iodine value is less than 5, the compression set of the vulcanized rubber at low temperature is poor, while the iodine value is 50.
If it exceeds, crosslinked gel tends to be generated during kneading / extrusion. The ratio (Mw / Mn) of the polystyrene-reduced weight average molecular weight (Mw) and the polystyrene-reduced number average molecular weight (Mn) of the (A) copolymer rubber by GPC (hereinafter, simply referred to as “Mw / Mn”) is 3. It is -10. In this case, if Mw / Mn is less than 3, workability is poor, while 10
If it exceeds, the strength of the vulcanized rubber becomes poor. Further, the Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the (A) copolymer rubber is 1
It is 0 to 100, preferably 30 to 90. In this case, when the Mooney viscosity is less than 10, the strength of the vulcanized rubber is poor, and when it exceeds 100, the kneading property is poor. In the present invention, the (A) copolymer rubber may be used alone or in combination of two or more.

(B) Copolymer rubber (B) A copolymer rubber containing (a) ethylene and (b) α-olefin as an essential component and optionally (c) propylene and / or (d) a non-conjugated diene. B (hereinafter,
It is simply referred to as "(B) copolymer rubber". Examples of the α-olefin having 6 to 12 carbon atoms (hereinafter referred to as “α-olefin (B)”) in 1) include 1-hexene and 3
-Methyl-1-pentene, 4-methyl-1-pentene,
1-heptene, 3-ethyl-1-pentene, 1-octene, 1-decene, 1-dodecene and the like can be mentioned, preferably 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene is used. These α-olefins (b) can be used alone or in admixture of two or more. The (ethylene and propylene) / α-olefin (II) molar ratio in the copolymer rubber (B) is 87/13 to 97/3, and preferably 90/10 to 97/3. In this case, when the (ethylene and propylene) / α-olefin (b) molar ratio is less than 87/13, the strength of the vulcanized rubber is poor, while
When it exceeds 7/3, the compression set of the vulcanized rubber at low temperatures is poor. Further, the copolymer rubber (B) is improved in compression set at low temperature by copolymerizing propylene. At this time, the ethylene / propylene molar ratio is 50/5.
It is 0 to 99/1, preferably 60/40 to 95/5. In this case, the ethylene / propylene molar ratio is 50/5
When it is less than 0, the strength of the vulcanized rubber is poor, while when it exceeds 99/1, the compression set of the vulcanized rubber at low temperatures is poor.
The ethylene content of the (B) copolymer rubber is higher than that of the (A) copolymer rubber, and preferably 5 mol% or more. In this case, if the ethylene content of the (B) copolymer rubber is equal to or less than that of the (A) copolymer rubber, the processability of the composition is poor and the vulcanized rubber is also poor in strength. Examples of the conjugated diene in the (B) copolymer rubber include the compounds exemplified for the (A) copolymer rubber, and 5-ethylidene-2-norbornene is particularly preferable. The conjugated dienes in this case can also be used alone or in combination of two or more. The content of non-conjugated diene is 0 in iodine value.
It is -20, preferably 5-15. In this case, if the iodine value exceeds 20, crosslinked gel may be generated during kneading and the surface of the vulcanized rubber may be damaged. The Mw / Mn of the (B) copolymer rubber is 3 to 10. In this case, when Mw / Mn is less than 3, workability is poor, and when it exceeds 10, the strength of the vulcanized rubber is poor.
(B) Mooney viscosity of copolymer rubber (ML _{1 +} 4,100
C) is 30-400, preferably 50-200.
It is. In this case, if the Mooney viscosity is less than 30, the strength and compression set of the vulcanized rubber will be impaired, while if it exceeds 400, the kneading processability and extrusion processability will be poor. further,
The Mooney viscosity of the (B) copolymer rubber is higher than that of the (A) copolymer rubber, and preferably 10 or more. In this case, if the Mooney viscosity of the (B) copolymer rubber is equal to or lower than that of the (A) copolymer rubber, the strength of the vulcanized rubber is poor. In the present invention, the (B) copolymer rubber may be used alone or in combination of two or more.
The weight ratio of the (A) copolymer rubber to the (B) copolymer rubber in the present invention is usually 40/60 to 99/1, preferably 50/50 to 95/5. In this case, if the weight ratio is less than 40/60, the low temperature properties of the vulcanized rubber tend to deteriorate, while if it exceeds 99/1, the strength of the vulcanized rubber tends to decrease.

The (A) copolymer rubber and the (B) copolymer rubber in the present invention can be prepared by a conventional method, for example,
And the like. The required monomer mixture is polymerized in a suitable solvent in the presence of a Ziegler catalyst such as a system consisting of a hydrocarbon solvent-soluble vanadium compound and an organoaluminum compound, if necessary by supplying hydrogen as a molecular weight regulator. how to. Conjugate the required monomer mixture in a suitable solvent.
In the presence of a catalyst consisting of a zirconium compound having an electron-bearing group as a ligand and an aluminoxane compound or a boron compound having an aromatic group that may be fluorinated, as a molecular weight modifier, if necessary. A method of supplying hydrogen to polymerize.

Hydrocarbon solvent soluble vanadium compounds include VOCl ₃ , VCl ₄ , VOCl ₃ and VCl
A reaction product of at least one compound selected from the group ₄ and alcohol is preferably used. Examples of the alcohol include methanol, ethanol, n-propanol, i-propanol, n-butanol, sec.
-Butanol, t-butanol, n-hexanol, n
-Octanol, 2-ethylhexanol, n-decanol, n-dodecanol and the like are used in one or more kinds, preferably alcohol having 3 to 8 carbon atoms. Examples of the organoaluminum compound include triethylaluminum, tri-i-butylaluminum, tri-n-hexylaluminum, diethylaluminum monochloride, di-i-butylaluminum monochloride, ethylaluminum sesquichloride and n-butylaluminum sesquichloride. Chloride, ethylaluminum dichloride, n-
Butylaluminum dichloride and the like, preferably ethylaluminum sesquichloride, n-butylaluminum sesquichloride, a mixture of ethylaluminum sesquichloride and tri-i-butylaluminum, n-
It is a mixture of butyl aluminum sesquichloride and tri-i-butyl aluminum. These organoaluminum compounds can be used alone or in combination of two or more.

Next, as zirconium compounds having a group having a conjugated π electron as a ligand, for example, bis (cyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dibromide, bis (cyclopentadiene) (Enyl) zirconium dimethyl, bis (cyclopentadienyl) zirconium diphenyl, dimethylsilylbis (cyclopentadienyl) zirconium dichloride, dimethylsilylbis (cyclopentadienyl)
Zirconium dimethyl, methylene bis (cyclopentadienyl) zirconium dichloride, ethylene bis (cyclopentadienyl) zirconium dichloride, bis (indenyl) zirconium dichloride, bis (indenyl) zirconium dimethyl, dimethylsilylbis (indenyl) zirconium dichloride, methylene bis (indenyl) ) Zirconium dichloride, bis (4,5, 6,
7-Tetrahydroindenyl) zirconium dichloride, bis (4,5,6,7-tetrahydroindenyl)
Zirconium dimethyl, dimethylsilyl bis (4,5,
6,7-Tetrahydro-1-indenyl) zirconium dichloride, dimethylsilylbis (4,5,6,7-tetrahydro-1-indenyl) zirconium dimethyl,
Ethylene bis (4,5,6,7-tetrahydro-1-indenyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dimethyl, dimethylsilylbis (3-methyl-) 1-cyclopentadienyl) zirconium dichloride, methylenebis (3-methyl-1-cyclopentadienyl) zirconium dichloride, bis (t-butylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (3-t-butyl-1) -Cyclopentadienyl) zirconium dichloride, bis (1,3-dimethylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (2,4-
Dimethyl-1-cyclopentadienyl) zirconium dichloride, bis (1,2,4-trimethylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (2,3,5-trimethyl-1-cyclopentadienyl) zirconium dichloride , Bis (fluorenyl) zirconium dichloride, dimethylsilylbis (fluorenyl) zirconium dichloride, (fluorenyl) (cyclopentadienyl) zirconium dichloride, dimethylsilyl (fluorenyl) (cyclopentadienyl) zirconium dichloride, (t-butylamide) (1 ，
2,3,4,5-pentamethylcyclopentadienyl)
Zirconium dichloride, dimethylsilyl (t-butylamide) (2,3,4,5-tetramethyl-1-cyclopentadienyl) zirconium dichloride, methylene (t-butylamide) (2,3,4,5-tetramethyl- 1-cyclopentadienyl) zirconium dichloride, (phenoxy) (1,2,3,4,5-pentamethylcyclopentadienyl) zirconium dichloride, dimethylsilyl (o-phenoxy) (2,3,4,5- Tetramethyl-1-cyclopentadienyl) zirconium dichloride, methylene (o-phenoxy) (2,3,3
4,5-tetramethyl-1-cyclopentadienyl) zirconium dichloride, ethylene (o-phenoxy)
Examples thereof include (2,3,4,5-tetramethyl-1-cyclopentadienyl) zirconium dichloride and compounds in which zirconium in these compounds is replaced with titanium or hafnium, but are not limited thereto. Absent. These transition metal compounds can be used alone or in combination of two or more kinds.

Examples of the aluminoxane compound include a linear aluminoxane compound represented by the following general formula [I] and a cyclic aluminoxane compound represented by the following general formula [II]. During _{R 2 Al-O- (Al (} R) -O) n -AlR 2 ... [I] (Al (R) -O) n + 2 ... [II] wherein each R be the same or different May have 1 to 1 carbon atoms
20 alkyl group, C6-40 aryl group, C7-40 alkaryl group or C7-40 aralkyl group, preferably a methyl group, an ethyl group, particularly preferably a methyl group, n is an integer of 2 to 50, preferably 4 to 30. These aluminoxane compounds can be used alone or in combination of two or more. Examples of the boron compound having an aromatic group that may be fluorinated include trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tri-n-butylammonium tetraphenylborate, and methyl tetraphenylborate (di-n).
-Butyl) ammonium, dimethylanilinium tetraphenylborate, methylpyridinium tetraphenylborate, methyl tetraphenylborate (2-cyanopyridinium), methyl tetraphenylborate (4-cyanopyridinium), tetrakis (pentafluorophenyl)
Trimethylammonium borate, triethylammonium tetrakis (pentafluorophenyl) borate, tri-n-butylammonium tetrakis (pentafluorophenyl) borate, methyl (di-n-butyl) ammonium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) ) Dimethylanilinium borate, methylpyridinium tetrakis (pentafluorophenyl) borate, methyl tetrakis (pentafluorophenyl) borate (2-cyanopyridinium),
Methyl tetrakis (pentafluorophenyl) borate (4-cyanopyridinium), tetrakis [bis (3,3
5-ditrifluoromethyl) phenyl] dimethylanilinium borate, ferrocenium tetraphenylborate,
Examples thereof include silver tetraphenylborate and ferrocenium tetrakis (pentafluorophenyl) borate, but are not limited thereto. These boron compounds may be used alone or in admixture of two or more. As the solvent, a (halogenated) hydrocarbon compound, preferably n-pentane, n-hexane, n-heptane, n-octane, i-octane, cyclohexane, toluene, xylene, methyl chloride, methylene chloride,
Chlorobenzene or the like is used.

The ethylene copolymer rubber composition of the present invention can be prepared by various methods such as the following methods. A method in which the (A) copolymer rubber and the (B) copolymer rubber are produced separately, and the respective copolymers are mixed in a solution state, and then the solvent is removed to obtain a solid composition. Using two reaction tanks connected in series, either (A) copolymer rubber or (B) copolymer rubber is produced in the first reaction tank, and in the second reaction tank, the first reaction tank A method for producing the other copolymer rubber in the presence of the copolymer rubber polymerized in step 1. Separately produced (A) copolymer rubber and (B) copolymer rubber in solid state with Banbury mixer, roll,
A method of mixing using an ordinary kneader such as an extruder. The ethylene-based copolymer rubber composition of the present invention is mixed with a filler, a softening agent, a foaming agent, a vulcanizing / crosslinking agent, etc., if necessary, and then crosslinked according to a commonly used method to produce a vulcanized rubber. To be done. As the filler to be mixed, for example, S
RF, GPF, FEF, MAF, HAF, ISAF, S
One or more kinds of carbon black such as AF, FT and MT, and one or more inorganic fillers such as fine particle silicic acid, heavy calcium carbonate, light calcium carbonate, magnesium carbonate, clay and talc are preferably used. The amount of the filler added is usually 30 to 200 parts by weight per 100 parts by weight of the total of the (A) copolymer rubber and the (B) copolymer rubber. As the softening agent, for example, an aromatic oil usually used for rubber,
One or more of process oils such as naphthenic oil and paraffin oil; vegetable oils such as coconut oil; synthetic oils such as alkylbenzene are used, preferably process oils, and paraffin oils are particularly preferable. The addition amount of the softening agent is (A)
The amount is usually 20 parts by weight or more per 100 parts by weight of the total amount of the copolymer rubber and the (B) copolymer rubber. Examples of the foaming agent include inorganic foaming agents such as ammonium carbonate, sodium bicarbonate, and anhydrous sodium nitrate; dinitrosopentamethylenetetramine, N, N'-dimethyl-N, N'-dinitrosoterephthalamide, benzenesulfonylhydrazide, p. , P'-oxybis (benzenesulfonyl hydrazide), 3,3'-disulfone hydrazide diphenyl sulfone, azoisobutyronitrile, azobisformamide, or another organic foaming agent. Further, together with the foaming agent, a urea-based, organic acid-based, metal salt-based, etc. foaming auxiliary agent may be used in combination. The amount of the foaming agent and the foaming aid added is usually 0.5 to 20 parts by weight, preferably 0.5 to 20 parts by weight, per 100 parts by weight of the total of the (A) copolymer rubber and the (B) copolymer rubber. 1 to 15 parts by weight, and the foaming aid is
Usually, it is 1 to 20 parts by weight.

As the vulcanizing / crosslinking agent, for example, powdered sulfur,
Sulfur such as precipitated sulfur, colloidal sulfur and insoluble sulfur; inorganic vulcanizing agents such as sulfur chloride, selenium and tellurium; sulfur-containing organic compounds such as morpholine disulfide, alkylphenol disulfide, thiuram disulfides and dithiocarbamate; 1,1- Di-t-butylperoxy-3,
3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, 2,5-dimethyl-2,5-di (t-
One or more organic peroxides such as butylperoxy) hexane and 1,3-bis- (t-butylperoxy-isopropyl) benzene are used. The addition amount of the vulcanizing / crosslinking agent is appropriately selected according to the type thereof. For example, in the case of sulfur, it is usually added per 100 parts by weight of the total amount of the (A) copolymer rubber and the (B) copolymer rubber. , 0.1 to 10 parts by weight,
Preferably it is 0.5 to 5 parts by weight. When sulfur is used as a vulcanization / crosslinking agent, a vulcanization accelerator and a vulcanization acceleration auxiliary may be used in combination, if necessary. Examples of vulcanization accelerators include aldehyde ammonia such as hexamethylenetetramine; diphenylguanidine, di (o-tolyl)
Guanidine, guanidines such as o-tolylupiguanide; thiocarbanilide, di (o-tolyl) thiourea,
Thioureas such as N, N'-diethylthiourea, tetramethylthiourea, trimethylthiourea and dilaurylthiourea; mercaptobenzothiazole, dibenzothiazole disulfide, 2- (4-morpholinothio) benzothiazole, 2- (2,4- Thiazoles such as dinitrophenyl) -mercaptobenzothiazole and N, N'-diethylthiocarbamoylthio) benzothiazole; N-t-butyl-2-benzothiazylsulfenamide, N, N'-dicyclohexyl-2-benzo Thiazyl sulfenamide, N, N'-diisopropyl-
Sulfenamides such as 2-benzothiazyl sulfenamide, N-cyclohexyl-2-benzothiazyl sulfenamide; tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, dipenta Thiurams such as methylenethiuram tetrasulfide; zinc dimethylthiocarbamate, zinc diethylthiocarbamate, zinc di-n-butylthiocarbamate, zinc ethylphenyldithiocarbamate, sodium dimethyldithiocarbamate, copper dimethyldithiocarbamate, dimethylthio Examples thereof include carbamate salts such as tellurium carbamate and iron dimethylthiocarbamate; and xanthate salts such as zinc butylthioxanthate. These vulcanization accelerators may be used alone or in admixture of two or more. The addition amount of the vulcanization accelerator is usually 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, per 100 parts by weight of the total of the (A) copolymer rubber and the (B) copolymer rubber. It is a department. Examples of vulcanization accelerators include metal oxides such as magnesium oxide, zinc white, litharge, red lead, and lead white; stearic acid, oleic acid,
Examples thereof include organic acids such as zinc stearate, and zinc white and stearic acid are particularly preferable. These vulcanization accelerators can be used alone or in combination of two or more. The addition amount of the vulcanization acceleration aid is usually 0.5 to 20 parts by weight based on 100 parts by weight of the total of the (A) copolymer rubber and the (B) copolymer rubber. When a peroxide is used as a vulcanizing / crosslinking agent, as a crosslinking aid, for example, sulfur, sulfur such as dipentamethylene thiuram tetrasulfide, or a compound thereof; polyethylene dimethacrylate, divinylbenzene, diallyl phthalate, trisulfate, etc. One or more polyfunctional monomers such as allyl cyanurate, metaphenylene bismaleimide and toluylene bismaleimide; and oxime compounds such as p-quinone oxime and p, p′-benzoylquinone oxime can be used in combination.

An antioxidant, which is usually used for rubber,
Other additives may be added in an appropriate ratio.
Furthermore, in the ethylene copolymer rubber composition of the present invention,
For example, butyl rubber, natural rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, other ethylene-
An α-olefin-non-conjugated diene copolymer, another ethylene-α-olefin copolymer, polyethylene, polypropylene and the like can be mixed and used. When preparing the ethylene copolymer rubber composition of the present invention, a conventionally known kneader, extruder, and vulcanizer can be used. The mixing method and mixing order of the filler, softening agent, foaming agent, cross-linking agent and the like to be mixed in the ethylene copolymer rubber composition of the present invention are not particularly limited, but, for example, using a Banbury mixer or the like, (A ) After mixing the copolymer rubber and the (B) copolymer rubber, a filler, a softening agent, etc., a vulcanizing agent, a foaming agent, a foaming auxiliary agent, etc. are added using a roll or the like. Then, by a method generally used for producing a vulcanized rubber, for example, foaming and vulcanization are carried out by placing in a mold of an arbitrary shape to raise the temperature, or an extruder is used to obtain an arbitrary shape. After molding, the vulcanized rubber is manufactured by heating in a vulcanizing tank to perform vulcanization.

[0014]

Embodiments of the present invention will be described below more specifically with reference to examples. However, the present invention is not limited to these examples. Physical properties in Examples and Comparative Examples were measured and evaluated by the following methods. (1) Propylene content and α-olefin content (mol%) Measured by ¹³ C-NMR method. (2) Iodine value It was measured by the iodine titration method. (3) Measured by the Mw / Mn GPC method. (4) Mooney viscosity (ML _{1 + 4} , 100 ° C.) Based on JIS K6300, it was measured at a measuring temperature of 100 ° C., a preheating time of 1 minute, and a measuring time of 4 minutes. (5) Processability Using an unvulcanized compound, roll temperature 50 ° C ± 5 ° C, nip width 2
Depending on the length of time and the winding state,
It was evaluated in four grades of excellent, good, good and bad. (6) Mooney scorch test Vm was measured at 125 ° C in accordance with JIS K6300. (7) Tensile test Based on JIS K6301, the tensile strength TB (MPa) and the elongation at break EB (%) were measured using a No. 3 test piece. (8) Hardness test According to JIS K6301, it was measured using an A type tester. (9) Compression set test According to JIS K6301, it was measured under the condition of 100 ° C. × 70 hours. (10) Low temperature torsion test T5 (° C) was measured according to JIS K6301.

[0015]

【Example】

Examples 1 to 3 and Comparative Examples 1 to 5 Using the respective copolymer rubbers shown in Table 1, the components excluding the vulcanizing agent component from the compounding formulation shown in Table 2 were used as BR type Banbury mixers (content 1.7. Rotation speed of 80 r
Compound (i) was obtained by kneading at pm and 130 ° C. for 200 seconds. Next, the vulcanizing agent component was added to the compound (i), and the mixture was kneaded for 5 minutes with a 10-inch roll kept at 50 ° C. to obtain a compound (ii). Next, this compound (ii) was heated by a hot press heated to 170 ° C. under a pressure of 100 kgf / cm ² for 15 minutes to prepare a vulcanized sheet and a sample for compression set test, and The physical properties were evaluated. Table 2 shows the evaluation results. As a result, in Examples 1 to 3, the mechanical properties such as strength and compression set were well balanced with the low temperature properties, and the processability was also good. On the other hand, Comparative Example 1 does not contain the (B) copolymer rubber of the present invention, and since the α-olefin of the low molecular weight copolymer rubber is propylene, the low temperature characteristics are good, but the strength is low. , The compression set was inferior. Comparative Example 2 does not include the (A) copolymer rubber of the present invention, and the α-olefin of the high molecular weight copolymer rubber is propylene, so that the strength is good, but the compression set and low temperature characteristics are low. It was inferior. Comparative Example 3 was inferior in strength, compression set, and low temperature characteristics because both α-olefins of the low molecular weight copolymer rubber and the high molecular weight copolymer rubber were propylene. In Comparative Example 4, since the α-olefin of the low molecular weight copolymer rubber was propylene, and the Mw / Mn of the low molecular weight copolymer rubber and the high molecular weight copolymer rubber was less than 3, strength and compression set , Low temperature characteristics are good,
The workability was poor. Furthermore, Comparative Example 5 does not contain the (A) copolymer rubber of the present invention, but contains only the (B) copolymer rubber, so that the strength is good, but the processability, compression set, and low temperature characteristics are poor. Was there.

[0016]

The copolymer rubber composition of the present invention has good processability and an excellent balance between strength and low temperature characteristics.
Therefore, the copolymer rubber composition of the present invention is particularly useful for hoses for automobiles, sealing members, etc., as well as general hoses, civil engineering
It can be used very suitably in a wide range of fields including seal members for construction, seal members for machines and devices, heat-resistant belts, and the like.

[Table 1]

[Table 2]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Fumio Tsutsumi, Inventor Nippon Gosei Rubber Co., Ltd. 2-1-1-24 Tsukiji, Chuo-ku, Tokyo

Claims (1)

[Claims] 1. A) (a) ethylene, (b) α-olefin and (c) non-conjugated diene, wherein the α-olefin has 6 to 20 carbon atoms and the ethylene / α-olefin molar ratio is 50 /. 50 to 95/5, the content of non-conjugated diene is 5 to 50 in terms of iodine value, and polystyrene conversion weight average molecular weight by gel permeation chromatography (M
w) to polystyrene-reduced number average molecular weight (Mn) (Mw / Mn) of 3 to 10, Mooney viscosity (ML _{1 + 4} , 1)
(B) (a) ethylene and (b) α-olefin, and optionally (c) propylene and / or (d) non-conjugated diene. Containing, the carbon number of α-olefin is 6 to 12, (ethylene and propylene) / α
-Olefin molar ratio is 87/13 to 97/3, ethylene / propylene molar ratio when containing propylene is 5
0/50 to 99/1, the content of the non-conjugated diene is 0 to 20 in terms of iodine value, and the ratio (Mw) of the polystyrene reduced weight average molecular weight (Mw) and the polystyrene reduced number average molecular weight (Mn) by gel permeation chromatography. / M
n) is 3 to 10, Mooney viscosity (ML _{1 + 4} , 100 ° C.) is 30 to 400, and an ethylene-based rubber containing a copolymer rubber having a higher ethylene content and a higher Mooney viscosity than the component (A). Copolymer rubber composition.