JPH08311267A - Ethylene copolymer rubber composition improved in blooming resistance and vulcanized rubber obtained therefrom - Google Patents

Abstract

PURPOSE: To obtain an ethylene copolymer rubber compsn. having a high vulcanization rate and improved in blooming resistance by compounding a specific copolymer rubber with sulfur or a sulfur compd. and a vulcanization accelerator in a specified wt. ratio. CONSTITUTION: The compsn. contains 100 pts.wt. random copolymer rubber made from ethylene, a 3-20C α-olefin, and at least one branched polyene compd. represented by the formula (wherein n is 1-5; R<1> is 1-5C alkyl; and R<2> and R<3> are each H or 1-5C alkyl), 0.5-10 pt.wt. vulcanizing agent comprising sulfur or a sulfur compd., and 1-20 pts.wt. vulcanization accelerator. The rubber has a molar ratio of ethylene units to α-olefin units of (40/60)-(95/5), an iodine value of 5-40, and an intrinsic viscosity [η] (at 135 deg.C in decalin) higher than 0.8dl/g and lower than 5.0dl/g. Examples of the sulfur compd. are sulfur chloride, sulfur dichloride, a high-molecular polysulfide, and a compd. liberating active sulfur at the vulcanization temp.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ethylene copolymer rubber composition having improved blooming, and more specifically, to prevent blooming from being caused by sulfur or a sulfur compound used as a vulcanizing agent and a vulcanization accelerator. It is possible to provide a vulcanized rubber product which has a high vulcanization rate, that is, a vulcanization speed is higher than that of a conventional rubber composition containing an ethylene / propylene / diene copolymer rubber as a main component, that is, vulcanization is performed in a short time. The present invention relates to an ethylene / α-olefin / polyene copolymer rubber composition and a vulcanized rubber comprising the composition.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Ethylene / propylene / diene copolymer rubber (hereinafter sometimes referred to as EPDM) is
Since the main chain of its molecular structure does not have unsaturated bonds, it has superior heat resistance, weather resistance, and ozone resistance compared to commonly used diene rubbers, and is used for electrical and electronic rubber parts, civil engineering and construction. Widely used in rubber parts for automobiles.

However, EPDM has a slower vulcanization rate than other general-purpose rubbers. In particular, when vulcanizing EPDM using sulfur or a sulfur compound as a vulcanizing agent, these vulcanizing agents and vulcanization accelerators should be added in order to increase the vulcanization rate to the same level as other general-purpose rubbers. It is necessary to use a large amount. That is, in the conventional EPDM, 2 to 5 times the amount of the vulcanization accelerator is used as compared with general-purpose rubbers such as natural rubber (NR), styrene-butadiene rubber (SBR), and butadiene (BR).

Sulfur, a sulfur compound, and a thiuram compound, a dithioate compound, and a thiazole compound, which are used as a vulcanizing agent for EPDM, and a vulcanization accelerator, are originally poor in compatibility with EPDM, and therefore they are not compatible with EPDM. When blended in a large amount, these vulcanizing agents and vulcanization accelerators contained in the obtained vulcanized rubber precipitate on the surface of the vulcanized rubber product and crystallize white, a so-called blooming phenomenon occurs. However, there is a problem of reducing the commercial value of vulcanized rubber products.

As a method for preventing the occurrence of such a blooming phenomenon, a method of combining vulcanization accelerators for suppressing blooming, a small amount of non-reactive phenol formaldehyde resin, fatty acid ester or the like is added to suppress blooming. Various methods such as a method for preventing blooming by devising a method and a vulcanization method have been conventionally proposed.

However, in the above-mentioned method, there is a problem that the processability and various physical properties of the vulcanized rubber are impaired and the cost is increased, and an effective blooming preventing method has not yet been found. is there.

Therefore, as a vulcanizing agent, EPDM does not impair the excellent processability, physical properties of vulcanized rubber, heat resistance, weather resistance, ozone resistance, paintability, adhesiveness and other properties that EPDM originally has. It is possible to provide a vulcanized rubber product having excellent blooming resistance, which prevents the occurrence of blooming due to the used sulfur or sulfur compound and a vulcanization accelerator, and to provide a vulcanized rubber product having a conventional EPDM as a main component. It has been desired to develop an ethylene-based copolymer rubber composition having a high vulcanization rate, that is, capable of performing sufficient vulcanization in a short time, and a vulcanized rubber composed of the composition.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, and has excellent processability inherent in EPDM, physical properties of vulcanized rubber, heat resistance,
It is possible to provide a vulcanized rubber product having excellent blooming resistance, without impairing various properties such as weather resistance, ozone resistance, and adhesiveness, and to provide a rubber composition containing EPDM as a main component in the related art. An object is to provide an ethylene-based copolymer rubber composition having a high vulcanization rate and a vulcanized rubber comprising the composition.

[0009]

SUMMARY OF THE INVENTION An ethylene copolymer rubber composition having improved blooming according to the present invention comprises ethylene, an α-olefin having 3 to 20 carbon atoms, and at least one of the following general formula [I]. 100 parts by weight of a random copolymer rubber (A) composed of the branched chain polyene compound, 0.5 to 10 parts by weight of sulfur or a sulfur compound (B), and 1 to 20 parts by weight of a vulcanization accelerator (C). Contains
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) in the range of 40/60 to 95/5, (Ii) the iodine value is in the range of 5-40, (ii
i) The intrinsic viscosity [η] measured in decalin at 135 ° C. is in a range represented by 0.8 <[η] <5.0 dl / g.

[0010]

Embedded image

[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.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The blooming-improved ethylene copolymer rubber composition and the vulcanized rubber comprising the composition according to the present invention will be specifically described below.

The ethylene-based copolymer rubber composition with improved blooming according to the present invention comprises a specific random copolymer rubber (A), sulfur or a sulfur compound (B), and a vulcanization accelerator (C). It is a vulcanizable rubber composition containing a specific ratio.

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 the α-olefin 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. The branched polyene compound is represented by the following general formula [I].

[0018]

Embedded image

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 a branched polyene compound (hereinafter also referred to as a 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.

[0024]

[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.

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

[0028]

Embedded image

[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 90/10, more preferably 55/45.
It is in the range of ~ 85/15.

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, the mechanical strength characteristics are excellent and the blooming resistance is excellent. A rubber composition capable of providing a vulcanized rubber product having excellent properties is obtained.

(Ii) This random copolymer rubber (A)
Has an iodine value of 5 to 40, preferably 8 to 35, and more preferably 10 to 30. When the random copolymer rubber (A) having an iodine value in the above range is used, a vulcanized rubber product having excellent blooming resistance can be provided, and a rubber composition having a high vulcanization rate can be obtained. .

(Iii) This random copolymer rubber (A)
Is in the range where the intrinsic viscosity [η] measured in decalin at 135 ° C. is represented by 0.8 <[η] <5.0 dl / g. When the random copolymer rubber (A) having an intrinsic viscosity [η] in the above range is used, a rubber composition having excellent processability can be 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 organoaluminum 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.

Further, 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] composed of 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 organoaluminum oxy 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.

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 the 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 the organoaluminum compound is used, it is usually 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 chain 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 the 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 above-mentioned preparation method of the random copolymer rubber (A) [unsaturated ethylene copolymer] is described in detail in Japanese Patent Application No. 7-69986 filed by the applicant of the present application. Has been done.

Sulfur or sulfur compound (B) Sulfur or sulfur compound (B) used in the present invention
Is used as a vulcanizing agent.

Specific examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, insoluble sulfur and the like. As a sulfur compound,
Specific examples thereof include sulfur chloride, sulfur dichloride, and polymer polysulfide. Further, a sulfur compound that releases active sulfur at the vulcanization temperature and vulcanizes, for example, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and the like can also be used.

In the present invention, powdered sulfur is preferably used. In the present invention, the sulfur or sulfur compound (B) is used in a proportion of 0.5 to 10 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the random copolymer rubber (A).

Since the above-mentioned random copolymer rubber (A) used in the present invention has a high vulcanization rate, sulfur or a sulfur compound (depending on the kind, combination and addition amount of vulcanization accelerators described later can be selected. The addition amount of B) can be reduced.

Vulcanization accelerator (C) Specific examples of the vulcanization accelerator (C) used in the present invention include N-cyclohexyl-2-benzothiazole sulfenamide and N-oxydiethylene-2-benzothiazo. -Sulfenamide compounds such as Rusulfenamide, N, N-diisopropyl-2-benzothiazol-sulfenamide; 2-mercaptobenzothiazole, 2- (2,4-dinitrophenyl) mercaptobenzothiazo- , 2- (2,6-diethyl-4-morpholinothio) benzothiazole, dibenzothiazyl disulfide and other thiazole compounds; diphenylguanidine, triphenylguanidine, diorsonitrile guanidine, orthonitrile biguanide,
Guanidine compounds such as diphenylguanidine phthalate; acetaldehyde-aniline reaction products, butyraldehyde-aniline condensates, hexamethylenetetramine, acetaldehyde ammonia and other aldehyde amines or aldehyde-ammonia compounds; 2-mercaptoimidazoline and other imidazoline compounds Thiourea compounds such as thiocarbanilide, diethyl thiourea, dibutyl thiourea, trimethyl thiourea, and diorsotolyl thiourea; tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide, tetraethyl thiuram disulfide, tetrabutyl thiuram disulfide, pentamethylene thiuram tetra Thiuram compounds such as sulfides; zinc dimethyldithiocarbamate,
Dithioxanthogen compounds such as zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, tellurium dimethyldithiocarbamate; dibutylxanthogen Zanthate compounds such as zinc acid; compounds such as zinc white can be mentioned.

An example of a preferable combination of the vulcanization accelerator (C) is dibenzothiazyl disulfide (MBT).
S), N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), tetramethylthiuram disulfide (TMTD) and dipentamethylenethiuram tetrasulfide (DPTT) in combination.

In the present invention, the vulcanization accelerator (C) is
1 to 100 parts by weight of the random copolymer rubber (A)
-20 parts by weight, preferably 2-10 parts by weight.

Other Components In the ethylene-based copolymer rubber composition according to the present invention, the above random copolymer rubber (A), sulfur as a vulcanizing agent or sulfur compound (B), and a vulcanization accelerator ( In addition to C), fillers, softeners, tackifiers, vulcanization aids, anti-aging agents, foaming agents, processing aids, heat stabilizers, weather stabilizers, antistatic agents, colorants, lubricants, difficult additives A flame retardant, an anti-blooming agent and other compounding agents for rubber can be compounded within a range not impairing the object of the present invention.

The above-mentioned fillers include fillers having a reinforcing property and fillers having no reinforcing property. Reinforcing filler is
It has the effect of enhancing the mechanical properties of vulcanized rubber, such as tensile strength, tear strength, and wear resistance. As such a filler, specifically, carbon black, silica, which may be surface-treated with a silane coupling agent or the like,
Examples include activated calcium carbonate and fine powder talc.
In the present invention, any carbon black that is usually used for rubber can be used regardless of its type.

Further, the filler having no reinforcing property increases the hardness of the rubber product without affecting the physical properties so much,
Used to reduce costs. As such a filler, specifically, talc, clay,
Examples include calcium carbonate.

Ethylene Copolymer Rubber Composition The ethylene copolymer rubber composition according to the present invention comprises a random copolymer (A), sulfur or a sulfur compound (B),
A general rubber compound from a vulcanization accelerator (C) and, if necessary, a compounding agent for rubber such as a filler, a softening agent, a vulcanization aid, an antioxidant, a foaming agent and a processing aid as described above. It can be prepared by a method for preparing a product.

For example, a Banbury mixer, a kneader,
Using an internal mixer such as Intermix, the random copolymer rubber (A) and other components are
After kneading at a temperature of 80 to 170 ° C. for 3 to 10 minutes, sulfur or a sulfur compound (B), a vulcanization accelerator (C) and the like are added if necessary, and rolls such as an open roll or a kneader is used. , 5 at roll temperature 40-80 ° C
It can be prepared by kneading for about 30 minutes and then dispensing. Thus, a ribbon-shaped or sheet-shaped rubber composition (blended rubber) is usually obtained.

When the kneading temperature in the above internal mixers is low, the vulcanizing agent such as sulfur or sulfur compound (B), vulcanization accelerator (C) and blowing agent should be kneaded at the same time. You can also

Vulcanized Rubber The vulcanized product (vulcanized rubber) of the ethylene-based copolymer rubber composition according to the present invention is prepared by using the unvulcanized rubber composition as described above.
Usually, an extruder, a calender roll, a press, an injection molding machine, a pre-molded into a desired shape by various molding methods such as a transfer molding machine, and simultaneously with molding or introducing the molded product into a vulcanization tank and heating, Alternatively, it can be obtained by vulcanization by irradiating with an electron beam.

When the unvulcanized rubber composition is vulcanized by heating, hot air, a fluidized bed of glass beads, UHF is used.
(Ultra-high frequency electromagnetic wave), steam, LCM (hot melt salt tank)
It is preferable to heat at a temperature of 150 to 270 ° C. for 1 to 30 minutes using a heating tank having a heating mode such as.

In the case of vulcanizing by electron beam irradiation without using a vulcanizing agent, the preformed rubber composition is treated with 0.1
An electron beam having an energy of -10 MeV, preferably 0.3-2 MeV, and an absorbed dose of 0.5-35 Mra.
d, preferably 0.5 to 10 Mrad.

A mold may or may not be used for molding / vulcanization. When a mold is not used, the above-mentioned unvulcanized rubber composition is usually molded continuously.
Vulcanized.

The vulcanized rubber molded and vulcanized as described above includes weather strips, door glass run channels, window frames, radiator hoses, brake parts, automobile industrial parts such as wiper blades, rubber rolls, belts,
It can be used for applications such as industrial rubber products such as packing and hoses, electric insulating materials such as anode caps and grommets, construction gaskets, civil engineering materials such as civil engineering sheets, and rubberized cloth.

The vulcanized foam obtained by heat-foaming an unvulcanized rubber compound containing a foaming agent can be used for heat insulating materials, cushioning materials, sealing materials and the like.

[0072]

The random copolymer rubber (A) composed of ethylene, an α-olefin having 3 to 20 carbon atoms and a branched polyene compound used in the present invention is ethylene and has 3 to 20 carbon atoms. Since the molar ratio with the α-olefin, the iodine value, and the intrinsic viscosity [η] are within the specific ranges, the vulcanization rate is faster than that of conventional EPDM. Therefore, when the random copolymer rubber (A) is vulcanized, the amount of the vulcanization accelerator (C) used is compared with that of the conventional EPDM.
Can be significantly reduced.

Further, this random copolymer rubber (A)
Has excellent properties such as weather resistance, ozone resistance, and heat aging resistance. The ethylene copolymer rubber composition according to the present invention contains the random copolymer rubber (A), sulfur or a sulfur compound (B) as a vulcanizing agent, and a vulcanization accelerator (C). Therefore, excellent processability inherent in EPDM, physical properties of vulcanized rubber, heat resistance, weather resistance,
It is possible to provide a vulcanized rubber having excellent blooming resistance without deteriorating various properties such as ozone resistance, paintability, adhesiveness, etc. Sulfurization speed is fast.

Since the vulcanized rubber according to the present invention is obtained by vulcanizing the rubber composition according to the present invention, it has excellent processability inherent in EPDM, physical properties of vulcanized rubber, heat resistance, and weather resistance. It has excellent blooming resistance without impairing various properties such as resistance, ozone resistance, paintability, and adhesiveness.

Therefore, the ethylene copolymer rubber composition and the vulcanized rubber according to the present invention having the above-mentioned effects, the window frame, the glass run channel, the door mirror boot, etc., which are required to have ozone resistance and adhesiveness. Various auto parts,
It is suitable for applications such as waterproof sheets that require weather resistance and adhesiveness, various civil engineering and building material parts, and various hoses that require heat resistance.

The present invention will be described below with reference to examples.
The present invention is not limited to these examples. The evaluation test methods for the ethylene / α-olefin / polyene copolymer rubber and the vulcanized rubber in Examples and Comparative Examples are as follows.

[1] Physical Property Test of Unvulcanized Rubber The 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 160 ° 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] Tensile Test JIS K 6301 (198) was prepared by punching out a vulcanized rubber sheet.
No. 3 type dumbbell test piece described in 9 years) was prepared, and the test piece was used in accordance with the method defined in JIS K 6301, paragraph 3, and the measurement temperature was 25 ° C. and the pulling speed was 500.
A tensile test was performed under the condition of mm / min to measure the stress at tensile break (T _B ) and the elongation at tensile break (E _B ).

[3] Hardness Test In the hardness test, the spring hardness H _S (JIS A hardness) was measured according to JIS K 6301 (1989).

[4] Compression set test The compression set test was conducted according to JIS K 6301 (1989).
The compression set (CS) of the test piece heat-aged at 100 ° C. for 22 hours was determined.

[5] Blooming test According to the blooming test A method, after leaving the test piece for 1 month in a thermostatic chamber at 25 ° C., the state of blooming on the surface of the test piece was visually observed.

In the blooming test B method, the test piece was placed in an ozone test tank having an ozone concentration of 50 pphm and 40 ° C., and after 48 hours, the occurrence of blooming on the surface of the test piece was visually observed.

The blooming resistance was evaluated as follows. (Four-level evaluation) ◎: Blooming is not observed. ○: Blooming is slightly generated. △: Blooming is generated. ×: Blooming is severely generated.

[0084]

[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 (17 mmol of triethylaluminum) having a concentration of 1 mol / liter was added and the mixture was stirred for 2 hours to prepare a catalyst.

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

[0087]

[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.

Next, 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, 123, 93, 79, 41, 27 ( Gas chromatography measurement conditions: 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, the temperature was raised to 200 ° C. at 10 ° C./min) ( 3) Infrared absorption spectrum (neat) Absorption peak: 3080 cm ^-1 , 2975 cm ^-1 , 2925 cm ^-1 , 2825 cm ^-1 , 1670 cm ^-1 , 1640 cm ^-1 , 1440 cm ^-1 , 1380 cm ^-1 , 1235 cm ^-1 , 1110 cm ^{-1. , 910cm -1, 830cm -1 (4} ) 1 H-NMR spectrum (solvent: CDCl ₃₎ absorption peaks Is shown below.

[0093]

[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 0.25 liter / liter) / hour.
6 liters were continuously supplied.

Further, 170 liters / hour of ethylene, 630 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 resulting ethylene / propylene / EMN copolymer rubber (copolymer rubber 1) had a molar ratio of ethylene and propylene (ethylene / propylene) of 68/32, an iodine value of 19, and 13
Intrinsic viscosity [η] measured in 5 ° C decalin is 2.3 dl
/ G.

[0099]

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

[0100]

[Table 2]

[0101]

Example 1 100 parts by weight of ethylene / propylene / EMN copolymer rubber (copolymer rubber 1) obtained in Reference Example 1, 5 parts by weight of zinc white, 1 part by weight of stearic acid, and HA
80 parts by weight of F carbon black [trade name: Seast 3, manufactured by Tokai Carbon Co., Ltd.] and naphthene-based process oil [trade name: Sansen 4240, manufactured by Nippon San Oil Co., Ltd.]
50 parts by weight were kneaded with a Banbury mixer [made by Kobe Steel, Ltd.] having a capacity of 1.7 liters for 5 minutes.

Then, the vulcanizing agent and vulcanization accelerator shown in Table 3 were added to the kneaded material obtained as described above to obtain 8
A rubber compound was prepared by kneading with an inch open roll (temperature of front roll and rear roll 50 ° C.) for 10 minutes.

This rubber compound was hot pressed 160
The test was conducted by vulcanizing and molding at 150 ° C. for 10 minutes under the condition of 150 kgf / cm ² to prepare a test piece. The results are shown in Table 3.

[0104]

EXAMPLE 2 Example 1 was repeated except that the copolymer rubber 1 of Reference Example 2 was used in place of the copolymer rubber 1. The results are shown in Table 3.

[0105]

Example 3 In Example 1, except that the copolymer rubber 3 of Reference Example 3 was used in place of the copolymer rubber 1, and the kind and blending amount of the vulcanization accelerator were changed as shown in Table 3. Was performed in the same manner as in Example 1. The results are shown in Table 3.

[0106]

Example 4 Example 1 was repeated except that the copolymer rubber 4 of Reference Example 4 was used in place of the copolymer rubber 1. The results are shown in Table 3.

[0107]

[Comparative Example 1] In Example 1, instead of the polymer 1, ethylene / propylene / 5-ethylidene-2- shown in Table 2 was used.
The same procedure as in Example 1 was carried out except that a norbornene copolymer rubber (copolymer rubber 5) was used. However, the vulcanization rate was slow and a proper vulcanized sheet could not be obtained.
The results are shown in Table 3.

[0108]

Comparative Example 2 In Example 1, copolymer rubber 5 shown in Table 2 was used in place of copolymer rubber 1, and the type and blending amount of the vulcanization accelerator were changed as shown in Table 3. Except for this, the same procedure as in Example 1 was performed. The results are shown in Table 3.

[0109]

[Table 3]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C08L 9/00 LAY C08L 9/00 LAY 23/18 23/18 (72) Inventor Tetsuo Tojo Mitsui Sekiyu Kagaku Kogyo Co., Ltd. 3 Chikusaigan, Ichihara, Chiba Prefecture (72) Inventor Toshiyuki Tsutsui 6-12 Waki, Waki-cho, Kuga-gun, Yamaguchi Mitsui Petrochemical Industry Co., Ltd. (72) Invention Person Toshihiro Ne Ne Waka 6-6, Waki, Kuga-gun, Yamaguchi Prefecture Mitsui Petrochemical Industry Co., Ltd.

Claims (2)

[Claims] 1. A random copolymer rubber (A) comprising 100 parts by weight of ethylene, an α-olefin having 3 to 20 carbon atoms and at least one branched polyene compound represented by the following general formula [I]. Parts, 0.5 to 10 parts by weight of sulfur or sulfur compound (B),
And a vulcanization accelerator (C) in an amount of 1 to 20 parts by weight. 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 in the range of 40/60 to 95/5, (ii) the iodine value is in the range of 5 to 40, and (ii)
i) An ethylene copolymer rubber with improved blooming, which has an intrinsic viscosity [η] measured in decalin at 135 ° C. in a range represented by 0.8 <[η] <5.0 dl / g. 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. A vulcanized rubber obtained by vulcanizing the ethylene / α-olefin / non-conjugated polyene copolymer rubber composition according to claim 1.