JPH07278231A - Crosslinked ethylene copolymer rubber - Google Patents

Abstract

PURPOSE:To obtain the title rubber excellent in mechanical properties within a short crosslinking time by crosslinking an ethylene/alpha-olefin/aromatic vinyl compound copolymer with a specified crosslinking agent. CONSTITUTION:The title rubber is formed by crosslinking an ethylene/alpha-olefin/ aromatic vinyl compound copolymer with a crosslinking agent comprising sulfur and/or an organic peroxide. The composition of the above copolymer is preferably such that the ethylene/alpha-olefin molar ratio is in the range of 30/70 to 90/10 and the aromatic vinyl compound content is in the range of 0.01-30mol%. The above copolymer has good compatibility with other rubbers, and therefore a rubber composition prepared by mixing the above rubber with another rubber and crosslinking the mixture exhibits desirable properties. When the above copolymer is mixed with a thermoplastic resin, and the copolymer is crosslinked during melt kneading of the thermoplastic resin, a thermoplastic elastomer resin composition excellent in impact resistance, etc., can be obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an ethylene / α-olefin / aromatic vinyl compound copolymer crosslinked rubber.
More specifically, it relates to an ethylene / α-olefin / aromatic vinyl compound copolymer crosslinked rubber having excellent crosslinkability.

[0002]

2. Description of the Related Art Ethylene / propylene / non-conjugated diene copolymer rubber (EPD) is a typical example of olefin rubber.
M). EPDM has excellent heat resistance, weather resistance, ozone resistance, and cold resistance, and although it is used in various fields, it has poor compatibility with general-purpose cross-linking agents, and the phenomenon of lumps of raw rubber remains even after the cross-linking operation. There were problems such as occurrence.

[0003] Crosslinked rubbers often use the method of elastomer blending in which several rubbers are mixed and crosslinked for the purpose of improving the performance thereof, and EPDM is mixed with other elastomers at the time of elastomer blending. There were many problems such as poor solubility and resulting deterioration of physical properties.

Further, conventionally, EPDM and ethylene / propylene copolymer rubber (EPM) are blended with a thermoplastic polyolefin resin and used for improving impact resistance of the thermoplastic resin and for imparting rubber performance. It was In particular, a thermoplastic elastomer obtained by causing dynamic cross-linking of EPM or EPDM during melting of a thermoplastic resin is thermoplastic but has an ordinary physical property at room temperature, which has been actively researched and developed in recent years. ing. However, kneading must be performed during the time required for crosslinking EPM and EPDM, and further improvement in crosslinking speed has been desired from the viewpoint of improving productivity.

At present, EPDM is industrially produced using a vanadium catalyst or a titanium catalyst. Then, for several years, EPDM production methods using metallocene catalysts have been shown. For example, JP-A-62-1217
JP-A-11 discloses an EP which uses a catalyst composed of a metallocene compound and an aluminoxane, has a narrow molecular weight distribution and a narrow composition distribution, and is excellent in transparency, non-adhesiveness and mechanical properties.
A method for manufacturing DM is illustrated. In addition, Japanese Patent Laid-Open No. 2-6
Japanese Patent No. 4111 describes a method for producing a high molecular weight EPDM using a catalyst composed of a metallocene compound and alumoxane. However, even with the EPDM manufactured in this way, the same problems as described above cannot be avoided.

On the other hand, a copolymer of ethylene and an aromatic vinyl compound such as an ethylene / styrene copolymer has been known for a long time. For example, JP-A-48-8385, JP-A-58-11511, or Polymer
Bulletin, 20, 237 (1988) exemplifies a method for producing an ethylene / styrene copolymer using a Ziegler-Natta catalyst. Regarding the method for producing a propylene / styrene copolymer, JP-A-60-26011, JP-A-2-206602, and JP-A-4-318.
No. 006 publication. With these methods, it was not possible to obtain a satisfactory polymerization activity.

An ethylene / α-olefin / aromatic vinyl compound copolymer with a new olefin polymerization catalyst has been proposed in the following series of prior art documents. That is,
Japanese Unexamined Patent Publication (Kokai) No. 3-250007 discloses a method for producing an alternating copolymer of ethylene and styrene having an isotactic structure using a catalyst system composed of a specific transition metal compound and an aluminoxane. In addition, Japanese Patent Laid-Open No. 3-1
No. 63088 uses a catalyst consisting of a constrained geometry complex and an alumoxane, ethylene / α-olefin /
A method for making styrene copolymers with high activity is shown. Similarly, Japanese Unexamined Patent Publication (Kokai) No. 5-194641 exemplifies a synthesis example of an ethylene / propylene / styrene copolymer using a catalyst obtained by contacting a constrained geometry complex with a Lewis acid. Further, JP-A-6-49132 discloses a method for producing an ethylene / styrene copolymer by using a catalyst composed of a specific transition metal compound and alumoxane.

However, as described above, although a method for producing an ethylene / α-olefin / aromatic vinyl compound copolymer and its polymer structure have been reported so far, there is no example applied to a crosslinked rubber. .

[0009]

The present invention is based on the EPD
By improving the cross-linking property, which is a problem of M, and shortening the cross-linking time,
An ethylene / α-olefin / aromatic vinyl compound copolymer crosslinked rubber having excellent mechanical properties is provided.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, completed the present invention. That is, the present invention relates to a crosslinked rubber obtained by crosslinking an ethylene / α-olefin / aromatic vinyl compound copolymer, and more specifically, an ethylene / α-olefin / aromatic vinyl compound copolymer is effective. It is an ethylene-based copolymer crosslinked rubber obtained by crosslinking with a different crosslinking agent. The details will be described below.

The α-olefin constituting the ethylene / α-olefin / aromatic vinyl compound copolymer used in the present invention has a carbon number of 3 or more, for example, propylene,
1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1
-Tridecene, 1-tetradecene, 1-pentadecene,
1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicodecene and the like,
These 1 type (s) or 2 or more types are used. Among them, propylene, 1-butene, 1-heptene, 1-hexene, 1-octene and the like are preferable because of easy availability.

Examples of the aromatic vinyl compound constituting the ethylene / α-olefin / aromatic vinyl compound copolymer used in the present invention include styrene, o-methylstyrene, m-methylstyrene and p-methyl. Styrene, o, p-dimethylstyrene, o-ethylstyrene,
Examples thereof include m-ethylstyrene, p-ethylstyrene, o-chlorostyrene, p-chlorostyrene and α-methylstyrene.

The ethylene / α-olefin / aromatic vinyl compound copolymer used in the present invention has the following composition and properties.

(1) The molar ratio of ethylene to α-olefin is preferably in the range of 30/70 to 90/10, and particularly in the range of 45/55 to 85/15 as rubber performance and cold resistance. It is preferable from the viewpoint of improvement.

(2) The content of aromatic vinyl compound is 0.0
It is preferably in the range of 1 to 30 mol%, and particularly preferably 0.
It is preferably in the range of 1 to 15 mol%. When the content of the aromatic vinyl compound is less than 0.01 mol%, the affinity with the cross-linking agent is lowered, and when it is more than 30 mol%, the low temperature properties may be deteriorated and the synthesis may be disadvantageous.

The ethylene / α-olefin / aromatic vinyl compound copolymer used in the present invention may be copolymerized with a non-conjugated diene monomer as the fourth component. Examples of the non-conjugated diene monomer include 1,4-pentadiene, 1,4-hexadiene, 4-methyl-1,5-
Heptadiene, 5-methylene-2-norbornene, 5 ethylidene-2-norbornene, 5-isopropenyl-2
-Norbornene, 2,5-norbonadiene, 1,6-cyclooctadiene, 2-ethylene-2,5-norbonadiene, 2-isopropenyl-2,5-norbonadiene,
Dicyclopentadiene, 1,6-octadiene, 1,7
-Octadiene, tricyclopentadiene and dihydrodicyclopentadienyloxyethylene and esters of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and the like, but are not limited to Not something. And 1 type or 2 or more types of these are used.

Ethylene / α-used in the present invention
The molecular weight of the olefin / aromatic vinyl compound-based copolymer is not particularly limited, but the number average molecular weight measured by gel permeation chromatography (GPC) is 10,000 to 10,000 in terms of polyethylene.
It is preferably 00, more preferably 1000
It is 0 to 600,000. This number average molecular weight is 1000
If it is less than 0, the mechanical properties of the obtained crosslinked rubber may be small. On the other hand, if the number average molecular weight is more than 1,000,000, the fluidity of the obtained crosslinked rubber may be lowered and molding processing may be difficult.

The method for producing the above-mentioned ethylene / α-olefin / aromatic vinyl compound copolymer is not particularly limited, and it can be produced using various catalysts such as titanium-based catalysts, vanadium-based catalysts or metallocene-based catalysts. it can. Above all, it is preferable to produce using a metallocene catalyst having excellent copolymerizability. By this method, it is possible to obtain a highly active copolymer having a narrow molecular weight distribution and narrow composition distribution.

In the crosslinked rubber of the ethylene / α-olefin / aromatic vinyl compound copolymer of the present invention, the crosslinkability is improved by appropriately selecting the crosslinker. Specifically, the dispersibility of the cross-linking agent is improved, and as a result, the physical properties represented by tensile properties are improved, the cross-linking time is shortened, and the raw rubber is less likely to be lumped. This can be understood by the fact that the solubility parameters of the polymer and the cross-linking agent are close to each other. Generally, the compatibility between a polymer and a heterogeneous compound can be arranged by the difference in solubility parameter, and the smaller the compatibility, the better the compatibility. For example, the solubility parameter of sulfur, which is a typical cross-linking agent, is 14.55 cal.
A ^1/2 cc ^-3/2, very different from the typical value of the ethylene / propylene copolymer (7.95cal ^1/2 cc ^-3/2). However, the ethylene / α-olefin / aromatic vinyl compound copolymer used in the present invention has a large solubility parameter and good compatibility with sulfur. As described above, the ethylene / α-olefin / aromatic vinyl compound copolymer used in the present invention becomes a good crosslinked product by applying sulfur crosslinking, and the same phenomenon as described above also occurs due to peroxide crosslinking, resulting in a good crosslinked product. Becomes

Examples of the cross-linking agent used here are t-butyl peroxide, di (t-butyl) peroxide, t-butylperoxy-isopropyl carbonate, t-butylcumyl peroxide, t-butylperoxybenzoate and diquat. Mill peroxide, cumene peroxide, benzoyl peroxide, cyclohexanone peroxide, diisopropylbenzene peroxide, 2,5-dimethylhexane-2,5-diperoxide, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexyne-3,2,5-dimethyl-
2,5-di (t-butyl) peroxyhexane, n-butyl-4,4-bis (t-butylperoxy) hexane, 3,3,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl Peroxide, p-
Chlorobenzoyl peroxide, 1,1-bis (t-
Butylperoxy) -3,3,5-trimethylcyclohexane, 2,2'-bis (t-butylperoxy) -p
-Diisopropylbenzene, 1,3-bis (t-butylperoxy-isopropyl) benzene and the like can be mentioned, and these can be used alone or in a mixture. It is also possible to use it in combination with sulfur crosslinking.

The amount of the crosslinking agent added is preferably 0.1 to 10 parts by weight per 100 parts by weight of the ethylene / α-olefin / aromatic vinyl compound copolymer used in the present invention.
If it is less than 0.1 part by weight, crosslinking may not be sufficiently carried out, and if it exceeds 10 parts by weight, odor may remain.

Further, in the present invention, when a crosslinking accelerator is used in combination, the crosslinking rate is improved, so that a crosslinking accelerator is preferably used in combination. Furthermore, since the ethylene / α-olefin / aromatic vinyl compound copolymer used in the present invention has a good compatibility with the crosslinking accelerator, its effect is particularly remarkable. As the crosslinking accelerator, N, N-diphenylguanidine, N, N-di (o-tolyl) guanidine, N, N-o
A guanidine derivative such as tolylguanidine and the like;
Thiourea such as N, N-dibutylthiourea, N, N'-diethylthiourea, dilaurylthiourea, 2-mercaptoimidazoline, trimethylthiourea, tetramethylthiourea; zinc dibutylxanthate, sodium isopropylxanthate, isopropylxanthate Xanthate salts such as zinc; zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc N-pentamethylenedithiocarbamate, zinc dibenzyldithiocarbamate, sodium dimethyldithiocarbamate, diethyl Sodium dithiocarbamate, sodium dibutyldithiocarbamate, copper dimethyldithiocarbamate, diethyldithiocarbamine Dithiocarbamate salts such as terrium acid, piperidinium pentamethylenedithiocarbamate, pipecoline piperidyldimethyldithiocarbamate, iron dimethyldithiocarbamate; aldehyde ammonia compounds such as hexamethylenetetramine, acetaldehyde aniline, butyraldehyde aniline; Thiazole compounds such as mercaptobenzothiazole, mercaptobenzothiazole sodium salt, dibenzothiazyl disulfide, 2- (4-morpholinodithio) benzothiazole, 2- (2,4-dinitrophenyl) mercaptobenzothiazole; tetramethyl Thiuram monosulfide, tetraethyl thiuram monosulfide, tetramethyl thiuram disulfide,
Thiuram sulfides such as tetraethyl thiuram disulfide, tetrabutyl thiuram disulfide, dipentamethylene thiuram tetrasulfide and the like; mercaptobenzothiazole, dibenzothiazyl disulfide,
Thiazole compounds such as 2-mercaptobenzothiazole zinc; N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-
Examples thereof include, but are not limited to, sulfenamide compounds such as benzothiazole sulfenamide and Nt-butylbenzothiazole sulfenamide. These crosslinking accelerators may be used alone or in combination of two or more.

When a crosslinking accelerator is used, it is used in an amount of 10 parts by weight or less, preferably 5 parts by weight or less, per 100 parts by weight of the copolymer. If the amount exceeds 10 parts by weight, the physical properties of the obtained crosslinked rubber may deteriorate.

It is also possible to use a crosslinking accelerator and a dispersant typified by zinc white, activated zinc white, surface-treated zinc white, zinc carbonate, litharge and magnesium oxide during the crosslinking.

Furthermore, it is effective to use a co-crosslinking agent in the crosslinking in the present invention, since the crosslinking effect is improved. Particularly, it is preferably used when crosslinking a copolymer containing no non-conjugated diene component.

Examples of the co-crosslinking agent include P.quinone dioxime, P.P dibenzoylquinone dioxime, N-methyl-N'-4-dinitrosoaniline, dinitrosobenzene, lauryl methacrylate and ethylene glycol dimetha. Acrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, diaryl fumarate, diaryl phthalate, tetraaryloxyethane, triaryl cyanurate, aryl methacrylate, Maleimide, phenyl maleimide,
N, N'-m-phenylene bismaleimide, maleic anhydride, itaconic acid, divinylbenzene, diarylmelamine, diphenylguanidine, divinyl adipate, vinyltoluene, 1,2-polybutadiene, liquid styrene-butadiene copolymer rubber, dipenta Examples thereof include methylene thiuram pentasulfide, mercaptobenzthiazole, and sulfur, and one or more of these are used as necessary.

In addition, scorch inhibitors represented by phthalic anhydride, benzoic acid, salicylic acid, nitroso compounds, coumarone resins, terpene resins, petroleum hydrocarbon compounds, tackifiers represented by rosin derivatives, and paraffinic softeners. A naphthene-based softening agent, an aroma-based softening agent, a softening agent represented by asphalt, petrolatum, ozokerite and the like can be added, if necessary.

Further, if necessary, calcium carbonate, mica, talc, silica, barium sulfate, calcium sulfate, kaolin, clay, pyroferrite, bentonite, serisanite, zeolite, nepheline sinite,
Intapulgite, wollastonite, ferrite, calcium silicate, magnesium carbonate, dolomite, antimony trioxide, zinc oxide, titanium oxide, magnesium oxide, iron oxide, molybdenum disulfide, carbon black, gypsum, quartz and other inorganic fillers and reinforcing agents Furthermore, organic and inorganic pigments can be blended. Further, a release agent, anti-blocking agent, slip agent, antistatic agent, lubricant, heat stabilizer, light stabilizer, UV absorber, weather resistance stabilizer, foaming agent,
Defoaming agent, rust preventive, anti-mold agent, ion trap agent, flame retardant,
A flame retardant aid or the like may be added if necessary.

The method for producing the crosslinked rubber of the present invention is not particularly limited, and a batch type kneader such as a roll, a Banbury mixer, a kneader, a continuous extruder such as a screw extruder or a rotor type continuous kneader is used. Mastication, mixing, etc. are carried out, and the obtained compound is extruded, shaped by any molding method such as injection, calendering, compression, blowing, foaming and transfer molding, and crosslinked.

The ethylene / α-olefin / aromatic vinyl compound copolymer has good compatibility with other rubbers, and a rubber composition obtained by mixing with other rubbers and then crosslinking the mixture exhibits preferable physical properties. Examples of the other rubbers herein include diene rubbers such as natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, EPM, EPDM,
Butyl rubber, acrylate copolymer rubber, chlorinated polyethylene, chlorosulfonated polyethylene, and other saturated type rubbers, especially natural rubber, butadiene rubber, styrene / butadiene copolymer rubber, and rubber composition obtained by using EPDM The physical properties of are excellent in balance and are preferable. One or two of the rubbers listed here
One or more kinds are mixed with the ethylene / α-olefin / aromatic vinyl compound copolymer, but other rubbers may be selected according to the purpose. For example, by mixing with another rubber, the mechanical properties and abrasion resistance of the ethylene / α-olefin / aromatic vinyl compound copolymer rubber are improved,
Ozone resistance is improved for diene rubbers and processability is improved for saturated rubbers.

In any of the saturated type rubber and the diene type rubber, the suitable compounding ratio at the time of mixing is not particularly limited. The compounding composition may be determined according to each purpose, but in order to exert the effect, the weight composition ratio with the other rubber mixed with the ethylene / α-olefin / aromatic vinyl compound copolymer is 1: It is preferably 9 to 9: 1.

The ethylene / α-olefin / aromatic vinyl compound copolymer used in the above mixing preferably has a non-conjugated diene component as one of the copolymerization components. This improves the cross-linking efficiency. Furthermore, in the rubber composition of the present invention, the above-mentioned crosslinking agent, crosslinking accelerator, crosslinking acceleration aid, dispersant, co-crosslinking agent, inorganic filler, reinforcing agent, flame retardant, pigment, antiaging agent, heat stabilizer. A light resistance stabilizer, a plasticizer, and a softening agent represented by mineral oil may be added. However, as the cross-linking form of the rubber composition of the present invention, it is preferable to select sulfur cross-linking and / or peroxide cross-linking, which improves the cross-linking efficiency and the physical properties of the composition.

Further, the method for producing the rubber composition of the present invention is not particularly limited, and batch kneaders such as rolls, Banbury mixers and kneaders, continuous kneaders such as screw extruders and rotor type continuous kneaders can be used. Use mastication,
Mixing, blending, etc., further, the obtained compound is extruded, shaped by any molding method such as injection, calendar, compression, blow, foaming and transfer molding,
Cross-linked

Further, ethylene used in the present invention /
A thermoplastic resin composition obtained by mixing an α-olefin / aromatic vinyl compound copolymer and a thermoplastic resin is preferable because it is excellent in impact resistance and the like. The thermoplastic resin mixed here is preferably a crystalline resin, and examples of such resin include polypropylene, polypropylene-based copolymers such as polypropylene-ethylene-propylene-based copolymers and ethylene-propylene-butene-1-based copolymers. Examples thereof include resins, polyethylene-based resins such as low-density polyethylene and linear low-density polyethylene, polybutene, and polyamide resins. Among these, polypropylene-based resins are preferably used from the viewpoint of heat resistance and processability. The addition amount of the ethylene / α-olefin / aromatic vinyl compound copolymer is preferably 1 part by weight or more and 1000 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin.

When the ethylene / α-olefin / aromatic vinyl compound copolymer is used in an uncrosslinked state, it is used in an amount of 1 part by weight or more and 50 parts by weight or less, preferably 3 parts by weight or more, relative to 100 parts by weight of the thermoplastic resin. 30 parts by weight or less is desirable. If it is less than 1 part by weight, the effect of improving the impact resistance due to the blending of the ethylene / α-olefin / aromatic vinyl compound copolymer is difficult to be exhibited, and if it exceeds 50 parts by weight, the surface of the molded product may be sticky.

A thermoplastic elastomer resin obtained by mixing the ethylene / α-olefin / aromatic vinyl compound copolymer of the present invention and a thermoplastic resin, and then crosslinking the copolymer during melt-kneading of the thermoplastic resin. The composition is a flexible material while having excellent moldability. In the production of this material, it is particularly preferable to use a method of crosslinking the ethylene / α-olefin / aromatic vinyl compound copolymer by peroxide crosslinking because the time required for production can be shortened.

When the ethylene / α-olefin / aromatic vinyl compound copolymer is used as a rubber component of the thermoplastic elastomer resin composition by crosslinking, the thermoplastic resin 1
60 parts by weight or more and 1000 parts by weight of the copolymer with respect to 00 parts by weight
It is desirable that the amount is not more than 100 parts by weight, more preferably not less than 150 parts by weight. If it is less than 100 parts by weight, the hardness will be remarkably high, and if it exceeds 1000 parts by weight, moldability may be poor.

The ethylene / α-olefin / aromatic vinyl compound copolymer used in the above-mentioned thermoplastic elastomer resin composition of the present invention has a non-conjugated diene component as one of the copolymerization components. Is preferred. This increases cross-linking efficiency. Further, the thermoplastic elastomer resin composition of the present invention, the above-mentioned crosslinking agent, crosslinking accelerator, crosslinking accelerator auxiliary agent, dispersant, co-crosslinking agent, inorganic filler, reinforcing agent, flame retardant, softening agent, pigment, An antiaging agent, a heat resistance stabilizer, a light resistance stabilizer, etc. may be added, and further, a crystal nucleating agent or a clarifying agent for the thermoplastic resin component may be added. It is also possible to add the above-mentioned other rubber together with the ethylene / α-olefin / aromatic vinyl compound copolymer as a crosslinked rubber component, and the other rubber is appropriately selected according to the purpose. Furthermore, when a polypropylene resin is used as the thermoplastic resin, low density polyethylene, linear low density polyethylene or the like may be used in combination for the purpose of improving processability.

In addition, 100 parts by weight of the thermoplastic elastomer resin composition of the present invention contains 30 mol% of 1,2-bond of butadiene in the copolymer of styrene and butadiene.
The above random or block copolymer is hydrogenated to obtain a polymer in which a butadiene component is hydrogenated.
Addition of 0 parts by weight or less is preferable because the compression set resistance is improved. However, if the addition amount exceeds 100 parts by weight, the workability may decrease.

The method for producing the thermoplastic elastomer resin composition of the present invention is not particularly limited, and batch-type kneaders such as rolls, Banbury mixers and kneaders, continuous kneaders such as screw extruders and rotor-type continuous kneaders, etc. Melt-kneading and crosslinking of the rubber component are carried out. However, the temperature inside the kneader must be equal to or higher than the melting point of the thermoplastic resin. The produced thermoplastic elastomer resin composition is taken out from the kneading machine, and then pelletized by a sheet pelletizing machine, an extruder, etc., if necessary, and finally extruded, injected, calendered, compressed, blown, foamed and transfer molded. It can be molded by any molding method.

[0041]

The present invention will be described below with reference to examples.
These are exemplary and not limiting. Various measurements in the examples were carried out by the following methods.

(Measurement of Propylene and Styrene Content of Ethylene / Propylene / Styrene Copolymer) 1,1,
2,2-tetrachloroethane-D ₂ as a solvent, 400M
Hz, ¹ H-NMR spectrum (J, manufactured by JEOL Ltd.)
It was calculated by NM GX400) measurement.

(Measurement of molecular weight and molecular weight distribution)
Gel permeation chromatography (manufactured by Millipore Corporation) at 140 ° C. using dichlorobenzene.
It was calculated in terms of polyethylene by using 150C type GPC).

Example 1 To a 5 l autoclave, 2250 ml of toluene, 150 ml of styrene and 600 ml of propylene were added, and ethylene was introduced at a rate of 12 kg / cm ² . next,
10 ml of toluene and 10 mmol of methylaluminoxane in another reaction vessel, and 10 μmo of (dimethyl (t-butylamido) (tetramethyl-η5-cyclopentadienyl) silane) dichloride titanium synthesized by a known method.
1 was added, the mixed solution was stirred for 20 minutes, and then introduced into an autoclave to initiate polymerization. This polymerization was carried out at 90 ° C. for 20 minutes while keeping the ethylene pressure at 12 kg / cm ² .

After the completion of the polymerization, the polymer was washed with a large amount of ethanol and dried under reduced pressure at 60 ° C. for 12 hours. As a result, the styrene content was 1 mol% and the propylene content was 45.
64 g of a mol% ethylene / propylene / styrene copolymer was obtained. This copolymer has a number average molecular weight of 33,000,
It was Mw / Mn = 2.3.

50 g of the obtained polymer was treated at a surface temperature of 50 ° C.
The mixture was kneaded for 1 minute with the 6-inch roll kneader set to. Then, 0.5 g of stearic acid and 25 g of HAF carbon black were added, and the mixture was kneaded for 3 minutes to give 0.16 g of sulfur.
Was added and kneading was continued for 1 minute. After that, zinc flower 1.
5 g and 1.5 g of dicumyl peroxide were added and kneaded for 1 minute to obtain a compound, which was used as a sample for measuring the crosslinking rate.

Separately, a compound was formed into a sheet of 2 mm and crosslinked at 160 ° C. for 20 minutes in a press molding machine.
The obtained press piece was used as a sample for a tensile test.

Comparative Example 1 1000 ml of toluene and 2000 ml of propylene were added to a 5 l autoclave, and 14 kg / c of ethylene was added.
It was introduced so as to be m ² . Next, 10 ml of toluene, 2 mmol of methylaluminoxane, and 2 μmol of diphenylmethane (cyclopentadienyl) (fluorenyl) zirconium dichloride synthesized by a known method were added to another reaction vessel, and the mixed solution was stirred for 20 minutes and then introduced into an autoclave. Then, the polymerization was started. This polymerization was carried out at 40 ° C. for 60 minutes while keeping the ethylene pressure at 10 kg / cm ² .

After completion of the polymerization, the polymer was washed with a large amount of ethanol and dried under reduced pressure at 60 ° C. for 12 hours. As a result, 75 g of an ethylene / propylene copolymer having a propylene content of 41 mol% was obtained. This copolymer had a number average molecular weight of 31,000 and Mw / Mn = 2.1.

50 g of the obtained polymer was treated at a surface temperature of 50 ° C.
The mixture was kneaded for 1 minute with the 6-inch roll kneader set to. Then, 0.5 g of stearic acid and 25 g of HAF carbon black were added, and the mixture was kneaded for 3 minutes to give 0.16 g of sulfur.
Was added and kneading was continued for 1 minute. After that, zinc flower 1.
5 g and 1.5 g of dicumyl peroxide were added and kneaded for 1 minute to obtain a compound, which was used as a sample for measuring the crosslinking rate.

Separately, a compound was formed into a 2 mm sheet and crosslinked in a press molding machine at 160 ° C. for 20 minutes.
The obtained press piece was used as a sample for a tensile test.

The composition obtained above was evaluated by the following methods. The results are shown in Table 1.

(Measurement of cross-linking speed) The scorch time was measured using a Mooney viscometer SMV-201 manufactured by Shimadzu Corporation and used as a standard of cross-linking speed. The measurement temperature was 125 ° C., the rotor speed was 2 rpm, t5 and t35 were measured, and Δ
The t30 was calculated.

(Tensile test) According to JIS K6301, test piece: No. 3 dumbbell, tensile speed: 500 mm
It was measured in minutes. Tensile strength and elongation were measured and evaluated by tensile product.

Tensile product = tensile strength (kg / cm ² ) ×
Elongation (%) / 10,000

[0056]

[Table 1]

[0057]

As described above, the ethylene of the present invention /
The crosslinked rubber of the α-olefin / aromatic vinyl compound copolymer becomes a crosslinked rubber that has a short time required for crosslinking and excellent mechanical properties.

Claims (5)

[Claims] 1. An ethylene-based copolymer characterized in that an ethylene / α-olefin / aromatic vinyl compound copolymer is crosslinked with a crosslinking agent composed of (a) sulfur and / or (b) an organic peroxide. Polymer crosslinked rubber. 2. The molar ratio of ethylene to α-olefin is 30.
Ethylene / α in the range of / 70 to 90/10 and the aromatic vinyl compound content in the range of 0.01 to 30 mol%.
-The ethylene-based copolymer crosslinked rubber according to claim 1, wherein the olefin / aromatic vinyl compound copolymer is crosslinked. 3. An ethylene-based copolymer crosslinked rubber composition, which comprises mixing an ethylene / α-olefin / aromatic vinyl compound copolymer with another rubber and then crosslinking the mixture. 4. The other rubber is one or more rubbers selected from the group consisting of natural rubber, butadiene rubber, styrene / butadiene rubber, and ethylene / α-olefin copolymer rubber. The ethylene-based copolymer crosslinked rubber composition according to claim 3. 5. An ethylene / α-olefin / aromatic vinyl compound copolymer is mixed with a thermoplastic resin, and then the ethylene / α-olefin / aromatic vinyl compound copolymer is cross-linked during melt kneading of the thermoplastic resin. A thermoplastic elastomer resin composition comprising: