JP2002121339A - Rubber composition and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition having excellent extrudability and inherent rubber properties of the component rubbers, which can produce an extrusion foamed rubber article suitable for a light-weight solid article having excellent appearance and stability in the cross-sectional shape, for examples, a seal article of a glass run channel, a window frame or a trunk, and the extrusion foamed rubber article. SOLUTION: The rubber composition comprises 100 parts by weight of an ethylene/α-olefine/non-conjugative polyene random copolymer rubber (A), 5-50 parts by weight of an ethylene/1-butene/non-conjugative polyene random copolymer rubber (B), and a softening agent (oil) (C), and has a specific gravity of 1.0-1.15, wherein the ethylene/α-olefine/non-conjugative polyene random copolymer rubber (A) can be obtained by copolymerizing ethylene, one or more of α-olefines selected from α-olefines having a carbon number of 3 or 5-20, and a non-conjugative polyene. The extrusion foamed rubber article can be obtained by extruding and foaming to mold the rubber composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition and its use, and more particularly, to a rubber composition capable of providing a lightweight extruded foamed rubber product while maintaining the physical properties of a conventional extruded foamed rubber product. The present invention relates to the use of a solid portion of a glass run channel product, a window frame product, an automotive water hose product, and a trunk seal product having a stable product shape with good extruded skin and extruded skin.

[0002]

BACKGROUND OF THE INVENTION Ethylene / α-olefin / non-conjugated polyene random copolymer rubbers such as EPDM have excellent weather resistance, heat resistance and ozone resistance, and are widely used especially for automobile weather strip products. ing. On the other hand, as for automobiles, due to carbon dioxide emission regulations and environmental problems, electric vehicles using both engines and electric motors, vehicles equipped with hydrogen engines, and the like have appeared instead of conventional gasoline engines. These vehicles are required to have as light a body as possible in order to improve the mileage and instantaneous power, and the goal of reducing the weight of all the parts used in the vehicles is set.

[0003] In relation to elastomer products, olefin-based thermoplastic elastomers (TPOs) are
Although rubber elasticity is inferior, its specific gravity is about 30% lighter than that of vulcanized rubber, and due to its good recyclability, it is rapidly becoming widely used for automotive weatherstrip products. . Vulcanized rubber has also been studied as a lightweight material by blending hollow glass beads or charcoal.However, these blends deteriorate the processability of the vulcanized rubber. There is hardly any practically used one, for example, because of poor physical properties.

[0004] Under such circumstances, the vulcanized rubber is foamed like a sponge using an organic foaming agent.
Technology is emerging. However, when trying to make the foam specific gravity comparable to that of the thermoplastic elastomer, first,
There is a problem that the surface texture of the product is excessively deteriorated, and further, since the cross-sectional shape of the product is not stabilized, the specific gravity of the final product cannot be reduced to a target level.

The present inventors have developed a glass run channel product,
To significantly reduce the weight of rubber products used for solid parts such as window frame products, automotive water hose products, trunk seal products, etc. Simply, a foaming agent is compounded into a compound of carbon black, oil, and calcium carbonate as the main auxiliary materials in a solid material such as rubber, which has been used so far, and sealing is performed by simultaneously performing extrusion molding and foam molding. Parts were made.

However, the stability of the cross section of the product as a sealing component and the mechanical strength of the sealing component have been reduced, and it has been impossible to commercialize the product. Therefore, the present inventors first paid attention to the fact that it is important that the solid material before foaming is as light as possible. Since the foamed rubber product obtained by performing the process deteriorates in physical properties and appearance, the solid material before foaming is
They came to the conclusion that a material having a low specific gravity and high mechanical strength would yield a lightweight solid material that could be commercialized.

In order to reduce the specific gravity of a solid material before foaming, it is necessary to increase the proportion of a material having a low specific gravity. Typical materials having a low specific gravity are polymers such as ethylene / α-olefin / non-conjugated polyene random copolymer rubber and oil (softening agent). In the relationship between the ethylene / α-olefin / non-conjugated polyene random copolymer rubber and the oil, if the compounding ratio of the rubber is increased, problems such as deterioration of extruded skin and excessively large die swell arise. Therefore, it is important how much oil that contributes to weight reduction can be blended.

However, simply increasing the mixing ratio of the oil to the rubber lowers the product hardness. Therefore, the required properties of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber are increased even if the oil is increased. Product hardness does not decrease or hardly decreases, mechanical strength,
It is important that the rubber elasticity does not deteriorate. Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and have studied ethylene, one or more α-olefins selected from α-olefins having 3 to 20 carbon atoms, and non-conjugated polyenes. 100 parts by weight of an ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) obtained by copolymerizing the above, and 5 to 50 parts by weight of an ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) Part and softener (oil)
It has been found that a rubber composition containing (C) and having a specific gravity of 1.0 to 1.15 is excellent in extrusion moldability and can provide a microfoamed product excellent in product appearance and product cross-sectional shape stability. Thus, the present invention has been completed.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems associated with the prior art as described above, and to provide a lightweight solid which is excellent in product appearance and product sectional shape stability without deteriorating rubber properties. Extrusion rubber compositions that can be provided, and lightweight solids composed of the compositions, such as extruded foamed rubber products, especially extruded foams suitable for use in sealing components such as glass run channel products, window frame products, trunk circumferences, etc. It aims to provide rubber products.

[0010]

SUMMARY OF THE INVENTION A rubber composition according to the present invention is obtained by copolymerizing ethylene, one or more α-olefins selected from α-olefins having 3 to 5 carbon atoms, and a non-conjugated polyene. 100 parts by weight of the obtained ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A),
Ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) 5 to 50 parts by weight, softener (oil) (C)
And a rubber composition having a specific gravity of 1.0 to 1.15.

It is preferable that the softener (oil) (C) is blended in an amount satisfying the following relational expression (1). Y-Y _blank ≧ 0.4 × X (1) [In the formula (1), Y represents 100% by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) in the rubber composition. Softener (oil) for part (C)
Y _blank is a rubber composition which does not contain the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B), and the addition amount of the softener (oil) (C) is only the above rubber composition In a rubber composition (1 _blank ) in which the hardness of the obtained cross-linked molded article is the same as that of the cross-linked molded article obtained from the rubber composition.
X is the blending amount of the softener (oil) (C) with respect to 100 parts by weight of the random copolymer rubber (A) of α-olefin / non-conjugated polyene, and X is ethylene / α-olefin / non-conjugated polyene in the rubber composition. The amount of the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) blended with respect to 100 parts by weight of the random copolymer rubber (A). All or a part of the softener (C) is the same
It may be oil-extended in the production process of the α-olefin / non-conjugated polyene random copolymer rubber (A).

Further, all or a part of the softener (C) may be kneaded in the kneading step of the rubber composition. The rubber composition according to the present invention may further contain a foaming agent (E) and / or a vulcanizing agent. The foaming agent (E) is ethylene / α-olefin /
The content is usually 0.05 to 5 parts by weight based on 100 parts by weight of the non-conjugated polyene random copolymer rubber (A).

The rubber composition according to the present invention may further contain an alkoxysilane compound represented by the following general formula [1] or [2].

[0014]

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[In the formula [1], R represents 1 carbon atom.
R ¹ is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, R ¹ is an alkyl group having 1 to 4 carbon atoms or a phenyl group, n is 0, 1 or 2;
² is a divalent linear or branched hydrocarbon group having 1 to 6 carbon atoms, and R ³ is 6 to 1 carbon atoms.
2 is an arylene group, m and p are each 0 or 1, and m and p are not simultaneously 0, q is 1 or 2, B is q is 1 In certain cases, it is -SCN or -SH, and when q is 2, it is -Sx- (where x is an integer of 2 to 8). ]

[0016]

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[In the formula [2], R represents 1 carbon atom.
R ¹ is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, R ¹ is an alkyl group having 1 to 4 carbon atoms or a phenyl group, n is 0, 1 or 2;
⁴ is a monovalent linear or branched unsaturated hydrocarbon group having 2 to 20 carbon atoms. The extruded rubber foam product according to the present invention is characterized by being obtained by extrusion foaming the rubber composition according to the present invention as described above.

The specific gravity of the extruded foamed rubber product is 0.8 to 0.8.
Desirably, it is 1.0. The average foam cell diameter of the extruded foam rubber product is desirably 400 μm or less. The extruded foamed rubber product according to the present invention can be suitably used as a sealing part.

[0019]

DETAILED DESCRIPTION OF THE INVENTION The rubber composition according to the present invention and its use will be specifically described. The rubber composition according to the present invention comprises: a specific ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A); an ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B); Agent (oil) (C). The rubber composition according to the present invention has a specific gravity of 1.0 to 1.15, preferably 1.0 to 1.10. In the rubber composition according to the present invention, if necessary, a foaming agent (E), further a foaming agent (E), a foaming aid, a vulcanizing agent, a vulcanization accelerator, a crosslinking agent, and a material other than the crosslinking aid. A rubber compounding agent (D) (for example, a pseudo-gelling inhibitor) can be compounded.

Ethylene / α-olefin / non-conjugated polyether
Non- random copolymer rubber (A) The ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) used in the present invention is selected from ethylene and α-olefins having 3 to 5 to 20 carbon atoms. 1
A rubber obtained by copolymerizing at least one kind of α-olefin with a non-conjugated polyene.

Such α-C 3-5-20 carbon atoms
As the olefin, specifically, propylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene,
Examples include 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicosene.
Among these, propylene, 4-methyl-1-pentene,
1-Hexene and 1-octene are preferred. That is, ethylene / propylene / non-conjugated polyene random copolymer rubber, ethylene / 4-methyl-1-pentene / non-conjugated polyene random copolymer rubber, ethylene / 1-hexene / non-conjugated polyene random copolymer rubber, ethylene -1-octene / non-conjugated polyene random copolymer rubber is preferably used.

As the non-conjugated polyene, specifically, 5-ethylidene-2-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, norbornadiene,
Cyclic non-conjugated polyenes such as methyltetrahydroindene; 1,4-hexadiene, 7-methyl-1,6-octadiene,
Examples thereof include linear non-conjugated polyenes such as 4-ethylidene-8-methyl-1,7-nonadiene, 4-ethylidene-1,7-undecadiene, and 4,8-dimethyl-1,4,8-decatriene.

These non-conjugated polyenes may be used alone.
Alternatively, two or more kinds can be used in combination. In the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) used in the present invention, the content of the structural unit derived from ethylene (ethylene content) is 49 to 8%.
0 mol%, preferably 57 to 75 mol%, more preferably 60 to 72 mol%, and contains 3, 5 to 20 carbon atoms.
Is from 19 to 50 mol%, preferably 22 to 50 mol%.
４０40 mol%, more preferably 23-35 mol%, and the content of the structural unit derived from the non-conjugated polyene (non-conjugated polyene content) is 1-20 mol%, preferably 3-
It is 15 mol%, more preferably 5 to 12 mol%.
The ethylene / α-olefin / ethylene / α-olefin / ethylene / α-olefin /
When the non-conjugated polyene random copolymer rubber (A) is used, a rubber composition which is excellent in low-temperature flexibility and can prepare an extruded foamed rubber product having good rubber elasticity is obtained. The composition of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) can be measured by a ¹³ C-NMR method.

The Mooney viscosity of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) [ML
(1 + 4) 100 ° C] is usually 50 to 300, preferably 70 to 200, and more preferably 80 to 150. This Mooney viscosity is within the above range.
-Use of the olefin / non-conjugated polyene random copolymer rubber (A) makes it possible to prepare an extruded foamed rubber product having mechanical strength characteristics required for a seal product, and to provide a rubber composition having excellent extrusion processability. can get.

In the present invention, the above-mentioned ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) can be used alone or in combination of two or more. The ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) having the above characteristics is described in “Polymer Production Process (published by the Industrial Research Institute, pp.309-330)” and the like. It can be prepared by a conventionally known method as described above.

Ethylene / 1-butene / non-conjugated polyene lan
Dam copolymer rubber (B) The ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) used in the present invention is obtained by copolymerizing ethylene, 1-butene and a non-conjugated polyene. Rubber. Specific examples of the non-conjugated polyene include cyclic non-conjugated polyenes such as 5-ethylidene-2-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, norbornadiene and methyltetrahydroindene; 1,4-hexadiene , 7-methyl-1,6-octadiene, 4-ethylidene
Examples include chain non-conjugated polyenes such as -8-methyl-1,7-nonadiene and 4-ethylidene-1,7-undecadiene.

These non-conjugated polyenes may be used alone.
Alternatively, two or more kinds can be used in combination. In the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) used in the present invention, the content of the structural unit derived from ethylene (ethylene content) is 49 to 98 mol%, preferably 69 to 98 mol%. And more preferably 7
The content of the structural unit derived from 1-butene (1-butene content) is 1 to 50 mol%, preferably 1 to 30 mol%, more preferably 1 to 20 mol%. The content of structural units derived from non-conjugated polyene (non-conjugated polyene content) is 1 to 20 mol%, preferably 1 to 20 mol%.
To 15 mol%, more preferably 1 to 10 mol%. Use of an ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) having an ethylene content, 1-butene content and a non-conjugated polyene content within the above ranges provides excellent low-temperature flexibility and good rubber elasticity. Thus, a rubber composition capable of preparing a suitable extruded foamed rubber product is obtained. The composition of the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) can be measured by a ¹³ C-NMR method.

Mooney viscosity [ML (1 + 4) of ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B)
100 ° C.] is usually 1 to 80, preferably 10 to 7
0, and more preferably 15 to 40. By using the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) having the Mooney viscosity within the above range, it is possible to prepare an extruded foamed rubber product having mechanical strength characteristics required as a seal product. And a rubber composition having excellent extrusion processability can be obtained.

The ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) having the above properties is
“Polymer Manufacturing Process (published by the Industrial Research Institute, P.30)
9-330)) and the like. Ethylene 1-butene
The non-conjugated polyene random copolymer rubber (B) is used in an amount of 5 to 50 parts by weight, preferably 15 to 40 parts by weight, based on 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A). And more preferably 20 to 4
It is used in a proportion of 0 parts by weight.

In the present invention, ethylene / 1-butene
The larger the blending amount of the non-conjugated polyene random copolymer rubber (B), the more the softener (C) is blended, so that the weight of the product can be reduced. However, this blending amount is 50 parts by weight. If it exceeds, the low-temperature flexibility of a foamed product such as a weather strip deteriorates, and it is difficult to mold a ribbon-shaped compound prepared before extrusion.
Or because it causes problems such as not getting into the extruder,
Not preferred.

Softener (C) The softener (C) used in the present invention is the above-mentioned ethylene
Process for producing a blend of α-olefin / non-conjugated polyene random copolymer rubber (A) and ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) and / or
Alternatively, the oil is oil-extended and / or added after production.

As such a softener (C), a softener usually used for rubber can be used. Specifically, petroleum softeners such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, petrolatum, etc .;
Coal tar softeners such as coal tar and coal tar pitch; fatty oil softeners such as castor oil, linseed oil, rapeseed oil and coconut oil; tall oil; sub; waxes such as beeswax, carnauba wax and lanolin; ricinol Acid, palmitic acid, barium stearate, calcium stearate,
Fatty acids and fatty acid salts such as zinc laurate; petroleum resins,
Synthetic polymer substances such as atactic polypropylene and coumarone indene resin can be exemplified. Among them, a petroleum softener is preferably used, and particularly, a process oil is preferably used.

Such a softening agent (C) is used in the rubber composition based on 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A). It is preferable that C) is blended in an amount satisfying the following relational expression (1). YY _blank ≧ 0.4X Formula (1) preferably 0.4X ≦ YY _blank ≦ 1.6X, more preferably 0.6X ≦ YY _blank ≦ 1.4X [in formula (1)] And Y are a softener (oil) (C) based on 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) in the rubber composition.
Y _blank is a rubber composition which does not contain the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B), and the addition amount of the softener (oil) (C) is only the above rubber composition In a rubber composition (1 _blank ) in which the hardness of the obtained cross-linked molded article is the same as that of the cross-linked molded article obtained from the rubber composition.
X is the blending amount of the softener (oil) (C) with respect to 100 parts by weight of the random copolymer rubber (A) of α-olefin / non-conjugated polyene, and X is ethylene / α-olefin / non-conjugated polyene in the rubber composition. The amount of the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) blended with respect to 100 parts by weight of the random copolymer rubber (A). The amount of the softener (oil) (C) added may satisfy the formula (1) as a whole, and the whole may be oil-extended in advance in the rubber (A) production process, and the whole may be rubber You may add in the kneading | mixing process of a composition. Alternatively, a part of the softener (oil) (C) is oil-extended in the rubber (A) production process,
The remainder may be added in the kneading step of the rubber composition.

In general, the extruded material has a very good balance of extrudability, designability (product appearance) and economy. In particular, when the product hardness H _A (according to JIS K6253, a flat portion of a vulcanized tubular sample is overlapped to a thickness of 12 mm and the product hardness determined by durometer A) exceeds 70, the extrudability is improved. Technology is needed. On the contrary, since the rubber composition according to the present invention is premised on microfoaming, it is required to further increase the hardness of the compound before foaming.

Under these circumstances, the fact that the softening agent (oil) can be compounded while keeping the product hardness constant has a very large effect on the improvement of the extrudability in the above-mentioned marginal compounding design, and the product skin and Contributes to stabilization of product cross-sectional shape. Rubber compounding agent (D) other than foaming agent (E) etc. The rubber compounding agent (D) other than the foaming agent (E) used as required in the present invention comprises a foaming agent (E), a foaming aid, It is a rubber auxiliary material compound excluding a vulcanizing agent, a vulcanization accelerator, a cross-linking agent and a cross-linking auxiliary agent. Examples of such a rubber compound (D) include a conventionally known rubber reinforcing agent, inorganic filler, and anti-aging agent. ,
Additives such as processing aids, pseudo-gelling inhibitors (herein, additives for preventing the gelling phenomenon occurring during kneading), coloring agents, dispersants, flame retardants, dehydrating agents, etc. No.

These rubber compounding agents (D) contain ethylene / α-olefin /
The specific gravity of the blend of the non-conjugated polyene random copolymer rubber (A) and the ethylene / 1-butene / non-conjugated polyene random copolymer (B) is 1.0 to 1.15, preferably 1.0 to 1. It is blended in such an amount that a rubber compound (I) of 1.10.

As the rubber reinforcing agent, specifically, F
EF grade carbon black is mentioned. In addition, SAF carbon black used for automobile tires and the like, IS
When fine particle carbon black such as AF carbon black is blended with the above rubber compound (I), under the same product hardness, the amount of the softener (C) is larger (specifically, as compared with the amount of the carbon black blended). Since the compounding amount of carbon black can be doubled), the weight of the extruded foamed rubber product can be reduced. However, these carbon blacks cannot be used because the surface of the extruded foamed rubber product deteriorates. In the present invention, if the carbon black of the FEF class which is an ultra-high structure type has a good extruded skin, the carbon black of the FEF class is
It is preferably used as a rubber compounding agent (D).

The rubber reinforcing agent is used in a total of 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) and the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B). On the other hand, usually 5-5
0 parts by weight, preferably 15 to 40 parts by weight. Specific examples of the inorganic filler include light calcium carbonate, heavy calcium carbonate, talc, clay and the like.

The type and amount of these inorganic fillers can be appropriately selected depending on the application.
Usually 1 to 150 parts by weight based on 100 parts by weight of the total of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) and the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) , Preferably 1 to 50
Parts by weight, more preferably 1 to 30 parts by weight.

Examples of the antioxidant include conventionally known amine, hindered phenol, and sulfur antioxidants, and these antioxidants are used in a range that does not impair the object of the present invention. Used. As the processing aid, a compound used for normal rubber processing can be used. Specifically, higher fatty acids such as ricinoleic acid, stearic acid, palmitic acid and lauric acid; salts of higher fatty acids such as barium stearate, zinc stearate and calcium stearate; ricinoleic acid, stearic acid, palmitic acid and lauric acid And higher fatty acid esters.

Such processing aids are usually ethylene
For a total of 100 parts by weight of the α-olefin / non-conjugated polyene random copolymer rubber (A) and the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B),
Usually, it is used in a proportion of 10 parts by weight or less, preferably 5 parts by weight or less, but it is desirable to appropriately determine an optimal amount according to required physical properties.

Examples of the pseudo-gelling inhibitor include alkoxysilane compounds represented by the following general formula [1] or [2].

[0043]

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In the above general formula [1], R is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and R ¹ is an alkyl group having 1 to 4 carbon atoms or A phenyl group, and n is 0, 1 or 2. R ² is a divalent linear or branched hydrocarbon group having 1 to 6 carbon atoms; R ³ is an arylene group having 6 to 12 carbon atoms; And p are
Each is 0 or 1, and m and p are simultaneously 0
Will not be.

Q is 1 or 2; B is -SCN or -SH when q is 1; and -Sx- when q is 2 (x is an integer of 2 to 8). There is).

[0046]

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In the general formula [2], R, R ¹ and n are the same as R, R ¹ and n in the general formula [1]. R ⁴ has 2 to 2 carbon atoms.
0 is a monovalent linear or branched unsaturated hydrocarbon group. Among the alkoxysilane compound represented by the above general formula [1], general formula [1] in B is -S ₄ - is a trialkoxysilane compound shown below is preferably used. (1) bis-3- (trimethoxysilyl) propyl - tetrasulfane (H ₃ CO) ₃ Si-
_{(CH 2) 3 -S 4 -} (CH 2) 3 -Si- (OCH 3) 3 (2) bis-3- (triethoxysilyl) propyl - tetrasulfane _{(H 5 C 2 O) 3} Si- ( CH _{2) 3} -S ₄ -
_{(CH 2) 3 -Si- (OC} 2 H 5) 3 (3) bis-3- (tripropoxysilyl) propyl - tetrasulfane _{(H 7 C 3 O) 3} Si- (CH 2) 3 -S 4
— (CH ₂ ) ₃ —Si— (OC ₃ H ₇ ) ₃ Of the above compounds, bis-3- (triethoxysilyl) propyl-tetrasulfane of the above (2) is particularly preferred.

Among the alkoxysilane compounds represented by the general formula [2], the following compounds are preferably used as the alkoxysilane compound. (4) 3-buten - when kneaded with triethoxysilane _{(C 2 H 5 O) 3} Si-CH 2 CH 2 CH = CH 2 rubber, carbon black and a kneader, or reduction in elongation of the compound after kneading, The roll winding property may be deteriorated. This is a phenomenon often observed in the kneading of EPDM, and is sometimes referred to as a “pseudo-gelation phenomenon”. When this phenomenon occurs, the dispersion of foaming becomes large, so it is preferable to mix a pseudo-gelling inhibitor in advance.

In the rubber composition according to the present invention, other known rubbers, ie, ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) and ethylene, may be used in a range not to impair the object of the present invention. Known rubbers other than 1-butene / non-conjugated polyene random copolymer rubber (B) can be blended. Specific examples of such other rubbers include isoprene-based rubbers such as natural rubber (NR) and isoprene rubber (IR), and butadiene rubber (B
R), conjugated diene rubbers such as styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), and chloroprene rubber (CR).

Further, conventionally known ethylene / α-olefin-based copolymer rubbers can also be used, for example, ethylene / propylene random copolymer (EPR) or the ethylene / α-olefin / non-conjugated polyene random copolymer. Ethylene / α-olefin / polyene copolymers (for example, EP) other than coalesced rubber (A) and ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B)
DM etc.) can be used.

Blowing agent (E) As the blowing agent (E) used as required in the present invention, specifically, sodium bicarbonate, sodium carbonate,
Inorganic blowing agents such as ammonium bicarbonate, ammonium carbonate and ammonium nitrite; nitroso compounds such as N, N'-dimethyl-N, N'-dinitrosoterephthalamide, N, N'-dinitrosopentamethylenetetramine; azodicarbonamide Azo compounds such as azobisisobutyronitrile, azobiscyclohexylnitrile, azodiaminobenzene, barium azodicarboxylate; benzenesulfonylhydrazide, toluenesulfonylhydrazide, p, p'-oxybis (benzenesulfonylhydrazide), diphenylsulfone- Sulfonyl hydrazide compounds such as 3,3'-disulfonyl hydrazide; and azide compounds such as calcium azide, 4,4'-diphenyldisulfonyl azide, and p-toluenesulfonyl azide.

In the present invention, the average cell diameter of the foamed cell of the extruded foamed product is 400 μm or less, preferably 300 μm.
m or less, and more preferably 200 μm or less, it is preferable to use a fine powder type foaming agent. The finer the average particle diameter, the better the stability of the product cross section when finely foamed. In the present invention, the foaming agent (E) is usually used in an amount of 0.05 to 5 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A). It is used in a proportion of 1 to 4 parts by weight, more preferably 0.2 to 3 parts by weight. When the amount of the foaming agent (E) is within the above range, a light-weight solid having a specific gravity of 1.0 or less can be obtained, and the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A ) And the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) can retain the inherent rubber elasticity (resistance to compression set (Cs)).

When the rubber composition according to the present invention is used for sealing parts, it is necessary that the extrusion cross-sectional shape and dimensions are stable. In the case of fine foaming, since the amount of the foaming agent to be mixed is small, foaming may vary depending on the dispersion state, and therefore it is necessary to sufficiently disperse the foaming agent. In the present invention, a foaming aid may be used together with the foaming agent (E), if necessary. The foaming aid acts to lower the decomposition temperature of the foaming agent, promote the decomposition, and make the air bubbles uniform.

Specific examples of such a foaming aid include organic acids such as salicylic acid, phthalic acid, stearic acid and oxalic acid, urea and derivatives thereof. Other components In the rubber composition according to the present invention, if necessary, a vulcanizing agent,
A vulcanization accelerator, a cross-linking agent, and a cross-linking aid can be blended within a range that does not impair the purpose of the present invention. These components are:
Usually, it is blended when the foaming agent (E) is added to the rubber compound (I).

Examples of the vulcanizing agent include sulfur and sulfur compounds. As the sulfur, specifically, powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur,
And insoluble sulfur. Specific examples of the sulfur compound include sulfur chloride, sulfur dichloride, and polymer polysulfide. Sulfur compounds that release active sulfur at the vulcanization temperature and vulcanize such as morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and the like can also be used.

In the present invention, the sulfur or the sulfur compound is ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) and ethylene / 1-butene
Non-conjugated polyene random copolymer rubber (B) total 10
Usually, 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.3 to 3 parts by weight with respect to 0 parts by weight.
Used in parts by weight.

When sulfur or a sulfur compound is used as the vulcanizing agent, it is preferable to use a vulcanization accelerator in combination. Specific examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazolesulfenamide, N-oxydiethylene-2-benzothiazolesulfenamide,
N, N-diisopropyl-2-benzothiazolesulfenamide, 2-mercaptobenzothiazole, 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- (2,6-diethyl-4-morpholinothio) benzothiazole , Thiazole compounds such as dibenzothiazyl disulfide; diphenylguanidine, triphenylguanidine, diornitrile guanidine, orthonitrile biguanide,
Guanidine compounds such as diphenylguanidine phthalate; aldehyde amine and aldehyde-ammonia compounds such as acetaldehyde-aniline reactant, butyraldehyde-aniline condensate, hexamethylenetetramine and acetaldehyde ammonia; imidazoline compounds such as 2-mercaptoimidazoline; thiocarbanilide;
Thiourea compounds such as diethylthiourea, dibutylthiourea, trimethylthiourea and diorthotolylthiourea; tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide and the like Thiuram compounds: zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, tellurium dimethyldithiocarbamate, and the like Dithiocarbamate compounds; xanthate compounds such as zinc dibutylxanthate ; It may include compounds such as zinc oxide (zinc white).

In the present invention, the vulcanization accelerator is selected from ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) and ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B). Usually 0.1 to 20 parts by weight, preferably 0.5 to 15 parts by weight, based on 100 parts by weight in total.
It can be used in a ratio of 1 part by weight, more preferably 1 to 10 parts by weight.

[0059] Examples of the crosslinking agent include organic peroxides. Specific examples of the organic peroxide include dicumyl peroxide, di-t-butyl peroxide,
-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butylcumyl peroxide, di-t-amyl peroxide, t-butylhydroperoxide, 2,5-dimethyl-2,5-di ( t-butylperoxy) hexyne-3,2,5-
Dimethyl-2,5-di (benzoylperoxy) hexane,
Dialkyl peroxides such as 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and α, α'-bis (t-butylperoxy-m-isopropyl) benzene; t-butylperoxy Acetate, t-butyl peroxyisobutyrate, t-butyl peroxypivalate, t-butyl peroxymaleic acid, t-butyl peroxy neodecanoate, t-butyl peroxybenzoate, di-t-butyl perate Peroxyesters such as oxyphthalate; ketone peroxides such as dicyclohexanone peroxide; and mixtures thereof. Among them, an organic peroxide having a temperature giving a half-life of 1 minute in the range of 130 to 200 ° C. is preferable, and in particular, dicumyl peroxide, di-t-butyl peroxide, di-t-butylperoxy-3,3 , 5-Trimethylcyclohexane, t-butylcumyl peroxide, di-t-amyl peroxide, t-
Organic peroxides such as butyl hydroperoxide are preferred.

The organic peroxide is used in a total of 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) and the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B). On the other hand, usually 0.1 ~
It is used in a proportion of 10 parts by weight, preferably 0.5 to 5 parts by weight. When an organic peroxide is used as a crosslinking agent, it is preferable to use a crosslinking assistant together.

Specific examples of such a crosslinking aid include sulfur; quinone dioxime compounds such as p-quinone dioxime; methacrylate compounds such as polyethylene glycol dimethacrylate; diallyl phthalate, triallyl cyanurate and the like. Allyl compound; maleimide compound; divinylbenzene, and the like. Such a crosslinking assistant is used in an amount of 0.5 to 2 mol, preferably about equimolar, based on 1 mol of the organic peroxide used.

As described above, the rubber composition according to the present invention comprises 100 parts by weight of an ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) and ethylene / 1-butene / non-conjugated It comprises 5 to 50 parts by weight of a polyene random copolymer rubber (B) and a softener (C), and has a specific gravity (measurement method: see Example 1) of 1.0 to 1.15, preferably 1 .0
1.10.

In the rubber composition according to the present invention, the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A), the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) and the softening agent In addition to agent (C),
Rubber compounding agent (D), foaming agent (E), and further a foaming aid,
It is preferable that a vulcanizing agent or a crosslinking agent, a vulcanization accelerator or a crosslinking aid is blended.

In the rubber composition according to the present invention, if necessary, a rubber reinforcing agent such as carbon black, an inorganic filler, etc. may be added to the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) and Before blending into the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B), a pseudo-gelling inhibitor may be blended into these rubbers in advance.

Rubber composition and extruded foamed rubber product
Preparation The rubber composition according to the present invention as described above is mixed with an ethylene / α-olefin / non-conjugated polyene random copolymer by an internal mixer (closed mixer) such as a Banbury mixer, a kneader or an intermix. Combined rubber (A), ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B), and softener (C) (for oil extension), and pseudo-gelling inhibitor at a temperature of 80 to 170 ° C After kneading for 2 to 20 minutes, the obtained blend is further mixed with a foaming agent (E), a foaming aid, a vulcanizing agent, a vulcanization accelerator, a crosslinking agent and a rubber compounding agent other than the crosslinking aid (D). (E.g., a rubber reinforcing agent, an inorganic filler), and if necessary, further mixing with a softener (C), kneading at a temperature of 80 to 170 ° C for 2 to 20 minutes, and then a foaming agent (E), and Vulcanizing agent (if necessary Sulfur) For example, the crosslinking agent (e.g. roll, such as an open roll organic peroxide), or by using a kneader, a vulcanization accelerator if necessary,
A crosslinking aid and a foaming aid are additionally mixed, and the roll temperature is 40 to 8
It can be prepared by kneading at 0 ° C. for 5 to 30 minutes and then dispensing.

The rubber composition according to the present invention can be prepared by mixing an ethylene / α-olefin / non-conjugated polyene random copolymer with an internal mixer (closed mixer) such as a Banbury mixer, a kneader or an intermix. Rubber (A), ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) and, if necessary, a pseudo-gelling inhibitor at a temperature of 80 to 170 ° C for 2 to 20
After kneading for minutes, the resulting blend is further added to a foaming agent (E), a foaming aid, a vulcanizing agent, a vulcanization accelerator, a crosslinking agent and a rubber compounding agent (D) other than the crosslinking aid (for example, rubber reinforcement). Agent, inorganic filler), and softener (C),
Kneading at a temperature of 80-170 ° C. for 2-20 minutes, then
Using a blowing agent (E) and, if necessary, a vulcanizing agent (for example, sulfur) and a cross-linking agent (for example, organic peroxide) using rolls such as an open roll, or a kneader, if necessary, promote vulcanization. It can be prepared by additionally mixing an agent, a crosslinking aid, and a foaming aid, kneading the mixture at a roll temperature of 40 to 80 ° C for 5 to 30 minutes, and then dispensing.

The rubber composition according to the present invention prepared as described above is formed into an intended shape by an extruder,
Vulcanization (crosslinking) can be carried out simultaneously with molding or by introducing the molded product into a vulcanization tank. This vulcanization (crosslinking)
It is performed by heating at a temperature of 0 to 270 ° C for 1 to 30 minutes. This vulcanization step is usually carried out continuously.
As a heating method in the vulcanization tank, a heating tank such as hot air, a fluidized bed of glass beads, UHF (ultra-high frequency electromagnetic wave), and steam can be used.

When a vulcanized rubber foam molded article (extruded foamed product) is produced from the rubber composition according to the present invention by the above-described method, uneven heat transmission causes uneven foaming,
The cross-sectional dimensions change in some parts, and the product may not be manufactured. Therefore, in order to finely foam, it is necessary to uniformly transmit heat to the material, and since it is the UHF vulcanization tank that can transmit the heat most efficiently, the UHF vulcanization is performed. A tank is preferably used.

The extruded foamed product according to the present invention can be prepared by vulcanization or crosslinking and foaming as described above, and has a specific gravity of 0.8 to 1.0, preferably 0.8 to 1.0.
It is 1-0.98, more preferably 0.85-0.95. The average foam cell diameter of this product is desirably 400 μm or less.

[0070]

Since the rubber composition according to the present invention has the above-mentioned constitution, it is excellent in extrudability, and has a random ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A).
And light weight solids having excellent product appearance and product cross-sectional shape stability without lowering the inherent rubber properties of the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B), such as glass run channel products;
It is possible to provide an extruded foamed rubber product suitable for use as a sealing component such as a window frame product and a trunk.

Since the extruded foamed rubber product according to the present invention is obtained by extrusion-molding the rubber composition according to the present invention, the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) and Ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) has been reduced in weight without lowering its inherent rubber physical properties,
Moreover, it is excellent in product appearance and product sectional shape stability.

[0072]

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. The ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) used in Examples and Comparative Examples,
The ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) and the foaming agent (E) are as follows. Ethylene, α-olefin and non-conjugated polyene random
Polymer rubber (A) Ethylene / propylene / 5-ethylidene-2-norbornene random copolymer rubber (EPT); ethylene content = 65 mol% propylene content = 30 mol% 5-ethylidene-2-norbornene (ENB) content = 5.0
Mol% Mooney viscosity [ML (1 + 4) 100 ° C] = 120 ethylene / 1-butene / non-conjugated polyene random copolymer
Rubber (B) Ethylene / 1-butene / 5-ethylidene-2-norbornene random copolymer rubber (EBT); ethylene content = 80 mol% 1-butene content = 11.5 mol% ENB content = 8.5 mol% Mooney viscosity [ML (1 + 4) 100 ° C] = 20 Foaming agent (E) (1) Foaming agent (E-1); trade name Neoservon N #
1000SW, manufactured by Eiwa Kasei Co., Ltd. (2) Foaming agent (E-2); trade name: Neocelbon N #
1000M, manufactured by Eiwa Chemical Co., Ltd.

[0073]

Example 1 A softener (Y _blank ) [manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process Oil ^™ PW-] was added to 100 parts by weight of ethylene / propylene / 5-vinyl-2-norbornene random copolymer rubber (EPT). 380], and 151 parts by weight of an oil-extended rubber, and ethylene / 1-butene / 5-vinyl-2-norbornene random copolymer rubber (EBT)
20 parts by weight and an additional softener (YY _blank ) [Diana Process Oil ^™ PW-3 manufactured by Idemitsu Kosan Co., Ltd.]
80] 19 parts by weight and carbon black [trade name Asahi #
60G, manufactured by Asahi Carbon Co., Ltd.] 130 parts by weight, Zinc Hua No. 1 5 parts by weight, stearic acid 1 part by weight, and a dehydrating agent [trade name: Vesta #PP, calcium carbonate manufactured by Inoue Lime Industry Co., Ltd.] 4 parts by weight and 2 parts by weight of a surfactant [Arkard 2HT-F, manufactured by Lion Corporation] in a volume of 1
The mixture was kneaded at 152 ° C. with a 6 liter Banbury mixer [manufactured by Kobe Steel Ltd.].

The kneading method is as follows.
A softener 51 is added to 100 parts by weight of ethylene / propylene / 5-vinyl-2-norbornene random copolymer rubber (EPT).
151 parts by weight of rubber oil-extended by weight and ethylene 1-
50 parts by weight of butene-5-vinyl-2-norbornene random copolymer rubber (EBT) are masticated for 30 seconds, then 5 parts by weight of Zinc Hua No. 1, 1 part by weight of stearic acid, 4 parts by weight of dehydrating agent, softening 19 parts by weight of a surfactant and 2 parts by weight of a surfactant, and finally 130 parts by weight of carbon black were added.
Kneaded for minutes and discharged. The temperature of the rubber compound (I) after discharging was 165 ° C. This kneading has a filling rate of 7
Performed at 5%.

Next, 8 was added to this rubber compound (I).
Wrapping around an inch roll (surface temperature of front roll: 50 ° C., surface temperature of rear roll: 50 ° C., rotation speed of front roll: 16 rpm, rotation speed of rear roll: 18 rpm), mercaptobenzothiazole [vulcanization accelerator; M, manufactured by Sanshin Chemical Industry Co., Ltd.], 1.5 parts by weight, dibenzothiazyl disulfide [vulcanization accelerator; trade name: Suncellar DM,
0.5 parts by weight, zinc-di-n-butyldithiocarbamate [vulcanization accelerator; trade name Suncellor BZ, manufactured by Sanshin Chemical Industry Co., Ltd.], 2.0 parts by weight, ethylenethio 1.0 part by weight of urea [vulcanization accelerator; trade name: Suncellar 22C, manufactured by Sanshin Chemical Industry Co., Ltd.]; dithiodimorpholine [vulcanizing agent: trade name: Sanfel R, manufactured by Sanshin Chemical Industry Co., Ltd.] 0 0.5 parts by weight, insoluble sulfur (vulcanizing agent)
5 parts by weight, OBSH-based foaming agent
# 1000M, manufactured by Eiwa Chemical Co., Ltd .; (E-2)] 0.2
The resulting mixture was kneaded for 7 minutes at a roll temperature of 60 ° C. using a 14-inch open roll [manufactured by Nippon Roll Co., Ltd.], and a rubber composition cut out of the roll into a ribbon was obtained. Specific gravity of the obtained rubber composition (JIS K622
0) was 1.13.

Next, the above rubber composition containing the foaming agent was extruded into a tube shape by an extruder, and a microwave vulcanizing tank (UHF) and a hot air vulcanizing tank (HAV) were connected in series. Sent to the molding line for vulcanization and foaming,
A tube-shaped vulcanized rubber foam having a thickness of 2 mm was obtained. The resulting foam, in accordance with JIS K6251, measurement temperature 23 ° C., subjected to tensile test at a tensile rate of 500 mm / min condition was measured tensile breaking strength T _B and elongation E _B. Table 1 shows the results.

At this time, assuming that the extruder head temperature is 80 ° C.,
The temperature of the UHF vulcanization tank was 200 ° C., and the microwave output was adjusted so that the UHF outlet temperature was 180 ° C. And the said rubber composition passed through the above-mentioned extruder and the UHF vulcanization tank, and was hot-air vulcanized to obtain a tubular, slightly foamed solid rubber. From the obtained tubular fine solid rubber, 2
A test piece of 0 mm × 20 mm was punched out, and dirt on the surface was wiped off with alcohol. Then, the test piece was placed at 25 ° C.
Under the atmosphere, an automatic hydrometer [Made by Toyo Seiki Seisakusho, M
-1 type], the specific gravity was measured from the mass difference between air and pure, and the specific gravity SG of sponge (product specific gravity in Table 1) was calculated. Table 1 shows the results.

The tubular microfoamed solid rubber obtained by hot air vulcanization in the same manner as described above was cut into a length of 30 mm and attached to a jig for measuring compression set. The specimen was compressed so that the height became half of the height before applying the load, and the jig was put into a 70 ° C. gear oven together with the jig.
Heat treated for hours. Then, the test piece was taken out of the compression device, allowed to cool for 30 minutes, the height of the test piece was measured, and the compression set was calculated by the following formula. The result is
It is shown in the table.

Compression set [%] = [(t ₀ −t ₁ ) / (t
_0- t ₂ ) ”× 100 t ₀ ; height of test piece before test t ₁ ; height of test piece after heat treatment of test piece and cooling after 30 minutes t ₂ ; test piece for measurement The height of the test piece attached to the fixture The tubular sponge rubber obtained by vulcanizing with hot air in the same manner as above was cut to a length of 30 mm, illuminated with a 60 W light bulb from above, and the surface gloss was reduced. The product skin was evaluated visually (sensory test) from the appearing angle by the following five-point scale. Table 1 shows the results.

<Scoring of Product Skin> 5 points: The gloss is strong and the flat surface is smooth. 3 points: Despite the gloss, the surface is slightly uneven. 1 point: No gloss and uneven surface. In addition, four points are in the state between 5 points and 3 points, and 2 points are in the state between 3 points and 1 point.

[0081]

Example 2 In Example 1, an ethylene / propylene / 5-vinyl-2-norbornene random copolymer rubber (E
(PT) 100 parts by weight of a softening agent [Diana Process Oil ^TM PW-380, manufactured by Idemitsu Kosan Co., Ltd.] 51 parts by weight Instead of 151 parts by weight of oil-extended rubber, ethylene / propylene / 5-vinyl-2 was used. -Softening agent [Idemitsu Kosan Co., Ltd.] in 100 parts by weight of norbornene random copolymer rubber (EPT)
Product name, Diana Process Oil ^TM PW-380]
Using 141 parts by weight of rubber with 41 parts by weight of EB
Example 1 was repeated except that the amounts of T, carbon black and additional softener were changed to 40 parts by weight, 120 parts by weight and 38 parts by weight, respectively. The results are shown in Table 1.

[0082]

Example 3 In Example 1, an ethylene / propylene / 5-vinyl-2-norbornene random copolymer rubber (E
(PT) 100 parts by weight of a softening agent [Diana Process Oil ^TM PW-380, manufactured by Idemitsu Kosan Co., Ltd.] 51 parts by weight Instead of 151 parts by weight of oil-extended rubber, ethylene / propylene / 5-vinyl-2 was used. -Softening agent [Idemitsu Kosan Co., Ltd.] in 100 parts by weight of norbornene random copolymer rubber (EPT)
Product name, Diana Process Oil ^TM PW-380]
Using 41 parts by weight of rubber oil-extended as EBT
And the additional softener in an amount of 40 parts by weight,
It was changed to 8 parts by weight, Si-69 [trade name as a pseudo antigelling agent in place of carbon black 130 parts by weight; Degussa Huels _{Ltd., (H 5 C 2 O)} 3 Si- (CH 2) _{3-
S 4 - (CH 2) 3} -Si (OC 2 H 5) 3] except for using carbon black 120 parts by weight were easily mixed with 0.5 parts by weight, it was carried out in the same manner as in Example 1. The results are shown in Table 1.

[0083]

Example 4 In Example 1, the ethylene / propylene / 5-vinyl-2-norbornene random copolymer rubber (E
(PT) 100 parts by weight of a softening agent [Diana Process Oil ^TM PW-380, manufactured by Idemitsu Kosan Co., Ltd.] 51 parts by weight Instead of 151 parts by weight of oil-extended rubber, ethylene / propylene / 5-vinyl-2 was used. -Softening agent [Idemitsu Kosan Co., Ltd.] in 100 parts by weight of norbornene random copolymer rubber (EPT)
Product name, Diana Process Oil ^TM PW-380]
Using 141 parts by weight of rubber with 41 parts by weight of EB
The amounts of T, carbon black and the additional softener were changed to 40 parts by weight, 120 parts by weight and 38 parts by weight, respectively, and instead of 0.2 parts by weight of the blowing agent (E-2), the blowing agent (E-1) was used. ) The same procedure was performed as in Example 1 except that 0.2 parts by weight was used. The results are shown in Table 1.

[0084]

Comparative Example 1 In Example 1, the amounts of EBT, carbon black, additional softener and foaming agent (E-2) were reduced to 0, 140, 0, and 0.3 parts by weight, respectively. Except having changed, it carried out similarly to Example 1. The results are shown in Table 1.

[0085]

Comparative Example 2 In Example 1, the amounts of EBT, additional softener and foaming agent (E-2) were each 0 parts by weight,
The same procedure as in Example 1 was carried out except that the parts were changed to 0 parts by weight and 0.3 parts by weight. The results are shown in Table 1.

[0086]

Comparative Example 3 In Example 1, an ethylene / propylene / 5-vinyl-2-norbornene random copolymer rubber (E
(PT) 100 parts by weight of a softening agent [Diana Process Oil ^TM PW-380, manufactured by Idemitsu Kosan Co., Ltd.] 51 parts by weight Instead of 151 parts by weight of oil-extended rubber, ethylene / propylene / 5-vinyl-2 was used. -Softening agent [Idemitsu Kosan Co., Ltd.] in 100 parts by weight of norbornene random copolymer rubber (EPT)
Product name, Diana Process Oil ^TM PW-380]
Using 141 parts by weight of rubber with 41 parts by weight of EB
Example 1 was repeated except that the amounts of T, carbon black and the additional softener were changed to 0 parts by weight, 120 parts by weight, and 0 parts by weight, respectively. The results are shown in Table 1.

In Examples 1-4, Y _blank
The amount of the softener (oil) (C) corresponding to the above is oil-extended in the rubber (A) manufacturing process, and the amount of the oil (C) corresponding to YY _blank is additionally blended in the rubber composition manufacturing process. But
It is not necessary to add the oil (C) by such a method, and the amount of the oil (C) that satisfies the formula (1) as a whole
Is sufficient to realize the effects of the present invention.

[0088]

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // (C08L 23/16 (C08L 23/16 23:08 23:08 91:00) 91:00) ( 72) Inventor Masaaki Kawasaki 3 Chigusa Beach, Ichihara City, Chiba Prefecture Mitsui Chemicals, Inc.In-house F-term (reference) 3D024 AA17 AA18 AB33 AB57 4F070 AA13 AA16 AB11 AB16 AC32 AC40 AC74 AC75 AC94 AC95 AE01 AE02 AE12 FA01 FA17 FB03 FB04 FB05 FC02 4F074 AA07 AA25 AA98 AC02 AD09 AD17 AG01 AG02 BA02 BA12 BB01 BB02 BB06 BB07 BC01 CA22 CC04Y CC06Y CC46 CC55 DA23 DA33 DA35 DA39 4J002 AE003 AE043 AE053 AG003 BB021 BB051 BB052 BB1330 EB133 EB133 037 EG ES007 ET007 EU117 EV117 EV127 EV137 EV167 EV277 EV287 EV347 EX038 EX078 EX088 FD010 FD023 FD026 FD147 FD327 GJ02 GL00 GN00

Claims (11)

[Claims] (1) ethylene and α having 3 to 5 carbon atoms.
-Ethylene obtained by copolymerizing at least one α-olefin selected from olefins with a non-conjugated polyene;
100 parts by weight of α-olefin / non-conjugated polyene random copolymer rubber (A), 5 to 50 parts by weight of ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B), and a softener (oil) ( C), wherein the specific gravity of the rubber composition is 1.0 to 1.15. 2. The rubber composition according to claim 1, wherein the softener (oil) (C) is compounded in an amount satisfying the following relational expression (1): YY _blank. ≧ 0.4 × X (1) [In the formula (1), Y is a softener based on 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) in the rubber composition. (Oil) (C)
Y _blank is a rubber composition which does not contain the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) and the amount of the softener (oil) (C) added is only the rubber composition And a rubber composition (1 _blank ) in which the hardness of the obtained cross-linked molded article is the same as that of the cross-linked molded article obtained from the rubber composition. X is the blending amount of the softener (oil) (C) with respect to 100 parts by weight of the polymer rubber (A), and X is the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A) 100 in the rubber composition.
It is a blend amount of the ethylene / 1-butene / non-conjugated polyene random copolymer rubber (B) with respect to parts by weight. ]. 3. The method according to claim 1, wherein all or a part of the softener (C) is oil-extended in the step of producing the ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A). The rubber composition according to claim 2. 4. The rubber composition according to claim 2, wherein all or a part of the softener (C) is kneaded in the kneading step of the rubber composition. 5. The rubber composition according to claim 1, further comprising a foaming agent (E) and / or a vulcanizing agent. 6. The foaming agent (E) is an ethylene / α-olefin / non-conjugated polyene random copolymer rubber (A)
The rubber composition according to claim 5, wherein the rubber composition is contained in an amount of 0.05 to 5 parts by weight based on 00 parts by weight. 7. Further, the following general formula [1] or [2]
The rubber composition according to any one of claims 1 to 6, further comprising an alkoxysilane compound represented by the formula: [In the formula [1], R is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and R ¹ is an alkyl group having 1 to 4 carbon atoms or a phenyl group. , n is 0, 1 or 2, R ² is the number of carbon atoms is 1 to 6, a divalent linear or branched hydrocarbon group, R ³ has a number of carbon atoms 6 to 12 are an arylene group, m and p are each 0 or 1, and m and p are not simultaneously 0, q is 1 or 2, B is q When it is 1, it is -SCN or -SH;
When q is 2, it is -Sx- (where x is an integer of 2 to 8). [In the formula [2], R is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and R ¹ is an alkyl group having 1 to 4 carbon atoms or a phenyl group. , N is 0, 1 or 2, and R ⁴ is a monovalent linear or branched unsaturated hydrocarbon group having 2 to 20 carbon atoms]. 8. An extruded foamed rubber product obtained by extrusion foaming the rubber composition according to any one of claims 1 to 7. 9. The extruded foamed rubber product has a specific gravity of 0.8 to 0.8.
The extruded foamed rubber product according to claim 8, wherein the ratio is 1.0. 10. The extruded foamed rubber product according to claim 8, wherein an average foamed cell diameter of the extruded foamed rubber product is 400 μm or less. 11. The extruded foamed rubber product according to claim 8, wherein the extruded foamed rubber product is a seal part.