JP5626797B2 - Rubber composition and rubber molded article containing low-viscosity ethylene copolymer - Google Patents

Description

  The present invention relates to a rubber composition containing a reactive plasticizer capable of imparting good moldability and physical properties without being extracted with oil. More specifically, the present invention relates to a rubber composition containing a low-viscosity ethylene-based copolymer having excellent crosslinking reactivity and physical properties and exhibiting a sufficient plasticizing effect, and a rubber molded product obtained therefrom.

  Ethylene / α-olefin copolymer rubber and ethylene / α-olefin / non-conjugated polyene copolymer rubber do not have unsaturated bonds in the main chain, so they have better weather resistance and heat resistance than conjugated diene rubbers. Excellent ozone resistance.

  Therefore, a rubber composition containing these copolymer rubbers, a crosslinked product of the composition, and a foamed product of the composition, using the above-mentioned properties, are used for automobile industrial parts, industrial rubber products, electrical insulating materials, Widely used in civil engineering materials and rubber products such as rubberized fabric.

  In particular, in ethylene / α-olefin / non-conjugated polyene copolymer rubber, double bonds derived from non-conjugated polyene can participate in the cross-linking reaction, and the cross-linking reaction results in better strength and rubber elasticity in rubber products. Widely used because it can be achieved.

Various catalysts have been proposed as catalysts capable of obtaining such an ethylene / α-olefin / non-conjugated polyene copolymer rubber (see, for example, Patent Document 1).
Conventionally, a Ziegler-Natta catalyst has been used as a catalyst for polymerization. Research on the catalyst has progressed, and a metallocene catalyst that is a single-site catalyst as proposed in Patent Document 1 has been developed, and it has become possible to synthesize polymers with extremely high stereoregularity.

This makes it possible to produce a polymer more suitable for rubber products, for example, having higher strength.
By the way, when manufacturing a rubber molded product, the rubber itself is required to have a certain fluidity and moldability. The conventional copolymer rubber described above needs to have a high molecular weight in order to obtain a certain mechanical strength and rubber elasticity, and generally does not have the fluidity and molding processability. Therefore, the fluidity and molding processability of the rubber during molding have been improved by blending the copolymer rubber with mineral oil such as paraffin oil as a plasticizer.

  For example, when the molded product is the automobile part, particularly a brake part, the part is in contact with oil (brake oil or the like), and therefore, a part of the copolymer rubber or the plasticizer is contained in the oil from the part. It must not be extracted or vice versa. However, due to the nature of the plasticizer, bleeding of the mineral oil from the copolymer rubber constituting the part is inevitable, and therefore a certain amount of extraction of the plasticizer into the oil (brake oil, etc.) is avoided. Absent. This leads to quality deterioration of the oil and the parts.

Therefore, a plasticizer that does not cause such a problem is desired, and research on a polymer material that can replace the mineral oil has been widely conducted.
For example, the molecular weight of the above-described ethylene / α-olefin / non-conjugated polyene copolymer is lowered to such an extent that it can be used as a plasticizer. The plasticizer thus obtained is blended with the rubber and molded, followed by a crosslinking reaction using unsaturated bonds derived from non-conjugated polyene (crosslinking reaction between plasticizers and between plasticizer and rubber). ), The plasticizer can be firmly fixed in the molded product. This avoids the problem of extraction into the oil.

Examples of such an ethylene / α-olefin / non-conjugated polyene copolymer type plasticizer include the plasticizer disclosed in Non-Patent Document 1.
However, this plasticizer is considered to be manufactured based on the conventional catalyst, and it takes a lot of time and energy for the catalyst washing process, so the manufacturing cost is high, and it contains many impurities such as chlorine and is colored. Furthermore, there is a problem that the stickiness is severe due to the non-uniform molecular structure.

  Patent Document 2 discloses a rubber composition using a copolymer rubber having an intrinsic viscosity of 0.4 to 1.6 dl / g. Patent Document 2 describes that the composition is suitable for automobile parts and the like.

  However, in the specification of the document, there is no description on how to produce such a low intrinsic viscosity copolymer rubber, and in the examples, it is described that a rubber having an intrinsic viscosity in the above range was used. It is only done. There is no description of how the rubber was manufactured, and even if it is a commercial product, no product name or even manufacturer name is shown. From such a description, it cannot be recognized that the copolymer rubber related to the invention claimed in Patent Document 2 is actually produced and used in Patent Document 2, and such a copolymer rubber is disclosed in Patent Document 2 cannot be said to be substantially disclosed.

  Further, Patent Document 3 discloses a low molecular weight ethylene / α-olefin / (optionally) non-conjugated polyene copolymer useful as an epoxy-grafted electrical circuit element encapsulating composition.

  The number average molecular weight of the copolymer is about 250 to about 20,000, and the intrinsic viscosity measured at 135 ° C. in tetralin of such a copolymer is about 0.025 to about 0.6 dl / g. 3 is described. Further, Patent Document 3 describes that the copolymer can be produced using a so-called metallocene catalyst and an aluminoxane cocatalyst.

  However, in Patent Document 3, a copolymer containing non-conjugated polyene as a monomer component is not produced at all, and the significance of using the catalyst is that the produced copolymer exhibits vinylidene unsaturation. Is only described.

JP-T-2001-522398 JP 2002-80662 A JP-A-62-95304

RUBBER WORLD, Volume 198, No. 3, pages 8, 11 (1988)

  An object of this invention is to provide the rubber composition containing the novel material which can be used as a useful reactive plasticizer which eliminated the problem of the prior art shown above.

  As a result of intensive studies to solve the above problems, the present inventors have found that the rubber composition containing the following low-viscosity ethylene copolymer and high-viscosity ethylene copolymer satisfying certain requirements is the above-mentioned The present inventors have found that the problems can be solved and have completed the present invention.

That is, the rubber composition of the present invention comprises 5 to 50 parts by weight of a low-viscosity ethylene copolymer (L) and 95 to 50 parts by weight of a high-viscosity ethylene copolymer (H) [provided that the copolymer (L) And the weight of the copolymer (H) is 100 parts by weight], and a cross-linking agent,
The low-viscosity ethylene copolymer (L) is an ethylene containing structural units derived from ethylene [A], an α-olefin [B] having 3 to 20 carbon atoms, and at least one non-conjugated polyene [C]. A copolymer,
(1) The structural unit derived from ethylene [A] is contained in 50 to 90 mol% in 100 mol% of all the structural units of the copolymer (L),
(2) The structural unit derived from the non-conjugated polyene [C] is contained in an amount of 1.0 to 5.0 mol% in 100 mol% of all the structural units of the copolymer (L),
(3) The intrinsic viscosity [η] measured in a decalin solution at 135 ° C. of the copolymer (L) is 0.25 to 0.55 dL / g,
(4) The inversion value represented by the following formula [I] of the copolymer (L) is 0.01 to 0.50:

数式［Ｉ］において、βγは、前記共重合体の主鎖を構成する任意のメチレン炭素に着目したとき、当該炭素から２ボンド離れた箇所及び反対側の３ボンド離れた箇所にメチン炭素が存在するメチレン炭素の¹³Ｃ−ＮＭＲピークの積分値の合計を示し、ββは、主鎖を構成する任意のメチレン炭素に着目したとき、当該炭素から２ボンド離れた両側にメチン炭素が存在するメチレン炭素の¹³Ｃ−ＮＭＲピークの積分値の合計を示し、
前記高粘度エチレン系共重合体（Ｈ）は、エチレン［Ａ’］、炭素原子数３〜２０のα−オレフィン［Ｂ’］、および少なくとも一種の非共役ポリエン［Ｃ’］に由来する構造単位を含むエチレン系共重合体であって、
（１’）前記エチレン［Ａ’］に由来する構造単位が、前記共重合体（Ｈ）の全構造単位１００モル％中、５０〜９０モル％含まれ、
（２’）前記非共役ポリエン［Ｃ’］に由来する構造単位が、前記共重合体（Ｈ）の全構造単位１００モル％中、０．５〜５．０モル％含まれ、
（３’）前記共重合体（Ｈ）の１３５℃のデカリン溶液中で測定した極限粘度[η]が、１．０〜５．０ｄＬ／ｇである、ゴム組成物である。

In Formula [I], βγ is a methine carbon present at a position 2 bonds away from the carbon and a position 3 bonds away from the opposite carbon when focusing on any methylene carbon constituting the main chain of the copolymer. Is the total integrated value of ¹³ C-NMR peaks of methylene carbon, and ββ is a methylene carbon in which methine carbon exists on both sides two bonds away from the carbon when focusing on any methylene carbon constituting the main chain Shows the sum of the integrated values of the ¹³ C-NMR peaks of
The high-viscosity ethylene copolymer (H) is a structural unit derived from ethylene [A ′], an α-olefin [B ′] having 3 to 20 carbon atoms, and at least one non-conjugated polyene [C ′]. An ethylene copolymer comprising
(1 ′) The structural unit derived from ethylene [A ′] is contained in an amount of 50 to 90 mol% in 100 mol% of all the structural units of the copolymer (H).
(2 ′) The structural unit derived from the non-conjugated polyene [C ′] is included in an amount of 0.5 to 5.0 mol% in 100 mol% of all the structural units of the copolymer (H).
(3 ′) A rubber composition having an intrinsic viscosity [η] measured in a decalin solution at 135 ° C. of the copolymer (H) of 1.0 to 5.0 dL / g.

  The intrinsic viscosity [η] measured in a 135 ° C. decalin solution of the low viscosity ethylene copolymer (L) is preferably 0.30 to 0.50 dL / g, and is derived from the ethylene [A]. The structural unit is preferably contained in an amount of 55 to 85 mol% in 100 mol% of all the structural units of the ethylene copolymer (L). As the nonconjugated polyene [C], 5-ethylidene-2- Norbornene (ENB) is preferred.

Moreover, it is preferable that the inversion value of the said low-viscosity ethylene-type copolymer (L) is 0.03-0.30.
By molding such a rubber composition of the present invention, a rubber molded article in which the problems associated with the above prior art are solved can be obtained. More specifically, the rubber molded article is obtained by performing crosslinking at the same time as or after molding the rubber composition.

  According to the present invention, there is provided a rubber composition that is excellent in fluidity and molding processability, has no coloring / stickiness of the reactive plasticizer as a component, and can provide a rubber molded product with very little extraction with oil. Provided.

Hereinafter, the present invention will be described in detail in the order of a rubber composition and a rubber molded product obtained therefrom.
[Rubber composition]
The rubber composition of the present invention is characterized by containing a specific low-viscosity ethylene copolymer (L), a specific high-viscosity ethylene copolymer (H), and a crosslinking agent. Hereinafter, each of these components will be described.

[Low viscosity ethylene copolymer (L)]
The low-viscosity ethylene copolymer (L) includes a structural unit derived from ethylene [A], a structural unit derived from an α-olefin [B] having 3 to 20 carbon atoms, and at least one non-conjugated polyene [C]. Including structural units derived from Hereinafter, each of these monomer components will be described.

<[A] ethylene>
The structural unit derived from ethylene [A] is a rubber molded product obtained from the rubber composition of the present invention containing a low-viscosity ethylene-based copolymer (L) (hereinafter also simply referred to as “copolymer (L)”). Gives low temperature impact resistance and excellent mechanical strength.

  Such a structural unit derived from ethylene [A] is contained in an amount of 50 to 90 mol%, preferably 55, in 100 mol% of all structural units of the copolymer (L) from the viewpoint of exerting its function. -85 mol% is contained, More preferably, it is contained 55-83 mol%.

Moreover, the ratio of the structural unit derived from ethylene [A] in all the structural units of the copolymer (L) can be measured by various known methods, for example, by measuring ¹ H-NMR spectrum. The percentage can be determined.

<[B] α-olefin having 3 to 20 carbon atoms>
A structural unit derived from an α-olefin [B] having 3 to 20 carbon atoms (hereinafter also simply referred to as “α-olefin [B]”) is flexible (low crystallinity) to the low-viscosity ethylene copolymer (L). )give.

  The number of carbon atoms of the α-olefin [B] is from the viewpoint of raw material cost, mechanical properties of the copolymer (L), and rubber elasticity of a molded product obtained from the rubber composition containing the copolymer (L) described later. , Preferably 3-8.

  Examples of such α-olefin [B] are propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-decene, Examples include dodecene, 1-tetradecene, 1-hexadecene, and 1-eicocene. Among these, propylene, 1-butene, 1-hexene and 1-octene are preferable.

The α-olefin [B] described above may be used alone or in combination of two or more.
In addition, the structural unit derived from the α-olefin [B] is obtained from the copolymer (L) in terms of the flexibility of the rubber composition of the present invention and the low temperature impact resistance of the rubber molded product obtained from the composition. In 100 mol% of all structural units, it is usually contained 9 to 49 mol%, preferably 14 to 44 mol%.

The ratio of the structural unit derived from the α-olefin [B] in the total structural unit of the copolymer (L) can be measured by various known methods, for example, by measuring ¹ H-NMR spectrum. The percentage can be determined.

<[C] at least one non-conjugated polyene>
A structural unit derived from at least one non-conjugated polyene [C] (hereinafter also simply referred to as “non-conjugated polyene [C]”) imparts crosslinking reactivity to the low-viscosity ethylene-based copolymer (L).

  The non-conjugated polyene [C] is not particularly limited as long as it has two or more polymerizable double bonds (usually 4 or less) and the double bonds are not conjugated to each other. A non-conjugated diene having 5 to 20 carbon atoms is preferable, and a non-conjugated diene having 5 to 15 carbon atoms is more preferable.

  Examples of such non-conjugated dienes include 5-ethylidene-2-norbornene (ENB), dicyclopentadiene, 5-vinyl-2-norbornene (VNB), norbornadiene and methyltetrahydroindene as cyclic nonconjugated dienes. Examples of the non-conjugated diene include 1,4-hexadiene and 7-methyl-1,6-octadiene.

  Among these, 5-ethylidene-2-norbornene (ENB), dicyclopentadiene and 5-vinyl-2-norbornene (VNB) are preferably used, and 5-ethylidene-2-norbornene (ENB) is particularly preferably used.

The non-conjugated polyene [C] described above may be used alone or in combination of two or more.
Further, the structural unit derived from the non-conjugated polyene [C] is contained in an amount of 1.0 to 5.0 mol% in 100 mol% of all the structural units of the copolymer (L) from the viewpoint of crosslinking reactivity. , Preferably 1.0 to 4.0 mol%, more preferably 1.0 to 3.5 mol%.

The proportion of structural units derived from non-conjugated polyene [C] in all structural units of copolymer (L) can be measured by various known methods, for example, by measuring ¹ H-NMR spectrum. The percentage can be determined.

<Low viscosity ethylene copolymer (L)>
The low-viscosity ethylene-based copolymer (L) includes structural units derived from the above-described ethylene [A], α-olefin [B], and nonconjugated polyene “C”, and the ethylene [A] and nonconjugated The content of structural units derived from polyene [C] is in a certain range. Hereinafter, the characteristics of the copolymer (L) will be described.

(Intrinsic viscosity [η])
The intrinsic viscosity [η] measured in a 135 ° C. decalin solution of the low viscosity ethylene copolymer (L) is very low as 0.25 to 0.55 dL / g, and the copolymer (L) is described later. It is useful as a reactive plasticizer that gives excellent fluidity and moldability to the high-viscosity ethylene copolymer (H). In addition, when the intrinsic viscosity is less than 0.25 dL / g, sufficient crosslinking reactivity is not exhibited. On the other hand, when the intrinsic viscosity is more than 0.55 dL / g, excellent fluidity and molding processability cannot be imparted.

  The intrinsic viscosity [η] is preferably 0.25 to 0.50 dL / g, more preferably 0.30 to 0.50 dL / g, and still more preferably 0.30 from the viewpoints of crosslinking reactivity and fluidity. ~ 0.49 dL / g.

  Conventionally, it has been difficult to put a unit derived from a non-conjugated polyene as a structural unit in a polymer having a low molecular weight (that is, low intrinsic viscosity) as used in a plasticizer. This is because in the Ziegler-Natta catalyst, the active species of the catalyst is not uniform and the non-conjugated polyene is not uniformly polymerized under the reaction conditions for polymerizing the low molecular weight polymer, resulting in a bias.

  Furthermore, the structural unit derived from the diene body, which is a typical non-conjugated polyene, has a free double bond as a side chain of the polymer, but its crosslinking reactivity is not so good. Therefore, in order to ensure a sufficient crosslinking reaction, it is necessary to put a certain amount or more of non-conjugated polyene in the polymer.

  In order to realize this, in Non-Patent Document 1, a polymer is produced by reacting a relatively large amount of non-conjugated polyene. Furthermore, since the polymer production method requires a step of removing the catalyst, a long-time washing process and a heat treatment are necessary, and impurities remaining in the polymer (for example, chlorine) and discoloration become a problem.

  The present inventors eliminated the catalyst removal step by using a specific metallocene catalyst, and carried out a copolymerization reaction so that the non-conjugated polyene was sufficiently taken in, and had an intrinsic viscosity enough to have sufficient fluidity. It has been found that low (ie low molecular weight) copolymers can be produced.

  The low-viscosity ethylene copolymer (L) is produced by such a one-step reaction and by using a metallocene catalyst that can produce a copolymer having a small molecular weight distribution. There is no problem of coloring and sticking that the ethylene / α-olefin / nonconjugated polyene copolymer described in Non-Patent Document 1 described in [Background Art] has. It is also excellent in terms of manufacturing cost.

(Inversion value)
The low-viscosity ethylene-based copolymer (L) is characterized in that the inversion value represented by the following formula [I] is in a small range of 0.01 to 0.50.

例えば重合成長中の鎖にプロピレンが重合して取り込まれる場合、成長末端の炭素とプロピレンの１位の炭素とが結合する場合と、成長末端の炭素とプロピレンの２位の炭素とが結合する場合の２通りが考えられる。

For example, when propylene is polymerized and incorporated into the chain during polymerization growth, the growth end carbon and the 1st carbon of propylene are bonded, and the growth end carbon and the 2nd carbon of propylene are bonded There are two possible ways.

  Here, due to the problem of steric hindrance and the characteristics of the catalyst (metallocene catalyst) used for the polymerization, the former, that is, the carbon at the growth end and the carbon at the 1st position of propylene are bonded. The latter occurs with a certain probability. This is called inversion, and the inversion value indicates the degree of occurrence of this inversion.

  In order to obtain the inversion value, attention is paid to the main chain constituting the copolymer of the present invention. Since the α-olefin [B] and the non-conjugated polyene [C] are incorporated in the copolymer, there are branches extending from the main chain, and the main chain constituting carbon to which the branched chain is bonded is methine. Carbon.

  Here, when attention is paid to the methylene carbon constituting the main chain, the methine carbon is present at a position adjacent to or further away from the methylene carbon. When there is methine carbon in the adjacent location, that is, 1 bond away, β, when methine carbon is present at 2 bonds away with one methylene carbon in between, and similarly 3 bonds away Is expressed as γ when 4 bonds are separated, and σ when separated by 5 bonds or more.

  Then, since the methine carbon exists on both sides of the methylene carbon of interest, for example, when a methine carbon exists at a location 2 bonds away from a certain methylene carbon and a location 3 bonds away from the opposite side, the methylene carbon is defined as βγ. write.

Examples of how each methylene carbon can be expressed using the above α to σ depending on whether there is no inversion or not are shown below.
・ If there is no inversion

・インバージョン（α−オレフィンの２，１−挿入）が有る場合

・ Inversion (2,1-insertion of α-olefin)

以上より、αβ、αδおよびβγは、インバージョンが生じた箇所に認められるメチレン炭素であり、そのような炭素は、インバージョンが起こらない箇所では認められない。前記３種のメチレン炭素のうち、βγのメチレン炭素は、¹³Ｃ−ＮＭＲによる測定で、簡便に測定できる（２７．５ｐｐｍ近傍のシングルピーク）。

From the above, αβ, αδ, and βγ are methylene carbons that are found at the places where inversion occurs, and such carbons are not found where no inversion occurs. Of the three types of methylene carbon, βγ methylene carbon can be easily measured by ¹³ C-NMR measurement (single peak in the vicinity of 27.5 ppm).

On the other hand, αα, αγ, ββ, βδ, and ασ are methylene carbons that are found in places where inversion does not occur, and such carbons are not found in places where inversion occurs. Among the five types of methylene carbon, the ββ methylene carbon can be easily measured by ³ C-NMR similarly to βγ (doublet peak in the vicinity of 24 to 25 ppm).

  Therefore, the ratio (βγ / ββ) of the total integrated value of βγ methylene carbon signal peaks and the total integrated value of ββ methylene carbon signal peaks is an indicator (inversion) Value).

  On the other hand, a peak counted as an inversion can also be generated from non-conjugated polyene [C], but in the present invention, the copolymerization amount of non-conjugated polyene [C] is as small as 1.0 to 5.0 mol%. Therefore, it shall not be included in the calculation of the inversion value.

For the above inversion calculation, Anal. Chem. 2004, 76, 5734-5747 of Seger, MR and Maciel, GE can be referred to.
The ¹³ C-NMR measurement for determining the inversion value is performed using, for example, an ECX400P type nuclear magnetic resonance apparatus (manufactured by JEOL), measurement temperature: 120 ° C., measurement solvent: orthodichlorobenzene / deuterated benzene. = 4/1, number of integrations: 8000 times.

  As described above, the low-viscosity ethylene copolymer (L) has an inversion value represented by the formula [I] in a small range of 0.01 to 0.50. The copolymer (L) having such an inversion value in the above-mentioned small range has a very uniform molecular structure, and a non-conjugated diene that gives crosslinking reactivity is efficiently introduced into the molecular chain. It is considered a thing. From the viewpoint of the uniformity of the molecular structure, the inversion value is preferably 0.03 to 0.30, more preferably 0.03 to 0.20.

(density)
From the viewpoint of flexibility, the low viscosity ethylene copolymer (L) preferably has a density measured according to JIS K 7112 of 850 to 900 kg / m ³ , and is 850 to 890 kg / m ³ . More preferably.

(Glass-transition temperature)
The glass transition temperature (Tg) of the low-viscosity ethylene-based copolymer (L) is −70 to −20 ° C. from the viewpoint of low-temperature impact resistance of the rubber molded product obtained from the rubber composition of the present invention. Preferably, it is −60 to −30 ° C.

  Next, the metallocene catalyst used for the production of the copolymer (L) described above and the polymerization conditions using the same will be described.

<Catalyst>
(Catalyst example 1)
Examples of the metallocene catalyst include transition metal compounds represented by the following general formula [I] or [II].

一般式［Ｉ］および［II］においてＹは、ケイ素原子もしくは炭素原子である。

In the general formulas [I] and [II], Y is a silicon atom or a carbon atom.

In the general formulas [I] and [II], R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ is selected from a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom, and a silicon-containing group, and may be the same or different, and R ¹ to R ¹⁴ Up to adjacent substituents may be bonded to each other to form a ring.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkyl group having 1 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and a substituted aryl ( aryl) group.

More specifically, for example, methyl group, ethyl group, n-propyl group, isopropyl group, allyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, amyl group, n -Pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decanyl group, 3-methylpentyl group, 1,1-diethylpropyl group, 1,1- Dimethylbutyl group, 1-methyl-1-propylbutyl group, 1,1-propylbutyl group, 1,1-dimethyl-2-methylpropyl group, 1-methyl-1-isopropyl-2-methylpropyl group, cyclopentyl group Cyclohexyl group, cycloheptyl group, cyclooctyl group, norbornyl group, adamantyl group, phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, xyl Group, isopropylphenyl group, t- butyl phenyl group, a naphthyl group, a biphenyl group, terphenyl group, phenanthryl group, anthracenyl group, and a benzyl group and a cumyl group,
Oxygen-containing groups such as methoxy group, ethoxy group and phenoxy group, nitrogen-containing groups such as nitro group, cyano group, N-methylamino group, N, N-dimethylamino group and N-phenylamino group, boranetriyl group and diboranyl group Examples of the hydrocarbon group include those containing a sulfur-containing group such as a boron-containing group such as sulfonyl group and sulfenyl group.

  The hydrocarbon group may have a hydrogen atom substituted with a halogen atom. Examples of such a halogen-substituted hydrocarbon group include a trifluoromethyl group, a trifluoromethylphenyl group, a pentafluorophenyl group, and a chlorophenyl group. Can be mentioned.

  Examples of the silicon-containing group include a silyl group, a siloxy group, a hydrocarbon-substituted silyl group, and a hydrocarbon-substituted siloxy group. More specifically, for example, methylsilyl group, dimethylsilyl group, trimethylsilyl group, ethylsilyl group, diethylsilyl group, triethylsilyl group, diphenylmethylsilyl group, triphenylsilyl group, dimethylphenylsilyl group, dimethyl-t-butylsilyl group And dimethyl (pentafluorophenyl) silyl group.

The cyclopentadienyl group having R ¹ to R ⁴ in the above general formulas [I] and [II] is an unsubstituted cyclopentadienyl group in which R ¹ to R ⁴ are hydrogen atoms, 3-t-butylcyclo Pentadienyl group, 3-methylcyclopentadienyl group, 3-trimethylsilylcyclopentadienyl group, 3-phenylcyclopentadienyl group, 3-adamantylcyclopentadienyl group, 3-amylcyclopentadienyl group and 3-position 1-substituted cyclopentadienyl group such as 3-cyclohexylcyclopentadienyl group, 3-t-butyl-5-methylcyclopentadienyl group, 3-t-butyl-5-ethylcyclopentadienyl group, 3-phenyl-5-methylcyclopentadienyl group, 3,5-di-t-butylcyclopentadienyl group, 3,5-dimethylcycle Examples include lopentadienyl group, 3-phenyl-5-methylcyclopentadienyl group, and 3-trimethylsilyl-5-methylcyclopentadienyl group such as 3,5-disubstituted cyclopentadienyl group. Not as long.

From the viewpoint of ease of synthesis of the transition metal compound, production cost, and copolymerization ability of the non-conjugated polyene [C], a cyclopentadienyl group that is unsubstituted (R ^{1 to} R ⁴ are hydrogen atoms) is preferable.
As the fluorenyl group having R ⁵ to R ¹² in the general formulas [I] and [II],
2-substituted 1-substituted fluorenyl groups such as unsubstituted fluorenyl group, 2-methylfluorenyl group, 2-t-butylfluorenyl group and 2-phenylfluorenyl group in which R ⁵ to R ¹² are hydrogen atoms; 4-position 1-substituted fluorenyl group such as methyl fluorenyl group, 4-t-butyl fluorenyl group and 4-phenyl fluorenyl group, or 2,7-di-t-butyl fluorenyl group and 3, 2,7-position or 3,6-position disubstituted fluorenyl group such as 6-di-t-butylfluorenyl group, 2,7-dimethyl-3,6-di-t-butylfluorenyl group and 2,7 -2,3,6,7-position 4-substituted fluorenyl group such as diphenyl-3,6-di-t-butylfluorenyl group or the following general formulas [V-I] and [V-II] such, a ring and R ⁶ and R ⁷ together Form, although such 2,3,6,7-position 4-substituted fluorenyl group and R ¹⁰ and R ¹¹ are bonded to each other to form a ring are exemplified, not limited.

一般式[V−I]および[V−II]中、Ｒ⁵、Ｒ⁸、Ｒ⁹、Ｒ¹²は前記一般式[I]あるいは［II］における定義と同様であり、
Ｒ^a、Ｒ^b、Ｒ^c、Ｒ^d、Ｒ^e、Ｒ^f、Ｒ^gおよびＲ^hは、それぞれ独立に水素原子または炭素数１〜５のアルキル基であり、隣接した置換基と互いに結合して環を形成していてもよい。

In the general formulas [V-I] and [V-II], R ⁵ , R ⁸ , R ⁹ and R ¹² are the same as defined in the general formula [I] or [II].
R ^a , R ^b , R ^c , R ^d , R ^e , R ^f , R ^g, and R ^h are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms and bonded to adjacent substituents. May form a ring.

Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an amyl group, and an n-pentyl group.
In the general formula [V-I], R ^x and R ^y are each independently a hydrocarbon group which may have an unsaturated bond having 1 to 3 carbon atoms, and R ^x is R ^a or R ^c is The bonded carbon may form a double bond, R ^y may form a double bond with R ^e or R ^g bonded carbon, R ^x and R ^y Are preferably saturated or unsaturated hydrocarbon groups having 1 or 2 carbon atoms.

  Specific examples of the compound represented by the general formula [V-I] or [V-II] include an octamethyloctahydrodibenzofluorenyl group represented by the following formula [V-III], Tetramethyldodecahydrodibenzofluorenyl group represented by V-IV], octamethyltetrahydrodicyclopentafluorenyl group represented by the following formula [V-V], and represented by the following formula [V-VI]. Hexamethyldihydrodicyclopentafluorenyl group, and b, h-dibenzofluorenyl group represented by the following formula [V-VII].

これらのフルオレニル基を含む上記一般式[I]または[II]で表される遷移金属化合物はいずれも非共役ポリエン［Ｃ］の共重合能に優れるが、Ｙがケイ素原子である場合、２，７位２置換フルオレニル基、３，６位２置換フルオレニル基、２，３，６，７位４置換フルオレニル基、上記一般式[V−I]に表される２，３，６，７位４置換フルオレニル基を有する遷移金属化合物が特に優れる。Ｙが炭素原子である場合、Ｒ⁵からＲ¹²が水素原子である無置換フルオレニル基、３，６位２置換フルオレニル基、２，３，６，７位４置換フルオレニル基、上記一般式[V−I]に表される２，３，６，７位４置換フルオレニル基を有する遷移金属化合物が特に非共役ポリエン［Ｃ］の共重合能に優れる。

Any of the transition metal compounds represented by the above general formula [I] or [II] containing these fluorenyl groups is excellent in the copolymerization ability of the nonconjugated polyene [C], but when Y is a silicon atom, 7-position 2-substituted fluorenyl group, 3,6-position 2-substituted fluorenyl group, 2,3,6,7-position 4-substituted fluorenyl group, 2,3,6,7-position 4 represented by the above general formula [V-I] A transition metal compound having a substituted fluorenyl group is particularly excellent. When Y is a carbon atom, an unsubstituted fluorenyl group in which R ⁵ to R ¹² are hydrogen atoms, a 3,6-positioned 2-substituted fluorenyl group, a 2,3,6,7-positioned 4-substituted fluorenyl group, the above general formula [V The transition metal compound having a 2,3,6,7-position 4-substituted fluorenyl group represented by -I] is particularly excellent in the copolymerization ability of the non-conjugated polyene [C].

  As for the polymerization activity, when Y is a silicon atom or a carbon atom, the 2,7-position 2-substituted fluorenyl group, the 3,6-position 2-substituted fluorenyl group, the 2,3,6,7-position 4-substituted fluorenyl group, the above general The transition metal compounds represented by the above general formulas [I] and [II] having a 2,3,6,7-position 4-substituted fluorenyl group represented by the formula [V-I] are particularly excellent.

In the above general formula [I], R ¹³ and R ¹⁴ may be the same or different from each other. As described above, R ¹³ and R ¹⁴ may be a hydrocarbon group, and among the hydrocarbon groups, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. , Cyclopentyl group, cyclohexyl group, cycloheptyl group, phenyl group, m-tolyl group, p-tolyl group, 4-t-butylphenyl group, p-chlorophenyl group, 4-biphenyl group, 2-naphthyl group, xylyl group, A benzyl group and an m-trifluoromethylphenyl group are preferred.

  In the transition metal compound represented by the general formula [II], A is a divalent saturated or unsaturated hydrocarbon group having 2 to 20 carbon atoms which may contain an aromatic ring, and Y is the A For example, a cycloalkylidene group such as a cyclohexylidene group represented by the following formula [VI-I], a cyclotetramethylenesilylene group represented by the following formula [VI-II] (1-silacyclopentylidene A cyclomethylenesilylene group such as a group).

（式［VI−I］及び［VI−II］において、●は、上記一般式［II］における（置換）シクロペンタジエニル基および（置換）フルオレニル基との結合点を表す。）
また、一般式［II］においてＡはＹとともに形成する環を含めて二つ以上の環構造を含んでいてもよい。

(In formulas [VI-I] and [VI-II], ● represents the point of attachment to the (substituted) cyclopentadienyl group and (substituted) fluorenyl group in general formula [II]).
In general formula [II], A may contain two or more ring structures including the ring formed with Y.

  Specific examples of the ring structure formed by combining Y with A include, in addition to the cyclohexylidene group represented by the above formula [VI-I], a cyclopropylidene group, a cyclobutylidene group, and a cyclopentylidene group. A cycloheptylidene group, a cyclooctylidene group, a bicyclo [3.3.1] nonylidene group, a norbornylidene group, an adamantylidene group, a tetrahydronaphthylidene group, a dihydroindanilidene group, and the like.

  Similarly, as the ring structure formed by combining Y with A, other than the cyclotetramethylenesilylene group (1-silacyclopentylidene group) represented by the above formula [VI-II], specifically, Examples thereof include a dimethylenesilylene group, a cyclotrimethylenesilylene group, a cyclopentamethylenesilylene group, a cyclohexamethylenesilylene group, and a cycloheptamethylenesilylene group.

In the general formulas [I] and [II], M is a titanium atom, a zirconium atom or a hafnium atom, preferably a titanium atom or a hafnium atom.
In the general formulas [I] and [II], Q is a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a neutral, conjugated or nonconjugated diene having 10 or less carbon atoms, an anionic ligand, and a lone electron. It is selected from neutral ligands that can be coordinated in pairs.

Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a chlorine atom.
Specific examples of the hydrocarbon group having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, 2-methylpropyl group, 1,1-dimethylpropyl group, 2,2-dimethylpropyl group. Group, 1,1-diethylpropyl group, 1-ethyl-1-methylpropyl group, 1,1,2,2-tetramethylpropyl group, sec-butyl group, t-butyl group, 1,1-dimethylbutyl group 1,1,3-trimethylbutyl group, neopentyl group, cyclohexylmethyl group, cyclohexyl group, 1-methyl-1-cyclohexyl group, benzyl group and the like, preferably methyl group, ethyl group and benzyl group.

  Specific examples of the neutral, conjugated or non-conjugated diene having 10 or less carbon atoms include s-cis- or s-trans-η4-1,3-butadiene, s-cis- or s-trans-η4-1. , 4-diphenyl-1,3-butadiene, s-cis- or s-trans-η4-3-methyl-1,3-pentadiene, s-cis- or s-trans-η4-1,4-dibenzyl-1 , 3-butadiene, s-cis- or s-trans-η 4 -2,4-hexadiene, s-cis- or s-trans-η 4-1,3-pentadiene, s-cis- or s-trans-η 4- 1,4-ditolyl-1,3-butadiene, s-cis- or s-trans-η4-1,4-bis (trimethylsilyl) -1,3-butadiene, and the like.

  Specific examples of the anionic ligand include alkoxy groups such as methoxy, t-butoxy and phenoxy, carboxylate groups such as acetate and benzoate, and sulfonate groups such as mesylate and tosylate.

  Specific examples of the neutral ligand capable of coordinating with the lone electron pair include organic phosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine and diphenylmethylphosphine, and tetrahydrofuran, diethyl ether, dioxane and 1,2 -Ethers such as dimethoxyethane.

Finally, in the above general formulas [I] and [II], j is an integer of 1 to 4, and when j is 2 or more, Qs may be the same or different.
Examples of the transition metal compounds described above are listed in JP-A-2011-1497.

  The transition metal compound can be produced by a known method, and the production method is not particularly limited. As a manufacturing method, for example, J. Org. Organomet. Chem. 63, 509 (1996), WO2006-123759, WO01 / 27124, JP2004-168744, JP2004-175759, and JP2000-, which are publications relating to applications by the present applicant. And the method described in Japanese Patent No. 212194.

(Catalyst example 2)
Moreover, the compound represented by the following general formula (X) can be mentioned as a metallocene catalyst which can be used for manufacture of a low-viscosity ethylene-type copolymer (L).

式（Ｘ）中、Ｒ’およびＲ’’はそれぞれ独立に、水素原子または炭素数１〜２０のヒドロカルビル基であり、Ｍはチタンであり、Ｙは−ＮＲ^*−であり、Ｚ^*は−ＳｉＲ^* ₂−であり、前記二つのＲ^*はそれぞれ独立に、水素原子または炭素数１〜２０のヒドロカルビル基であり、ｐおよびｑのうち一方は０であり、他方は１であり、
ｐが０かつｑが１である場合には、Ｍは＋２の酸化状態であり、Ｘ’は１，４−ジフェニル−１，３−ブタジエンまたは、１，３−ペンタジエンであり、
ｐが１かつｑが０である場合には、Ｍは＋３の酸化状態であり、Ｘは２−（Ｎ，Ｎ−ジメチルアミノ）ベンジルである。

In formula (X), R ′ and R ″ are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, M is titanium, Y is —NR ^* —, and Z ^* is − SiR ^* ₂ - a and each said two R ^* is independently a hydrocarbyl group of hydrogen atom or a C 1-20, 0 is one of p and q, the other is 1,
when p is 0 and q is 1, M is in the +2 oxidation state, X ′ is 1,4-diphenyl-1,3-butadiene or 1,3-pentadiene;
When p is 1 and q is 0, M is in the +3 oxidation state and X is 2- (N, N-dimethylamino) benzyl.

The compound having the structure represented by the general formula (X) includes (t-butylamide) from the viewpoint of suppressing fogging and solids due to the ultra-low molecular weight component of the resulting low viscosity ethylene copolymer (L). Dimethyl (η ⁵ -2-methyl-s-indacene-1-yl) silane titanium (II) 1,3-pentadiene (also known as: (t-butylamido) dimethyl (η ⁵ -2-methyl-s-indacene-1- Yl) silane titanium (II) 1,3-pentadiene) (a compound having a structure represented by the following formula (XI)) is particularly preferred. In addition, the compound which has a structure represented by a following formula (XI) can be obtained by the method described in the Japanese translations of PCT publication No. 2001-522398, for example.

前記一般式（Ｘ）で表わされる構造を有する化合物は、非共役ポリエン［Ｃ］の重合性に優れている。また、このようなメタロセン触媒を用いて合成される低粘度エチレン系共重合体（Ｌ）は、分子量分布および組成分布が狭く、均一な分子構造を有する共重合体である。このため、共重合体（Ｌ）を含むゴム組成物およびそれから得られる成形品は、表面外観に優れる傾向がある。

The compound having the structure represented by the general formula (X) is excellent in the polymerizability of the non-conjugated polyene [C]. In addition, the low-viscosity ethylene copolymer (L) synthesized using such a metallocene catalyst is a copolymer having a narrow molecular weight distribution and composition distribution and a uniform molecular structure. For this reason, the rubber composition containing the copolymer (L) and the molded product obtained therefrom tend to be excellent in surface appearance.

(Cocatalyst)
The low-viscosity ethylene copolymer (L) can be synthesized using, for example, the metallocene catalyst mentioned above as a main catalyst and an organoaluminum compound such as a boron compound and / or trialkylaluminum as a cocatalyst.

Examples of the boron compound include trityltetrakis (pentafluorophenyl) borate, trimethylammonium tetrakis (pentafluorophenyl) borate, di (hydrogenated tallowalkyl) methylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (penta Fluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate, tri (s-butyl) ammonium tetrakis (pentafluorophenyl) borate, N, N- Dimethylanilinium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium n-butyltris Orophenyl) borate, N, N-dimethylanilinium benzyltris (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (4- (t-butyldimethylsilyl) -2,3,5,6-tetrafluorophenyl ) Borate, N, N-dimethylanilinium tetrakis (4- (triisopropylsilyl) -2,3,5,6-tetrafluorophenyl) borate, N, N-dimethylanilinium pentafluorophenoxytris (pentafluorophenyl) Borate, N, N-diethylanilinium tetrakis (pentafluorophenyl) borate, N, N-dimethyl-2,4,6-trimethylanilinium tetrakis (pentafluorophenyl) borate, trimethylammonium tetrakis (2,3,4, 6- Trifluorophenyl) borate, triethylammonium tetrakis (2,3,4,6-tetrafluorophenyl) borate, tripropylammonium tetrakis (2,3,4,6-tetrafluorophenyl) borate, N, N-dimethylanilinium Tetrakis (2,3,4,6-tetrafluorophenyl) borate, N, N-diethylanilinium tetrakis (2,3,4,6-tetrafluorophenyl) borate and N, N-dimethyl-2,4,6 -Trimethylanilinium tetrakis (2,3,4,6-tetrafluorophenyl) borate;
Di (isopropyl) ammonium tetrakis (pentafluorophenyl) borate, tri (n-butyl) ammonium tetrakis (2,3,4,6-tetrafluorophenyl) borate, dimethyl (t-butyl) ammonium tetrakis (2,3,4) , 6-tetrafluorophenyl) borate and dialkylammonium salts such as dicyclohexylammonium tetrakis (pentafluorophenyl) borate;
Trisubstituted phosphonium tetrakis (pentafluorophenyl) borate, tri (o-tolyl) phosphonium tetrakis (pentafluorophenyl) borate, and tri (2,6-dimethylphenyl) phosphonium tetrakis (pentafluorophenyl) borate Phosphonium salts;
Disubstituted such as diphenyloxonium tetrakis (pentafluorophenyl) borate, di (o-tolyl) oxonium tetrakis (pentafluorophenyl) borate, and di (2,6-dimethylphenyl) oxonium tetrakis (pentafluorophenyl) borate Oxonium salts prepared;
Disubstituted sulfoniums such as diphenylsulfonium tetrakis (pentafluorophenyl) borate, di (o-tolyl) sulfonium tetrakis (pentafluorophenyl) borate, and bis (2,6-dimethylphenyl) sulfonium tetrakis (pentafluorophenyl) borate Salt.

Examples of the organoaluminum compound include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum and tri-n-octylaluminum, tricycloalkylaluminum, isobutylaluminum dichloride, diethylaluminum chloride, ethylaluminum dichloride, ethylaluminum sesquichloride, Methylaluminum dichloride, dimethylaluminum chloride, diisobutylaluminum hydride,
Examples include LiAl (C ₂ H ₅ ) ₄ , LiAl (C ₇ H ₁₅ ) ₄ , and organic aluminum oxy compounds.

  The organoaluminum oxy compound may be a conventionally known aluminoxane, or may be a benzene-insoluble organoaluminum oxy compound as exemplified in JP-A-2-78687.

<Polymerization conditions>
The reaction temperature when synthesizing the low-viscosity ethylene copolymer (L) is usually from -20 to 200 ° C, preferably from 0 to 150 ° C. The polymerization pressure is usually in the range of more than 0 MPa and 8 MPa (gauge pressure) or less, preferably more than 0 MPa and 5 MPa (gauge pressure) or less.

  The reaction time (average residence time when copolymerization is carried out in a continuous process) varies depending on conditions such as catalyst concentration and polymerization temperature, but is usually 0.5 minutes to 5 hours, preferably 10 minutes to 3 hours. . Furthermore, molecular weight regulators such as hydrogen can be used.

When the olefin is polymerized using the metallocene catalyst as described above, the transition metal compounds represented by the above general formulas [I], [II] and [X] are usually 10 ⁻¹² to 1 liter per reaction volume. The amount used is 10 ⁻² mol, preferably 10 ⁻¹⁰ to 10 ⁻⁸ mol.

  The cocatalyst used with the transition metal compound has a molar ratio [cocatalyst / M] of the cocatalyst and all transition metal atoms (M) in the transition metal compound of usually 0.1 / 1 to 1000/1. The amount is preferably 1/1 to 500/1.

  In the present invention, the production of the copolymer (L) can be carried out by any of a liquid phase polymerization method such as solution (dissolution) polymerization and suspension polymerization or a gas phase polymerization method, and is not particularly limited. It is preferable to have the process of obtaining a reaction liquid.

  The step of obtaining a polymerization reaction liquid means using an aliphatic hydrocarbon as a polymerization solvent and in the presence of the metallocene catalyst and the cocatalyst, the ethylene [A], the α-olefin [B], the non-conjugated polyene [ C] and optionally other monomers are copolymerized to obtain a polymerization reaction solution of ethylene [A] .α-olefin [B] .non-conjugated polyene [C] (.other monomers) copolymer.

  Examples of the polymerization solvent include aliphatic hydrocarbons and aromatic hydrocarbons. Specifically, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane and kerosene, alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclopentane, benzene, toluene and xylene And aromatic hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane.

These can be used alone or in combination of two or more. Further, the α-olefin itself used for polymerization can also be used as a polymerization solvent.
Of the polymerization solvents described above, hexane is preferred from the viewpoint of separation and purification from the resulting ethylene copolymer.

The polymerization reaction can be carried out in any of batch, semi-continuous and continuous methods. Furthermore, the polymerization can be performed in two or more stages having different reaction conditions.
For example, the polymerization reaction can be completed by carrying out the polymerization reaction as described above and adding an acidic alcohol such as methanol into the reaction system.

  The molecular weight of the ethylene polymer obtained by the polymerization reaction can also be adjusted by allowing hydrogen to be present in the polymerization system or changing the polymerization temperature. Specifically, the presence of a large amount of hydrogen in the polymerization system can reduce the molecular weight of the resulting ethylene copolymer, and as a result, the low viscosity ethylene copolymer in the limiting viscosity range of the present invention. A coalescence (L) can be obtained. Furthermore, the molecular weight of the resulting ethylene copolymer can be kept small by keeping the polymerization temperature at a moderate reaction condition without increasing the polymerization temperature, and as a result, the range of the intrinsic viscosity can be achieved.

  Furthermore, the molecular weight of the ethylene copolymer can be adjusted by the amount of the cocatalyst used.

[High viscosity ethylene copolymer (H)]
The rubber composition of the present invention contains a high-viscosity ethylene copolymer (H) (hereinafter also simply referred to as “copolymer (H)”), to which the low-viscosity ethylene copolymer (L) is reacted. It is blended as a plasticizer. A rubber having a skeleton other than the copolymer (H) (for example, a diene rubber such as natural rubber) has insufficient mixing with the copolymer (L). In this combination, the copolymer (L ) Does not exhibit a sufficient plasticizing effect.
The copolymer (H) includes structural units derived from ethylene [A ′], α-olefin [B ′] having 3 to 20 carbon atoms, and at least one non-conjugated polyene [C ′].

<[A '] Ethylene>
The structural unit derived from ethylene [A ′] gives high-viscosity ethylene copolymer (H) high temperature impact resistance and excellent mechanical strength.

  Such a structural unit derived from ethylene [A ′] is contained in an amount of 50 to 90 mol% in 100 mol% of all structural units of the copolymer (H) from the viewpoint of exerting its function, preferably It is contained in an amount of 55 to 85 mol%, more preferably 55 to 83 mol%.

Moreover, the ratio of the structural unit derived from ethylene [A '] in all the structural units of the copolymer (H) can be measured by various known methods, for example, by measuring ¹ H-NMR spectrum. The said ratio can be calculated | required.

<[B '] C3-C20 α-olefin>
A structural unit derived from an α-olefin [B ′] having 3 to 20 carbon atoms (hereinafter also simply referred to as “α-olefin [B ′]”) is flexible (low in the high viscosity ethylene copolymer (H)). Crystallinity).

The number of carbon atoms of the α-olefin [B ′] is preferably 3 to 8 from the viewpoints of raw material costs and mechanical properties.
Examples of such α-olefins [B ′] include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1 -Dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene and the like can be mentioned. Among these, propylene, 1-butene, 1-hexene and 1-octene are preferable.

The α-olefin [B ′] described above may be used singly or in combination of two or more.
The structural unit derived from α-olefin [B ′] is a copolymer (H) from the viewpoint of the flexibility of the rubber composition of the present invention and the low temperature impact resistance of a rubber molded product obtained from the composition. The total structural unit is usually contained in an amount of 9 to 49 mol%, preferably 14 to 44 mol%.

The proportion of structural units derived from α-olefin [B ′] in all structural units of copolymer (H) can be measured by various known methods, for example, by measuring ¹ H-NMR spectrum. The said ratio can be calculated | required.

<[C ′] at least one non-conjugated polyene>
The structural unit derived from at least one non-conjugated polyene [C ′] (hereinafter also simply referred to as “non-conjugated polyene [C ′]”) imparts crosslinking reactivity to the high viscosity ethylene copolymer (H).

  The non-conjugated polyene [C ′] is not particularly limited as long as it has two or more double bonds (usually 4 or less) and the double bonds are not conjugated to each other. A non-conjugated diene having ˜20 is preferable, and a non-conjugated diene having 5 to 15 carbon atoms is more preferable.

  Examples of such non-conjugated dienes include 5-ethylidene-2-norbornene (ENB), dicyclopentadiene, 5-vinyl-2-norbornene (VNB), norbornadiene and methyltetrahydroindene as cyclic nonconjugated dienes. Examples of the non-conjugated diene include 1,4-hexadiene and 7-methyl-1,6-octadiene.

  Among these, 5-ethylidene-2-norbornene (ENB), dicyclopentadiene and 5-vinyl-2-norbornene (VNB) are preferably used, and 5-ethylidene-2-norbornene (ENB) is particularly preferably used.

The non-conjugated polyene [C ′] described above may be used alone or in combination of two or more.
In addition, the structural unit derived from the non-conjugated polyene [C ′] is contained in an amount of 0.5 to 5.0 mol% in 100 mol% of all the structural units of the copolymer (H) from the viewpoint of crosslinking reactivity. Preferably 1.0 to 4.0 mol%.

The proportion of structural units derived from non-conjugated polyene [C ′] in all structural units of copolymer (H) can be measured by various known methods, for example, by measuring ¹ H-NMR spectrum. The said ratio can be calculated | required.

<High viscosity ethylene copolymer (H)>
The high-viscosity ethylene-based copolymer (H) includes structural units derived from the above-described ethylene [A ′], α-olefin [B ′], and non-conjugated polyene “C ′”, and the ethylene [A ′ ] And the content of structural units derived from non-conjugated polyene [C ′] are in a certain range. Hereinafter, the characteristics of the copolymer (H) will be described.

(Intrinsic viscosity [η])
The intrinsic viscosity [η] measured in a 135 ° C. decalin solution of the high viscosity ethylene copolymer (H) is 1.0 to 5.0 dL / g. If the intrinsic viscosity is less than 1.0 dL / g, the rubber molded product of the present invention has poor long-term rubber elasticity and fatigue resistance, whereas if it is greater than 5.0 dL / g, the molding processability of the rubber composition of the present invention is poor. This is not preferable because it is significantly worse.
The intrinsic viscosity [η] is preferably 1.5 to 4.5 dL / g from the viewpoint of rubber elasticity.

(density)
The high viscosity ethylene copolymer (H) has a density measured in accordance with JIS K 7112 of usually 850 to 900 kg / m ³ , preferably 850 to 890 kg / m ³ .

(Glass-transition temperature)
The glass transition temperature (Tg) of the high viscosity ethylene copolymer (H) is usually −70 to −20 ° C., preferably −60 to −30 ° C.

  The copolymer (H) described above can be produced using, for example, the same metallocene catalyst and cocatalyst as those used for the production of the copolymer (L), and the polymerization conditions are also the same. In order to increase the intrinsic viscosity, the amount of hydrogen used is reduced or the polymerization temperature is increased.

  The copolymer (H) can also be produced by various other known methods. For example, the copolymer (H) is commercially available as Mitsui EPT4045M (manufactured by Mitsui Chemicals, Inc.), and thus can be easily obtained.

[Crosslinking agent]
The rubber composition of the present invention contains a crosslinking agent in addition to the copolymers (L) and (H). Examples of the crosslinking agent include vulcanizing agents, vulcanization accelerators, and vulcanization aids.

<Vulcanizing agent>
Examples of the vulcanizing agent include sulfur compounds, organic peroxides, phenol resins, and oxime compounds.

  As the sulfur compound, sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, selenium dithiocarbamate and the like are preferable, and sulfur and tetramethylthiuram disulfide are more preferable.

  The compounding quantity of a sulfur type compound is 0.1-10 weight part normally with respect to a total of 100 weight part of the weight of a copolymer (L) and the weight of a copolymer (H). When the blending amount is within the above range, the obtained crosslinked product (rubber molded product) is excellent in mechanical properties, which is preferable.

  Examples of the organic peroxide include dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2, 5-Dimethyl-2,5-di (t-butylperoxy) hexyne-3, di-t-butylperoxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane and t-dibutylhydroperoxide are preferred. Dicumyl peroxide, di-t-butyl peroxide and di-t-butylperoxy-3,3,5-trimethylcyclohexane are more preferable.

  The compounding quantity of an organic peroxide is 0.001-0.05 mol normally with respect to the total 100g of the weight of a copolymer (L) and the weight of a copolymer (H). It is preferable for the amount of the organic peroxide to be within the above range since the mechanical properties of the resulting crosslinked product are excellent.

The compounding quantity of the said phenol resin is 0.1-10 weight part normally with respect to a total of 100 weight part of the weight of a copolymer (L) and the weight of a copolymer (H).
The compounding quantity of the said oxime compound is 0.1-10 weight part normally with respect to a total of 100 weight part of the weight of a copolymer (L) and the weight of a copolymer (H).
The vulcanizing agents described above may be used singly or in combination of two or more.

<Vulcanization accelerator>
Next, when a sulfur compound is used as the vulcanizing agent, it is preferable to use a vulcanization accelerator in combination.

Examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazole sulfenamide, N, N′-diisopropyl-2-benzothiazole sulfenamide, 2- Mercaptobenzothiazole (for example, Sunseller M (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), 2- (4-morpholinodithio) penzothiazole (for example, Noxeller MDB-P (trade name; manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) )), 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- (2,6-diethyl-4-morpholinothio) benzothiazole and dibenzothiazyl disulfide (eg Sunceller DM (trade name; Sanshin) Thiazole vulcanization accelerators such as Chemical Industry));
Guanidine vulcanization accelerators such as diphenylguanidine, triphenylguanidine and diorthotolylguanidine;
Aldehyde amine vulcanization accelerators such as acetaldehyde / aniline condensate and butyraldehyde / aniline condensate;
Imidazoline-based vulcanization accelerators such as 2-mercaptoimidazoline;
Thiourea vulcanization accelerators such as diethylthiourea and dibutylthiourea;
Tetramethylthiuram monosulfide (for example, Sunseller TS (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetramethylthiuram disulfide (for example, Sunseller TT (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetraethylthiuram disulfide (for example, , Sunseller TET (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetrabutyl thiuram disulfide (for example, Sunseller TBT (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)) and dipentamethylene thiuram tetrasulfide (for example, Sunseller TRA ( Thiuram-based vulcanization accelerators such as trade name; manufactured by Sanshin Chemical Industry Co., Ltd.);
Dithioate-based vulcanization such as zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate (eg Sunseller PZ, Sunseller BZ and Sunseller EZ (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)) and tellurium diethyldithiocarbamate Accelerator;
Acceleration of thiourea vulcanization such as ethylenethiourea (for example, Sunseller BUR (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.), Sunseller 22-C (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)) and N, N′-diethylthiourea Agent;
Xanthate vulcanization accelerators such as zinc dibutylxatogenate;
In addition, zinc white (for example, META-Z102 (trade name; manufactured by Inoue Lime Industry Co., Ltd., zinc oxide)) can be used.

The compounding quantity of a vulcanization accelerator is 0.1-20 weight part normally with respect to a total of 100 weight part of the weight of a copolymer (L) and the weight of a copolymer (H). A vulcanization accelerator may be used individually by 1 type, and may be used in combination of 2 or more type.
It is preferable that the blending amounts of the vulcanizing agent and the vulcanization accelerator described above are in the above range since the mechanical properties of the resulting crosslinked product (rubber molded product) are excellent.

<Vulcanization aid>
Furthermore, examples of the vulcanization aid mentioned as an example of the crosslinking agent include quinone dioxime vulcanization aids such as p-quinone dioxime;
Acrylic vulcanization aids such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate;
Allylic vulcanization aids such as diallyl phthalate and triallyl isocyanurate (for example, M-60 (trade name; manufactured by Nippon Kasei Co., Ltd.));
Other maleimide vulcanization aids;
Divinylbenzene;
Examples thereof include zinc oxide and magnesium oxide / zinc flower (for example, META-Z102 (trade name; manufactured by Inoue Lime Industry Co., Ltd.)), and can be appropriately selected depending on the application.

A vulcanization auxiliary may be used individually by 1 type, and may be used in combination of 2 or more type.
The compounding quantity of a vulcanization adjuvant is 1-50 weight part normally with respect to a total of 100 weight part of the weight of a copolymer (L) and the weight of a copolymer (H).

(Rubber composition)
The rubber composition of the present invention contains the low-viscosity ethylene copolymer (L), the high-viscosity ethylene copolymer (H), and the crosslinking agent described above.

  The copolymer (L) can be produced by a simple copolymerization reaction in one step, has a low intrinsic viscosity, and does not contain foreign substances that may be generated when pyrolyzed. It is excellent in fluidity and can be used as an excellent reactive plasticizer for the copolymer (H).

The content of the crosslinking agent in the rubber composition of the present invention varies depending on the type as described above. Further, the contents of the copolymers (L) and (H) are 5 to 50 parts by weight of the copolymer (L) and 95 to 50 parts by weight of the copolymer (H) from the viewpoint of rubber elasticity and fatigue resistance. (However, the total of the weight of the copolymer (L) and the weight of the copolymer (H) is 100 parts by weight), preferably 10 to 40 parts by weight of the copolymer (L) The coalescence (H) is 90 to 60 parts by weight.
The rubber composition of the present invention described above may contain other components in addition to the copolymers (L) and (H) and the crosslinking agent as necessary.

<Other ingredients>
Examples of the other components include foaming agents, foaming aids, reinforcing agents, inorganic fillers, softeners, anti-aging agents (stabilizers), processing aids, activators, and hygroscopic agents, and the rubber of the present invention. It mix | blends in the said composition according to the use, the objective, etc. of a composition.

Examples of the foaming agent include inorganic foaming agents such as sodium bicarbonate and sodium carbonate;
Nitroso compounds such as N, N′-dinitrosopentamethylenetetramine and N, N′-dinitrosotephthalamide;
Azo compounds such as azodicarbonamide and azobisisobutyronitrile; hydrazide compounds such as benzenesulfonyl hydrazide and 4,4′-oxybis (benzenesulfonyl hydrazide);
Organic foaming agents such as calcium azide and azide compounds such as 4,4′-diphenyldisulfonyl azide.

  Moreover, as those commercially available products, for example, VINYHALL AC-2F (trade name; manufactured by Eiwa Kasei Kogyo Co., Ltd.), VINYHALL AC # LQ (trade name; manufactured by Eiwa Kasei Kogyo Co., Ltd., azodicarbonamide (abbreviated as ADCA)), neoselbon N # 1000SW (trade name; manufactured by Eiwa Chemical Industry Co., Ltd., 4,4′-oxybis (benzenesulfonyl hydrazide (abbreviation: OBSH)), and cellular D (trade name; manufactured by Eiwa Chemical Industries, Ltd., N, N′-dinitrosopenta Methylenetetramine (abbreviation DPT)) and the like.

The blending amount of the foaming agent is usually 1 to 70 parts by weight with respect to 100 parts by weight as a total of the weight of the copolymer (L) and the weight of the copolymer (H).
The foaming aid exhibits actions such as a reduction in the decomposition temperature of the foaming agent, acceleration of decomposition, or uniformization of bubbles. Examples of such foaming aids include organic acids such as salicylic acid, phthalic acid, stearic acid, oxalic acid and citric acid or salts thereof;
Urea or its derivatives are exemplified.

Examples of these commercially available products include cell paste K5 (trade name; manufactured by Eiwa Kasei Kogyo Co., Ltd., urea) and FE-507 (trade name: manufactured by Eiwa Kasei Kogyo Co., Ltd., baking soda).
The blending amount of the foaming aid is 0.1 to 5 parts by weight with respect to 100 parts by weight as the total of the weight of the copolymer (L) and the weight of the copolymer (H).

  The rubber composition of the present invention may contain a reinforcing agent or an inorganic filler for the purpose of improving mechanical properties such as tensile strength, tear strength and abrasion resistance of a rubber molded product obtained from the composition. Good.

  Examples of the reinforcing agent include Asahi # 55G, Asahi # 50HG and Asahi # 60G (trade name; manufactured by Asahi Carbon Co., Ltd.) and seast (SRF, GPF, FEF, MAF, HAF, ISAF, SAF, FT, MT, etc.) Carbon black (manufactured by Tokai Carbon Co., Ltd.); those obtained by surface-treating these carbon blacks with a silane coupling agent, etc .; silica; activated calcium carbonate; fine talc and fine silicate.

Of these, Asahi # 55G, Asahi # 50HG, Asahi # 60G, Seast FEF and the like are preferable.
Examples of the inorganic filler include light calcium carbonate, heavy calcium carbonate, talc and clay, and talc is particularly preferable. Moreover, as talc, for example, commercially available MISTRON VAPOR (manufactured by Nippon Mystron) can be used.

The compounding amount of the reinforcing agent or the inorganic filler is usually 30 to 800 parts by weight with respect to 100 parts by weight in total of the weight of the copolymer (L) and the weight of the copolymer (H).
When the compounding amount of the reinforcing agent or the inorganic filler is within the above range, the rubber composition of the present invention is excellent in kneading processability, and the resulting rubber molded product (crosslinked molded product) has mechanical properties such as strength and flexibility. Moreover, it is excellent in compression set.

Examples of the softener include process oils (for example, Diana process oil PW-380, Diana process oil PS-430 (trade name; manufactured by Idemitsu Kosan Co., Ltd.)), lubricating oil, paraffin oil, liquid paraffin, petroleum asphalt, and petroleum jelly. Petroleum softeners;
Coal tar softeners such as coal tar and coal tar pitch;
Fatty oil-based softeners such as mash oil, linseed oil, rapeseed oil, soybean oil and coconut oil;
Waxes such as beeswax, carnauba wax and lanolin;
Fatty acids or salts thereof such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate and zinc laurate;
Naphthenic acid, pine oil and rosin or derivatives thereof;
Synthetic polymer materials such as terpene resins, petroleum resins, atactic polypropylene and coumarone indene resins;
Ester softeners such as dioctyl phthalate, dioctyl adipate and dioctyl sebacate;
Other examples include microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, liquid thiocol, hydrocarbon-based synthetic lubricating oil, tall oil, and sub (factis).

Of these, petroleum softeners are particularly preferred. A softening agent may be used individually by 1 type, and may be used in combination of 2 or more types.
The blending amount of such a softening agent can be appropriately selected depending on its use. The blending amount of the softener is a maximum of usually 300 parts by weight with respect to a total of 100 parts by weight of the weight of the copolymer (L) and the weight of the copolymer (H). When the rubber molded product obtained from the rubber composition of the present invention is used for automobile parts, the use of the above-mentioned petroleum softener should be minimized to avoid oil extraction.

The rubber composition of the present invention can prolong the product life by using an anti-aging agent as in the case of a normal rubber composition.
Examples of the anti-aging agent include conventionally known anti-aging agents such as amine-based anti-aging agents, phenol-based anti-aging agents and sulfur-based anti-aging agents. Specifically, aromatic secondary amine-based antioxidants such as phenylbutylamine and N, N′-di-2-naphthyl-p-phenylenediamine;
Phenolic antioxidants such as dibutylhydroxytoluene and tetrakis [methylene (3,5-di-t-butyl-4-hydroxy) hydrocinnamate] methane;
Thioether-based antioxidants such as bis [2-methyl-4- (3-n-alkylthiopropionyloxy) -5-tert-butylphenyl] sulfide;
Dithiocarbamate anti-aging agents such as nickel dibutyldithiocarbamate;
2-mercaptobenzoylimidazole and zinc salt of 2-mercaptobenzimidazole;
And sulfur-based antioxidants such as dilauryl thiodipropionate and distearyl thiodipropionate. These anti-aging agents may be used alone or in combination of two or more.

  The amount of the anti-aging agent is usually 0.3 to 10 parts by weight with respect to 100 parts by weight as the total of the weight of the copolymer (L) and the weight of the copolymer (H). When the blending amount of the antioxidant is within the above range, there is no bloom on the surface of the obtained rubber composition, and it is preferable because vulcanization is not inhibited.

  As said processing aid, what is generally mix | blended with rubber | gum as a processing aid can be widely used. Specific examples include ricinoleic acid, palmitic acid, lauric acid, stearic acid, stearates, barium stearate, zinc stearate, and calcium stearate. Of these, stearic acid is preferred.

  The blending amount of the processing aid is usually 10 parts by weight or less with respect to 100 parts by weight in total of the weight of the copolymer (L) and the weight of the copolymer (H). A blending amount of the processing aid in the above range is preferable because there is no bloom on the surface of the resulting rubber composition and vulcanization inhibition is not caused.

Examples of the activator include amines such as di-n-butylamine, dicyclohexylamine, monoethanolamine, Acting B (trade name; manufactured by Yoshitake Pharmaceutical Co., Ltd.) and Acting SL (trade name; produced by Yoshitake Pharmaceutical Co., Ltd.);
Diethylene glycol, polyethylene glycol (for example, PEG # 4000 (trade name; manufactured by Lion)), lecithin, triarylate melitrate and zinc compounds of aliphatic and aromatic carboxylic acids (for example, Struktol activator 73, Struktol IB 531 and Struktol FA 541 (trade name; manufactured by Scill & Seilacher)) and the like;
Zinc peroxide preparations such as ZEONET ZP (trade name; manufactured by Nippon Zeon);
Octadecyltrimethylammonium bromide;
Synthetic hydrotalcite;
Special quaternary ammonium compounds (for example, ARCARD 2HF (trade name; manufactured by Lion Akzo Co., Ltd.)) are included.

Among these, polyethylene glycol (for example, PEG # 4000 (trade name; manufactured by Lion Corporation)) and Arcade 2HF are preferable.
These activators may be used individually by 1 type, and may be used in combination of 2 or more types. The compounding amount of the activator is usually 0.2 to 10 parts by weight with respect to 100 parts by weight in total of the weight of the copolymer (L) and the weight of the copolymer (H).

  Examples of the hygroscopic agent include calcium oxide (for example, VESTA-18 (trade name; manufactured by Inoue Lime Industry Co., Ltd.), silica gel, sodium sulfate, molecular sieve, zeolite, white carbon, etc. Among these, calcium oxide is preferable.

  The hygroscopic agent can be appropriately selected depending on the application, and can be used singly or in combination of two or more. The amount of the hygroscopic agent is usually 0.5 to 15 parts by weight with respect to 100 parts by weight as the total of the weight of the copolymer (L) and the weight of the copolymer (H).

<Characteristics of rubber composition>
The rubber composition of the present invention described above includes a low-viscosity ethylene copolymer (L) that can impart excellent fluidity and moldability as described above. There is no problem of stickiness.

  Further, as described above, the copolymer (L) is produced without a step of washing and removing the catalyst in the production thereof, so that the production cost is superior to the polymer produced as a conventional plasticizer. ing.

  Such a copolymer (L) and a crosslinking agent are blended with the copolymer (H) to form a rubber composition, which is molded and crosslinked, whereby a desired rubber molded product can be obtained. Specifically, for example, from the rubber composition of the present invention, molded articles such as rubber products such as automobile industrial parts, industrial rubber products, electrical insulating materials, civil engineering materials, and rubberized fabrics can be suitably obtained. . The molded products for various uses obtained from the rubber composition of the present invention will be described in detail later.

  The rubber composition of the present invention contains a low-viscosity ethylene copolymer (L), which is an excellent reactive plasticizer, and thus has excellent fluidity and Mooney viscosity [ML (1 + 4) measured at 125 ° C. 125 ° C.] is usually 5 to 40, preferably 10 to 40, more preferably 15 to 40, and particularly preferably 20 to 40.

The Mooney viscosity can be measured according to JIS K 6300, for example, using a Mooney viscometer (SMV202 type manufactured by Shimadzu Corporation).
<Method for producing rubber composition>
The manufacturing method of the rubber composition of this invention is not specifically limited, The various well-known method of mixing a polymer component and an additive is employable.

  As an example of the production method, each component contained in the rubber composition is used, for example, by using a kneader known in the art such as a mixer, a kneader, or a roll, and a continuous kneader such as a twin screw extruder. The method of mixing, the method of preparing the solution which each component contained in a rubber composition melt | dissolved or disperse | distributed, and removing a solvent are mentioned.

[Rubber molded products]
The rubber composition of the present invention can be obtained by molding the rubber composition of the present invention described above and crosslinking at the same time (Production Method 1) or by crosslinking after molding (Production Method 2).

  As an example of the production method 1, the rubber composition of the present invention is produced by using an extrusion molding machine, a calender roll, a press, an injection molding machine, a transfer molding machine, hot air, a glass bead fluidized bed, UHF (ultra high frequency electromagnetic wave), steam. Alternatively, a method of preforming into a desired shape by various molding methods using a heating tank of a heating form such as an LCM (hot molten salt tank) and heating simultaneously with the preforming can be mentioned.

  In this method, the above-mentioned vulcanizing agent is used, and a vulcanization accelerator and / or a vulcanization auxiliary is used in combination as necessary. The heating conditions are generally 140 to 300 ° C., preferably 150 to 270 ° C., and usually 0.5 to 30 minutes, preferably 0.5 to 20 minutes. A crosslinking reaction occurs by such heating, and the low-viscosity ethylene copolymer (L) undergoes a polymerization reaction with each other or with the high-viscosity ethylene copolymer (H) to form a polymer. A rubber molded product having a high strength and being firmly fixed inside is obtained.

When molding and cross-linking the rubber composition, a mold may or may not be used. When no mold is used, the rubber composition of the present invention is usually continuously molded and crosslinked.
Examples of the production method 2 include a method in which the rubber composition is preformed by the above molding method, the molded product is introduced into a vulcanization tank and heated, and a method in which the molded product is irradiated with an electron beam. .

The heating conditions in the case of introducing into the vulcanization tank and heating are the same as those in the method of heating simultaneously with the above preforming.
Next, in the method of irradiating the electron beam, the preformed material is irradiated with an electron beam of 0.1 to 10 MeV so that the absorbed dose is, for example, 0.5 to 35 Mrad, preferably 0.5 to 20 Mrad. As a result, a low-viscosity ethylene copolymer (L) forms a polymer and a rubber molded product having high strength is obtained.

  For example, the rubber molded article of the present invention produced by the method described above can be used in various fields. Specifically, as the molded product, automobile parts, marine parts, civil engineering and building parts, medical parts, parts for electrical and electronic equipment, transportation equipment and leisure parts, hoses (radiator hoses, heater hoses, etc.) Anti-vibration rubber, sheets, various belts, various packings, sealing materials, potting materials, coating materials and the like can be suitably formed.

Examples of the automotive parts include glass run channels, weather strip sponges, door opening trims, sealing members, grommets, automobile engine gaskets, electrical parts or oil filter sealing materials; igniter HICs or automotive hybrid IC potting materials;
Automotive body, automotive window glass, engine control board coating material;
Examples thereof include gaskets such as oil pans or timing belt covers, moldings, headlamp lenses, sunroof seals, and adhesives for mirrors.

  Examples of the weather strip sponge include door weather strip, trunk weather strip, luggage weather strip, roof side rail weather strip, sliding door weather strip, ventilator weather strip, sliding roof weather strip, front window weather strip, rear window weather strip, Examples include a quarter window weather strip, a lock pillar weather strip, a door glass outer weather strip, and a door glass inner weather strip.

Examples of the marine component include a wiring connection branch box, an electrical system component or a sealing material for electric wires; an adhesive for electric wires or glass, and the like.
Examples of the civil engineering building parts include, for example, joint joints for glass screens in commercial buildings, joints around glass with sashes, interior joints in toilets, washrooms or showcases, joints around bathtubs, and prefabricated houses Sealant for building materials used for joints for exterior walls of sizing boards and joints for sizing boards; Sealant for double-glazed glass; Sealant for civil engineering used for road repairs; Paint / bonding for metal, glass, stone, slate, concrete or tile Agent; adhesive sheet, waterproof sheet or vibration-proof sheet.

Examples of the medical parts include medical rubber plugs, syringe gaskets, and decompression blood vessel rubber plugs.
Examples of the parts for electrical / electronic equipment include heavy electrical parts, weak electrical parts, circuit / board sealing materials, potting materials, coating materials or adhesives for electric / electronic equipments; Insulating sealing materials; rolls for OA equipment; vibration absorbers; grommets; or gel or capacitor encapsulating materials.

Examples of the transport aircraft parts include automobiles, ships, airplanes, and railway vehicles.
Examples of the leisure parts include swimming members such as swimming caps, diving masks and earplugs; gel cushioning members such as sports shoes and baseball gloves.

  Examples of the anti-vibration rubber include anti-vibration rubber for automobiles (engine mount, liquid seal engine mount, damper pulley, chain damper, carburetor mount, torsional damper, strut mount, rubber bush, bumper rubber, helper rubber, and spring seat. , Shock absorber, air spring, body mount, bumper guard, muffler support, rubber coupling, center bearing support, clutch rubber, differential mount, suspension bush, sliding bush, cushion strut bar, stopper, handle damper, radiator supporter or muffler hanger ), Anti-vibration rubber for railways (slab mat, ballast mat or track mat) and anti-vibration rubber for industrial machinery (expansion joint, Carboxymethyl Bull joints, bushings, mounted), and the like.

As said sheet | seat, a roofing sheet, a water stop sheet, etc. are mentioned, for example.
The various belts include transmission belts (V belts, flat belts, toothed belts, timing belts) and conveyor belts (light conveyor belts, cylindrical belts, rough top belts, flanged conveyor belts, U-shaped guides) Transport belt, transport belt with V-shaped guide) and the like.

  The sealing material is suitably used as a sealing material for, for example, a refrigerator, a freezer, a washing machine, a gas meter, a microwave oven, a steam iron, and an electric leakage breaker. The sealing material refers to a material to be sealed (sealed or sealed). Further, in various industries such as machinery, electricity, chemistry, etc., a material used for the purpose of watertightness and airtightness of the joint portion and the contact portion is also a sealing material in a broad sense.

  The potting material is suitably used for potting, for example, a transformer high-voltage circuit, a printed circuit board, a high-voltage transformer with a variable resistance section, an electrical insulation component, a semiconductive component, a conductive component, a solar cell, or a television flyback transformer. It is done.

  The coating material is, for example, various circuit elements such as high-voltage thick film resistors or hybrid ICs; HICs, electrical insulating parts; semiconductive parts; conductive parts; modules; printed circuits; ceramic substrates; diodes, transistors or bonding wires It is suitably used for coating a buffer material such as a semiconductive element; or an optical fiber for optical communication.

  In addition to the above, rubber molded products of the present invention include automotive cup / seal materials (master cylinder piston cup, wheel cylinder piston cup, constant velocity joint boot, pin boot, dust cover, piston seal, packing, O-ring, diaphragm, dam Windshield, door mirror bracket, seal head lamp, seal cowl top), industrial sealing materials (capacitor packing, O-ring, packing), foam (hose protection sponge, cushion sponge, insulation sponge, insulation pipe), Covered wires, wire joints, electrical insulation components, semiconductive rubber components, OA equipment rolls (charging rolls, transfer rolls, developing rolls, paper feed rolls), industrial rolls (iron rolls, paper rolls, printing wire rolls) , Anode carrier Molded products for applications such as cable caps, plug caps, ignition cables, lamp socket covers, terminal covers, wiper blades, various tubes (vacuum tubes, tire tubes), air springs, shoe soles, shoe heels, tire sidewalls, fabric coatings, etc. It can form suitably.

EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited by these.
The physical properties of the copolymers obtained in Examples and Comparative Examples were measured according to the methods shown below.

[Molar amount of structural unit derived from ethylene [A]]
^It calculated | required by the intensity | strength measurement by a < ¹ > H-NMR spectrum meter.
[Molar amount of structural unit derived from non-conjugated polyene [C]]
^It calculated | required by the intensity | strength measurement by a < ¹ > H-NMR spectrum meter.

[Intrinsic viscosity]
Intrinsic viscosity [η] was measured using a fully automatic intrinsic viscometer manufactured by Koiso Co., Ltd. at a temperature of 135 ° C. and a measurement solvent: decalin.

[Inversion value]
The inversion value here is defined as the ratio of ββ and βγ (βγ / ββ), and is given by the following formula (I) from the peak integrated value obtained by a ¹³ C-NMR spectrum meter.

¹³Ｃ−ＮＭＲの条件は以下の通りである。

The conditions for ¹³ C-NMR are as follows.

Measuring device: ECX400P nuclear magnetic resonance apparatus (manufactured by JEOL)
Measurement temperature: 120 ° C
Measurement solvent: orthodichlorobenzene / deuterated benzene = 4/1
Integration count: 8000 times.

[Copolymer 1]
Continuously using a polymerization vessel having a volume of 23 L equipped with a stirring blade, ternary consisting of component [A]: ethylene, component [B]: propylene, component [C]: 5-ethylidene-2-norbornene (ENB) The polymerization reaction of the copolymer was performed at 80 ° C.

The polymerization solvent is hexane (feed amount 3.4 L / h), ethylene feed amount 210 g / h, propylene feed amount 200 g / h, ENB feed amount 45 g / h, and hydrogen (H ₂ ) feed amount. Was continuously fed to the polymerization vessel at 12 NL / h.

(T-Butylamido) -dimethyl (η ⁵ -2-methyl-s-indacene) which is a catalyst having a structure represented by the above formula (XI) as a main catalyst while maintaining a polymerization pressure (gauge pressure) at 3.6 MPa -1-yl) silanetitanium (II) 1,3-pentadiene was continuously fed to the polymerization vessel so that the feed rate was 0.0033 mmol / h.

Moreover, 0.0165 mmol / h of trityltetrakis (pentafluorophenyl) borate [(C ₆ H ₅ ) ₃ CB (C ₆ F ₅ ) ₄ ] as a cocatalyst and triisobutylaluminum (hereinafter “TIBA”) as an organoaluminum compound ) Was continuously fed to the polymerization vessel so that the feed rate was 1.0 mmol / h, and the reaction was carried out with an average residence time of 30 minutes.

  Thus, a polymerization liquid containing 12.2% by weight of a copolymer composed of ethylene, propylene and ENB was obtained. A small amount of methanol was added to the polymerization solution extracted from the lower part of the polymerization vessel to stop the polymerization reaction, and the copolymer was separated from the solvent by flash drying, and then dried under reduced pressure at 80 ° C. overnight. The physical properties of the obtained copolymer 1 are shown in Table 1.

[Copolymer 2]
Copolymer 1 was synthesized except that the ethylene feed amount was changed to 200 g / h, the propylene feed amount was 205 g / h, the ENB feed amount was 40 g / h, and the hydrogen (H ₂ ) feed amount was changed to 11.2 NL / h. A copolymer was synthesized in the same manner. The physical properties of the obtained copolymer 2 are shown in Table 1.

[Copolymer 3]
A copolymer was synthesized in the same manner as the copolymer 1 except that the ethylene feed amount was changed to 290 g / h, the propylene feed amount was changed to 145 g / h, and the ENB feed amount was changed to 34 g / h. The physical properties of the obtained copolymer 3 are shown in Table 1.

[Copolymer 4]
A copolymer was synthesized in the same manner as the copolymer 1 except that the ENB feed amount was changed to 18 g / h. The physical properties of the obtained copolymer 4 are shown in Table 1.

[Copolymer 5]
A copolymer was synthesized in the same manner as the copolymer 1 except that the ethylene feed amount was changed to 190 g / h and the hydrogen (H ₂ ) feed amount was changed to 13.1 NL / h. The physical properties of the obtained copolymer 5 are shown in Table 1.

[Copolymer 6]
A copolymer was synthesized in the same manner as the copolymer 1 except that the ethylene feed amount was changed to 190 g / h, the ENB feed amount was changed to 57 g / h, and the hydrogen (H ₂ ) feed amount was changed to 13.1 NL / h. did. The physical properties of the obtained copolymer 6 are shown in Table 1.

[Copolymer 7]
The copolymer 1 was synthesized except that the ethylene feed amount was changed to 190 g / h, the propylene feed amount was 185 g / h, the ENB feed amount was 52 g / h, and the hydrogen (H ₂ ) feed amount was changed to 9.9 NL / h. A copolymer was synthesized in the same manner. The physical properties of the obtained copolymer 7 are shown in Table 1.

[Copolymer 8]
Liquid type EPDM [trade name: Triline 67 (trademark), manufactured by Lion copolymer, ethylene content 55.8 mol%, ENB content 3.4 mol%, [η] 0.41 dl / g, inversion value 0.91]. The physical properties are shown in Table 1.

以下の実施例１〜３および比較例１〜５において、ゴム組成物を調製し、以下に示す測定方法により、これらおよび得られるゴム成形品の各種物性を測定した。

In Examples 1 to 3 and Comparative Examples 1 to 5 below, rubber compositions were prepared, and various physical properties of these and the rubber molded products obtained were measured by the measurement methods shown below.

[Compound viscosity; ML (1 + 4) 125 ° C.]]
The physical property test of the unvulcanized rubber composition was conducted according to JIS K6300. Specifically, the Mooney viscosity was measured at 125 ° C. using a Mooney viscometer (SMV202 type manufactured by Shimadzu Corporation).

[Evaluation of roll processability of compound]
MIXTRON BB MIXER (Kobe Steel Ltd., BB-4 type, volume 2.95L, rotor 4WH), 100 parts by weight of rubber component (low viscosity ethylene copolymer (L)) (Copolymers 1 to 8) 35 parts by weight and 65 parts by weight of Mitsui EPT4045M which is a high viscosity ethylene copolymer (H) Mitsui EPT4045M is manufactured by Mitsui Chemicals, Inc. Intrinsic viscosity measured in decalin solution at 135 ° C. with 56.9 mol% derived structural unit, 2.3 mol% derived structural unit derived from non-conjugated polyene [C ′] (5-ethylidene-2-norbornene) [η] is 1.64 dL / g and the inversion value is 0.11), 5 parts by weight of “Zinc oxide 2” (trade name; manufactured by Sakai Chemical Industry Co., Ltd.) as a vulcanization aid As a processing aid 1 part by weight of thetearic acid, 80 parts by weight of “Asahi # 60G” (trade name; manufactured by Asahi Carbon Co., Ltd., carbon black) as a reinforcing agent, and “Diana Process Oil PS-430” as a softener in a reference example ( 30 parts by weight of a product name (made by Idemitsu Kosan Co., Ltd.) was added and kneaded. The kneading conditions were a rotor rotation speed of 50 rpm, a floating weight pressure of 3 kg / cm ² , a kneading time of 5 minutes, and a kneading discharge temperature of 140 to 170 ° C.

Next, after confirming that the temperature of the kneaded material reached 40 ° C., 100 g of the kneaded material was wound around the roll using a 6-inch open roll, and the state at that time was observed, and the compound from the roll using a knife was used. The handling property when cutting out was evaluated according to the following criteria.
○: Good wrapping property on the roll is shown, and the compound can be easily peeled off from the roll. ×: The compound is not stably wound by bagging or sticking, and the compound cannot be peeled off from the roll.
The winding conditions were such that the roll temperature was the front roll / rear roll = 50 ° C./50° C., the roll peripheral speed was the front roll / rear roll = 18 rpm / 15 rpm, and the roll gap was 0.5 mm.

[Preparation of rubber molded product]
A kneaded material was prepared by the same operation using the same raw materials as described in [Evaluation of roll workability of compound].

  Next, after confirming that the temperature of the kneaded product reached 40 ° C., a 6-inch roll was used as a vulcanization accelerator for the kneaded product (the weight of the rubber component in the kneaded product was 100 parts by weight). "Sunseller M" (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.) 0.5 parts by weight, "Sunseller TT" (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.) as 1.0 parts by weight as a vulcanization accelerator, As a vulcanizing agent, 1.5 parts by weight of sulfur was kneaded. The kneading conditions were as follows: roll temperature: front roll / rear roll = 50 ° C./50° C., roll peripheral speed: front roll / rear roll = 18 rpm / 15, roll gap was 2 mm, and kneading time was 10 minutes.

  Next, the kneaded product was vulcanized at 160 ° C. for 20 minutes using a press molding machine to prepare a rubber sheet having a thickness of 2 mm. The obtained rubber molded article was subjected to a tensile test, a hardness test, an extractability test, and an ozone resistance test by the following methods.

[Tensile test]
The rubber molded product was subjected to a tensile test according to JIS K6251 under the conditions of a measurement temperature of 23 ° C. and a tensile speed of 500 mm / min, and the strength at break (TB) and elongation at break (EB) were measured.

[Hardness test]
The rubber molded product hardness (type A durometer, HA) was measured by using 6 sheets of 2 mm sheet-like rubber molded products having a smooth surface and stacking flat portions to a thickness of about 12 mm. However, those in which foreign matter was mixed in the test piece, those having bubbles, and those having scratches were not used. Moreover, the dimension of the measurement surface of the test piece was set to such a size that measurement was possible at a position where the tip of the push needle was 12 mm or more away from the end of the test piece.

[Extractability test]
A 2 cm square test piece was punched out of the rubber molded product, and the weight of the test piece was measured. Thereafter, the taken out test piece was left in a fume hood for 1 hour and further subjected to a drying treatment in a vacuum dryer at a drying temperature of 80 ° C. and a drying time of 2 hours. After being taken out and left at room temperature for 30 minutes, the weight of the test piece was measured. The weight change rate was determined from the value obtained by subtracting the pre-test weight from the post-test weight and dividing by the pre-test weight.

[Ozone resistance test]
The rubber molded product was subjected to an ozone resistance test in accordance with JIS K6259 under the conditions of a measurement temperature of 40 ° C., an ozone concentration of 50 ± 5 pphm), and a test time of 72 hours to determine whether the rubber molded product had surface tackiness. The case where the surface state was the same as before the test was evaluated as ◯, and the case where tackiness (solid) was observed was evaluated as ×.

[Example 1]
The rubber composition and rubber molded product of the present invention were obtained by the following production method.
100 parts by weight of rubber component [(high viscosity ethylene copolymer (H); Mitsui EPT4045M (Mitsui Chemicals) Co., Ltd.) and 65 parts by weight of a low-viscosity ethylene copolymer (L); 35 parts by weight of copolymer 1), “Zinc oxide 2 types” (trade name; 5 parts by weight (manufactured by Sakai Chemical Industry Co., Ltd.), 1 part by weight of stearic acid as a processing aid, and 80 parts by weight of “Asahi # 60G” (trade name; manufactured by Asahi Carbon Co., Ltd., carbon black) as a reinforcing agent In the examples, 30 parts by weight of “Diana Process Oil PS-430” (trade name; manufactured by Idemitsu Kosan Co., Ltd.) was further kneaded as a softening agent. The kneading conditions were a rotor speed of 50 rpm, a floating weight pressure of 3 kg / cm ² , a kneading time of 5 minutes, and a kneading discharge temperature of 152 ° C.

  Next, after confirming that the temperature of the kneaded product reached 40 ° C., “Sunseller M” (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.) was added to the kneaded product using a 6-inch roll as a vulcanization accelerator. .5 parts by weight, 1.0 part by weight of “Sunseller TT” (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.) as a vulcanization accelerator, and 1.5 parts by weight of sulfur as a vulcanizing agent were kneaded. The kneading conditions were as follows: roll temperature: front roll / rear roll = 50 ° C./50° C., roll peripheral speed: front roll / rear roll = 18 rpm / 15 rpm, roll gap of 2 mm, and kneading time 10 minutes.

  Next, the kneaded product was vulcanized at 160 ° C. for 20 minutes using a press molding machine to prepare a rubber sheet having a thickness of 2 mm. About the obtained rubber molding, said tension test, hardness test, extractability test, and ozone resistance test were done by the said method. Table 2 shows the physical properties of the rubber composition and the physical properties of the rubber sheet molded product.

[Example 2]
The same procedure as in Example 1 was performed except that the low viscosity ethylene copolymer (L) was changed to the copolymer 2. The evaluation results of the obtained rubber composition and the physical properties of the rubber sheet molded product are shown in Table 2.

Example 3
The same procedure as in Example 1 was performed except that the low-viscosity ethylene copolymer (L) was changed to the copolymer 3. The evaluation results of the composition obtained and the physical properties of the rubber sheet molded product are shown in Table 2.

[Comparative Example 1]
The same procedure as in Example 1 was performed except that the low viscosity ethylene copolymer (L) was changed to the copolymer 4. The evaluation results of the obtained rubber composition and the physical properties of the rubber sheet molded product are shown in Table 2.

[Comparative Example 2]
The same procedure as in Example 1 was performed except that the low viscosity ethylene copolymer (L) was changed to the copolymer 5. The evaluation results of the obtained rubber composition and the physical properties of the rubber sheet molded product are shown in Table 2.

[Comparative Example 3]
The same procedure as in Example 1 was performed except that the low viscosity ethylene copolymer (L) was changed to the copolymer 6. The evaluation results of the obtained rubber composition and the physical properties of the rubber sheet molded product are shown in Table 2.

[Comparative Example 4]
The same procedure as in Example 1 was performed except that the low-viscosity ethylene copolymer (L) was changed to the copolymer 7. The evaluation results of the obtained rubber composition and the physical properties of the rubber sheet molded product are shown in Table 2.

[Comparative Example 5]
The same procedure as in Example 1 was performed except that the low viscosity ethylene copolymer (L) was changed to the copolymer 8. The evaluation results of the obtained rubber composition and the physical properties of the rubber sheet molded product are shown in Table 2.

Claims (7)

5-50 parts by weight of low viscosity ethylene copolymer (L) and 95-50 parts by weight of high viscosity ethylene copolymer (H) [However, the weight of copolymer (L) and copolymer (H) And the total weight is 100 parts by weight], and a rubber composition comprising a crosslinking agent,
The low-viscosity ethylene copolymer (L) is obtained by using a metallocene catalyst represented by the following general formula (X), a boron compound and / or an organoaluminum compound, and ethylene [A], carbon An ethylene copolymer comprising a structural unit derived from an α-olefin [B] having 3 to 20 atoms and at least one non-conjugated polyene [C],
(1) The structural unit derived from ethylene [A] is contained in 50 to 90 mol% in 100 mol% of all the structural units of the copolymer (L),
(2) The structural unit derived from the non-conjugated polyene [C] is contained in an amount of 1.0 to 5.0 mol% in 100 mol% of all the structural units of the copolymer (L),
(3) The intrinsic viscosity [η] measured in a decalin solution at 135 ° C. of the copolymer (L) is 0.25 to 0.55 dL / g,
(4) The inversion value represented by the following formula [I] of the copolymer (L) is 0.01 to 0.50:

(In the formula [I], when βγ is focused on an arbitrary methylene carbon constituting the main chain of the copolymer, methine carbon is present at a position 2 bonds away from the carbon and at a position 3 bonds away from the opposite side. Shows the sum of the integrated values of the ¹³ C-NMR peaks of the methylene carbon present,
ββ represents the total integrated value of ¹³ C-NMR peaks of methylene carbon in which methine carbon is present on both sides separated by 2 bonds from the carbon when focusing on an arbitrary methylene carbon constituting the main chain. )

(In the formula (X), R ′ and R ″ are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, M is titanium, Y is —NR ^* —, and Z ^* is -SiR ^* _2- , and the two R ^{* s} are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, one of p and q is 0, and the other is 1.
when p is 0 and q is 1, M is in the +2 oxidation state, X ′ is 1,4-diphenyl-1,3-butadiene or 1,3-pentadiene;
When p is 1 and q is 0, M is in the +3 oxidation state and X is 2- (N, N-dimethylamino) benzyl. );
The high-viscosity ethylene copolymer (H) is a structural unit derived from ethylene [A ′], an α-olefin [B ′] having 3 to 20 carbon atoms, and at least one non-conjugated polyene [C ′]. An ethylene copolymer comprising
(1 ′) The structural unit derived from ethylene [A ′] is contained in an amount of 50 to 90 mol% in 100 mol% of all the structural units of the copolymer (H).
(2 ′) The structural unit derived from the non-conjugated polyene [C ′] is included in an amount of 0.5 to 5.0 mol% in 100 mol% of all the structural units of the copolymer (H).
(3 ′) A rubber composition having an intrinsic viscosity [η] measured in a decalin solution at 135 ° C. of the copolymer (H) of 1.0 to 5.0 dL / g. The intrinsic viscosity measured at decalin solution at 135 ° C. Low viscosity ethylene copolymer (L) [η] is, according to claim 1, which is a 0.30~0.50dL / g Rubber composition. Structural units derived from the ethylene [A] is the total structural units in 100 mole% of the ethylene copolymer (L), according to claim 1 or 2, characterized in that included 55 to 85 mol% Rubber composition. The rubber composition according to any one of claims 1 to 3 , wherein the non-conjugated polyene [C] is 5-ethylidene-2-norbornene (ENB). The rubber composition according to any one of claims 1 to 4 , wherein an inversion value of the low-viscosity ethylene-based copolymer (L) is 0.03 to 0.30. A rubber molded product obtained by molding the rubber composition according to any one of claims 1 to 5 . A rubber molded product obtained by crosslinking after molding the rubber composition according to any one of claims 1 to 5 , or after molding.