JP2022102670A - AUTOMOTIVE RUBBER COMPONENT CONTAINING ETHYLENE-α OLEFIN-NONCONJUGATED POLYENE COPOLYMER, AND METHOD FOR PRODUCING THE SAME - Google Patents

Abstract

To provide an automotive rubber component such as an automotive radiator hose having excellent thermal aging resistance, comprising an ethylene-α olefin-nonconjugated polyene copolymer composition.SOLUTION: An automotive rubber component contains (A) an ethylene-α olefin-nonconjugated polyene copolymer, (B) a plasticizer, (C) magnesium hydroxide, and (D) organic peroxide.SELECTED DRAWING: None

Description

The present invention relates to an automobile rubber component such as a radiator hose for an automobile having excellent heat aging resistance and containing an ethylene / α-olefin / non-conjugated polyene copolymer and a method for producing the same.

For automobiles, industrial machinery, construction machinery, motorbikes, agricultural machinery, etc., radiator hoses for cooling the engine, drain hoses for radiator overflow, heater hoses for room heating, air conditioner drain hoses, wiper water supply hoses, roof drain hoses, professionals Rubber parts such as various hoses such as lacto hoses are attached. Ethylene-propylene-diene copolymer (EPDM) having good ozone resistance, weather resistance, and heat resistance is used for these hoses.

For example, it is known that in a radiator hose for an automobile, a phenomenon in which the hose itself is corroded and deteriorated due to a minute current flowing through the vehicle body occurs, which causes water leakage. As a solution to this problem, as described in Patent Documents 1 and 2, it is said that improvement of the volume resistivity of the hose material and no addition of zinc oxide are effective.

On the other hand, rubber parts for automobiles such as radiator hoses have high strength and excellent hydrolyzability because the engine room becomes hot, and have excellent durability against ethylene glycol solvents, alkaline solvents, and acidic solvents. , It is required to further improve the heat aging property.

Japanese Unexamined Patent Publication No. 2001-031813 Japanese Unexamined Patent Publication No. 2012-72291

An object of the present invention is to obtain an automobile rubber component such as a radiator hose for an automobile, which is composed of an ethylene / α-olefin / non-conjugated polyene copolymer composition and has excellent heat resistance and aging resistance.

The present invention
(A) Ethylene / α-olefin / non-conjugated polyene copolymer,
(B) Plasticizer,
(C) Magnesium hydroxide, and (D) Organic peroxide,
The present invention relates to rubber parts for automobiles, which are characterized by containing.

The rubber parts for automobiles of the present invention have significantly improved heat aging resistance and are excellent in durability.

FIG. 1 is a schematic view of a continuous polymerization apparatus for producing the ethylene / propylene / VNB copolymer (A-1) used in the examples.

<< Ethylene / α-olefin / non-conjugated polyene copolymer (A) >>
Ethylene / α-olefin / non-conjugated polyene copolymer (A) [hereinafter, may be referred to as “copolymer (A)”, which is one of the components contained in the rubber component for automobiles of the present invention. ] Is an ethylene / α-olefin / non-conjugated polyene copolymer having a structural unit derived from ethylene (a1), α-olefin (a2) and non-conjugated polyene (a3).

The α-olefin (a2) constituting the copolymer (A) is usually an α-olefin having 3 to 20 carbon atoms, and is propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1. -Pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene and the like can be mentioned. Of these, α-olefins having 3 to 8 carbon atoms such as propylene, 1-butene, 1-hexene, and 1-octene are preferable, and propylene is particularly preferable. Since such α-olefins have a relatively low raw material cost, the obtained copolymer (A) exhibits excellent mechanical properties, and rubber parts for automobiles having rubber elasticity can be obtained. preferable.

The α-olefin (a2) constituting the copolymer (A) according to the present invention may be used alone or in combination of two or more. That is, the copolymer (A) contains a structural unit derived from at least one kind of α-olefin (a2) having 3 to 20 carbon atoms, and two or more kinds of α having 3 to 20 carbon atoms. -It may contain a structural unit derived from the olefin (a2).

The non-conjugated polyene (a3) constituting the copolymer (A) according to the present invention is not particularly limited as long as it is a compound having two or more unconjugated unsaturated bonds, but is not particularly limited as long as it is a compound having two or more unconjugated unsaturated bonds, but the following general formulas (I) and (II). A non-conjugated polyene containing two or more partial structures selected from the group consisting of two or more in a molecule is preferable.

上記非共役ポリエン（ａ３）としては、具体的には、５－ビニル－２－ノルボルネン（ＶＮＢ）、ノルボルナジエン、１，４－ヘキサジエン、ジシクロペンタジエンなどが挙げられる。これらのうちでは、入手容易性が高く、重合後の架橋反応時に過酸化物との反応性が良好で、エチレン系共重合体組成物の耐熱老化性が向上しやすいことから、非共役ポリエン（ａ３）がＶＮＢを含むことが好ましく、非共役ポリエン（ａ３）がＶＮＢであることがより好ましい。非共役ポリエン（ａ３）は一種単独で用いても、二種以上を用いてもよい。

Specific examples of the non-conjugated polyene (a3) include 5-vinyl-2-norbornene (VNB), norbornadiene, 1,4-hexadiene, and dicyclopentadiene. Among these, non-conjugated polyenes (non-conjugated polyenes) are highly available, have good reactivity with peroxides during the cross-linking reaction after polymerization, and easily improve the heat aging resistance of the ethylene-based copolymer composition. It is preferable that a3) contains VNB, and it is more preferable that the non-conjugated polyene (a3) is VNB. The non-conjugated polyene (a3) may be used alone or in combination of two or more.

The copolymer (A) according to the present invention is further selected from the group consisting of the above general formulas (I) and (II) in addition to the structural units derived from the above (a1), (a2) and (a3). It may have a structural unit derived from a non-conjugated polyene (a4) containing only one partial structure in the molecule.

Examples of the non-conjugated polyene (a4) include 5-ethylidene-2-norbornene (ENB), 5-methylene-2-norbornene, 5- (2-propenyl) -2-norbornene, and 5- (3-butenyl) -2. -Norbornene, 5- (1-methyl-2-propenyl) -2-norbornene, 5- (4-pentenyl) -2-norbornene, 5- (1-methyl-3-butenyl) -2-norbornene, 5-( 5-hexenyl) -2-norbornene, 5- (1-methyl-4-pentenyl) -2-norbornene, 5- (2,3-dimethyl-3-butenyl) -2-norbornene, 5- (2-ethyl- 3-Butenyl) -2-norbornene, 5- (6-heptenyl) -2-norbornene, 5- (3-methyl-5-hexenyl) -2-norbornene, 5- (3,4-dimethyl-4-pentenyl) -2-Norbornene, 5- (3-ethyl-4-pentenyl) -2-Norbornene, 5- (7-octenyl) -2-Norbornene, 5- (2-Methyl-6-Heptenyl) -2-Norbornene, 5 -(1,2-dimethyl-5-hexenyl) -2-norbornene, 5- (5-ethyl-5-hexenyl) -2-norbornene, 5- (1,2,3-trimethyl-4-pentenyl) -2 -Norbornene and the like. Among these, ENB is preferable because it is easily available, has high reactivity with sulfur and a vulcanization accelerator during the crosslinking reaction after polymerization, it is easy to control the crosslinking rate, and it is easy to obtain good mechanical properties. .. The non-conjugated polyene (a4) may be used alone or in combination of two or more.

When the copolymer (A) according to the present invention contains a structural unit derived from the non-conjugated polyene (a4), the proportion thereof is not particularly limited as long as the object of the present invention is not impaired, but is usually used. , 0 to 20% by weight, preferably 0 to 8% by weight, more preferably 0.01 to 8% by weight (however, (a1), (a2), (a3), (a4). The total weight fraction of is 100% by weight).

It is preferable that the copolymer (A) according to the present invention satisfies the following requirements (i) to (v) (hereinafter, also referred to as requirements (i) to (v), respectively).
(I) The molar ratio of ethylene (a1) / α-olefin (a2) is 40/60 to 99.9 / 0.1.
(Ii) The weight fraction of the constituent unit derived from the non-conjugated polyene (a3) is 0.07% by weight to 10% by weight in 100% by weight of the ethylene / α-olefin / non-conjugated polyene copolymer.
(Iii) The weight average molecular weight (Mw) of the ethylene / α-olefin / non-conjugated polyene copolymer and the weight fraction (% by weight) of the structural unit derived from the non-conjugated polyene (a3). )) And the molecular weight of the non-conjugated polyene (a3) (molecular weight of (a3)) satisfy the following formula (1).
4.5 ≦ Mw × weight fraction of (a3) / 100 / molecular weight of (a3) ≦ 40 ... (1)
(Iv) Complex viscosity η ^* ₍ ω _{= 0.1)} (Pa · sec) at frequency ω = 0.1 rad / s and frequency ω = 100 rad obtained by linear viscous elasticity measurement using a leometer (190 ° C). The ratio P (η ^* ₍ ω _{= 0.1)} / η ^* ₍ ω _{= 100)} ) to the complex viscosity η ^* ₍ ω _{= 100)} (Pa · sec) at / s, the extreme viscosity [η], and the above non-viscosity. The weight fraction of the structural unit derived from the conjugated polyene (a3) (weight fraction of (a3)) satisfies the following formula (2).
P / ([η] ^2.9 ) ≤ (a3) weight fraction x 6 ... (2)
(V) The number of long-chain branches per 1000 carbon atoms (LCB _1000C ) obtained using 3D-GPC and the natural logarithm [Ln (Mw)] of the weight average molecular weight (Mw) are given by the following formula (3). Meet.
LCB _1000C ≤1-0.07 x Ln (Mw) ... (3)

≪Requirement (i) ≫
Requirement (i) specifies that the molar ratio of ethylene (a1) / α-olefin (a2) in the copolymer (A) satisfies 40/60 to 99.9 / 0.1. The molar ratio is preferably 50/50 to 90/10, more preferably 55/45 to 85/15, and even more preferably 55/45 to 78/22.

By using the copolymer (A) satisfying the requirement (i), it is possible to obtain rubber parts for automobiles having excellent rubber elasticity, mechanical strength and flexibility. The amount of ethylene (content of the structural unit derived from ethylene (a1)) and the amount of α-olefin (content of the structural unit derived from α-olefin (a2)) in the copolymer (A) are ¹³ C-. It can be obtained by NMR.

≪Requirements (ii) ≫
The requirement (ii) is that in the polymer (A) according to the present invention, the weight fraction of the structural unit derived from the non-conjugated polyene (a3) is 100% by weight of the copolymer (A) (that is, the total composition). It is specified that the weight fraction of the unit is in the range of 0.07% by weight to 10% by weight in 100% by weight). The weight fraction of the structural unit derived from this non-conjugated polyene (a3) is preferably 0.1% by weight to 8.0% by weight, more preferably 0.5% by weight to 5.0% by weight.

The copolymer (A) satisfying the requirement (ii) has sufficient hardness and excellent mechanical properties, and when crosslinked using a peroxide, it exhibits a high crosslinking rate. The amount of the non-conjugated polyene (a3) in the copolymer (A) (content of the structural unit derived from the non-conjugated polyene (a3)) can be determined by ¹³ C-NMR.

≪Requirements (iii)≫
The requirement (iii) is derived from the weight average molecular weight (Mw) of the polymer (A) and the non-conjugated polyene (a3) in the polymer (A) in the polymer (A) according to the present invention. It specifies that the weight fraction of the constituent unit (weight fraction of (a3): weight%) and the molecular weight of the non-conjugated polyene (a3) (molecular weight of (a3)) satisfy the above formula (1). Is. The above formula (1) of the requirement (iii) is preferably the following formula (1').
4.5 ≤Mw x (a3) weight fraction / 100 / (a3) molecular weight ≤35 ... (1')

When the copolymer (A) according to the present invention satisfies the requirement (iii), the content of the structural unit derived from the non-conjugated polyene (a3) is appropriate, the cross-linking performance is sufficient, and the cross-linking speed is increased. It is possible to manufacture rubber parts for automobiles that are excellent and exhibit excellent mechanical properties. The weight average molecular weight (Mw) of the copolymer (A) can be determined as a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

In the copolymer (A) according to the present invention, when "weight fraction of Mw × (a3) / molecular weight of 100 / (a3)" satisfies the above formula (1) or (1'), the degree of crosslinking is appropriate. Therefore, it is possible to manufacture rubber parts for automobiles having an excellent balance between mechanical properties and heat aging resistance. If the value of "weight fraction of Mw × (a3) / 100 / molecular weight of (a3)" is too low, the crosslinkability may be insufficient and the crosslinking rate may be slowed down, and if the value is too high. , Excessive cross-linking may occur and the mechanical properties may deteriorate.

≪Requirements (iv) ≫
The requirement (iv) is the complex viscosity η ^* ₍ ω _{= 0.1} ) at the frequency ω = 0.1 rad / s obtained by the linear viscous elasticity measurement (190 ° C.) of the copolymer (A) using a reometer. ₎ (Pa · sec) and complex viscosity η ^* ₍ ω _{= 100)} (Pa · sec) at frequency ω = 100 rad / s ratio P (η ^* ₍ ω _{= 0.1)} / η ^* ₍ ω _{= 100)} ), The extreme viscosity [η], and the weight fraction of the constituent unit derived from the non-conjugated polyene (a3) (weight fraction of (a3): weight%) are specified to satisfy the above formula (2). It is something to do. The above equation (2) of the requirement (iv) is preferably the following equation (2').
P / ([η] ^2.9 ) ≤ (a3) weight fraction x 5.7 ... (2')

Here, the ratio P (η ^* ₍ ω)) of the complex viscosity η ^* ₍ ω _{= 0.1)} at the frequency ω = 0.1 rad / s and the complex viscosity η ^* ₍ ω _{= 100)} at the frequency ω = 100 rad / s. _{= 0.1)} / η ^* ₍ ω _{= 100)} ) represents the frequency dependence of viscosity, and P / ([η] ^2.9 ), which corresponds to the left side of equation (2), indicates short-chain branching, molecular weight, etc. Although there is an effect, it tends to show a high value when there are many long-chain branches. Generally, in an ethylene / α-olefin / non-conjugated polyene copolymer, the more structural units derived from the non-conjugated polyene, the more long-chain branches tend to be contained. However, the copolymer (A) according to the present invention. Is considered to be able to satisfy the above formula (2) because it has fewer long-chain branches than the conventionally known ethylene / α-olefin / non-conjugated polyene copolymer.

In the present invention, the P value is a complex viscosity at 0.1 rad / s obtained by measuring the viscoelasticity measuring device Ares (manufactured by Rheometric Scientific) at 190 ° C., strain 1.0%, and changing the frequency. And the complex viscosity at 100 rad / s, the ratio (η ^* ratio) was calculated. The ultimate viscosity [η] means a value measured in decalin at 135 ° C.

≪Requirements (v) ≫
The requirement (v) is the natural number of long-chain branches (LCB _1000C ) per 1000 carbon atoms obtained by using 3D-GPC of the copolymer (A) according to the present invention, and the natural weight average molecular weight (Mw). The logarithm [Ln (Mw)] specifies that the above equation (3) is satisfied. The above formula (3) of the requirement (v) is preferably the following formula (3').
LCB _1000C ≤1-0.071 × Ln (Mw) ... (3')

The upper limit of the long chain branching content per unit carbon number of the copolymer (A) according to the present invention is specified by the above formula (3) or (3').

When the copolymer (A) according to the present invention satisfies the requirement (v), the proportion of long-chain branches contained is small, the curing characteristics when cross-linking is performed using a peroxide are excellent, and the heat aging property is excellent. It is possible to obtain excellent rubber parts for automobiles.

Here, Mw and the number of long-chain branches per 1000 carbon atoms (LCB _1000C ) can be obtained by a structural analysis method using 3D-GPC. Specifically, in the present specification, it is obtained as follows.

Using a 3D-high temperature GPC device PL-GPC220 type (manufactured by Polymer Laboratories), the absolute molecular weight distribution was determined, and at the same time, the ultimate viscosity was determined with a viscometer. The main measurement conditions are as follows.
Detector: Differential refractometer / Built-in GPC device 2-angle light scattering photometer PD2040 type (manufactured by Precison Detectors)
Bridge type viscometer PL-BV400 type (manufactured by Polymer Laboratories)
Column: TSKgel GMH _HR -H (S) HT x 2 + TSKgel GMH _HR -M (S) x 1 (each has an inner diameter of 7.8 mmφ x length of 300 mm)
Temperature: 140 ℃
Mobile phase: 1,2,4-trichlorobenzene (containing 0.025% BHT)
Injection volume: 0.5 mL
Sample concentration: ca 1.5mg / mL
Sample filtration: Filtration with a 1.0 μm pore size sintered filter In the above, the dn / dc value required to determine the absolute molecular weight is the dn / dc value of 0.053 for standard polystyrene (molecular weight 190000) and the differential refractometer per unit injection mass. It was determined for each sample from the response intensity.

From the relationship between the ultimate viscosity obtained from the viscometer and the absolute molecular weight obtained from the light scattering photometer, the long-chain branching parameter g'i for each elution component was calculated from the following formula (v-1).

Here, the relational expression of [η] = KM ^v ; v = 0.725 was applied.
Further, each average value was calculated as g'from the following equations (v-2), (v-3), and (v-4). The Trendline, which was assumed to have only short-chain branches, was determined for each sample.

Further, using g'w, the number of branch points BrNo per molecular chain, the number of long-chain branching LCB _1000C per 1000 carbons, and the degree of branching λ per unit molecular weight were calculated. The following formulas (v-5) of Zimm-Stockmayer were used to calculate BrNo, and the following formulas (v-6) and (v-7) were used to calculate LCB _1000C and λ. g is a long-chain branching parameter obtained from the radius of inertia Rg, and the following simple correlation is made with g'determined from the ultimate viscosity. Various values of ε in the equation have been proposed depending on the shape of the molecule. Here, the calculation was performed on the assumption that ε = 1 (that is, g'= g).

λ = BrNo / M ... (V-6)
LCB _1000C = λ × 14000 ... (V-7)
In the formula (V-7), "14000" represents the molecular weight of 1000 pieces in methylene (CH ₂ ) units.

The ultimate viscosity [η] of the copolymer (A) according to the present invention is preferably 0.1 to 5 dL / g, more preferably 0.5 to 5.0 dL / g, still more preferably 0.9 to 4. It is 0 dL / g.

The weight average molecular weight (Mw) of the copolymer (A) according to the present invention is preferably 10,000 to 600,000, more preferably 30,000 to 500,000, still more preferably 50,000 to 400. It is 000.

It is preferable that the copolymer (A) according to the present invention has both the above-mentioned extreme viscosity [η] and weight average molecular weight (Mw).
In the copolymer (A) according to the present invention, as described above, the non-conjugated polyene (a3) preferably contains VNB, and more preferably VNB. That is, in the above-mentioned formulas (1), (2) and the formula (4) described later, it is preferable that the "weight fraction of (a3)" is the "weight fraction of VNB" (% by weight).

As described above, the copolymer (A) according to the present invention is further derived from the non-conjugated polyene (a4) in addition to the structural units derived from the above (a1), (a2) and (a3). The constituent unit may be included in a weight fraction of 0% by weight to 20% by weight (however, the total weight fraction of (a1), (a2), (a3), and (a4) is 100% by weight). preferable. In this case, it is preferable to satisfy the requirement (vi) below.

≪Requirements (vi)≫
The weight average molecular weight (Mw) of the copolymer (A) according to the present invention, the weight fraction of the structural unit derived from the non-conjugated polyene (a3) (weight fraction (% by weight) of (a3)), and non-coupling. The weight fraction of the constituent unit derived from the conjugated polyene (a4) (the weight fraction (% by weight) of (a4)), the molecular weight of the non-conjugated polyene (a3) (the molecular weight of (a3)), and the non-conjugated polyene ( The molecular weight of a4) (molecular weight of (a4)) satisfies the following formula (4).
4.5 ≤ Mw x {(weight fraction of (a3) / 100 / molecular weight of (a3)) + (weight fraction of (a4) / 100 / molecular weight of (a4))} ≤ 45 ... 4)
In the formula (4), the content of the non-conjugated diene (the sum of (a3) and (a4)) in one molecule of the copolymer is specified.

When the copolymer (A) containing the structural unit derived from the above (a4) satisfies the formula (4), a rubber component for an automobile having excellent mechanical properties and heat aging resistance can be obtained.
The requirement (vi) is not satisfied, and “Mw × {(weight fraction of (a3) / 100 / molecular weight of (a3)) + (weight fraction of (a4) / 100 / (a4)) in the formula (4). If the value of "Molecular weight)}" is too low, that is, if the content of non-conjugated diene is too low, sufficient cross-linking may not be achieved and appropriate mechanical properties may not be obtained, and if the value is too high, that is, non-conjugated diene. If the content of the conjugated diene is too large, the cross-linking may be excessive and the mechanical properties may be deteriorated, and the heat aging property may be further deteriorated.

≪Requirements (vii)≫
The copolymer (A) according to the present invention is not particularly limited, but is a complex obtained by linear viscous elasticity measurement (190 ° C.) using a leometer at a frequency of ω = 0.01 rad / s. Viscosity η ^* ₍ ω _{= 0.01)} (Pa · sec), complex viscosity η ^* ₍ ω _{= 10)} (Pa · sec) at frequency ω = 10 rad / s, and apparent origin from non-conjugated polymer (a3). It is preferable that the iodine value satisfies the following formula (5).
Log {η ^* ₍ ω _{= 0.01)} } / Log {η ^* ₍ ω _{= 10)} } ≤0.0753 × {apparent iodine value derived from non-conjugated polyene (a3)} +1.42 ... (5) )

Here, the complex viscosity η ^* ₍ ω _{= 0.01)} and the complex viscosity η ^* ₍ ω _{= 10)} are measured as the complex viscosity η ^* ₍ ω _{= 0.1)} and the complex viscosity η ^* ₍ ω _{= 100)} in the requirement (iv). Other than the frequency, it is obtained in the same way. Further, the apparent iodine value derived from the non-conjugated polyene (a3) can be obtained by the following formula.
Apparent iodine value derived from (a3) = weight fraction of (a3) x 253.81 / molecular weight of (A3)

In the above equation (5), the left side represents the shear rate dependence which is an index of the long chain branch amount, and the right side represents the index of the content of the non-conjugated polyene (a3) which is not consumed as the long chain branch during polymerization. When the copolymer (A) satisfies the above formula (5), the degree of long-chain branching is not too high, which is preferable. On the other hand, when the above formula (5) is not satisfied, it can be seen that the proportion of the copolymerized non-conjugated polyene (a3) consumed for the formation of the long chain branch is large.

Further, the copolymer (A) according to the present invention preferably contains a structural unit derived from the non-conjugated polyene (a3) in a sufficient amount, and is derived from the non-conjugated polyene (a3) in the copolymer. It is more preferable that the weight fraction of the constituent unit (weight fraction (% by weight) of (a3)) and the weight average molecular weight (Mw) of the copolymer satisfy the following formula (6).
6-0.45 × Ln (Mw) ≦ (a3) weight fraction ≦ 10 ... (6)

Further, in the copolymer (A) according to the present invention, the number of structural units (na3) derived from the non-conjugated polyene ( _a3 ) per weight average molecular weight (Mw) is preferably 6 or more, more preferably. Is 6 or more and 40 or less, more preferably 7 or more and 39 or less, and particularly preferably 10 or more and 38 or less.

The copolymer (A) according to the present invention contains a sufficient amount of a structural unit derived from a non-conjugated polyene (a3) such as VNB, has a low long-chain branching content, and uses a peroxide. It has excellent curing properties when cross-linking, good moldability, excellent balance of physical properties such as mechanical properties, and particularly excellent heat aging resistance.

Further, in the copolymer (A) according to the present invention, the number of structural units (na4) derived from the non-conjugated polyene ( _a4 ) per weight average molecular weight (Mw) is preferably 29 or less, more preferably. Is 10 or less, more preferably less than 1.

In such a copolymer (A), the content of the structural unit derived from the non-conjugated polyene (a4) such as ENB is suppressed to the extent that the object of the present invention is not impaired, and post-crosslinking is unlikely to occur, which is sufficient. Has excellent heat aging resistance.

Here, it is derived from the number of structural units (n _a3 ) derived from the non-conjugated polyene (a3) or the non-conjugated polyene (a4) per weight average molecular weight (Mw) of the copolymer (A) according to the present invention. The number of structural units ( _na4 ) is the molecular weight of the non-conjugated polyene (a3) or (a4) and the weight fraction of the structural units derived from the non-conjugated polyene (a3) or (a4) in the copolymer (((a4)). It can be obtained by the following formula from the weight fraction (% by weight) of a3) or (a4) and the weight average molecular weight (Mw) of the copolymer (A).

(N _a3 ) = (Mw) × {weight fraction of (a3) / 100} / molecular weight of non-conjugated polyene (a3) (n _a4 ) = (Mw) × {weight fraction of (a4) / 100} / Molecular weight of non-conjugated polyene (a4)

In the copolymer (A) according to the present invention, the number (n _a3 ) and (n _a4 ) of the respective structural units derived from the non-conjugated polyenes (a3) and (a4) per weight average molecular weight (Mw) are determined. When all of them satisfy the above range, the copolymer (A) has a small long-chain branching content, excellent curing characteristics when cross-linking using a peroxide, good moldability, and a machine. It is preferable because it has an excellent balance of physical properties such as physical properties, is less likely to cause post-crosslinking, and is particularly excellent in heat aging resistance.

<< Method for producing ethylene / α-olefin / non-conjugated polyene copolymer (A) >>
The ethylene / α-olefin / non-conjugated polyene copolymer (A) according to the present invention includes ethylene (a1), α-olefin (a2), non-conjugated polyene (a3), and if necessary, non-conjugated polyene. It is a copolymer obtained by copolymerizing a monomer composed of (a4).

The copolymer (A) according to the present invention may be prepared by any production method as long as the above requirements (i) to (iv) are satisfied, but the monomer is copolymerized in the presence of the metallocene compound. It is preferable that it is obtained by copolymerizing a monomer in the presence of a catalytic system containing a metallocene compound, and more preferably.

As a specific method for producing the above-mentioned copolymer (A) according to the present invention, for example, a production method using a metallocene catalyst described in JP-A-2018-119096 and International Publication No. 2015/122495 is adopted. It can be manufactured by.

<< Ethylene / α-olefin / (non-conjugated polyene) copolymer (F) >>
In addition to the above-mentioned copolymer (A), the rubber component for an automobile of the present invention includes ethylene, α-olefin, (non-conjugated polyene copolymer) (F) [hereinafter, abbreviated as "copolymer (F)". May be done. ] Is an ethylene / α-olefin / (non-) obtained by randomly copolymerizing ethylene (b1) and α-olefin (b2), or ethylene (b1), α-olefin (b2) and non-conjugated polyene (b3). Conjugated polyene) It is a copolymer and may be a copolymer containing no non-conjugated polyene or a copolymer containing a non-conjugated polyene.

The α-olefin (b2) constituting the copolymer (F) is usually an α-olefin having the same carbon number of 3 to 20 as the α-olefin (a2) constituting the copolymer (A) according to the present invention. For example, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene. , 1-Eikosen and the like. Of these, α-olefins having 3 to 8 carbon atoms such as propylene, 1-butene, 1-hexene, and 1-octene are preferable, and propylene and 1-butene are particularly preferable. Since such α-olefins have a relatively low raw material cost, the obtained copolymer (F) exhibits excellent mechanical properties, and rubber parts for automobiles having rubber elasticity can be obtained. preferable.

The α-olefin (b2) constituting the copolymer (F) according to the present invention may be used alone or in combination of two or more. That is, the copolymer (F) contains a structural unit derived from at least one kind of α-olefin (b2) having 3 to 20 carbon atoms, and two or more kinds of α having 3 to 20 carbon atoms. -It may contain a structural unit derived from an olefin (b2).

The non-conjugated polyene (b3) constituting the copolymer (F) according to the present invention has a non-conjugated unsaturated bond in the same category as the non-conjugated polyene (a4) constituting the copolymer (A) according to the present invention. It is a compound having two or more, specifically, a non-conjugated polyene containing one partial structure selected from the group consisting of the above general formula (I) in the molecule, specifically, a non-conjugated polyene (b3). ), 5-Etilidene-2-norbornene (ENB), 5-methylene-2-norbornene, 5- (2-propenyl) -2-norbornene, 5- (3-butenyl) -2-norbornene, 5- (1) -Methyl-2-propenyl) -2-norbornene, 5- (4-pentenyl) -2-norbornene, 5- (1-methyl-3-butenyl) -2-norbornene, 5- (5-hexenyl) -2- Norbornene, 5- (1-methyl-4-pentenyl) -2-norbornene, 5- (2,3-dimethyl-3-butenyl) -2-norbornene, 5- (2-ethyl-3-butenyl) -2- Norbornene, 5- (6-heptenyl) -2-norbornene, 5- (3-methyl-5-hexenyl) -2-norbornene, 5- (3,4-dimethyl-4-pentenyl) -2-norbornene, 5- (3-Ethyl-4-pentenyl) -2-norbornene, 5- (7-octenyl) -2-norbornene, 5- (2-methyl-6-heptenyl) -2-norbornene, 5- (1,2-dimethyl) -5-hexenyl) -2-norbornene, 5- (5-ethyl-5-hexenyl) -2-norbornene, 5- (1,2,3-trimethyl-4-pentenyl) -2-norbornene and the like can be mentioned. Among these, ENB is preferable because it is easily available, has high reactivity with sulfur and a vulcanization accelerator during the crosslinking reaction after polymerization, it is easy to control the crosslinking rate, and it is easy to obtain good mechanical properties. .. The non-conjugated polyene (b3) may be used alone or in combination of two or more.

The ethylene / α-olefin / non-conjugated polyene copolymer (F) according to the present invention usually has a molar ratio of ethylene to α-olefin (ethylene / α-olefin) of 40/60 to 90/10, preferably 40/60 to 90/10. Those in the range of 50/50 to 80/20, particularly preferably 55/45 to 70/30 are desirable.

These non-conjugated polyenes (b3) are used alone or in admixture of two or more, and the copolymerization amount thereof is 1 to 40, preferably 2 to 35, and more preferably 3 to 30 in terms of iodine value. Is desirable.

Among these non-conjugated polyenes, 5-ethylidene-2-norbornene (ENB) is preferable.
The ethylene / α-olefin / non-conjugated polyene copolymer (F) according to the present invention has an extreme viscosity [η] measured in 135 ° C. decahydronaphthalene, preferably 0.1 to 5 dL / g, more preferably 0. It is .5 to 5.0 dL / g, more preferably 0.9 to 4.0 dL / g.

The copolymer (F) according to the present invention may be a modified product obtained by graft-copolymerizing an unsaturated carboxylic acid or a derivative thereof, for example, an acid anhydride.
Examples of the copolymer (F) according to the present invention include ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / propylene / non-conjugated polyene copolymer and ethylene / 1-butene / non-conjugated polyene. Polymers are preferred.

The polymer (F) according to the present invention may be used alone or in combination of two or more. The ethylene / α-olefin / (non-conjugated polyene) copolymer (F) having the above-mentioned characteristics is described in "Polymer Production Process (Published by Kogyo Chosakai Co., Ltd., pp. 309-330)" and the like. It can be prepared by a known method as described above.

<< Plasticizer (B) >>
Specific examples of the plasticizer (B), which is one of the components contained in the rubber parts for automobiles according to the present invention, include process oil, lubricating oil, paraffin oil, liquid paraffin, petroleum asphalt, vaseline, and liquid ethylene / propylene. Mineral oils such as petroleum-based softeners such as polymers and liquid ethylene / 1-butene copolymers; Coultal-based softeners such as paraffin oil; Fats such as paraffin oil, linseed oil, rapeseed oil, soybean oil and palm oil Oil-based softeners; waxes such as beeswax and carnauba wax; fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate or salts thereof; naphthenic acid, pine oil, rosin or derivatives thereof; terpene resin, Synthetic polymer substances such as petroleum resin and Kumaron inden resin; ester-based softeners such as dioctylphthalate and dioctyl adipate; In addition, microcrystallin wax, liquid polybutadiene, modified liquid polybutadiene, hydrocarbon-based synthetic lubricating oil, tall oil, sub (Factis) and the like, mineral oils such as petroleum-based softeners are preferable, and paraffin-based hydrocarbons such as process oils are more preferable, and the kinematic viscosity at 40 ° C. is in the range of 300 mm ² / s to 500 mm ² / s. Paraffinic hydrocarbons in are preferred.

<< Magnesium hydroxide (C) >>
Magnesium hydroxide (C), which is one of the components contained in the rubber parts for automobiles of the present invention, is a kind of additives for rubber and plastics. The shape of the magnesium hydroxide (C) according to the present invention is not particularly limited, but the average aspect ratio of the particles is preferably 10 or more, more preferably 15 to 200, and further preferably 20 to 200.

The magnesium hydroxide (C) according to the present invention is, for example, stearic acid, anionic surfactant, phosphoric acid ester, silane coupling agent, titanate coupling agent, aluminum coupling agent, silicone-based treatment agent, water glass. , Silica, and one or more compounds selected from the group consisting of cationic surfactants may be surface-treated.

Magnesium hydroxide (C) according to the present invention is manufactured and sold by, for example, Kyowa Chemical Industry Co., Ltd. under trade names such as Kisma 5, Kisma 8, and Kisma 10A.

<< Organic Peroxide (D) >>
The organic peroxide (D), which is one of the components contained in the rubber component for automobiles of the present invention, is a kind of cross-linking agent, and specifically, dicumyl peroxide (DCP) and di-tert-butyl peroxide. , 2,5-Di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (tert- Butylperoxy) Hexin-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4- Bis (tert-butylperoxy) peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, ert-butylperoxyisopropyl carbonate, diacetylperoxide, lauroyl peroxide, tert-butylkumil Peroxides and the like can be mentioned.

Of these, dicumyl peroxide (DCP), 2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl. -2,5-di- (tert-butylperoxy) hexane-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethyl Organic peroxides such as cyclohexane and n-butyl-4,4-bis (tert-butylperoxy) valerates are preferred.

<Rubber parts for automobiles>
The rubber component for an automobile of the present invention comprises the ethylene / α-olefin / non-conjugated polyene copolymer (A), the plasticizer (B), the magnesium hydroxide (C), and the organic peroxide (D). including.

Hereinafter, in addition to the ethylene / α-olefin / non-conjugated polyene copolymer (A) constituting the rubber component for automobiles of the present invention, the plasticizer (B), the magnesium hydroxide (C), and the organic peroxide The composition containing the oxide (D) may be referred to as a "copolymer composition".

Since the copolymer composition constituting the rubber component for automobiles of the present invention contains the above-mentioned plasticizer (B) and the above-mentioned magnesium hydroxide (C), the roll processability is good.
The copolymer composition constituting the rubber parts for automobiles of the present invention preferably contains 30 parts by mass or less of the plasticizer (B), more preferably 10 parts by mass, based on 100 parts by mass of the copolymer (A). ~ 30 parts by mass, the above (C) magnesium hydroxide by 7 to 20 parts by mass, more preferably 8 to 15 parts by mass, further preferably 9 to 11 parts by mass, and the above organic peroxide (D) by 0.1. The composition contains to 4 parts by mass, more preferably 2.0 to 3.5 parts by mass, and further preferably 2.5 to 3 parts by mass.

When the copolymer composition constituting the rubber component for an automobile of the present invention contains the copolymer (F) in addition to the copolymer (A), the blending amount of the plasticizer (B) and the like is determined. The total amount of the copolymer (A) and the copolymer (F): the blending amount with respect to 100 parts by mass.

Further, when the ethylene-based copolymer composition constituting the rubber component for automobiles of the present invention contains the copolymer (F) in addition to the copolymer (A), the copolymer (A) and the copolymer (A) are used. The amount of the copolymer (F) is in the range of 0 to 50 parts by weight, preferably 15 to 50 parts by weight, and more preferably 30 to 50 parts by weight.

The copolymer composition constituting the rubber component for an automobile of the present invention is composed of the above-mentioned copolymer (A), the above-mentioned plasticizer (B), the above-mentioned magnesium hydroxide (C), and the above-mentioned organic peroxide (D). In addition, if necessary, the above-mentioned copolymer (F) and other components can be blended within a range that does not impair the effects of the present invention. Examples of other components include other polymers, carbon black, cross-linking aids, vulcanization accelerators, vulcanization aids, and inorganic fillers. At least one selected from softeners, anti-aging agents (stabilizers), processing aids, fatty acid amides, activators, hygroscopic agents, heat-resistant stabilizers, weather-resistant stabilizers, antistatic agents, colorants, lubricants, thickeners, etc. May contain seeds. Also. Each polymer and additive may be used alone or in combination of two or more. Further, if necessary, known foaming agents, foaming aids, colorants, dispersants, flame retardants and the like can also be used as other components.

<Crosslinking aid, vulcanization accelerator and vulcanization aid>
Examples of the cross-linking aid include sulfur; a quinone-dioxym-based cross-linking aid such as p-quinone dioxime; an acrylic cross-linking aid such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate; diallyl phthalate and triallyl isocyanurate. Allyl-based cross-linking aids such as; Maleimide-based cross-linking aids; Divinylbenzene; Zinc oxide (for example, ZnO # 1 and zinc oxide 2 types (JIS standard (K-1410)), manufactured by Huxitec Co., Ltd.), magnesium oxide, etc. Examples thereof include metal oxides such as active zinc oxide (for example, zinc oxide such as "META-Z102" (trade name; manufactured by Inoue Lime Industry Co., Ltd.)).

When a cross-linking aid is used, the blending amount of the cross-linking aid in the copolymer composition is usually 0.5 to 10 mol, preferably 0.5 to 7 mol, based on 1 mol of the organic peroxide. It is preferably 1 to 6 mol.

<Carbon black>
Carbon black, which can be blended in the copolymer composition constituting the rubber component for automobiles of the present invention, is a kind of known rubber reinforcing agent blended in the rubber composition, and is an inorganic substance usually called carbon black. be.

Specific examples of the carbon black according to the present invention include Asahi # 55G, Asahi # 60G, Asahi # 60UG (all manufactured by Asahi Carbon Co., Ltd.), Seest (V, SO, 116, 3, 6, 9, Carbon black (manufactured by Tokai Carbon Co., Ltd.) of SP, TA, etc.), and these carbon blacks are surface-treated with a silane coupling agent or the like.

When the copolymer composition constituting the rubber component for an automobile of the present invention contains carbon black, the blending amount thereof is 100 parts by mass of the copolymer (A) or the copolymer (A) and the copolymer (F). ) Is generally 30 to 50 parts by mass, preferably 35 to 45 parts by mass with respect to 100 parts by mass.

<Inorganic filler>
As a specific example of the inorganic filler that can be blended in the copolymer composition constituting the rubber component for automobiles of the present invention, one kind or two or more kinds such as light calcium carbonate, heavy calcium carbonate, talc and clay are used. Of these, heavy calcium carbonate such as "Whiten SB" (trade name; Shiraishi Calcium Co., Ltd.) is preferable.

When the copolymer composition constituting the rubber component for an automobile of the present invention contains an inorganic filler, the blending amount thereof is 100 parts by mass of the copolymer (A) or a copolymer with the copolymer (A) ( It is generally 70 to 90 parts by mass, preferably 75 to 85 parts by mass with respect to 100 parts by mass of the total amount of F).

<Anti-aging agent (stabilizer)>
By blending an antiaging agent (stabilizer) with the copolymer composition constituting the rubber component for an automobile of the present invention, the life of the molded product to be formed can be extended. Examples of such an 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.

Further, as an antioxidant, an aromatic secondary amine-based antioxidant such as phenylbutylamine, N, N-di-2-naphthyl-p-phenylenediamine; dibutylhydroxytoluene, tetrakis [methylene (3,5-di-) t-butyl-4-hydroxy) hydrocinnamate] Phenolic anti-aging agents such as methane (trade name: Irganox 1010, manufactured by BASF); bis [2-methyl-4- (3-n-alkylthiopropionyloxy)- 5-t-butylphenyl] Thioether-based antiaging agent such as sulfide; Dithiocarbamate-based antiaging agent such as nickel dibutyldithiocarbamate; 2-mercaptobenzoylimidazole (trade name: Sandant MB, manufactured by Sanshin Chemical Industry Co., Ltd.) , 2-Mercaptobenzoimidazole, zinc salt of 2-mercaptobenzoimidazole, dilaurylthiodipropionate, distearylthiodipropionate and other sulfur-based antioxidants.

These antioxidants can be used alone or in combination of two or more, and the blending amount thereof is 100 parts by mass of the copolymer (A) or a copolymer (A) and a copolymer (a). It is usually 0.3 to 15 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the total amount of F). Within such a range, the heat-resistant aging property of the rubber parts for automobiles obtained from the crosslinked product of the copolymer composition is more remarkably improved, and there is no bloom on the surface of the rubber parts for automobiles. Crosslink inhibition can suppress the occurrence.

<Processing aid>
As the processing aid according to the present invention, those generally blended in rubber as a processing aid can be widely used.

Specific examples of the processing aid include ricinoleic acid, stearic acid, palmitic acid, lauric acid, barium stearate, zinc stearate, calcium stearate, esters and the like. Of these, stearic acid is preferred.

The blending amount of the processing aid is 100 parts by mass of the copolymer (A) contained in the copolymer composition, or 100 parts by mass of the total amount of the copolymer (A) and the copolymer (F). It is usually 10 parts by mass or less, preferably 8.0 parts by mass or less.

<Activator>
Specific examples of the activator include amines such as di-n-butylamine, dicyclohexylamine and monoeranolamine; diethylene glycol, polyethylene glycol, lecithin, trialilute melilate, aliphatic carboxylic acid or zinc compound of aromatic carboxylic acid and the like. Activators; Zinc peroxide modifiers; Cutadecyltrimethylammonium bromide, synthetic hydrotalcites, special quaternary ammonium compounds and the like.

When the activator is contained, the blending amount thereof is usually 0 with respect to 100 parts by mass of the copolymer (A) or 100 parts by mass of the total amount of the copolymer (A) and the copolymer (F). .2 to 10 parts by mass, preferably 0.3 to 5 parts by mass.

<Heat absorbent>
Specific examples of the hygroscopic agent include calcium oxide, silica gel, sodium sulfate, molecular sieve, zeolite, white carbon and the like.

When a hygroscopic agent is contained, the blending amount thereof is usually 0 with respect to 100 parts by mass of the copolymer (A) or 100 parts by mass of the total amount of the copolymer (A) and the copolymer (F). .5 to 15 parts by mass, preferably 1.0 to 12 parts by mass.
The rubber component for an automobile of the present invention may be a single layer or a multilayer including a fiber reinforcing layer.

<Fiber reinforcement layer>
The fiber base material used for the fiber reinforcing layer constituting the rubber component for automobiles of the present invention may be made of polyamide alone, or polyamide and other reinforcing fibers such as glass fiber, PAN-based carbon fiber, pitch-based carbon fiber, and the like. It may be composed of a combination of alumina fiber, silicon carbide fiber, aluminum borate fiber, polyester fiber and the like.

Examples of the polyamides constituting the fiber substrate include aliphatic polyamides such as nylon 6, nylon 6, 6 and nylon 6, 10; polymethoxylylen adipamide (MXD6), polyhexamethylene terephthalamide (6T), and the like. Alternatively, semi-aromatic polyamides such as copolymerized polyamides containing these units; total aromatic polyamides such as polybenzamide, polypphenylene terephthalamide, polym phenylene isophthalamide can be mentioned.

These polyamide fibers are used as fiber substrates in the form of filaments or staple fibers, and are used as substrates in their own known forms such as cord yarns, spun yarns, woven fabrics, knits, and non-woven fabrics. Of course, these base materials may be used in a single layer or in two or more layers.

<Manufacturing method of rubber parts for automobiles>
The rubber parts for automobiles of the present invention can be manufactured by various known manufacturing methods. The preferred method for producing a rubber component for an automobile of the present invention is the above ethylene / α-olefin / non-conjugated polyene copolymer (A), the above plasticizer (B), the above magnesium hydroxide (C), and the above organic peroxide. This is a method in which the product (D) is mixed and then molded by an extrusion method.

If the rubber component for an automobile of the present invention is a hose such as a radiator hose or a heater hose having a fiber reinforcing layer, the ethylene-based copolymer composition is extruded by an extruder for the inner layer to form a tubular inner layer by an extrusion method. A reinforcing thread is spirally knitted on the outer periphery thereof using a spiral device to provide a reinforcing thread layer, and then the ethylene-based copolymer composition is extruded by an extrusion method so as to cover the reinforcing thread with an extruder for the outer layer. Can be manufactured by molding.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.
In the examples and comparative examples, the following copolymers were used.

(1) Ethylene / α-olefin / non-conjugated polyene copolymer (A)
As the ethylene / α-olefin / non-conjugated polyene copolymer (A), the ethylene / propylene / non-conjugated polyene copolymer (A-1) obtained in Production Example 1 was used.

[Manufacturing Example 1]
Using the continuous polymerization apparatus shown in FIG. 1, the ethylene / propylene / VNB copolymer (A-1) was produced as follows.

In a polymerization reactor C having a volume of 300 liters, 58.3 L / hr of hexane solvent dehydrated and purified from tube 6 and 4.5 mmol / hr of triisobutylaluminum (TiBA) from tube 7, (C ₆ H ₅ ) ₃ CB ( C ₆ F ₅ ) ₄ was continuously supplied at 0.150 mmol / hr, and di (p-tolyl) methylene (cyclopentadienyl) (octamethyloctahydrodibenzofluorenyl) zirconium dichloride was continuously supplied at 0.030 mmol / hr. .. At the same time, ethylene is continuously supplied into the polymerization reactor C at 6.6 kg / hr, propylene at 9.3 kg / hr, hydrogen at 18 liters / hr, and VNB at 340 g / hr, respectively, from tubes 2, 3, 4, and 5. Then, the copolymerization was carried out under the conditions of a polymerization temperature of 87 ° C., a total pressure of 1.6 MPaG, and a residence time of 1.0 hour.

The ethylene / propylene / VNB copolymer solution produced in the polymerization reactor C is continuously discharged through the tube 8 at a flow rate of 88.0 liters / hr and raised to a temperature of 170 ° C. (pressure is 4.1 MPaG). It was supplied to the phase separator D. At this time, ethanol, which is a polymerization inhibitor, was continuously introduced into the tube 8 in an amount of 0.1 mol times the amount of TiBA in the liquid component extracted from the polymerization reactor C.

In the phase separator D, the solution of the ethylene / propylene / VNB copolymer is mixed with a concentrated phase (lower phase portion) containing most of the ethylene / propylene / VNB copolymer and a dilute phase (upper phase portion) containing a small amount of polymer. ) And separated.

The separated concentrated phase is led to the heat exchanger K via the tube 11 at 85.4 liters / hr, and further led into the hopper E, where the solvent is evaporated and separated to form an ethylene / propylene / VNB copolymer. Was obtained in an amount of 7.8 kg / hr.

The physical characteristics of the obtained ethylene / propylene / VNB copolymer (A-1) were evaluated as described above. The results are shown in Table 1. The molecular weight distribution of the obtained copolymer (A-1) was bimodal.

(2) Ethylene / α-olefin / (non-conjugated polyene) copolymer (F)
As the ethylene / α-olefin / (non-conjugated polyene) copolymer (F), the following ethylene / propylene copolymer [trade name Mitsui EPT 0045] manufactured by Mitsui Chemicals, Inc .: ethylene content = 51% by mass, Mooney Viscosm ML _{(1 + 4)} 100 ° C. = 40] was used.

[Physical characteristics of uncrosslinked copolymer composition]
(Mooney viscosity (ML (1 + 4) 100 ° C.))
The Mooney viscosity (ML (1 + 4) 100 ° C.) at 100 ° C. was measured under the condition of 100 ° C. using a Mooney viscometer (SMV202 type manufactured by Shimadzu Corporation) in accordance with JIS K6300.

(Roll workability)
Using a 14-inch roll (manufactured by Nippon Roll Co., Ltd.), the surface temperature of the front roll is 50 ° C, the surface temperature of the rear roll is 50 ° C, the rotation speed of the front roll is 16 rpm, the rotation speed of the rear roll is 18 rpm, and the roll gap is 5 mm. , The compound was wrapped around the roll and the condition of the sheet was observed. From the state of the uncrosslinked copolymer composition (composition) when the formulations obtained in the first step of Examples and Comparative Examples were kneaded with a roll to the edge of the uncrosslinked copolymer composition (composition). The bagging resistance was evaluated.

The edges of the uncrosslinked copolymer composition (composition) were evaluated according to the following scores 1-5.
Score 1: There are large cracks on the edges of the composition, and part of the composition falls off.
Score 2: Large cracks on the edges of the composition.
Score 3: There are small cracks on the edges of the composition.
Score 4: There are microcracks on the edges of the composition.
Score 5: No cracks on the edges of the composition.

The bagging resistance of the uncrosslinked copolymer composition (composition) was evaluated according to the following scores 1 to 5.
Score 1: The composition does not wrap around the roll at all and immediately baggs.
Score 2: The composition temporarily wraps around the roll, but quickly peels off the roll and baggs.
Score 3: The composition wraps around the roll and often peels off the bank, but does not bagg.
Score 4: The composition easily wraps around the roll and, very rarely, peels off the bank portion, but does not bagg.
Score 5: The composition easily wraps around the roll, does not come off the bank portion at all, and does not bagg.

<Physical characteristics of rubber parts (crosslinked products) for automobiles>
(Tension breaking point stress, tensile breaking point elongation)
The tensile breaking point stress and the tensile breaking point elongation of the sheet were measured by the following methods.

A sheet was punched out to prepare a No. 3 dumbbell test piece described in JIS K 6251 (1993), and the test piece was used at a measurement temperature of 25 ° C. according to the method specified in JIS K6251 Section 3. A tensile test was performed under the condition of a tensile speed of 500 mm / min, and the tensile breaking point stress (TB) and the tensile breaking point elongation (EB) were measured.

(Durometer A hardness)
According to JIS K 6253, the hardness of the sheet (type A durometer, HA) was measured by stacking flat parts to a thickness of about 12 mm using six 2 mm sheet-shaped rubber molded products having a smooth surface. However, the test pieces containing foreign matter, air bubbles, and scratches were not used. The size of the measurement surface of the test piece was set so that the tip of the push needle could be measured at a position 12 mm or more away from the end of the test piece.

(Heat-resistant aging)
The sheet was subjected to a heat aging test in which the sheet was held at 180 ° C. for 72h, 168h, and 336h for each time according to JIS K 6257. The hardness, tensile breaking point stress, and tensile breaking point elongation of the sheet after the heat aging test are the same as those in the [Hardness (Durometer-A)] item and the above [Modulus, tensile breaking point stress, tensile breaking point elongation] item. It was measured by the method of.

AH (Duro-A) is obtained from the difference in hardness before and after the heat aging test, and after the test for the values before the heat aging test from the tensile breaking point stress (TB) and tensile breaking point elongation (EB) before and after the heat aging test. The rate of change was determined as AC (TB) and AC (EB), respectively.

[Example 1]
As the first step, 60 parts by mass of the ethylene / propylene / VNB copolymer (A-1) obtained in Production Example 1 and an ethylene / propylene copolymer were used using a BB-4 type Banbury mixer (manufactured by Kobe Steel). (Mitsui EPT 0045) 40 parts by mass is kneaded for 1 minute, and then 10 parts by mass of high aspect ratio magnesium hydroxide (Kisuma 10, manufactured by Kyowa Chemical Industry Co., Ltd.) having an aspect ratio of 67, zinc flower ( ZnO # 1, manufactured by Hakusui Tech Co., Ltd.) 5 parts by mass, talc [Mistron vapor talc (MVT), manufactured by Nippon Mistron Co., Ltd.) 80 parts by mass, carbon black (Asahi # 60UG, Asahi Carbon Co., Ltd.) 40 parts by mass, paraffin-based process oil (Diana Process PW-380, manufactured by Idemitsu Kosan Co., Ltd.) 33 parts by mass, primary anti-aging agent (trade name: Irganox 1010, manufactured by BASF) [Old defense 1010] 3 parts by mass , Secondary anti-aging agent (trade name: Sandant MB, manufactured by Sanshin Chemical Industry Co., Ltd.) [Old protection MB] 6 parts by mass and 1 part by mass of stearic acid were added and kneaded at 140 ° C. for 2 minutes. Then, the ram was raised and cleaned, and further kneaded for 1 minute, and the kneaded product was discharged at about 150 ° C. to obtain the first-stage compound.

Next, as the second step, the compound obtained in the first step is subjected to 6-inch roll (manufactured by NOF CORPORATION, front roll surface temperature 50 ° C., rear roll surface temperature 50 ° C., front roll). 16 rpm, rear roll rotation speed 18 rpm), add 6.8 parts by mass of dicumyl peroxide (Parkmill D-40C, manufactured by NOF) [DCP-40C], and knead for 10 minutes. An uncrosslinked ethylene-based copolymer composition was obtained. The physical characteristics of the copolymer composition were evaluated using this copolymer composition.

This uncrosslinked copolymer composition was extruded into a sheet and then pressed at 160 ° C. for 20 minutes using a 100-ton press molding machine to prepare a crosslinked sheet having a thickness of 2 mm. Using this, the physical properties of the crosslinked sheet were measured. The results are shown in Table 2.

[Examples 2 to 8]
The copolymer composition and the crosslinked sheet were produced in the same manner as in Example 1 with the formulations shown in Table 2, and further evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 1]
The copolymer composition and the crosslinked sheet were produced in the same manner as in Example 1 with the formulations shown in Table 3, and further evaluated in the same manner as in Example 1. The results are shown in Table 3.

The ethylene / propylene / non-conjugated polyene copolymer (F) and the compounding agent used in Comparative Example 1 are shown below.

<Ethylene / propylene / non-conjugated polyene copolymer (F)>
(1) Mitsui Chemicals Co., Ltd. Mitsui EPT ^TM Brand name 3090EM: Ethylene content = 48% by mass, Mooney viscosity ML _{(1 + 4)} 125 ° C = 59
(2) Mitsui Chemicals Co., Ltd. Mitsui EPT ^TM Brand name 3072EM: Ethylene content = 64% by mass, Mooney viscosity ML _{(1 + 4)} 125 ° C = 51

<Filler, plasticizer>
Carbon black: Asahi # 52 (trade name) [manufactured by Asahi Carbon Co., Ltd.]
Plasticizer: Diana Process Oil PW-90 (trade name) [manufactured by Idemitsu Kosan Co., Ltd.]
Clay: BURGESS NO. 30 (Product name) [Made by BURGESS PIGMENT]
Activator: Polyethylene glycol: Product name PEG # 4000 (Product name) [manufactured by NOF CORPORATION]

<Vulcanization accelerator, vulcanization agent>
Vulcanization accelerator: Sunseller CZ (trade name) [manufactured by Sanshin Chemical Industry Co., Ltd.], Sunseller BZ (trade name) [Sanshin Chemical Industry Co., Ltd.], Sunseller TT (trade name) [Sanshin Chemical Industry (trade name) Co., Ltd.], Sunseller TRA (trade name) [Sanshin Chemical Industry Co., Ltd.], Sunseller TE (trade name) [Sanshin Chemical Industry Co., Ltd.], Sanfel R (trade name) [Sanshin Chemical Industry Co., Ltd. ]
Vulcanizer: Sulfur

C Polymerization reactor D Phase separator E Hopper F Pump G Heat exchanger H Heat exchanger

Claims (13)

(A) Ethylene / α-olefin / non-conjugated polyene copolymer,
(B) Plasticizer,
(C) Magnesium hydroxide, and (D) Organic peroxide,
A rubber component for automobiles characterized by containing. The rubber for automobiles according to claim 1, wherein the plasticizer (B) according to claim 1 is a paraffinic hydrocarbon and has a kinematic viscosity at 40 ° C. of 300 mm ² / s to 500 mm ² / s. parts. The rubber component for an automobile according to claim 1, wherein the amount of the (B) plasticizer according to claim 1 is 30 parts by mass or less. The rubber component for an automobile according to any one of claims 1 to 3, wherein the magnesium hydroxide (C) according to claim 1 is 7 to 20 parts by mass. The rubber component for an automobile according to any one of claims 1 to 4, wherein the organic peroxide (D) according to claim 1 is a dicumyl peroxide. The ethylene / α-olefin / non-conjugated polyene copolymer according to claim 1 contains ethylene (a1), an α-olefin (a2) having 3 to 20 carbon atoms, and the following general formula (I). It has a structural unit derived from a non-conjugated polyene (a3) containing two or more partial structures selected from the group consisting of (II) and (II) in total, and meets the following requirements (i) to (vii). The automobile rubber component according to any one of claims 1 to 5, which is characterized by satisfying.

(I) The molar ratio of ethylene / α-olefin is 40/60 to 99.9 / 0.1;
(Ii) The weight fraction of the constituent unit derived from the non-conjugated polyene (C) is 0.07% by weight to 10% by weight in 100% by weight of the ethylene / α-olefin / non-conjugated polyene copolymer;
(Iii) The weight average molecular weight (Mw) of the ethylene / α-olefin / non-conjugated polyene copolymer and the weight fraction (% by weight) of the constituent unit derived from the non-conjugated polyene (C). )) And the molecular weight of the non-conjugated polyene (C) (molecular weight of (C)) satisfy the following formula (1);
4.5 ≤ Mw x weight fraction of (C) / 100 / molecular weight of (C) ≤ 40 ... Equation (1)
(Iv) Complex viscosity η ^* ₍ ω _{= 0.1)} (Pa · sec) at frequency ω = 0.1 rad / s and frequency ω = obtained by linear viscous elasticity measurement (190 ° C) using a leometer. The ratio P (η ^* ₍ ω _{= 0.1)} / η ^* ₍ ω _{= 100)} ) to the complex viscosity η ^* ₍ ω _{= 100)} (Pa · sec) at 100 rad / s, the ultimate viscosity [η], and the above. The weight fraction of the constituent unit derived from the non-conjugated polyene (C) (weight fraction of (C)) satisfies the following formula (2);
P / ([η] ^2.9 ) ≤ (C) weight fraction x 6 ... Equation (2)
(V) The ratio (molecular weight distribution; Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is in the range of 8 to 30;
(Vi) The number average molecular weight (Mn) is 30,000 or less;
(Vii) The chart obtained by GPC measurement shows two or more peaks, and the area of the peak appearing on the side with the smallest molecular weight is in the range of 1 to 20% of the total peak area. The intrinsic viscosity [η] of the ethylene / α-olefin / non-conjugated polyene copolymer according to claim 1 is 0.1 to 5 dL / g, and the weight average molecular weight (Mw) is 10,000 to 600. The rubber component for an automobile according to any one of claims 1 to 6, wherein the content is 000. 1. The non-conjugated polyene (a3) of the (A) ethylene / α-olefin / non-conjugated polyene copolymer according to claim 1 contains 5-vinyl-2-norbornene (VNB). The rubber component for an automobile according to any one of 7 to 7. An automobile rubber hose obtained from the automobile rubber component according to any one of claims 1 to 8. An automobile seal part obtained from the automobile rubber part according to any one of claims 1 to 8. It is a manufacturing method of rubber parts for automobiles.
(A) Ethylene / α-olefin / non-conjugated polyene copolymer,
(B) Plasticizer,
(C) Magnesium hydroxide, and (D) Organic peroxide,
A method for manufacturing a rubber part for an automobile, which comprises molding by an extrusion method after mixing. The method for manufacturing a rubber part for an automobile according to claim 11, wherein the organic peroxide (D) according to claim 11 is a dicumyl peroxide. The method for manufacturing a rubber component for an automobile according to claim 11, wherein the organic peroxide (D) according to claim 11 is 0.1 to 4.0 parts by mass.

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