JP7449757B2 - Ethylene/α-olefin/nonconjugated polyene copolymer composition and its uses - Google Patents

Description

The present invention relates to an ethylene/α-olefin/non-conjugated polyene copolymer composition, and more particularly to an ethylene/α-olefin copolymer composition that can provide a molded product with good surface smoothness during injection moldability and excellent engine oil barrier properties. -Relating to olefin/nonconjugated polyene copolymer compositions and their uses.

Olefinic thermoplastic elastomer, which is made by crosslinking a composition of ethylene/α-olefin/nonconjugated polyene copolymer and crystalline olefin polymer, which is a type of thermoplastic elastomer, is lightweight and easy to recycle. As an energy-saving and resource-saving thermoplastic elastomer, it is widely used in automobile parts such as hoses, pipes, and boots (blow-molded products), especially as a substitute for vulcanized rubber (for example, Patent Document 1 and 2).

However, although there is a constant demand for weight reduction in these automobile parts to improve fuel efficiency, the thermoplastic elastomers used tend to have a high specific gravity because they contain a large amount of filler, which hinders the weight reduction of parts. Was. In addition, these automotive parts are used in areas that come into contact with lubricating oil and grease, but olefin-based thermoplastic elastomers generally have low oil resistance against paraffin-based process oils, so olefin-based thermoplastic elastomers are These automobile parts containing plastic elastomers also have low oil resistance, and further improvements are required.

Japanese Patent Application Publication No. 2001-294714 JP2011-202136A

An object of the present invention is to obtain an ethylene/α-olefin/vinylnorbornene copolymer composition that has good injection moldability and surface smoothness and can provide a molded article with excellent engine oil barrier properties.

The present invention provides an ethylene/α-olefin/non-conjugated polyene having structural units derived from (A) ethylene (a1), an α-olefin having 3 to 20 carbon atoms (a2), and the following non-conjugated polyene (a3). 60 to 90% by mass of copolymer (A), and (B) structural units derived from ethylene (b1), α-olefin having 3 to 20 carbon atoms (b2), and the following nonconjugated polyene (b3). 40 to 10% by mass of the ethylene/α-olefin/nonconjugated polyene copolymer (B) [the total amount of copolymer (A) and copolymer (B) is 100% by mass]. ] and its uses.

The non-conjugated polyene (a3) constituting the copolymer (A) has at least one partial structure selected from the following general formula (I) and a partial structure selected from the group consisting of the following general formula (II) in the molecule. It is a non-conjugated polyene (a3) containing at least one of.

The non-conjugated polyene (b3) constituting the copolymer (B) is a non-conjugated polyene (b3) that does not contain a partial structure selected from the group consisting of the above general formula (II) in its molecule.

The ethylene/α-olefin/nonconjugated polyene copolymer composition of the present invention has good injection moldability, and the molded product obtained by molding the composition has good surface smoothness and engine oil barrier properties. Because of its excellent properties, it can be used in a variety of applications including automobile parts.

《Ethylene/α-olefin/non-conjugated polyene copolymer (A)》
Ethylene/α-olefin/non-conjugated polyene copolymer (A), which is one of the copolymers constituting the ethylene/α-olefin/non-conjugated polyene copolymer composition of the present invention [hereinafter referred to as “copolymer (A)". ] is an ethylene/α-olefin/non-conjugated polyene copolymer having constitutional units 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 includes 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. Among these, α-olefins having 3 to 8 carbon atoms such as propylene, 1-butene, 1-hexene, and 1-octene are preferred, and propylene is particularly preferred. Such α-olefins are preferable because their raw material costs are relatively low, the resulting copolymer (A) exhibits excellent mechanical properties, and molded articles with rubber elasticity can be obtained.

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 at least one structural unit derived from an α-olefin (a2) having 3 to 20 carbon atoms, and two or more structural units derived from an α-olefin having 3 to 20 carbon atoms. - May contain a structural unit derived from olefin (a2).

The non-conjugated polyene (a3) constituting the copolymer (A) according to the present invention has at least one partial structure selected from the following general formula (I) and a moiety selected from the group consisting of the following general formula (II). Contains at least one structure in the molecule.

Specific examples of the non-conjugated polyene (a3) include 5-vinyl-2-norbornene (VNB) and 1,4-hexadiene. Among these, non-conjugated polyene (a3) is highly available, has good reactivity with peroxide during crosslinking reaction after polymerization, and easily improves the heat resistance of the polymer composition, so non-conjugated polyene (a3) is VNB 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.

In addition to the structural units derived from the above (a1), (a2), and (a3), the copolymer (A) according to the present invention is further selected from the group consisting of the above general formulas (I) and (II). 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, 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 - Examples include norbornene. Among these, ENB is preferred because it is easily available, has high reactivity with sulfur and vulcanization accelerator during the crosslinking reaction after polymerization, is easy to control the crosslinking rate, and 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 structural units derived from the above-mentioned non-conjugated polyene (a4), the proportion thereof is not particularly limited as long as it does not impair the purpose of the present invention, but usually , 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 sum of the weight fractions is 100% by weight).

The copolymer (A) according to the present invention preferably 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 structural 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) Weight average molecular weight (Mw) of the ethylene/α-olefin/non-conjugated polyene copolymer and the weight fraction of the structural unit derived from the non-conjugated polyene (a3) (weight fraction of (a3) (wt%) )) 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 viscoelasticity measurement (190°C) using a rheometer The ratio P ₍ ^{η * (} _{ω = 0.1)} /η ^* ₍ ω _{=100) ) to the complex viscosity η * ( ω =100} ) (Pa・sec) at The weight fraction of the structural unit derived from the conjugated polyene (a3) (the weight fraction of (a3)) satisfies the following formula (2).
Weight fraction of P/([η] ^2.9 )≦(a3)×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 expressed by the following formula (3) satisfy.
LCB _1000C ≦1-0.07×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. , this molar ratio is preferably 50/50 to 90/10, more preferably 55/45 to 85/15, even more preferably 55/45 to 78/22.

By using a copolymer (A) that satisfies requirement (i), a copolymer composition with excellent rubber elasticity, mechanical strength, and flexibility can be obtained. The amount of ethylene (content of structural units derived from ethylene (a1)) and the amount of α-olefin (content of structural units derived from α-olefin (a2)) in the copolymer (A) are ¹³ C- It can be determined by NMR.

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

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

≪Requirement (iii)≫
Requirement (iii) is derived from the weight average molecular weight (Mw) of the copolymer (A) and the non-conjugated polyene (a3) in the copolymer (A) in the copolymer (A) according to the present invention. Specifies that the weight fraction of the structural 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) It is. The above formula (1) of requirement (iii) is preferably the following formula (1').

4.5≦Mw×weight fraction of (a3)/100/molecular weight of (a3)≦35...(1')
By satisfying requirement (iii), the copolymer (A) according to the present invention has an appropriate content of structural units derived from the non-conjugated polyene (a3), exhibits sufficient crosslinking performance, and has a high crosslinking rate. It is possible to produce a molded article that exhibits 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 "Mw x weight fraction of (a3)/100/molecular weight of (a3)" satisfies the above formula (1) or (1'), the degree of crosslinking is appropriate. Therefore, it is possible to produce a vibration-proof rubber with excellent mechanical properties and heat aging resistance in a well-balanced manner. If the value of "Mw x weight fraction of (a3)/100/molecular weight of (a3)" is too low, the crosslinking property may be insufficient and the crosslinking rate may be slow; if the value is too high, the crosslinking rate may become slow. However, excessive crosslinking may occur, resulting in deterioration of mechanical properties.

≪Requirement (iv)≫
Requirement (iv) is the complex viscosity η ^* ₍ ω ₌ 0.1 at frequency ω = 0.1 rad/s obtained by linear viscoelasticity measurement (190°C) using a rheometer) of the above copolymer (A). ₎ (Pa・sec) and the complex viscosity η ^* ₍ ω ₌₁₀₀₎ (Pa・sec) at frequency ω=100 rad/s P(η ^* ₍ ω _=0.1) /η ^* ₍ ω ₌₁₀₀₎ ), the intrinsic viscosity [η], and the weight fraction of the structural unit derived from the nonconjugated polyene (a3) (weight fraction of (a3): weight %) satisfy the above formula (2). It is something to do. The above formula (2) of requirement (iv) is preferably the following formula (2').

P/([η] ^2.9 )≦Weight fraction of (a3)×5.7...(2')
Here _, ^the _{ratio P} ( ^{η *} _{( ω =0.1)} /η ^* ₍ ω ₌₁₀₀₎ ) represents the frequency dependence of viscosity, and P/([η] ^2.9 ), which is the left side of equation (2), represents short chain branching, molecular weight, etc. Although there is an influence, it tends to show a high value when there are many long chain branches. In general, ethylene/α-olefin/non-conjugated polyene copolymers tend to contain more long chain branches as they contain more structural units derived from non-conjugated polyenes, but the copolymer (A) of the present invention It is thought that the above formula (2) can be satisfied because the long chain branching is smaller than that of conventionally known ethylene/α-olefin/nonconjugated polyene copolymers.

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

≪Requirement (v)≫
Requirement (v) is the natural number of long chain branches per 1000 carbon atoms (LCB _1000C ) and weight average molecular weight (Mw) obtained using 3D-GPC of the copolymer (A) according to the present invention. This specifies that the logarithm [Ln(Mw)] satisfies the above formula (3). The above formula (3) of 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').

Since the copolymer (A) according to the present invention satisfies requirement (v), it contains a small proportion of long chain branches, has excellent curing properties when crosslinked using peroxide, and has good heat aging resistance. A molded article with excellent properties can be obtained.

Here, Mw and the number of long chain branches per 1000 carbon atoms (LCB _1000C ) can be determined by a structural analysis method using 3D-GPC. In this specification, specifically, it was determined as follows.

Using a 3D-high temperature GPC device PL-GPC220 model (manufactured by Polymer Laboratories), the absolute molecular weight distribution was determined, and at the same time, the limiting viscosity was determined using a viscometer. The main measurement conditions are as follows.
Detector: Differential refractometer/GPC device built-in 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 (inner diameter 7.8mmφ x length 300mm per column)
Temperature: 140℃
Mobile phase: 1,2,4-trichlorobenzene (containing 0.025% BHT)
Injection volume: 0.5mL
Sample concentration: ca 1.5mg/mL
Sample filtration: Filtered with a sintered filter with a pore size of 1.0 μm In the above, the dn/dc value required to determine the absolute molecular weight is the dn/dc value of standard polystyrene (molecular weight 190000) of 0.053 and the value of the differential refractometer per unit injection mass. It was determined for each sample based on the response intensity.

From the relationship between the intrinsic 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 eluted component was calculated from the following formula (v-1).

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

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

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

The intrinsic 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, and even more preferably 0.9 to 4. It is 0 dL/g.

Further, 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, and still more preferably 50,000 to 400. ,000.

It is preferable that the copolymer (A) according to the present invention satisfies both the above intrinsic 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, more preferably VNB. That is, in the above-mentioned formulas (1), (2), and the below-mentioned formula (4), it is preferable that "the weight fraction of (a3)" is "the weight fraction of VNB" (weight %).

As mentioned above, the copolymer (A) according to the present invention has structural units derived from the above non-conjugated polyene (a4) in addition to the structural units derived from the above (a1), (a2) and (a3). The structural unit may be included in a weight fraction of 0% 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 following requirement (vi).

≪Requirement (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) (the weight fraction (wt%) of (a3)), The weight fraction of the structural unit derived from the conjugated polyene (a4) (the weight fraction (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) (the molecular weight of (a4)) satisfies the following formula (4).

4.5≦Mw×{(weight fraction of (a3)/100/molecular weight of (a3))+(weight fraction of (a4)/100/molecular weight of (a4))}≦45...( 4)
Formula (4) specifies the content of non-conjugated diene (total of (a3) and (a4)) in one molecule of the copolymer.

When the copolymer (A) containing the structural unit derived from the above (a4) satisfies formula (4), a molded article having excellent mechanical properties and heat aging resistance can be obtained.
Requirement (vi) is not satisfied and "Mw x {(weight fraction of (a3)/100/molecular weight of (a3)) + (weight fraction of (a4)/100/(a4) If the value of the molecular weight (molecular weight of If the content of the conjugated diene is too large, crosslinking may be excessive, resulting in deterioration of mechanical properties and further deterioration of heat aging resistance.

≪Requirement (vii)≫
Although the copolymer (A) according to the present invention is not particularly limited, complex The viscosity η ^* ₍ ω _=0.01) (Pa sec), the complex viscosity η ^* ₍ ω ₌₁₀₎ (Pa sec) at frequency ω = 10 rad/s, and the apparent viscosity derived from the nonconjugated polyene (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, complex viscosity η ^* ₍ ω _=0.01) and complex viscosity η * ₍ ω ₌₁₀₎ are measured as complex viscosity ^{η * (} _{ω =0.1)} and complex viscosity η ^* ₍ ω ₌₁₀₀₎ in requirement (iv). Everything except the frequency can be found in the same way. Further, the apparent iodine value derived from the non-conjugated polyene (a3) is determined by the following formula.

Apparent iodine value derived from (a3) = weight fraction of (a3) x 253.81/molecular weight of (A3) In the above formula (5), the left side represents the shear rate dependence, which is an indicator of the amount of long chain branching, The right side represents an index of the content of non-conjugated polyene (a3) that is not consumed as long chain branches during polymerization. It is preferable that the copolymer (A) satisfies the above formula (5) because the degree of long chain branching is not too high. On the other hand, when the above formula (5) is not satisfied, it can be seen that a large proportion of the copolymerized non-conjugated polyene (a3) is consumed in the formation of long chain branches.

Furthermore, the copolymer (A) according to the present invention preferably contains a sufficient amount of structural units derived from the non-conjugated polyene (a3), and It is more preferable that the weight fraction of the structural unit (the weight fraction (wt%) 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)
In addition, the copolymer (A) according to the present invention preferably has a number (n _a3 ) of structural units derived from the non-conjugated polyene (a3) per weight average molecular weight (Mw), more preferably 6 or more. is 6 or more and 40 or less, more preferably 7 or more and 39 or less, particularly preferably 10 or more and 38 or less.

The copolymer (A) according to the present invention contains a sufficient amount of structural units derived from a non-conjugated polyene (a3) such as VNB, has a small content of long chain branches, and can be prepared by using a peroxide. It has excellent curing properties when crosslinking, good moldability, excellent balance of physical properties such as mechanical properties, and particularly excellent heat aging resistance.

Furthermore, the copolymer (A) according to the present invention preferably has a number (n _a4 ) of structural units derived from the non-conjugated polyene (a4) per weight average molecular weight (Mw), more preferably 29 or less. 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 a range that does not impair the purpose of the present invention, and it is difficult to cause post-crosslinking and has sufficient It has excellent heat aging resistance.

Here, the number (n _a3 ) of structural units derived from the non-conjugated polyene (a3) or the number of structural units derived from 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 (n _a4 ) is determined by 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 (( It can be determined by the following formula from the weight fraction (wt%) 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) of each structural unit derived from non-conjugated polyene (a3) and (a4) per weight average molecular weight (Mw) _a3 ) and (n _a4 ) both satisfy the above ranges, the copolymer (A) has a low long chain branch content and has good curing properties when crosslinked using peroxide. It is preferable because it has excellent moldability, good balance of physical properties such as mechanical properties, and is difficult to cause post-crosslinking and has particularly excellent 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 comprises ethylene (a1), an α-olefin (a2), a non-conjugated polyene (a3), and optionally a non-conjugated polyene. It is a copolymer formed by copolymerizing monomers consisting of (a4).

The above copolymer (A) according to the present invention may be prepared by any method as long as it satisfies the above requirements (i) to (iv), but it may be prepared by copolymerizing monomers in the presence of a metallocene compound. It is preferable that the polymer be obtained by copolymerizing monomers in the presence of a catalyst system containing a metallocene compound.

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 pamphlet is adopted. It can be manufactured by

《Ethylene/α-olefin/non-conjugated polyene copolymer (B)》
Ethylene/α-olefin/non-conjugated polyene copolymer (B), which is one of the copolymers constituting the ethylene/α-olefin/non-conjugated polyene copolymer composition of the present invention [hereinafter referred to as “copolymer (B)". ] has structural units derived from ethylene (b1), an α-olefin having 3 to 20 carbon atoms (b2), and the following nonconjugated polyene (b3).

The α-olefin (b2) constituting the copolymer (B) according to the present invention is the same α-olefin as the α-olefin (a2) constituting the copolymer (A) according to the present invention, such as , 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 Examples include. Among these, α-olefins having 3 to 8 carbon atoms such as propylene, 1-butene, 1-hexene, and 1-octene are preferred, and propylene and 1-butene are particularly preferred. Such α-olefins are preferable because their raw material costs are relatively low, the resulting copolymer (B) exhibits excellent mechanical properties, and molded articles with rubber elasticity can be obtained.

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

The non-conjugated polyene (b3) constituting the copolymer (B) according to the present invention is a non-conjugated polyene (b3) that does not contain a partial structure selected from the group consisting of the following general formula (II) in its molecule.

The non-conjugated polyene (b3) constituting the copolymer (B) according to the present invention includes norbornadiene, dicyclopentadiene, 5-ethylidene-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.

Among these non-conjugated polyenes (b3), they are easily available, have high reactivity with sulfur and vulcanization accelerators during the crosslinking reaction after polymerization, make it easy to control the crosslinking rate, and provide good mechanical properties. Norbornadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene (ENB) are preferred because they are easy to use.

The copolymer (B) according to the present invention preferably satisfies the following requirements (i) to (v) (hereinafter also referred to as requirements (i) to (v), respectively).
(i) The molar ratio of ethylene (b1)/α-olefin (b2) is 40/60 to 99.9/0.1.
(ii) The weight fraction of the structural unit derived from the non-conjugated polyene (b3) is 0.07% by weight to 10% by weight based on 100% by weight of the ethylene/α-olefin/non-conjugated polyene copolymer.

The copolymer (B) according to the present invention can be used alone or in combination of two or more. The ethylene/α-olefin/non-conjugated polyene copolymer (B) having the above-mentioned properties is described, for example, in "Polymer Manufacturing Process (Published by Kogyo Kenkyukai Co., Ltd., pp. 309-330)", JP-A-Sho. It can be prepared by various known methods such as those described in Japanese Patent No. 55-137113.

Further, the copolymer (B) according to the present invention can be produced, for example, by employing the production method using a metallocene catalyst described in JP-A-2018-119096 and International Publication No. 2015/122495 pamphlet. Can be done.

<Ethylene/α-olefin/nonconjugated polyene copolymer composition>
The ethylene/α-olefin/non-conjugated polyene copolymer composition (hereinafter sometimes abbreviated as "copolymer composition") of the present invention contains 60 to 90% by mass of the above copolymer (A). , preferably 65 to 90% by mass, more preferably 65 to 90% by mass, and the above copolymer (B) 40 to 10% by mass, preferably 35 to 10% by mass, more preferably 30 to 10% by mass [ The total amount of copolymer (A) and copolymer (B) is 100% by mass. ] A copolymer composition characterized by comprising:

The copolymer composition of the present invention contains the above-mentioned copolymer (A) and the above-mentioned copolymer (B) in the above-mentioned amounts, so that it has good injection moldability, good surface smoothness, and is suitable for use in engines. A molded article with excellent oil barrier properties is obtained.

In addition to the above-mentioned copolymer (A) and above-mentioned copolymer (B), the copolymer composition of the present invention may contain other components as necessary within a range that does not impair the effects of the present invention. . Other ingredients include, for example, a crosslinking agent, a crosslinking aid, a vulcanization accelerator, a vulcanization aid, a filler, a softener, an anti-aging agent, a processing aid, an activator, a heat stabilizer, a weathering stabilizer, and an electrostatic charger. It may contain at least one selected from inhibitors, colorants, lubricants, thickeners, and the like. Also. Each additive may be used alone or in combination of two or more.

<Crosslinking agent, crosslinking aid, vulcanization accelerator, and vulcanization aid>
As a crosslinking agent, rubber such as organic peroxide, phenol resin, sulfur compound, hydrosilicone compound, amino resin, quinone or its derivative, amine compound, azo compound, epoxy compound, isocyanate compound, etc. Examples include crosslinking agents commonly used in crosslinking. Among these, organic peroxides and sulfur-based compounds (hereinafter also referred to as "vulcanizing agents") are preferred.

Examples of organic peroxides include dicumyl peroxide (DCP), di-tert-butyl peroxide, 2,5-di-(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-di-( tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3, 1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)hexane, -butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(tert-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert- Examples include butyl peroxybenzoate, ert-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butyl cumyl peroxide.

Among these organic peroxides, 2,5-dimethyl-2,5-di-( tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3, 1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxyisopropyl)benzene, -butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(tert-butylperoxy)valerate, 1,1-di(tert-butylperoxy)cyclohexane, 2,2-di( Particularly preferred are tert-butylperoxy)butane, 1,1-di(tert-amylperoxy)cyclohexane, and the like.

When using an organic peroxide as a crosslinking agent, the amount thereof in the copolymer composition is generally 0 to 100 parts by mass of the total amount of copolymer (A) and copolymer (B). .1 to 30 parts by weight, preferably 5 to 25 parts by weight, more preferably 10 to 20 parts by weight. It is preferable that the amount of the organic peroxide is within the above range because the copolymer composition exhibits excellent crosslinking properties without blooming on the surface of the resulting molded article.

When using an organic peroxide as a crosslinking agent, it is preferable to use a crosslinking aid together. Examples of crosslinking aids include sulfur; quinonedioxime crosslinking aids such as p-quinonedioxime; acrylic crosslinking aids such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate; diallyl phthalate and triallyl isocyanurate. Allyl crosslinking aids such as; maleimide crosslinking aids; divinylbenzene; zinc oxide (for example, ZnO #1, zinc oxide 2 types (JIS standard (K-1410)), manufactured by Hakusuitec Co., Ltd.), magnesium oxide, Examples include metal oxides such as activated zinc white (for example, zinc oxide such as "META-Z102" (trade name; manufactured by Inoue Lime Industry Co., Ltd.)).

When using a crosslinking aid, the amount of the crosslinking aid in the copolymer composition is usually 0.5 to 10 mol, preferably 0.5 to 7 mol, and more per 1 mol of organic peroxide. Preferably it is 1 to 6 mol.

Examples of the sulfur compound (vulcanizing agent) include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, and selenium dithiocarbamate.

When a sulfur-based compound is used as a crosslinking agent, the amount of the sulfur compound in the copolymer composition is usually 0.00 parts per 100 parts by mass of the total amount of copolymer (A) and copolymer (B). The amount is 1 to 10 parts by weight, preferably 0.2 to 7.0 parts by weight, and more preferably 0.3 to 5.0 parts by weight. When the amount of the sulfur-based compound is within the above range, there is no blooming on the surface of the resulting molded product, and the copolymer composition exhibits excellent crosslinking properties.

When using a sulfur-based compound as a crosslinking agent, it is preferable to use a vulcanization accelerator together.
Examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazolesulfenamide, N-oxydiethylene-2-benzothiazolesulfenamide, N,N'-diisopropyl-2-benzothiazolesulfenamide, 2 -Mercaptobenzothiazole (for example, Suncella M (trade name; manufactured by Sanshin Kagaku Kogyo Co., Ltd.)), 2-(4-morpholinodithio)penzothiazole (for example, Noxela MDB-P (trade name; manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) ), 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-diethyl-4-morpholinothio)benzothiazole and dibenzothiazyl disulfide (for example, Suncella DM (trade name; Thiazole-based vulcanization accelerators such as (manufactured by Shin Kagaku Kogyo Co., Ltd.); guanidine-based vulcanization accelerators such as diphenylguanidine, triphenylguanidine, and diorthotolylguanidine; Aldehyde amine-based vulcanization accelerators; imidazoline-based vulcanization accelerators such as 2-mercaptoimidazoline; tetramethylthiuram monosulfide (e.g., Suncella TS (trade name; manufactured by Sanshin Kagaku Kogyo Co., Ltd.)), tetramethylthiuram disulfide (e.g. , Suncella TT (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetraethylthiuram disulfide (for example, Suncella TET (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetrabutylthiuram disulfide (for example, Suncella TBT (trade name; (manufactured by Sanshin Kagaku Kogyo Co., Ltd.)) and thiuram-based vulcanization accelerators such as dipentamethylenethiuram tetrasulfide (for example, Suncella TRA (trade name; made by Sanshin Kagaku Kogyo Co., Ltd.)); zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate , dithioate salt-based vulcanization accelerators such as zinc dibutyldithiocarbamate (e.g., Sunceller PZ, Sunceller BZ and Sunceller EZ (trade name; manufactured by Sanshin Kagaku Kogyo Co., Ltd.)) and tellurium diethyldithiocarbamate; ethylenethiourea (e.g., Sunceller Thiourea-based additives such as BUR (trade name; manufactured by Sanshin Kagaku Kogyo Co., Ltd.), Suncella 22-C (trade name; manufactured by Sanshin Kagaku Kogyo Co., Ltd.)), N,N'-diethylthiourea, and N,N'-dibutylthiourea. Sulfurization accelerator: Xanthate-based vulcanization accelerators such as zinc dibutylxatogenate can be mentioned.

When using a vulcanization accelerator, the amount of the vulcanization accelerator in the copolymer composition is as follows: It is generally 0.1 to 20 parts by weight, preferably 0.2 to 15 parts by weight, and more preferably 0.5 to 10 parts by weight. When the amount of the vulcanization accelerator is within the above range, the copolymer composition exhibits excellent crosslinking properties without blooming on the surface of the resulting molded article. When using a sulfur-based compound as a crosslinking agent, a vulcanization aid can be used in combination.

Examples of vulcanization aids include zinc oxide (for example, ZnO #1, zinc oxide 2, manufactured by Hakusui Tech Co., Ltd.), magnesium oxide, activated zinc white (for example, "META-Z102" (trade name: Inoue lime), Examples include zinc oxide (manufactured by Kogyo Co., Ltd.).
When using a vulcanization aid, the amount of the vulcanization aid in the ethylene copolymer composition is as follows: It is usually 1 to 20 parts by mass.

<Filler>
The filler constituting the ethylene copolymer composition of the present invention is a known rubber reinforcing agent blended into a rubber composition, and is an inorganic substance usually called carbon black or inorganic reinforcing agent.

Specifically, fillers related to the present invention include Asahi #55G, Asahi #60UG (manufactured by Asahi Carbon Co., Ltd.), Seast (V, SO, 116, 3, 6, 9, SP, TA, etc.) carbon black (manufactured by Tokai Carbon Co., Ltd.), these carbon blacks surface-treated with a silane coupling agent, etc., and silica, activated calcium carbonate, fine talc, fine silicic acid, light calcium carbonate, heavy Examples include calcium carbonate, talc, and clay.

These fillers may be used alone or in a mixture of two or more.
As the filler according to the present invention, carbon black, light calcium carbonate, heavy calcium carbonate, talc, clay, etc. are preferably used.

When the copolymer composition of the present invention contains a filler, it is usually 50 to 300 parts by mass, preferably 80 parts by mass, based on 100 parts by mass of the total amount of copolymer (A) and copolymer (B). It may be blended in a range of 250 parts by mass.

<Softener>
Examples of softeners include process oil, lubricating oil, paraffin oil, liquid paraffin, petroleum asphalt, petroleum softeners such as vaseline; coal tar softeners such as coal tar; castor oil, linseed oil, rapeseed oil, and Fatty oil-based softeners such as bean oil and coconut oil; waxes such as beeswax and carnauba wax; naphthenic acid, pine oil, rosin or derivatives thereof; synthetic polymer substances such as terpene resin, petroleum resin, coumaron indene resin; dioctyl Ester-based softeners such as phthalate and dioctyl adipate; others include microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, hydrocarbon-based synthetic lubricating oils, tall oil, and sub(factice); among these, petroleum-based softeners Processing oils are particularly preferred.

When the ethylene copolymer composition contains a softener, the amount of the softener is generally 2 parts by mass per 100 parts by mass of the total amount of copolymer (A) and copolymer (B). ~100 parts by weight, preferably 10 to 100 parts by weight.

<Fatty acid amide>
The fatty acid amide, which is one of the components contained in the copolymer composition of the present invention, is an amide of higher fatty acids, and specifically includes stearamide, oxystearoamide, oleylamide, erucic acid amide, lauryl amide, Monoamides of higher fatty acids such as palmitytylamide, behenamide, methylolamide; diamides of higher fatty acids such as methylene bis stearamide, ethylene bis stearamide, ethylene bis oleylamide, ethylene bis laurylamide; Complex amides of higher fatty acids such as stearyl oleylamide, N-stearyl erucamide, and N-oleyl palmitamide; Plastrogin ^TM (manufactured by Fujisawa Pharmaceutical Co., Ltd.), Plastrogin S ^TM (manufactured by Fujisawa Pharmaceutical Co., Ltd.) Examples include special fatty acids commercially available under trade names such as

<Anti-aging agent (stabilizer)>
By incorporating an anti-aging agent (stabilizer) into the copolymer composition of the present invention, the life of the seal packing formed therefrom can be extended. Examples of such anti-aging agents include conventionally known anti-aging agents, such as amine anti-aging agents, phenol anti-aging agents, and sulfur anti-aging agents.

Examples of antiaging agents include aromatic secondary amine antiaging agents such as phenylbutylamine and N,N-di-2-naphthyl-p-phenylenediamine; dibutylhydroxytoluene, tetrakis[methylene(3,5-di Phenolic anti-aging agents such as -t-butyl-4-hydroxy)hydrocinnamate]methane; bis[2-methyl-4-(3-n-alkylthiopropionyloxy)-5-t-butylphenyl]sulfide, etc. Thioether anti-aging agent; Dithiocarbamate anti-aging agent such as nickel dibutyl dithiocarbamate; 2-mercaptobenzoylimidazole, 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, dilaurylthiodipropionate, distearyl There are sulfur-based anti-aging agents such as thiodipropionate.

When the ethylene copolymer composition contains an anti-aging agent, the amount of the anti-aging agent is as follows: It is usually 0.3 to 10 parts by weight, preferably 0.5 to 7.0 parts by weight. When the amount of the anti-aging agent is within the above range, there will be no blooming on the surface of the resulting molded product, and furthermore, the occurrence of vulcanization inhibition can be suppressed.

<Processing aid>
As the processing aid, a wide variety of processing aids that are generally blended into rubber can be used. Specific examples include ricinoleic acid, stearic acid, palmitic acid, lauric acid, barium stearate, zinc stearate, calcium stearate, zinc laurate, and esters. Among these, stearic acid is preferred.

When the copolymer composition contains a processing aid, it is usually incorporated in an amount of 1 to 3 parts by mass based on 100 parts by mass of the total amount of copolymer (A) and copolymer (B). can do. It is preferable that the blending amount of the processing aid is within the above range because it provides excellent processability such as kneading processability, extrusion processability, and injection moldability.
The processing aids may be used alone or in combination of two or more.

<Activator>
Examples of the activator include amines such as di-n-butylamine, dicyclohexylamine, and monoelanolamine; diethylene glycol, polyethylene glycol, lecithin, triaryl utmerate, and zinc compounds of aliphatic carboxylic acids or aromatic carboxylic acids. Activators; zinc peroxide preparations; tadecyltrimethylammonium bromide, synthetic hydrotalcites, special quaternary ammonium compounds.

When the copolymer composition contains an activator, the amount of the activator is usually 0.00 parts by mass based on 100 parts by mass of the total amount of copolymer (A) and copolymer (B). The amount is 2 to 10 parts by weight, preferably 0.3 to 5 parts by weight.

<Moisture absorbent>
Specific examples of the moisture absorbent include calcium oxide, silica gel, sodium sulfate, molecular sieve, zeolite, and white carbon.

When a moisture absorbent is contained, its amount is usually 0.5 to 15 parts by mass, preferably 1 part by mass, based on 100 parts by mass of the total amount of copolymer (A) and copolymer (B). .0 to 12 parts by mass.

The copolymer composition of the present invention is a composition containing the above copolymer (A) and the above copolymer (B), but in addition to the above copolymer (A) and the above copolymer (B), , the above-mentioned compounding agents (additives) may be included. When the copolymer composition of the present invention contains the above-mentioned compounding agent (additive), the above-mentioned copolymer (A) and the above-mentioned copolymer (B), the above-mentioned copolymer (A) and the above-mentioned copolymer Total amount: based on 100 parts by mass, preferably 20 to 300 parts by mass of carbon black, more preferably 30 to 300 parts by mass, still more preferably 50 to 250 parts by mass, and preferably 0.1 to 10 parts by mass of the fatty acid amide. parts by mass, more preferably 0.2 to 8 parts by mass, even more preferably 0.5 to 5 parts by mass, and preferably 10 to 300 parts by mass, more preferably 10 to 250 parts by mass of the above inorganic filler (ground calcium carbonate). parts by weight, more preferably 20 to 200 parts by weight, and the above organic peroxide preferably 0.2 to 30 parts by weight, more preferably 0.2 to 25 parts by weight, even more preferably 0.5 to 20 parts by weight. Included within the range of

<Crosslinked product of copolymer composition>
The crosslinked product of the copolymer composition of the present invention is obtained by crosslinking the copolymer composition of the present invention.
As a method for crosslinking the copolymer composition of the present invention, the above-mentioned copolymer composition may be kneaded using a conventionally known kneading device such as an open type mixing roll, a closed type Banbury mixer, an extruder, a kneader, a continuous mixer, etc. used. Among these, a closed-type kneading device is preferred, and kneading is preferably performed in an atmosphere of an inert gas such as nitrogen gas or carbon dioxide gas.

《Applications of copolymer composition》
The copolymer composition of the present invention is molded by commonly used molding methods, such as injection molding, extrusion molding, hollow molding, and compression molding. Applications include automotive parts (clean side ducts, bellows-shaped hollow rubber products such as grommets, weather strips, ceiling materials, interior sheets, bumper moldings, side moldings, air spoilers, air duct hoses, cup holders, handbrake grips, shift knob covers, Seat adjustment knob, flapper door seal, wire harness grommet, rack and pinion boot, suspension cover boot, glass guide, inner belt line seal, roof guide, trunk lid seal, molded quarter wind gasket, corner molding, glass encapsulation, hood seals, glass run channels, secondary seals, clean side ducts, various packings, etc.), civil engineering and building materials parts (waterstop materials, joint materials, architectural window frames, etc.), sporting goods (grips for golf clubs, tennis rackets, etc.) ), industrial parts (hose tubes, gaskets, etc.), home appliance parts (hoses, gaskets, etc.), medical equipment parts, electric wires, and miscellaneous goods.

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

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

[Production Example 1] Production of ethylene-propylene-vinylnorbornene copolymer (A-1) Ethylene, propylene, and 5-vinyl-2-norbornene were continuously produced using a 300 L polymerization vessel equipped with stirring blades. The polymerization reaction of (VNB) was carried out at 87°C. Using hexane (feed amount: 32.6 L/h) as the polymerization solvent, the ethylene feed amount was 3.6 kg/h, the propylene amount was 6.1 kg/h, the VNB feed amount was 290 g/h, and Hydrogen was continuously supplied to the polymerization vessel so that the amount of hydrogen fed was 6.3 NL/h. While maintaining the polymerization pressure at 1.6 MPaG and the polymerization temperature at 87°C, using di(p-tolyl)methylene(cyclopentadienyl)(octamethyloctahydrodibenzofluorenyl)zirconium dichloride as the main catalyst, the feed amount was It was continuously supplied to the polymerization vessel at a rate of 0.0015 mmol/h. In addition, (C ₆ H ₅ ) ₃ CB(C ₆ F ₅ ) ₄ was fed as a cocatalyst at a feed rate of 0.0075 mmol/h, and triisobutylaluminum (TIBA) was fed as an organic aluminum compound at a feed rate of 20 mmol/h. Each was continuously supplied to the polymerization vessel.

In this way, a solution containing 15.2% by weight of an ethylene-propylene-VNB copolymer formed from ethylene, propylene and VNB was obtained. A small amount of methanol was added to the polymerization reaction solution taken out from the bottom of the polymerization vessel to stop the polymerization reaction, and after separating the ethylene/propylene/VNB copolymer from the solvent by steam stripping treatment, the pressure was reduced at 80°C overnight. Dry.

Through the above operations, an ethylene-propylene-VNB copolymer (A-1) formed from ethylene, propylene and VNB was obtained at a rate of 4.7 kg/hour. The physical properties of the obtained copolymer (A-1) were measured by the method described above. The results are shown in Table 1.

(2) Ethylene/α-olefin/nonconjugated polyene copolymer (B)
Ethylene/1-butene/dicyclopentadiene (DCPD) copolymer produced by the production method described in Comparative Example 3 of JP-A-55-137113 as the ethylene/α-olefin/nonconjugated polyene copolymer (B) Combined (B-1) was used.

The obtained ethylene/1-butene/dicyclopentadiene copolymer (B-1) had an ethylene content of 75.3% by weight, a DCPD content of 5.3% by weight, and an intrinsic viscosity [η] of 1. It was .29 dl/g.

[Physical properties of uncrosslinked copolymer composition]
(Mooney viscosity (ML(1+4)100℃))
Mooney viscosity at 100°C (ML(1+4) 100°C) was measured at 100°C using a Mooney viscometer (Model SMV202, manufactured by Shimadzu Corporation) in accordance with JIS K6300.

(Mooney Scorch (Vm, t5; 145℃))
Mooney scorch was measured in accordance with JIS K6300 using a Mooney viscometer (Model SMV202, manufactured by Shimadzu Corporation) at 145°C.

(vulcanization speed)
Using the copolymer compositions (before crosslinking) in Examples and Comparative Examples, the scorch time (TS1) and The vulcanization rate (TC90) was measured as follows.

The sample was set in a measuring device, and the change in torque obtained under conditions of constant temperature and constant shear rate was measured to obtain a vulcanization curve. From this vulcanization curve, find the minimum value S' _Min and maximum value S' _Max of torque, and calculate the time required for the torque to increase by 1 point from the time of measurement start as TS1, (S' _Max - S' _Min ) x 0 The time taken to reach .9 was defined as the vulcanization rate (TC90; minutes).

<Physical properties of molded product (crosslinked product)>
(Tensile stress at break, tensile elongation at break)
The tensile stress at break and the tensile elongation at break of the sheet were measured by the following methods.

A No. 3 dumbbell test piece as described in JIS K 6251 (1993) was prepared by punching out the sheet, and using this test piece, the measurement temperature was 25°C, according to the method specified in JIS K6251 Section 3. A tensile test was conducted at a tensile speed of 500 mm/min, and the modulus at 100% elongation (M100), tensile stress at break (TB), and tensile elongation at break (EB) were measured.

(Durometer A hardness)
In accordance with JIS K 6253, the hardness (type A durometer, HA) of the sheet was measured using six 2 mm sheet rubber molded products with smooth surfaces, stacking the flat parts to a thickness of about 12 mm. However, test pieces with foreign matter mixed in, bubbles, or scratches were not used. In addition, the dimensions of the measurement surface of the test piece were such that measurements could be made at a position where the indenter tip was 12 mm or more away from the end of the test piece.

(Engine oil barrier property test)
1. Add 1.8 g of product name: NISSAN Engine Oil SN Strong Save X-OW20 to a 2 mm thick sheet folded into a cylindrical stainless steel container with a diameter of 10 cm and a height of 10 cm.
2. Close the lid and heat in the oven at 130℃.
3. After 24 hours, the presence or absence of oil permeation and the appearance of oil adhesion on the sheet surface were confirmed and evaluated using the following ratings.

Rating 4: No oil permeation.
Rating 3: Oil permeation. ; Visual confirmation not possible; Oil adheres to hands when touched.
Rating 2: Oil permeation. ;Visually confirmed; Oil attached.
Rating 1: Oil permeation. ;Visually confirmed; drops are visible.

(Injection moldability)
Using an injection mold, the ethylene/α-olefin/non-conjugated polyene copolymer composition (compound 2) obtained in Examples and Comparative Examples was injected at a mold temperature of 170°C and held for 10 minutes. A round bellows-shaped pipe was obtained.

The injection-molded round bellows pipe had a length of 100 mm, an outer diameter of 120 mm, a wall thickness of 2 mm, a pitch between the bellows peaks of 15 mm, and a depth of 10 mm from the peaks to the valleys of the bellows.
The molded round bellows-shaped pipe was removed from the mold, and the appearance of the round bellows-shaped pipe was observed, and if there was a crack in even a part of the bellows part (present), if there was no crack at all (no crack). .
Further, if the round bellows-shaped pipe was smooth, the surface smoothness was evaluated as (good), and if the surface was not smooth with corrugations observed, it was evaluated as (bad).

[Example 1]
Using MIXTRON BB MIXER (manufactured by Kobe Steel, Ltd., BB-4 type, volume 2.95L, rotor 4WH), 80 parts by mass of the copolymer (A-1) obtained in Production Example 1 and the copolymer (B-1) Total amount with 20 parts by mass: 100 parts by mass (copolymer composition), 5 parts by mass of ZnO #1 (trade name Meta Z102 manufactured by Inoue Lime Industries Co., Ltd.) as a crosslinking aid, As processing aids, 2 parts by mass of stearic acid, 169 parts by mass of carbon black (trade name: Asahi #60UG, manufactured by Asahi Carbon Co., Ltd.), 100 parts by mass of calcium bicarbonate (trade name: Whiten SB, manufactured by Bihoku Funka Kogyo Co., Ltd.), 119 parts by mass of paraffinic process oil (trade name: Diana Process Oil PW-100, manufactured by Idemitsu Kosan Co., Ltd.) as a softener, and 1 part by mass of phenolic antioxidant (trade name: Irganox 1010, manufactured by BASF Japan Ltd.) as an anti-aging agent. , 2 parts by mass of 2-mercaptobenzimidazole (trade name: Sandant MB, manufactured by Sanshin Kagaku Kogyo Co., Ltd.) as an anti-aging agent, and fatty acid amide (trade name: Structol WB16: Calcium soap & saturated fatty acid amide mixture, manufactured by S&S Japan Co., Ltd.) as a lubricant. After blending 2 parts by mass of the following, the mixture was kneaded to obtain a blend 1.

The kneading conditions for preparing Compound 1 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 170°C.
The Mooney viscosity ML(1+4) 100° C. of Formulation 1 was measured using a Mooney viscometer (Model SMV202 manufactured by Shimadzu Corporation) according to JIS K6300 (1994).

Next, after confirming that the temperature of Formulation 1 reached 40°C, using a 6-inch roll, 2,5-dimethyl-2,5-di-(tert-butylperoxy) was added to Formulation 1 as a crosslinking agent. ) 18.5 parts by mass of hexane [trade name Perhexa 25B-40 (purity: 40%) manufactured by NOF Corporation] was added and kneaded to obtain a blend 2.

The kneading conditions when preparing Compound 2 were: roll temperature: front roll/rear roll = 50°C/50°C, roll circumferential speed: front roll/rear roll = 18 rpm/15 rpm, roll gap: 2 mm, kneading time: 8 minutes. Compound 2 was obtained.

Compound 2 was pressed using a press molding machine at 170° C. for 10 minutes to produce a 2 mm thick crosslinked sheet. The physical properties of the obtained crosslinked sheet were evaluated by the method described above.
The evaluation results are shown in Table 2.

[Comparative example 1]
Instead of the copolymer composition used in Example 1, the copolymer (A-1) obtained in Production Example 1 is used alone, and the amount of additives is changed to the amount listed in Table 1. A crosslinked sheet was obtained in the same manner as in Example 1 except for this.

The physical properties of the obtained crosslinked sheet were evaluated by the method described above. The evaluation results are shown in Table 1.

Claims (3)

(A) Ethylene/α-olefin/non-conjugated polyene copolymer (A) having structural units derived from ethylene (a1), propylene (a2), and 5-vinyl-2-norbornene (VNB) (a3). 60 to 90% by mass, and (B) an ethylene/α-olefin/non-conjugated polyene copolymer (B) having structural units derived from ethylene (b1), 1-butene (b2), and dicyclopentadiene (b3). ) in an amount of 40 to 10% by mass (the total amount of copolymer (A) and copolymer (B) is 100% by mass). A copolymer composition comprising : A crosslinked molded article comprising the copolymer composition according to claim 1. The crosslinked molded article according to claim 2, wherein the crosslinked molded article is a bellows-shaped hollow body.