Copolymer composition and crosslinked molded article

Abstract

The present invention aims to provide an ethylene-α-olefin-non-conjugated polyene copolymer composition that has excellent heat aging resistance and low-temperature properties, as well as excellent bloom resistance, and a crosslinked molded article obtained from this copolymer composition. [Solution] A copolymer composition comprising: a copolymer (S) having constituent units derived from ethylene (A), constituent units derived from an α-olefin (B) having 3 to 20 carbon atoms, and constituent units derived from a specific non-conjugated polyene (C), satisfying specific requirements; a hydrosilyl group-containing compound (Y) which is a specific organohydrogenpolysiloxane having at least one silicon atom-bonded aralkyl group and at least two silicon atom-bonded hydrogen atoms in the molecule; a platinum-based catalyst; carbon black; and an amine-based antioxidant, wherein the copolymer composition contains 5 to 150 parts by mass of carbon black per 100 parts by mass of the copolymer (S), and the copolymer (S) includes a constituent unit derived from 1-butene as a constituent unit derived from the α-olefin (B).

Description

[Technical Field]

[0001] The present invention relates to an ethylene-α-olefin-nonconjugated polyene copolymer composition and a crosslinked molded article obtained by crosslinking the copolymer composition. [Background technology]

[0002] Copolymer compositions obtained by hydrosilicone crosslinking of ethylene-α-olefin-non-conjugated polyene random copolymers have superior mechanical strength, heat aging resistance, and compression set compared to sulfur vulcanization and peroxide crosslinking, and are characterized by the ability to perform continuous crosslinking, making them promising for application in sealing components such as packings and gaskets.

[0003] Patent Document 1 proposes a copolymer composition in which, at relatively low temperatures of 50 to 130°C during kneading and molding, the scorching time is long to prevent crosslinking during kneading, while at the crosslinking temperature of 150 to 200°C, crosslinking can occur in a short time. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-131527 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the copolymer composition described in Patent Document 1 had the problem of having poor properties such as rubber elasticity at low temperatures. Meanwhile, the performance requirements for ethylene copolymer compositions used in fuel cell gaskets are becoming increasingly stringent. Specifically, improvement in bloom is required. Bloom is a phenomenon in which additives and other substances in a composition migrate to the surface of the composition, causing solid material to detach. When bloom occurs, the surface appearance deteriorates, potentially reducing its aesthetic appeal. Furthermore, a decrease in the additive content in the composition may lead to a decrease in the composition's performance. Here, when using a copolymer composition obtained by crosslinking an ethylene-α-olefin-non-conjugated polyene random copolymer with hydrosilicone for use as a fuel cell gasket, it was found that bloom occurred depending on the type of antioxidant added when an anti-aging agent was added to impart further heat aging resistance. In view of the above circumstances, the present invention aims to provide an ethylene-α-olefin-non-conjugated polyene copolymer composition that has excellent heat aging resistance and low-temperature properties, as well as excellent bloom resistance, and a crosslinked molded article obtained from this copolymer composition. [Means for solving the problem]

[0006] As a result of diligent research to solve the above problems, the inventors of this invention discovered that the above problems could be solved by employing a specific anti-aging agent, and thus completed the present invention.

[0007] The present invention provides the following: [1] A copolymer (S) having constituent units derived from ethylene (A), constituent units derived from α-olefin (B) having 3 to 20 carbon atoms, and constituent units derived from a non-conjugated polyene (C) containing a total of two or more substructures selected from the following formulas (I) and (II) in the molecule, and satisfying the following requirements (i) and (ii), A hydrosilyl group-containing compound (Y) is an organohydrogenpolysiloxane represented by the following formula (a), having at least one silicon atom-bonded aralkyl group and at least two silicon atom-bonded hydrogen atoms in the molecule, Platinum-based catalysts, Carbon black and, A copolymer composition comprising an amine-based antioxidant, The copolymer composition contains 5 to 150 parts by mass of carbon black per 100 parts by mass of the copolymer (S), The copolymer (S) contains, as a structural unit derived from the α-olefin (B), a structural unit derived from 1-butene, copolymer composition: (i) The ratio [A] / [B] of the number of moles [A] of the structural unit derived from ethylene (A) to the number of moles [B] of the structural unit derived from the α-olefin (B) is 40 / 60 to 90 / 10; (ii) The mass fraction of the structural unit derived from the non-conjugated polyene (C) is 0.07 to 10.0% by mass based on all the structural units constituting the copolymer (S).

Chemical formula

Chemical formula

[10] The copolymer composition according to any one of [1] to [9], wherein the copolymer (S) comprises a structural unit derived from 5-vinyl-2-norbornene as a structural unit derived from the non-conjugated polyene (C).

[11] A crosslinked molded article obtained by crosslinking a copolymer composition described in any of [1] to

[10] .

[12] The cross-linked molded article described in

[11] , wherein the TR70 obtained when a TR test is performed in accordance with JIS K 6261-4 is -35°C or lower.

[13] A fuel cell gasket obtained using any of the copolymer compositions described in [1] to

[10] . [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an ethylene-α-olefin-non-conjugated polyene copolymer composition that has excellent heat aging resistance and low-temperature properties, as well as excellent bloom resistance, and a crosslinked molded article obtained from this copolymer composition. [Modes for carrying out the invention]

[0009] <Copolymer composition> The copolymer composition according to the present invention comprises a copolymer (S), a hydrosilyl group-containing compound (Y), a platinum-based catalyst, carbon black, and an amine-based antioxidant. In this specification and in the claims, "parts by mass" refers to parts by mass calculated on a solid content basis, excluding solvents. Furthermore, a numerical range represented by "~" means a range of numbers whose lower and upper limits are the numbers before and after the "~".

[0010] In this specification, when M is an olefin constituting a polymer, the expression "constituent unit derived from M" is sometimes used. This refers to "constituent unit corresponding to M," that is, a constituent unit having a pair of bonds formed when the π bond constituting the double bond of M opens.

[0011] [Copolymer (S)] The copolymer (S) used in the present invention has constituent units derived from ethylene (A), constituent units derived from α-olefin (B) having 3 to 20 carbon atoms, and constituent units derived from non-conjugated polyene (C).

[0012] With respect to all constituent units of the copolymer (S), the total mass fraction of constituent units derived from ethylene (A), constituent units derived from α-olefin (B) having 3 to 20 carbon atoms, and constituent units derived from non-conjugated polyene (C) is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 100% by mass. In one preferred and exemplary embodiment of the present invention, the copolymer (S) consists only of constituent units derived from ethylene (A), constituent units derived from α-olefin (B) having 3 to 20 carbon atoms, and constituent units derived from non-conjugated polyene (C).

[0013] Examples of α-olefins (B) having 3 to 20 carbon atoms (hereinafter sometimes simply referred to as "α-olefins (B)") include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene. Of these, α-olefins having 3 to 8 carbon atoms, such as propylene, 1-butene, 1-hexene, and 1-octene, are preferred, with propylene and 1-butene being more preferred, and 1-butene being particularly preferred. Such α-olefins are preferred because their raw material costs are relatively low, the resulting copolymer (S) exhibits excellent mechanical properties, and a molded article with rubber elasticity can be obtained. These α-olefins may be used individually or in combination of two or more.

[0014] The copolymer (S) contains a structural unit derived from 1-butene as a structural unit derived from the α-olefin (B). The copolymer composition containing the copolymer (S) containing the structural unit derived from 1-butene exhibits excellent low-temperature properties.

[0015] With respect to the constituent units derived from α-olefin (B), the mass fraction of constituent units derived from 1-butene is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass, and particularly preferably 100% by mass (meaning that the constituent units derived from α-olefin (B) consist only of constituent units derived from 1-butene). If the mass fraction of the constituent units derived from 1-butene is above a preferred lower limit, it is easier to obtain better low-temperature characteristics.

[0016] A non-conjugated polyene (C) is a non-conjugated polyene that contains a total of two or more substructures selected from the following formulas (I) and (II) in its molecule.

[0017] [ka]

[0018] Examples of non-conjugated polyenes (C) include 5-vinyl-2-norbornene (VNB), norbornadiene, 1,4-hexadiene, and dicyclopentadiene. Of these, it is preferable that the non-conjugated polyene (C) contains VNB, and more preferably VNB, because it is readily available, forms good hydrosilicone crosslinking, and improves the heat resistance of the polymer composition. The non-conjugated polyene (C) may be used alone or in combination of two or more types.

[0019] The copolymer (S) used in the present invention may further contain constituent units (CX) derived from a non-conjugated polyene (CX) that contains only one substructure selected from the group consisting of general formulas (I) and (II) in the molecule, to the extent that the effects of the present invention are not impaired. Examples of such non-conjugated polyenes (CX) 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, and 5-(2-ethyl-3-butenyl) Examples include 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, and 5-(1,2,3-trimethyl-4-pentenyl)-2-norbornene.

[0020] Among these non-conjugated polyenes (CX), ENB is preferred because it is readily available, the crosslinking rate during hydrosilicone crosslinking is easy to control, and good mechanical properties are easily obtained. Non-conjugated polyenes (CX) may be used alone or in combination of two or more types. When the copolymer (S) used in the present invention contains constituent units derived from non-conjugated polyene (CX), the mass fraction thereof is preferably 0 to 20% by mass, more preferably 0 to 10% by mass, and even more preferably 0.01 to 8% by mass, relative to the total constituent units of the copolymer (S). However, the copolymer (S) used in the present invention does not necessarily have to contain constituent units derived from non-conjugated polyene (CX). In one preferred and exemplary embodiment of the present invention, the copolymer (S) does not contain constituent units derived from non-conjugated polyene (CX).

[0021] The copolymer (S) used in the present invention may include constituent units derived from biomass-derived monomers as constituent units derived from at least one monomer selected from the aforementioned ethylene (A), α-olefins having 3 to 20 carbon atoms (B), non-conjugated polyenes (C), and optional non-conjugated polyenes (CX).

[0022] Here, the monomer derived from biomass is carbon 14 10 C isotopes -12 ~10 -14 While it contains a certain proportion, the corresponding monomers derived from fossil fuels are 14 Due to the radioactive decay of C 14 It is known that it does not contain carbon. Therefore, monomers derived from biomass and monomers derived from fossil fuels are different. 14 They can be distinguished by whether or not they contain C isotopes. It is preferable from the viewpoint of reducing environmental impact that the copolymer (S) contains structural units derived from biomass-derived monomers.

[0023] Furthermore, the copolymer (S) used in the present invention may contain structural units derived from chemically recycled monomers. Here, "chemically recycled" means obtained by depolymerizing, thermally decomposing, etc., polymers such as waste plastics, or by first converting polymers such as waste plastics into intermediates by depolymerizing, thermally decomposing, etc., and then producing the copolymer using these intermediates as raw materials. Chemically recycled monomers can be obtained by known methods. It is preferable for the copolymer (S) to contain structural units derived from chemically recycled monomers from the viewpoint of reducing environmental impact (mainly waste reduction).

[0024] Mooney viscosity of copolymer (S) at 100°C "ML" (1+4) "100℃" is preferably 5 to 100, more preferably 10 to 50, even more preferably 20 to 40, and particularly preferably 25 to 35. Copolymer (S) "ML (1+4)If the temperature is above the preferred lower limit of 100℃, it is easier to obtain better kneading processability. (1+4) If the temperature is below the preferred upper limit of 100°C, it is easier to obtain better processability during molding, such as extrusion and injection moldability. Note that the copolymer (S) is "ML (1+4) In "100℃", M is in Mooney units, L is the rotor shape, (1+4) means 1 minute of preheating and 4 minutes of rotor rotation, and 100℃ represents the measurement temperature. For measurement, for example, a Mooney viscometer SMV-202 (manufactured by Shimadzu Corporation) can be used.

[0025] The intrinsic viscosity [η] of the copolymer (S) is preferably 0.5 to 4.0 dL / g, more preferably 1.0 to 3.0 dL / g, and even more preferably 1.5 to 2.0 L / g. If the intrinsic viscosity [η] of the copolymer (S) is above a preferred lower limit, it is easier to obtain better physical properties. If the intrinsic viscosity [η] of the copolymer (S) is below a preferred upper limit, it is easier to obtain better processability. The intrinsic viscosity [η] of the copolymer (S) is measured in decalin at 135°C, using the same method as detailed in the explanation of requirement (iv) below.

[0026] The weight-average molecular weight (Mw) of the copolymer (S) is preferably 10,000 to 600,000, more preferably 100,000 to 400,000, even more preferably 150,000 to 300,000, and particularly preferably 200,000 to 250,000. If the weight-average molecular weight (Mw) of the copolymer (S) is above a preferred lower limit, it is easier to obtain better physical properties. If the weight-average molecular weight (Mw) of the copolymer (S) is below a preferred upper limit, it is easier to obtain better processability. Note that the weight-average molecular weight (Mw) of the copolymer (S) refers to the weight-average molecular weight measured by 3D-GPC.

[0027] The copolymer (S) in the present invention satisfies the following requirements (i) to (ii). In addition to requirements (i) and (ii), it is preferable that it satisfies one or more of the following requirements (iii) to (v), more preferably two or more requirements, and particularly preferably all of the following requirements (i) to (v).

[0028] (i) The ratio [A] / [B], which is the number of moles of constituent units derived from ethylene (A) to the number of moles of constituent units derived from α-olefin (B) [B], is 40 / 60 to 90 / 10. (ii) The mass fraction of the constituent units derived from the non-conjugated polyene (C) is 0.07 to 10.0% by mass relative to the total constituent units of the copolymer (S).

[0029] (iii) (n C ) is between 4.5 and 80. (n C ) = (Mw) × {mass fraction of (C) / 100} / molecular weight of (C) ... (1) However, in formula (1), (Mw) is the weight-average molecular weight of the copolymer (S), the mass fraction of (C) is the mass fraction of the constituent units derived from the non-conjugated polyene (C), and the molecular weight of (C) is the molecular weight of the non-conjugated polyene (C).

[0030] (iv) Complex viscosity η at frequency ω = 0.1 rad / s, obtained by linear viscoelasticity measurement (190°C) using a rheometer. * (ω=0.1) (Pa·sec) and complex viscosity η at frequency ω = 100 rad / s * (ω=100) The ratio P(η) to (Pa·sec) * (ω=0.1) / η * (ω=100) The intrinsic viscosity [η] (in decalin at 135°C) and the mass fraction of the constituent units derived from the non-conjugated polyene (C) (mass fraction of (C)) satisfy the following equation (2). P / ([η] 2.9 ) ≤ (C) Mass fraction × 6 ···(2)

[0031] (v) Complex viscosity η at frequency ω = 0.01 rad / s, obtained by linear viscoelasticity measurement (190°C) using a rheometer. * (ω=0.01) (Pa·sec) and complex viscosity η at frequency ω = 10 rad / s * (ω=10) The (Pa·sec) and the apparent iodine value derived from the non-conjugated polyene (C) satisfy the following formula (3). Log{η * (ω=0.01)} / log{η * (ω=10)}≦0.0753 × {Apparent iodine value derived from unconjugated polyene (C)} + 1.42 ···(3)

[0032] Requirement (i) specifies that the ratio [A] / [B], which is the ratio of the number of moles [A] of ethylene (A)-derived constituent units [B] in the copolymer (S) used in the present invention to the number of moles [B] of α-olefin (B), satisfies 40 / 60 to 90 / 10.

[0033] [A] / [B] is preferably 50 / 50 to 90 / 10, more preferably 55 / 45 to 80 / 20, and even more preferably 60 / 40 to 70 / 30. The copolymer (S) is preferred because, when requirement (i) is met, the molded article obtained by hydrosilicone crosslinking the copolymer (S) exhibits excellent rubber elasticity and has excellent mechanical strength and flexibility. Furthermore, the ratio [A] / [B] of the number of moles of constituent units derived from ethylene (A) in the copolymer (S) to the number of moles of constituent units derived from α-olefin (B) is: 13 This can be determined by 13C-NMR.

[0034] Requirement (ii) specifies that in the copolymer (S), the mass fraction of the constituent units derived from the non-conjugated polyene (C) is 0.07 to 10.0% by mass relative to the total constituent units of the copolymer (S). The mass fraction of the constituent units derived from this non-conjugated polyene (C) is preferably 0.1 to 5.0 mass%, more preferably 0.5 to 3.0 mass%, even more preferably 0.8 to 2.0 mass%, and particularly preferably 1.0 to 1.5 mass%.

[0035] Copolymer (S) is preferred because, by satisfying requirement (ii), the crosslinked molded article obtained from the copolymer composition according to the present invention has sufficient hardness and excellent mechanical properties. Furthermore, crosslinking copolymer (S) with hydrosilicone is preferred because it exhibits a fast crosslinking rate, allowing for efficient production of crosslinked molded articles. Furthermore, the mass fraction of constituent units derived from the non-conjugated polyene (C) in the copolymer (S) is: 13 This can be determined by 13C-NMR.

[0036] The mass fraction of the constituent units derived from the non-conjugated polyene (C) is preferably such that the weight-average molecular weight (Mw) of the copolymer (S) satisfies the following formula (4). 6 - 0.45 × Ln(Mw) ≤ (C) Mass fraction ≤ 10 ···(4) Here, in equation (4) above, "Ln(Mw)" represents the natural logarithm of Mw.

[0037] Requirement (iii) is obtained by the following formula (1) (n C The range of ) is specified as 4.5 to 80. (n C ) = (Mw) × {mass fraction of (C) / 100} / molecular weight of (C) ... (1) However, in formula (1), (Mw) is the weight-average molecular weight of the copolymer (S), the mass fraction of (C) is the mass fraction of the constituent units derived from the non-conjugated polyene (C), and the molecular weight of (C) is the molecular weight of the non-conjugated polyene (C). Note that weight-average molecular weight (Mw) refers to the weight-average molecular weight measured by 3D-GPC. (n C ) is preferably 4.5 or more and 78 or less, and more preferably 4.5 or more and 75 or less.

[0038] (n C ) is the number of constituent units derived from the unconjugated polyene (C) per weight-average molecular weight (Mw) of the copolymer (S). (n C When the value is above the lower limit, it is easier to obtain a sufficient crosslinking rate when crosslinking hydrosilicone. Furthermore, when it is below the upper limit, excessive crosslinking is less likely to occur, and the resulting crosslinked molded article exhibits superior mechanical properties. When copolymer (S) satisfies requirement (iii), the long-chain branching content of each copolymer is within an appropriate range. As a result, the hydrosilicone crosslinking rate is fast, the resulting crosslinked molded article has an excellent balance of physical properties such as mechanical properties, and is less prone to post-crosslinking, and is particularly excellent in heat aging resistance, which is preferable.

[0039] If the copolymer (S) contains constituent units (CX), then (n) can be calculated using the following formula (1'). C+CX Preferably, the ratio is 4.5 to 80, more preferably 4.5 to 78, and even more preferably 4.5 to 75. (n C+CX ) = (Mw) × [{(Mass fraction of C) / 100} / Molecular weight of C + {(Mass fraction of CX) / 100} / Molecular weight of CX] ... (1') (n C+CX ) is the total number of constituent units derived from non-conjugated polyenes (C) and non-conjugated polyenes (CX) per weight-average molecular weight (Mw) of the copolymer (S).

[0040] Requirement (iv) is the complex viscosity η of copolymer (S) at a frequency ω = 0.1 rad / s, obtained by linear viscoelastic measurement (190°C) using a rheometer. * (ω=0.1) (Pa·sec) and complex viscosity η at frequency ω = 100 rad / s * (ω=100) The ratio P(η) to (Pa·sec) * (ω=0.1) / η * (ω=100)The intrinsic viscosity [η] (in decalin at 135°C) and the mass fraction of the constituent units derived from the non-conjugated polyene (C) (mass fraction of (C): mass%) satisfy the following formula (2). P / ([η] 2.9 ) ≤ (C) Mass fraction × 6 ... (2)

[0041] As a rheometer, an Ares viscoelasticity measuring device (manufactured by Rheometric Scientific) was used, and measurements were performed at 190°C and 1.0% strain, while varying the frequency. Intrinsic viscosity [η] (in decalin at 135°C) is the value measured in decalin at 135°C.

[0042] The copolymer (S) more preferably satisfies the following formula (2'). P / ([η] 2.9 ) ≤ (C) Mass fraction × 5.7···(2') ratio P(η * (ω=0.1) / η * (ω=100) ) represents the frequency dependence of viscosity and corresponds to the left side of equations (2) and (2'), P / ([η] 2.9 Although influenced by factors such as short-chain branching and molecular weight, the value tends to be higher when there are many long-chain branches.

[0043] Generally, in ethylene-α-olefin-non-conjugated polyene copolymers, the more constituent units derived from non-conjugated polyenes they tend to contain, the more long-chain branching they have. However, the copolymer (S) used in the present invention is thought to satisfy formula (2) above because it has fewer long-chain branching units than conventionally known ethylene-α-olefin-non-conjugated polyene copolymers.

[0044] Requirement (v) is the complex viscosity η of copolymer (S) at a frequency ω = 0.01 rad / s, obtained by linear viscoelastic measurement (190°C) using a rheometer. * (ω=0.01) (Pa·sec) and complex viscosity η at frequency ω = 10 rad / s * (ω=10)It is specified that the [Pa·sec] and the apparent iodine value derived from the non-conjugated polyene (C) satisfy the following formula (3). Log{η * (ω=0.01)} / Log{η * (ω=10)}≤0.0753×{apparent iodine value derived from non-conjugated polyene (C)} + 1.42 ···(3)

[0045] In formula (3), η * (ω=0.01) is the complex viscosity η * (Pa·sec) obtained by linear viscoelastic measurement (190 °C) using a rheometer at a frequency ω = 0.01 rad / s. Also, η * (ω=10) is the complex viscosity η * (Pa·sec) obtained by linear viscoelastic measurement (190 °C) using a rheometer at a frequency ω = 10 rad / s. And, "Log{η * (ω=0.01)}" and "Log{η * (ω=10)}" respectively represent the common logarithm of η * (ω=0.01) and the common logarithm of η * (ω=10) . Here, η * (ω=0.01) and η * (ω=10) are obtained in the same manner as the complex viscosity η * (ω=0.1) and the complex viscosity η * (ω=100) in requirement (iv) except for the measurement frequency.

[0046] In formula (3), the apparent iodine value derived from the non-conjugated polyene (C) is obtained by the following formula. Apparent iodine value derived from (C) = mass fraction of (C) × 253.81 / molecular weight of (C)

[0047] In equation (3) above, the left side represents the shear rate dependence, which is an indicator of the amount of long-chain branching, and the right side represents an indicator of the content of unconjugated polyenes (C) that are not consumed as long-chain branching during polymerization. If requirement (v) is met, it is preferable because the degree of long-chain branching is not too high. If requirement (v) is not met, it indicates that a large proportion of the copolymerized non-conjugated polyene (C) was consumed in the formation of long-chain branching.

[0048] The copolymer composition of the present invention may contain two or more copolymers (S). For example, (i) The molar ratio of ethylene / α-olefin with 3 to 20 carbon atoms, and / or (b) Iodine value It is also possible to use a mixture of two or more different polymers.

[0049] In the present invention, there are no particular limitations on the method for producing the copolymer (S), but it is preferable that it is obtained by copolymerizing monomers in the presence of a metallocene compound, and more preferably that it is obtained by copolymerizing monomers in the presence of a catalyst system containing a metallocene compound. Specifically, for example, it can be manufactured by the method described in International Publication No. 2015 / 122495.

[0050] [Hydrosilyl group-containing compound (Y)] The hydrosilyl group-containing compound (Y) in the present invention is represented by the following formula (a) and is an organohydrogenpolysiloxane having at least one silicon atom-bonded aralkyl group and at least two silicon atom-bonded hydrogen atoms in the molecule.

[0051] [ka]

[0052] In equation (a), n and p are independently 0 or positive numbers, m is between 1 and 20, the sum of n, m, and p is between 5 and 50, and multiple R 1 , R 2Each of these is independently a monovalent alkyl group, and R a It is an aralkyl group, and the two Rs are each independently R 1 ,R 2 , hydrogen atom, and R a It is one of the groups consisting of -[O-Si(R 1 )(R a )]-,-[O-Si(R 1 )H]- and -[O-Si(R 1 )(R 2 The constituent units of )- may be arranged in a block-like manner or randomly, provided that when n=1, at least one of the two R is a hydrogen atom, and when n=0, both of the two R are hydrogen atoms.

[0053] Such hydrosilyl group-containing compounds (Y) are linear organohydrogenpolysiloxanes with a relatively low degree of siloxane polymerization and containing at least one silicon atom-bonded aralkyl group and at least two silicon atom-bonded hydrogen atoms within the molecule.

[0054] By selectively using a hydrosilyl group-containing compound (Y) in combination with a copolymer (S), it is possible to obtain molded articles with particularly excellent physical properties such as scorch resistance, moldability, elongation at fracture, and compression molding strain, and in particular, the applicability to weatherstrip sponge materials is improved.

[0055] In formula (a), m is the number of diorganosiloxy units having silicon atom bonded aralkyl groups, and is a number in the range of 1 to 20, may be a number in the range of 2 to 10, and is particularly preferably a number in the range of 3 to 6.

[0056] In formula (a), n is the number of organohydrogensiloxy units having silicon-bonded hydrogen atoms in the side chain, and may be 2 or more, or it may be 0 or 1. Here, when n=1, at least one of the two R atoms is a hydrogen atom, and when n=0, both R atoms are hydrogen atoms. Thus, the hydrosilyl group-containing compound (Y) represented by formula (a) has at least two silicon-bonded hydrogen atoms in its molecule.

[0057] Furthermore, even if n is a number other than 0 or 1, it is not prevented that one or both of the R atoms at both ends of the molecular chain are silicon-bonded hydrogen atoms. Moreover, it is preferable that n is a number other than 0 or 1, and more preferably that n ≥ m. More specifically, n may be a number in the range of 3 to 10, and is particularly preferable to be a number in the range of 3 to 9.

[0058] In formula (a), p is the number of diorganosiloxy units that do not contain aralkyl groups or silicon-bonded hydrogen atoms, and may be 0, or may be in the range of the number obtained by dividing the total degree of polymerization of diorganosiloxane units, which is expressed as the sum of n, m, and p described later, by the values ​​of n and m. For example, p may be a number in the range of 0 to 12, a number in the range of 0 to 10, a number in the range of 0 to 5, a number in the range of 0 to 2, and is preferred.

[0059] The hydrosilyl group-containing compound (Y) has a relatively low degree of siloxane polymerization, and the sum of the above values ​​of n, m, and p is 5 to 50, preferably 5 to 20, and may be 5 to 15. The hydrosilyl group-containing compound (Y), which is the crosslinking agent of the present invention, is particularly preferably a number in the range of 3 to 6 for m, a number in the range of 3 to 9 for n, and a number in the range of 0 to 2 for p.

[0060] In equation (a), R is R 1 ,R 2 , hydrogen atom, R a It may be any of the groups selected from , except that if n=0 or 1, both or one of R is a hydrogen atom. R in the formula 1 ,R 2is a monovalent alkyl group, which may be the same or different from each other, and some of the carbon atom-bonded hydrogen atoms may be substituted with halogen atoms. Such alkyl groups may be alkyl groups having 1 to 20 carbon atoms, and industrially, they may be methyl groups.

[0061] In equation (a), R a R is an aralkyl group, preferably an aralkyl group having 7 to 20 carbon atoms, and preferably an aralkyl group having 7 to 15 carbon atoms. Examples of such aralkyl groups include phenylalkyl groups such as benzyl, phenylethyl, phenylpropyl, and phenylbutyl groups. The aralkyl group preferably has an alkylene structure between an aryl group such as a phenyl group and the silicon atom to which the aralkyl group is bonded, and preferably contains at least one branched unit represented by -CH(CH3)- in the alkylene structure. In the present invention, R is particularly preferably a This is an aralkyl group represented as -CH2-CH(CH3)-C6H5.

[0062] The aralkyl group is a characteristic functional group that gives hydrosilyl group-containing compounds (Y) usefulness as crosslinking agents. In particular, the presence of the aralkyl group together with silicon-bonded hydrogen atoms in this component, where n, m, and p are within the above ranges, significantly improves the physical properties of the resulting molded product. The copolymer composition of the present invention may contain only one hydrosilyl group-containing compound (Y), or it may contain two or more.

[0063] In the copolymer composition of the present invention, the amount of hydrosilyl group-containing compound (Y) per 100 parts by mass of copolymer (S) is preferably 0.1 to 100 parts by mass, more preferably 1.0 to 50 parts by mass, even more preferably 3.0 to 20 parts by mass, and particularly preferably 5.0 to 10 parts by mass. Here, if the copolymer composition of the present invention contains two or more hydrosilyl group-containing compounds (Y), it is preferable that the total amount of these hydrosilyl group-containing compounds (Y) equals the above blending amount.

[0064] [Platinum-based catalyst] Platinum-based catalysts are addition reaction catalysts and can be used without particular limitations as long as they promote the addition reaction (hydrosilylation reaction of alkenes) between the alkenyl group of the copolymer (S) and the hydrosilyl group of the hydrosilyl group-containing compound (Y). Examples of platinum-based catalysts include elemental platinum (platinum black), chloroplatinic acid, platinum-olefin complexes, platinum-alcohol complexes, or platinum supported on a support such as alumina or silica.

[0065] Specific platinum-based catalysts can be any known catalysts typically used in addition-hardening curing, such as the fine-powdered metal-platinum catalyst described in U.S. Patent No. 2,970,150, the chloroplatinic acid catalyst described in U.S. Patent No. 2,823,218, the platinum-hydrocarbon complex compounds described in U.S. Patent No. 3,159,601 and U.S. Patent No. 159,662, the chloroplatinic acid-olefin complex compounds described in U.S. Patent No. 3,516,946, and the platinum-vinylsiloxane complex compounds described in U.S. Patent No. 3,775,452 and U.S. Patent No. 3,814,780. The copolymer composition of the present invention may contain two or more platinum-based catalysts.

[0066] In the copolymer composition of the present invention, the amount of platinum-based catalyst blended per 100 parts by mass of copolymer (S) is preferably 0.00001 to 0.030 parts by mass, more preferably 0.0001 to 0.020 parts by mass, and even more preferably 0.001 to 0.010 parts by mass. Here, the platinum-based catalyst used in the present invention may be a commercially available product, and some commercially available platinum-based catalysts contain only a few percent of the active ingredient as a platinum-based catalyst. In such cases, the blending amount of platinum-based catalyst will be an amount that takes into account the amount of the active ingredient.

[0067] [Carbon Black] The copolymer composition of the present invention contains carbon black. Carbon black functions as a reinforcing agent, and its inclusion improves the processability of the copolymer composition, and also improves mechanical properties such as tensile strength, tear strength, and abrasion resistance.

[0068] As carbon black, known types such as Asahi #50HG, Asahi #55G, Asahi #60UG (all manufactured by Asahi Carbon Co., Ltd.), Seast SVH, Seast V, Seast G-SO (all manufactured by Tokai Carbon Co., Ltd.) can be used. These can be used individually or in combination of two or more types. Furthermore, the carbon black that can be used in this invention may be untreated or may be surface-treated with a silane coupling agent or the like.

[0069] In the copolymer composition of the present invention, the amount of carbon black blended per 100 parts by mass of copolymer (S) is 5 to 150 parts by mass. The blending amount is preferably 10 to 100 parts by mass, more preferably 20 to 80 parts by mass, even more preferably 30 to 70 parts by mass, and particularly preferably 40 to 60 parts by mass. If the amount of carbon black included is within the aforementioned range, a copolymer composition with excellent dynamic modulus (dynamic modulus / static modulus), processability, and mechanical properties can be obtained.

[0070] The copolymer composition of the present invention may contain reinforcing agents other than carbon black to improve physical properties such as tensile stress at fracture and tensile elongation at fracture, to the extent that it does not impair the effects of the present invention. Other reinforcing agents besides carbon black include silica, calcium carbonate, activated calcium carbonate, fine talc, and fine silicic acid. Two or more reinforcing agents other than carbon black may be included in the mixture.

[0071] [Amine-based antioxidants] The copolymer composition of the present invention contains an amine-based antioxidant. By employing an amine-based antioxidant, the copolymer composition of the present invention can suppress the occurrence of bloom, which is likely to occur when other antioxidants (e.g., phenol-based antioxidants) are used, and tends to be advantageous in terms of design and low-temperature properties.

[0072] Examples of amine-based antioxidants include aromatic primary amine antioxidants and aromatic secondary amine antioxidants. An example of an aromatic primary amine antioxidant is p,p'-diaminodiphenylmethane. Examples of aromatic secondary amine antioxidants include phenylbutylamine (N-butylaniline), N,N-di-2-naphthyl-p-phenylenediamine, bis[(1,1,3,3-tetramethylbutyl)phenyl]amine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, N-phenyl-1-naphthylamine, p-(p-toluenesulfonylamide)diphenylamine, N-isopropyl-N'-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, and N-(3-methacryloyloxy-2-hydroxypropyl)-N'-phenyl-p-phenylenediamine. As an amine-based antioxidant, an aromatic secondary amine-based antioxidant is more preferred. In one preferred and exemplary embodiment of the present invention, the amine-based antioxidant is bis[(1,1,3,3-tetramethylbutyl)phenyl]amine.

[0073] The content of the amine-based antioxidant in the copolymer composition of the present invention is preferably 0.005 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, even more preferably 0.1 to 4 parts by mass, and particularly preferably 1 to 3 parts by mass, per 100 parts by mass of copolymer (S). Furthermore, from the viewpoint of suppressing the occurrence of bloom, it is preferable that the copolymer composition of the present invention does not contain any antioxidants other than amine-based antioxidants, such as phenol-based antioxidants, nor any hindered phenol-based antioxidants.

[0074] [Reaction inhibitor] The copolymer composition of the present invention preferably contains a reaction inhibitor. The reaction inhibitor is a compound that has the function of suppressing the crosslinking reaction (hydrosilylation addition reaction to an alkene) between the alkenyl group of the copolymer (S) and the hydrosilyl group of the hydrosilyl group-containing compound (Y). The inclusion of a reaction inhibitor is preferable in that it stabilizes the processability of the composition during kneading and molding.

[0075] Specific examples of reaction inhibitors include, for example, benzotriazole; acetylene alcohols such as 1-hexyn-3-ol, 3-methyl-1-butyn-3-ol, 3,6-dimethyl-4-octin-3,6-diol, 2,4,7,9-tetramethyl-5-decine-4,7-diol, 1-ethynyl-1-cyclohexanol, and 3,5-dimethyl-1-hexyn-3-ol; acrylonitrile; N,N-diallyl acetylene alcohols. Examples of amide compounds include toamides, N,N-diallylbenzamide, N,N,N',N'-tetraallyl-o-phthalate diamide, N,N,N',N'-tetraallyl-m-phthalate diamide, and N,N,N',N'-tetraallyl-p-phthalate diamide; and others such as sulfur, phosphorus, nitrogen, amine compounds, sulfur compounds, phosphorus compounds, tin, tin compounds, and tetramethyltetravinylcyclotetrasiloxane. Among these compounds, 1-ethynyl-1-cyclohexanol and 3,5-dimethyl-1-hexyne-3-ol are particularly preferred. In one preferred and exemplary embodiment of the present invention, the reaction inhibitor is 1-ethynyl-1-cyclohexanol. The copolymer composition of the present invention may contain two or more reaction inhibitors.

[0076] In the copolymer composition of the present invention, the amount of reaction inhibitor blended per 100 parts by mass of copolymer (S) is preferably greater than 0 parts by mass and 2 parts by mass or less, more preferably 0.05 to 1.0 parts by mass, and even more preferably 0.1 to 0.5 parts by mass.

[0077] [Softener] The copolymer composition of the present invention may contain a softening agent. The softener is a known softener that is incorporated into the rubber composition. Specifically, these include petroleum-based softeners such as process oil, lubricating oil, paraffin oil, liquid paraffin, petroleum asphalt, and petrolatum; coal tar-based softeners such as coal tar; fatty oil-based softeners such as castor oil, linseed oil, rapeseed oil, soybean oil, and coconut oil; waxes such as beeswax and carnauba wax; naphthenic acid, pine oil, rosin or its derivatives; synthetic polymers such as terpene resins, petroleum resins, and coumarone indene resins; ester-based softeners such as dioctyl phthalate and dioctyl adipate; and others such as microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, hydrocarbon-based synthetic lubricants, tall oil, and sub(factis). Of these, petroleum-based softeners are preferred, and paraffin-based process oils are particularly preferred. The copolymer composition of the present invention may contain two or more softening agents.

[0078] When the copolymer composition of the present invention contains a softening agent, it is preferably used in the range of 5 to 150 parts by mass, more preferably 10 to 150 parts by mass, and particularly preferably 10 to 120 parts by mass, per 100 parts by mass of copolymer (S). If the amount of softening agent is within the above range, a copolymer composition with low tack and excellent processability, heat aging resistance, mechanical properties, etc. can be obtained.

[0079] [Desiccant] The copolymer composition of the present invention may contain a hygroscopic agent. Examples of desiccants include calcium oxide, silica gel, sodium sulfate, molecular sieves, zeolite, and white carbon. Of these, calcium oxide is preferred. The amount of desiccant added is preferably 0.5 to 15 parts by mass, more preferably 1.0 to 12 parts by mass, and even more preferably 1.0 to 10 parts by mass, per 100 parts by mass of copolymer (S). The copolymer composition of the present invention may contain two or more desiccants.

[0080] [Organic peroxide] The copolymer composition of the present invention may contain an organic peroxide. Examples of organic peroxides include dicumyl peroxide (DCP), 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)hexine-3, 1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(tert-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, ert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide.

[0081] When the copolymer composition of the present invention contains an organic peroxide, the amount of organic peroxide blended per 100 parts by mass of copolymer (S) is preferably 0.2 to 6 parts by mass, more preferably 0.2 to 4.8 parts by mass, and even more preferably 0.2 to 4 parts by mass. Furthermore, the total amount of the hydrosilyl group-containing compound (Y) and the organic peroxide per 100 parts by mass of the copolymer (S) is preferably 0.01 to 0.15 equivalents, more preferably 0.01 to 0.1 equivalents, and even more preferably 0.02 to 0.1 equivalents. Furthermore, the equivalent ratio [Y / Z] of the hydrosilyl group-containing compound (Y) and the organic peroxide is preferably 23 / 77 to 99 / 1, and more preferably 47 / 53 to 99 / 1. Here, crosslinking in the copolymer composition of the present invention is carried out by an addition reaction between the alkenyl group of the copolymer (S) and the hydrosilyl group of the hydrosilyl group-containing compound (Y) in the presence of the platinum-based catalyst. Therefore, the copolymer composition of the present invention may in many cases not necessarily contain organic peroxides. In one preferred and exemplary embodiment of the present invention, the copolymer composition of the present invention does not contain organic peroxides.

[0082] [Crosslinking agent] The copolymer composition of the present invention may contain a crosslinking aid. Examples of crosslinking aids include methacrylate compounds such as polyethylene glycol dimethacrylate; allyl compounds such as diallyl phthalate and triallyl cyanurate; maleimide compounds; and divinylbenzene. Such crosslinking aids are preferably used in an amount of 0.5 to 2 moles, more preferably about equimolars, per mole of the hydrosilyl group-containing compound (Y) used.

[0083] [Filler] The copolymer composition of the present invention may contain fillers in order to reduce compounding costs. Examples of fillers include talc and clay. These fillers may be used individually or in combination of two or more. Such fillers are preferably used in an amount of 1 to 500 parts by mass, more preferably 1 to 400 parts by mass, and even more preferably 1 to 300 parts by mass, per 100 parts by mass of copolymer (S). When the amount of filler is within the above range, the mechanical properties of the resulting molded article, such as tensile strength, tear strength, and abrasion resistance, can be improved.

[0084] [Processing aid] The copolymer composition of the present invention may contain processing aids. As processing aids, a wide range of substances commonly used in rubber processing can be used. Specifically, these include ricinoleic acid, stearic acid, palmitic acid, lauric acid, barium stearate, zinc stearate, calcium stearate, zinc laurate, or esters. These processing aids may be used individually or in combination of two or more.

[0085] The processing aid can be appropriately blended in an amount of preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less, per 100 parts by mass of copolymer (S). When the amount of processing aid is within the above range, the processability such as kneading processability, extrusion processability, and injection moldability is excellent.

[0086] [Activating agent] The copolymer composition of the present invention may contain an activator. Examples of activators include glycols such as polyethylene glycol and diethylene glycol; and amines such as di-n-butylamine and triethanolamine. These activators may be used individually or in combination of two or more. The activator can be appropriately blended in an amount of preferably 0.2 to 15 parts by mass, preferably 0.3 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass, per 100 parts by mass of copolymer (S).

[0087] [Other compounding agents, etc.] In addition to the above components, the copolymer composition of the present invention may appropriately contain rubber compounding agents known on their own, such as metal salts of α,β-unsaturated organic acids, crosslinking accelerators, plasticizers, tackifiers, etc., as long as the objective of the present invention is not impaired.

[0088] [Other resins] The copolymer composition of the present invention may contain resins or rubbers other than copolymer (S) to the extent that the effects of the present invention are not impaired. The amount of resins or rubbers other than copolymer (S) in the copolymer composition of the present invention is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and preferably not included, per 100 parts by mass of copolymer (S). In one preferred and exemplary embodiment of the present invention, the copolymer composition of the present invention does not contain resins or rubbers other than copolymer (S).

[0089] Examples of resins other than copolymers (S) include general-purpose resins such as polyethylene, polypropylene, and polystyrene. Examples of rubber include silicone rubber, ethylene-propylene random copolymer rubber (EPR), natural rubber, styrene-butadiene rubber, isoprene rubber, butadiene rubber, and chloroprene rubber.

[0090] [Foaming agent] The copolymer composition of the present invention may contain a foaming agent in order to obtain a foamed crosslinked molded article. Foaming agents include physical foaming agents such as carbon dioxide, nitrogen, air, and water; inorganic foaming agents such as sodium bicarbonate (baking soda), sodium carbonate, ammonium bicarbonate, ammonium carbonate, and ammonium nitrite; nitroso compounds such as N,N'-dimethyl-N,N'-dinitrosotelephthalamide and N,N'-dinitrosopentamethylenetetramine (DPT); azodicarbonamide (ADCA), azobisisobutyronitrile, azocyclohexylnitrile, azodiaminobenzene, and variol. Examples include azo compounds such as um azodicarboxylate; sulfonyl hydrazide compounds such as benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, p,p'-oxybis(benzenesulfonyl hydrazide), diphenylsulfon-3,3'-disulfonyl hydrazide, and OBSH(4,4'-oxybisbenzenesulfonyl hydrazide); and azide compounds such as calcium azide, 4,4-diphenyldisulfonyl azide, and p-toluenesulfonyl azide. Among these, inorganic blowing agents are preferred because they enable low specific gravity and high crosslink density of foamed molded articles, and sodium bicarbonate is particularly preferred.

[0091] In addition to the foaming agent, a foaming aid may be added as needed. The foaming aid exhibits effects such as lowering the decomposition temperature of the foaming agent, accelerating decomposition, or homogenizing bubbles. Examples of foaming aids include organic acids or their salts, such as salicylic acid, phthalic acid, stearic acid, oxalic acid, and citric acid; urea or its derivatives. Examples of commercially available products include Cell Paste K5 (trade name; manufactured by Eiwa Kasei Kogyo Co., Ltd., urea) and FE-507 (trade name; manufactured by Eiwa Kasei Kogyo Co., Ltd., baking soda). The amount of foaming aid added is usually 0.1 to 5 parts by mass, preferably 0.5 to 4 parts by mass, per 100 parts by mass of copolymer (S).

[0092] Furthermore, physical foaming using high-pressure gas is also possible. That is, for example, when extruding at a temperature near the melting point of the resin, a volatile or inorganic gas-based foaming agent can be injected under pressure through an inlet provided in the middle of the extruder, and the foam can be continuously obtained by extruding it from the die. Specific examples of physical foaming agents include volatile foaming agents such as Freon, butane, pentane, hexane, and cyclohexane, and inorganic gas-based foaming agents such as nitrogen, air, water, and carbon dioxide. In addition, bubble nucleation agents such as calcium carbonate, talc, clay, and magnesium oxide may be added during extrusion foaming. The blending ratio of the physical foaming agent is usually 5 to 60 parts by mass, preferably 10 to 50 parts by mass, per 100 parts by mass of copolymer (S). If the blending ratio of the physical foaming agent is too low, the foaming properties of the foam will decrease, and conversely, if it is too high, the strength of the foam will decrease.

[0093] [Manufacturing of copolymer compositions] To obtain the copolymer composition of the present invention, methods similar to those used for known general rubber compositions can be employed. Specifically, these are as follows: The copolymer can be prepared by kneading a copolymer (S), carbon black, and other components such as an antioxidant as needed at a temperature of 80-170°C for 3-10 minutes using internal mixers such as Banbury mixers, kneaders, and intermixers (first kneading), then adding a hydrosilyl group-containing compound (Y), a platinum-based catalyst, and other compounding agents such as a reaction inhibitor as needed, or other rubbers or resins, and then kneading the mixture using rolls such as open rolls or a kneader at a roll temperature of 50-130°C for 5-30 minutes (second kneading), followed by dispensing. In this way, a copolymer composition in the form of ribbons or sheets is usually obtained.

[0094] To obtain the copolymer composition of the present invention, it is also preferable to knead the copolymer (S), the hydrosilyl group-containing compound (Y), and other components as needed (first kneading), and then knead the resulting mixture with a platinum-based catalyst, a reaction inhibitor as needed, and other components as needed (second kneading).

[0095] Specifically, a copolymer (S), a hydrosilyl group-containing compound (Y), and other components as needed are kneaded at 80-170°C for 1-10 minutes, preferably at 110-170°C for 1-8 minutes (first kneading). Then, a platinum-based catalyst, a reaction inhibitor as needed, and other components as needed are added to the resulting mixture and kneaded at 10-100°C for 1-20 minutes, preferably at 20-80°C for 3-15 minutes (second kneading).

[0096] Carbon black may be added during either the first or second mixing stage, but it is preferable to add it during the first mixing stage. The same applies when adding other reinforcing agents, softeners, etc. When adding other rubber compounding agents, such as metal salts of α,β-unsaturated organic acids, hygroscopic agents, antioxidants, fillers, processing aids, surfactants, plasticizers, and tackifiers, it is preferable to add them during the first kneading stage, and crosslinking aids and crosslinking accelerators are preferable to add during the second kneading stage.

[0097] For the first mixing stage, any known mixing device capable of processing at high temperatures can be used. Specifically, examples include Banbury mixers, kneaders, and extruders. Mixing equipment used for the second mixing stage includes rollers, kneaders, and extruders, which allow for easy temperature control.

[0098] By dividing the mixing of each component into a first and second mixing stage, the mixing time can be shortened compared to mixing all components together without separation. Furthermore, since cross-linking can be suppressed during the first mixing stage, the temperature during the first mixing stage can be increased, making it possible to remove moisture in a shorter time.

[0099] <Crosslinked molded body> The crosslinked molded article according to the present invention is a crosslinked molded article obtained by crosslinking the copolymer composition of the present invention. The crosslinked molded article of the present invention preferably has a TR70 of -35°C or lower when subjected to a TR test in accordance with JIS K 6261-4, more preferably -37°C or lower, even more preferably -39°C or lower, and particularly preferably -41°C or lower. A crosslinked molded article can be obtained by pre-molding the copolymer composition of the present invention into a desired shape using various molding machines such as an extrusion machine, calender roll, press molding machine, injection molding machine, or transfer molding machine, or by introducing the molded article into a crosslinking tank and heating it to crosslink it simultaneously with the molding process. If the copolymer composition of the present invention contains a foaming agent, foaming will also proceed along with crosslinking, resulting in a foamed crosslinked molded article (foamed molded article).

[0100] Any known heating method can be used without limitation, but it is particularly preferable to heat the material at a temperature of 150-200°C for 1-30 minutes using a heating bath with heating modes such as far-infrared heating furnaces, hot air, glass bead fluidized beds, UHF (ultra-high frequency electromagnetic waves), steam, or LCM (molten salt chamber). For molding and crosslinking, molds may or may not be used. An example of molding using molds is press molding. In this case, molding and crosslinking are performed during the press molding process. If molds are not used, the rubber composition is usually molded and crosslinked continuously.

[0101] It is also preferable to perform primary crosslinking of the copolymer composition of the present invention by press molding, remove it from the mold to obtain a primary molded body, and then perform secondary crosslinking of the obtained primary molded body in a heat transfer medium. Specifically, the copolymer composition of the present invention can be press-molded at 120-200°C for 1-20 minutes, preferably at 150-200°C for 10-18 minutes, to perform primary crosslinking and remove from the mold to obtain a primary molded body. The obtained primary molded body can then be secondary crosslinked in a heat transfer medium at 120-160°C for 10-24 hours, preferably at 140-160°C for 15-20 minutes. The heat transfer fluids used for secondary crosslinking include air, steam, paraffin-based process oil, and molten salt.

[0102] When primary crosslinking is performed by press molding, the crosslinked material does not become hot due to shear heating. Therefore, it is possible to suppress the generation of low-molecular-weight siloxanes and the degradation of the polymer. Furthermore, in press molding where crosslinking occurs in a sealed state, some of the generated low-molecular-weight siloxane remains inside the crosslinked material. However, by performing secondary crosslinking in a heat transfer medium, it is possible to volatilize the low-molecular-weight siloxane and obtain a crosslinked material with a low amount of low-molecular-weight siloxane.

[0103] The cross-linked molded articles of the present invention can be used in a variety of applications. Specifically, they are suitably used in tire rubber, O-rings, industrial rolls, packings (e.g., condenser packings), gaskets, belts (e.g., heat-insulating belts, copier belts, conveyor belts), hoses such as automotive hoses (e.g., water hoses, brake reservoir hoses, radiator hoses, air hoses), vibration-damping rubber, vibration-damping or vibration-reducing materials (e.g., engine mounts, motor mounts), muffler hangers, sponges (e.g., weatherstrip sponges, heat-insulating sponges, protective sponges, micro-foamed sponges), cables (ignition cables, cabtyre cables, high-tension cables), wire covering materials (high-voltage wire covering materials, low-voltage wire covering materials, marine wire covering materials), glass run channels, colored surface materials, paper feed rolls, roofing sheets, and the like. In a preferred and exemplary embodiment of the present invention, the crosslinked molded article of the present invention is used for fuel cell gaskets. That is, the fuel cell gasket of the present invention is obtained using the copolymer composition of the present invention, and can also be said to include a crosslinked material of the copolymer composition of the present invention. [Examples]

[0104] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0105] <Measurement Methods and Evaluation Methods> The physical properties of the copolymers, uncrosslinked copolymer compositions (polymer compositions immediately after the completion of the second stage of kneading described below, the same applies hereinafter), and crosslinked molded articles of each example were measured and evaluated by the following methods.

[0106] [Composition of copolymer] The mass fraction (mass%) of each constituent unit of the copolymer is: 13 The copolymer was determined by measurement using 1C-NMR. The measurement was performed using an ECX400P nuclear magnetic resonance spectrometer (JEOL), with a measurement temperature of 120°C, a measurement solvent of orthodichlorobenzene / deuterated benzene = 4 / 1, and 8000 cumulative cycles. 13 The spectrum was obtained by measuring the 1C-NMR spectrum. The molar amount (mol%) of each constituent unit of the copolymer is 1 The H-NMR spectrum is measured and obtained 1 The components were determined by measuring the intensity of the peaks corresponding to each constituent unit in the 1H-NMR spectrum. Details of the measurement conditions are described in International Publication No. 2015 / 122415.

[0107] [Iodine value of copolymers] The iodine value of the copolymer was determined by titration. Specifically, it was measured using the following method. 0.5 g of copolymer was dissolved in 60 ml of carbon tetrachloride, a small amount of Wies' reagent and 20% potassium iodide solution were added, and the mixture was titrated with 0.1 mol / L sodium thiosulfate solution. Near the endpoint, a starch indicator was added, and the mixture was titrated while stirring well until the pale purple color disappeared. The amount of iodine consumed per 100 g of sample was then calculated.

[0108] [Mooney viscosity of copolymers] Mooney viscosity of copolymers ML (1+4) The 100°C measurement was performed using a Mooney viscometer "SMV-202" (manufactured by Shimadzu Corporation) in accordance with JIS K6300 (1994).

[0109] [Intrinsic viscosity of copolymers] The intrinsic viscosity [η] of the copolymer was measured using a fully automatic intrinsic viscometer manufactured by Rigosha Co., Ltd., at a temperature of 135°C and using decalin as the measurement solvent.

[0110] [Molecular weight of copolymer] The weight-average molecular weight (Mw) of the copolymer refers to the weight-average molecular weight measured by 3D-GPC. The measurement equipment and conditions are as follows:

[0111] Detector: Differential refractometer / GPC device built-in 2-angle light scattering photometer PD2040 type (manufactured by Precison Detectors) Bridge-type viscometer PL-BV400 (Manufactured by Polymer Laboratories)

[0112] Column: TSKgel GMH HR -H(S)HT x 2 bottles + TSKgel GMH HR -M(S)×1 piece (Each piece has an inner diameter of 7.8mmφ and a length of 300mm) Temperature: 140℃ Mobile phase: 1,2,4-trichlorobenzene (containing 0.025% BHT) Injection volume: 0.5mL Sample concentration: Ca 1.0 mg / mL Sample filtration: Filtered using a 1.0 μm pore size sintered filter.

[0113] [P value of copolymer] Using an Ares viscoelasticity measuring device (manufactured by Rheometric Scientific) as the rheometer, the complex viscosity η was measured at a frequency ω = 0.01 rad / s under conditions of 190°C and 1.0% strain. * (ω=0.01) Complex viscosity η at frequency ω = 0.1 rad / s * (ω=0.1) Complex viscosity η at frequency ω = 10 rad / s * (ω=10) , and the complex viscosity η at frequency ω = 100 rad / s * (ω=100)(All units are Pa·sec) were measured. Also, from the obtained results, η * (ω=0.1) and η * (ω=100) The ratio of complex viscosity to (η) * The P value (η) of the copolymer (ratio) * (ω=0.1) / η * (ω=100) ), and η * (ω=0.01) The common logarithm and η * (ω=10) The ratio to the common logarithm was calculated.

[0114] [Physical properties of unvulcanized rubber (vulcanization rate)] Using the uncrosslinked copolymer compositions in each example, a cure meter test was performed using the measuring instrument: MDR2000P (MDR (Moving Die Rheometer) manufactured by ALPHA TECHNOLOGIES) under measurement conditions of 180°C and 20 minutes, and S'Max-S'Min, tc10, and tc90 were measured as follows.

[0115] A sample was placed in a measuring device, and the torque change obtained under constant temperature and constant shear rate conditions was measured to obtain a vulcanization curve. From this vulcanization curve, the minimum torque S'Min and maximum torque S'Max were determined, and the time (in minutes) until the torque became (S'Max-S'Min)×0.1 and (S'Max-S'Min)×0.9, respectively, were defined as tc10 and tc90, respectively, with the start of measurement as the reference point. Here, tc10 represents the vulcanization start point, and tc90 represents the optimal vulcanization point. In this invention, tc90 was defined as the vulcanization rate.

[0116] Furthermore, the time it takes for the torque to increase by 1 point (1 dNm) from the minimum torque value S'Min was defined as the vulcanization induction time (TS1: minutes). Furthermore, the maximum slope of the vulcanization curve was defined as the peak rate (dNm / min).

[0117] [Bloom test] The uncrosslinked copolymer compositions in each example were press-molded in a mold at 180°C for 10 minutes using a press molding machine to obtain a 2 mm thick sheet-like crosslinked molded body. The obtained crosslinked molded bodies were left to stand at 25°C for 5 months. After 5 months, the surface of the crosslinked molded bodies was visually observed to evaluate the presence or absence of bloom. Here, the assessment of the presence or absence of bloom was specifically based on the following criteria. "No bloom": No discoloration (whitening) of the sample surface. "Bloom present": Discoloration (whitening) of the sample surface is present.

[0118] [Hardness test (Duro-A hardness)] The uncrosslinked copolymer compositions from each example were press-molded in a mold at 180°C for 10 minutes using a press molding machine to obtain 2 mm thick sheet-like crosslinked molded bodies. Six of the obtained crosslinked molded bodies from each example were stacked to form a 12 mm thick test specimen, and its hardness (Duro-A) was measured according to JIS K 6253-3. The dimensions of the measurement surface of the test specimen were such that the indenter tip could be used to measure hardness at a distance of 12 mm or more from the edge of the specimen.

[0119] [Tensile test] In each example, the uncrosslinked copolymer composition was press-molded in a mold at 180°C for 10 minutes using a press molding machine to obtain a 2 mm thick sheet-like crosslinked molded body. Each of the obtained crosslinked molded bodies was punched out to prepare a No. 3 dumbbell test specimen as described in JIS K 6251 (1993). Using this test specimen, a tensile test was performed under the conditions of a measurement temperature of 23°C and a tensile speed of 500 mm / min, according to the method specified in Section 3 of JIS K 6251, and the tensile stress at fracture TB (MPa) and the tensile elongation at fracture EB (%) were measured.

[0120] [Evaluation of heat aging resistance] In each example, the uncrosslinked copolymer composition was press-molded in a mold at 180°C for 10 minutes using a press molding machine to obtain a 2 mm thick sheet-like crosslinked molded body. This body was then subjected to a thermal aging test by holding it at 150°C for 336 hours (14 days). The thermal aging test was conducted in accordance with JIS K 6257, under atmospheric pressure in a gear oven. For the cross-linked molded articles after the thermal aging test, the hardness was measured using the same method as in the "hardness test (Duro-A hardness)" described above, and the tensile stress at fracture TB (MPa) and the tensile elongation at fracture EB (%) were measured using the same method as in the "tensile test" described above.

[0121] AH(Duro-A) was determined from the difference in hardness before and after the thermal aging test. The rate of change after the test relative to the pre-thermal aging value was determined from the tensile fracture stress (TB) and tensile fracture elongation (EB) before and after the thermal aging test, as Ac(TB) and Ac(EB), respectively. Here, AH, Ac(TB), and Ac(EB) are specifically the values ​​shown in the following formula: AH = HA1 - HA0 HA1: Duro-A hardness measured after thermal aging test HA0: Duro-A hardness measured before thermal aging test Ac(TB)(%) = (TB1 - TB0) / TB0 × 100 TB1: TB measured after thermal aging test TB0: TB measured before the thermal aging test Ac(EB)(%) = (EB1 - EB0) / EB0 × 100 EB1: EB measured after thermal aging test EB0: EB measured before the thermal aging test

[0122] [TR Test (Low-Temperature Elastic Recovery Test)] In each example, the uncrosslinked copolymer composition was press-molded in a mold at 180°C for 10 minutes using a press molding machine to obtain a sheet-like crosslinked molded body with a thickness of 2 mm. The obtained sheets were subjected to a TR test (low-temperature elastic recovery test) in accordance with JIS K 6261-4 to measure their cold resistance. In this test, a stretched sheet is frozen, and its recovery from stretching is measured by continuously increasing the temperature. (The temperatures at which the length of the test specimen shrinks (recovers) by 10%, 30%, 50%, 65%, 70%, and 75% due to the temperature increase are denoted as TR10, TR30, TR50, TR65, TR70, and TR75, respectively.) Lower TR10 and TR70 (unit: °C) values ​​indicate superior cold resistance.

[0123] [Compression set (CS)] In each example, the uncrosslinked copolymer composition was crosslinked at 180°C for 15 minutes using a press molding machine equipped with a cylindrical mold, in accordance with JIS K 6262, to obtain a crosslinked molded body with a diameter of 29 mm and a height (thickness) of 12.5 mm. This crosslinked molded body was used as the test specimen. The specimen was compressed by 25% relative to its height before loading (12.5 mm) and treated at 150°C for 72 hours, 23°C for 22 hours, or -40°C for 22 hours. The specimen was then removed, left at room temperature for 30 minutes, and its height was measured. The compression set (%) was then calculated using the following formula. Compression set (%) = {(t0-t1) / (t0-t2)} × 100 t0: Height of the test specimen before testing. t1: Height of the test specimen after heat treatment under the above conditions and leaving it at room temperature for 30 minutes. t2: Height of the test specimen when mounted on the measuring mold.

[0124] <Copolymer Manufacturing> The copolymers used in each example were prepared using the method described in the following production example.

[0125] [Manufacturing Example 1: Production of ethylene-1-butene-VNB copolymer (S-1)] The polymerization reaction of ethylene, 1-butene, and 5-vinyl-2-norbornene (VNB) was carried out continuously at 95°C using a 300 L polymerizer equipped with stirring blades. Hexane (feed rate: 30.5 L / h) was used as the polymerization solvent and was continuously supplied to the polymerizer at a rate of 5.3 kg / h for ethylene, 21.5 kg / h for 1-butene, 566 g / h for VNB, and 10 NL / h for hydrogen.

[0126] While maintaining a polymerization pressure of 1.6 MPaG and a polymerization temperature of 95°C, di(p-tolyl)methylene(cyclopentadienyl)(octamethyloctahydrodibenzofluorenyl)zirconium dichloride was continuously supplied to the polymerizer as the main catalyst at a feed rate of 0.00903 mmol / h. In addition, (C6H5)3CB(C6F5)4 was continuously supplied to the polymerizer as a co-catalyst at a feed rate of 0.045 mmol / h, and triisobutylaluminum (TIBA) was continuously supplied to the polymerizer as an organoaluminum compound at a feed rate of 30 mmol / h.

[0127] In this way, a solution containing 20% ​​by mass of ethylene-1-butene-VNB copolymer formed from ethylene, 1-butene, and VNB was obtained. A small amount of methanol was added to the polymerization reaction solution withdrawn from the bottom of the polymerizer to stop the polymerization reaction, and the ethylene-1-butene-VNB copolymer was separated from the solvent by steam stripping, and then dried under reduced pressure at 80°C overnight.

[0128] Through the above procedure, ethylene-1-butene-VNB copolymer (S-1) was obtained at a rate of 8.5 kg per hour. The physical properties of the obtained copolymer (S-1) were measured using the method described above. The physical properties of copolymer (S-1), including the numerical values ​​related to requirements (i) to (v), are shown in Table 1 below. Copolymer (S-1) satisfied all requirements (i) to (v). [Table 1]

[0129] <Hydrosilyl group-containing compounds> The hydrosilyl group-containing compounds used in each example are as follows:

[0130] [Hydrosilyl group-containing compound (Y-1)] 536 g of methylhydrogenpolysiloxane, represented by the following formula (a-1-1), was charged into the reactor and heated to 40°C while stirring under a nitrogen flow. A toluene solution of platinum-1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane complex (Pt concentration 0.3 wt%) was added, and 265 g of α-methylstyrene was added dropwise while maintaining the reaction temperature at 40-90°C.

[0131] [ka]

[0132] After the dropwise addition was complete, the mixture was stirred at 85°C for 2 hours. Then, 0.5 g of the reaction solution was taken, and the reaction rate of the Si-H groups was confirmed to be approximately 36% by the alkaline decomposition gas generation method (decomposing the remaining Si-H groups with an ethanol / aqueous solution of KOH, and calculating the reaction rate of the Si-H groups from the volume of hydrogen gas generated). Next, the reaction solution was heated under reduced pressure to 135°C and the low-boiling components were removed by distillation for 2 hours to obtain 673 g of the hydrosilyl group-containing compound (Y-1).

[0133] The resulting hydrosilyl group-containing compound (Y-1) is 29 Si-NMR confirmed that the compound is represented by the following formula (a-1). The obtained hydrosilyl group-containing compound (Y-1) was measured for viscosity at 25°C using an Ubbelohde-type viscosity tube in accordance with JIS-Z-8803, and the result was 26 mmHg. 2 It was / s.

[0134] [ka]

[0135] <Amine-based antioxidants and other antioxidants> The anti-aging agents used in each example are as follows: Amine-based antioxidant: Nocrack AD-F (octylated diphenylamine (bis[(1,1,3,3-tetramethylbutyl)phenyl]amine)), manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Phenolic antioxidant: BASF Japan Ltd., Irganox 1010 (Tetrakis[methylene(3,5-di-tert-butyl-4-hydroxy)hydrocinnamate]methane) Phenolic antioxidant: BASF Japan Ltd., Irganox 1035 (bis[3-[3,5-di(tert-butyl)-4-hydroxyphenyl]propionic acid]thiobisethylene) Polyphenol-based anti-aging agent: Nocrac NS-7 (2,5-di-tert-butylhydroquinone), manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0136] <Other ingredients> The other components used in each example are as follows: Carbon black: Asahi Carbon Co., Ltd., Asahi #60UG. Reaction inhibitor: 1-ethynyl-1-cyclohexanol, manufactured by Nisshin Chemical Industry Co., Ltd. Catalyst: Dow Toray SRX212 Catalyst, complex salt of chloroplatinic acid and 1,3-divinyltetramethyldisiloxane (concentration between 1.0% and less than 3.0%).

[0137] <Example 1, and Comparative Examples 1-4> For each of Example 1 and Comparative Examples 1-4, the copolymer compositions were prepared as follows. In the first stage, the raw materials shown in "<Formulation> First Stage" of Table 2-1 were kneaded at 140°C for 2 minutes using a BB-4 Banbury mixer (manufactured by Kobe Steel, Ltd.). After that, the ram was raised and cleaned, and kneaded for another minute, then discharged at approximately 150°C to obtain the first stage formulation.

[0138] Next, in the second step, the mixture obtained in the first step was wound onto an 8-inch roll (manufactured by Nippon Roll Co., Ltd., with a front roll surface temperature of 50°C, a rear roll surface temperature of 50°C, a front roll rotation speed of 16 rpm, and a rear roll rotation speed of 18 rpm). The raw materials shown in "<Vulcanization System> Second Step" of Table 2-1 were added to this, and the mixture was kneaded for 10 minutes to obtain a copolymer composition in the form of an uncrosslinked composition.

[0139] [evaluation] For each of Example 1 and Comparative Examples 1 to 4, the physical properties of the copolymer composition and the crosslinked molded article were measured and evaluated using the method described in "Measurement Method and Evaluation Method" above. The results are shown in Tables 2-1 and 2-2. In the following description, the copolymer composition and crosslinked molded article obtained in Example 1 may be referred to as "Copolymer Composition of Example 1" and "Crosslinked Molded Article of Example 1," respectively, and the copolymer composition and crosslinked molded article obtained in Comparative Example X (where X is any of 1 to 4) may be referred to as "Copolymer Composition of Comparative Example X" and "Crosslinked Molded Article of Comparative Example X," respectively.

[0140] [Table 2-1]

[0141] [Table 2-2]

[0142] As shown in Table 2-2, among copolymer compositions containing ethylene-1-butene-VNB copolymer (S-1), the crosslinked molded article obtained from the copolymer composition of Example 1 containing an amine-based antioxidant showed excellent low-temperature properties, with TR10 and TR70 in the TR test being low at -66°C and -44°C, respectively. Furthermore, the compression set (CS) (treated at -40°C for 22 hours) was also low at 37%, demonstrating excellent low-temperature properties. In addition, the crosslinked molded article showed no bloom formation, indicating good bloom resistance.

[0143] In contrast, the crosslinked molded article obtained from the copolymer composition of Comparative Example 1, which did not contain an antioxidant, did not exhibit blooming, but the changes in Duro-A hardness and EB before and after the heat aging test were large, indicating insufficient heat aging resistance. On the other hand, the crosslinked molded articles obtained from the copolymer compositions of Comparative Examples 2 to 4, which contained amine-based antioxidants other than amine-based antioxidants, exhibited heat aging resistance equivalent to that of the crosslinked molded article of Example 1, but blooming was observed. In particular, the crosslinked molded articles obtained from the copolymer compositions of Comparative Examples 2 to 3, which contained phenol-based antioxidants, showed a TR70 of -33°C in the TR test, which was higher than that of the crosslinked molded article of Example 1, and a compression set (CS) (treated at -40°C for 22 hours) of 53%. This indicates that crosslinked molded articles obtained from copolymer compositions containing a phenolic antioxidant tend to have inferior bloom resistance, as well as inferior cold resistance and low-temperature properties, compared to the crosslinked molded article of Example 1 obtained from a copolymer composition containing an amine antioxidant.

Claims

1. A copolymer (S) having constituent units derived from ethylene (A), constituent units derived from α-olefin (B) having 3 to 20 carbon atoms, and constituent units derived from a non-conjugated polyene (C) containing a total of two or more substructures selected from the following formulas (I) and (II) in the molecule, and satisfying the following requirements (i) and (ii), A hydrosilyl group-containing compound (Y) is an organohydrogenpolysiloxane represented by the following formula (a), having at least one silicon atom-bonded aralkyl group and at least two silicon atom-bonded hydrogen atoms in the molecule, Platinum-based catalysts, Carbon black and, A copolymer composition comprising an amine-based antioxidant, The copolymer composition contains 5 to 150 parts by mass of carbon black per 100 parts by mass of the copolymer (S), The copolymer (S) is a copolymer composition comprising a constituent unit derived from 1-butene as a constituent unit derived from the α-olefin (B): (i) The ratio [A] / [B], which is the ratio of the number of moles [A] of constituent units derived from ethylene (A) to the number of moles [B] of constituent units derived from α-olefin (B), is between 40 / 60 and 90 / 10; (ii) The mass fraction of the constituent units derived from the non-conjugated polyene (C) is 0.07 to 10.0% by mass relative to the total constituent units of the copolymer (S). 【Chemistry 1】 【Chemistry 2】 (In formula (a), n and p are each independently 0 or a positive number, m is 1 to 20, the sum of n, m, and p is 5 to 50, and a plurality of R 1 , R 2 are each independently a monovalent alkyl group, R a is an aralkyl group, and two Rs are each independently R 1 , R 2 , a hydrogen atom, or any one selected from the group consisting of R a . The structural units of -[O-Si(R 1 )(R a )]-, -[O-Si(R 1 )H]-, and -[O-Si(R 1 )(R 2 )]- may be arranged in a block pattern or randomly arranged, provided that when n = 1, at least one of the two Rs is a hydrogen atom, and when n = 0, both of the two Rs are hydrogen atoms.)

2. The copolymer composition according to claim 1, comprising 0.1 to 100 parts by mass of the hydrosilyl group-containing compound (Y) per 100 parts by mass of the copolymer (S).

3. The copolymer composition according to claim 1, comprising 0.00001 to 0.030 parts by mass of the platinum-based catalyst per 100 parts by mass of the copolymer (S).

4. The copolymer composition further comprises a reaction inhibitor. The copolymer composition according to claim 1, wherein the reaction inhibitor is contained in an amount of more than 0 parts by mass and 2 parts by mass or less per 100 parts by mass of the copolymer (S).

5. The copolymer composition according to claim 1, comprising 0.005 to 10 parts by mass of the amine-based antioxidant per 100 parts by mass of the copolymer (S).

6. The copolymer composition according to claim 1, wherein the amine-based antioxidant is an aromatic secondary amine-based antioxidant.

7. The Mooney viscosity ML of the copolymer (S) at 100°C (1+4) The copolymer composition according to claim 1, wherein 100°C is 5 to 100.

8. The copolymer composition according to claim 1, wherein the copolymer (S) satisfies one or more of the following requirements (iii) to (v): (iii) (n) which can be found by formula (1) below C The value is between 4.5 and 80. (n C ) = (Mw) × {mass fraction of (C) / 100} / molecular weight of (C) ... (1) However, in formula (1), (Mw) is the weight-average molecular weight of the copolymer (S), the mass fraction of (C) is the mass fraction of the constituent units derived from the unconjugated polyene (C), and the molecular weight of (C) is the molecular weight of the unconjugated polyene (C); (iv) Complex viscosity η at frequency ω = 0.1 rad / s, obtained by linear viscoelasticity measurement (190°C) using a rheometer. * （ω＝０．１） (Pa·sec) and the complex viscosity η at frequency ω = 100 rad / s * （ω＝１００） The ratio P(η) to (Pa·sec) * （ω＝０．１） / η * （ω＝１００） The intrinsic viscosity [η] (in decalin at 135°C) and the mass fraction of the constituent units derived from the non-conjugated polyene (C) (mass fraction of (C)) satisfy the following formula (2): P / ([η] 2.9 ) ≤ (C) mass fraction × 6 ... (2) (v) Complex viscosity η at frequency ω = 0.01 rad / s, obtained by linear viscoelasticity measurement (190°C) using a rheometer. * (ω=0.01) (Pa·sec) and the complex viscosity η at frequency ω = 10rad / s * (ω=10) (Pa·sec) and the apparent iodine value derived from the non-conjugated polyene (C) satisfy the following formula (3). Log{η} * (ω=0.01) } / Log{η * (ω=10) } ≤ 0.0753 × {Apparent iodine value derived from unconjugated polyene (C)} + 1.42 ... (3)

9. The copolymer composition according to claim 1, wherein the constituent units derived from α-olefin (B) consist only of constituent units derived from 1-butene.

10. The copolymer composition according to claim 1, wherein the copolymer (S) includes a constituent unit derived from 5-vinyl-2-norbornene as a constituent unit derived from the non-conjugated polyene (C).

11. A crosslinked molded article obtained by crosslinking a copolymer composition according to any one of claims 1 to 10.

12. The crosslinked molded article according to claim 11, wherein the TR70 obtained when a TR test is performed in accordance with JIS K 6261-4 is -35°C or lower.

13. A fuel cell gasket obtained using the copolymer composition described in any one of claims 1 to 10.

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