Resin compositions, fuel cell gaskets, and molded articles

Abstract

To obtain a resin composition that exhibits excellent heat aging resistance, has excellent tensile fracture stress, and has improved tensile fracture elongation and tensile stress. [Solution] A resin composition comprising an ethylene-α-olefin-non-conjugated polyene copolymer (A) having structural units derived from ethylene [A1], structural units derived from α-olefin [A2] having 4 to 20 carbon atoms, and structural units derived from a non-conjugated polyene [A3] containing a total of two or more substructures selected from the group consisting of the following general formulas (I) and (II) in the molecule, and satisfying specific requirements, carbon black (B), an antioxidant (C), an organic peroxide (D), and a crosslinking aid (E), wherein the copolymer (A) contains 5 to 150 parts by mass of carbon black (B), 0.5 to 7.0 parts by mass of the antioxidant (C), and 1.0 to 30 parts by mass of the organic peroxide (D) per 100 parts by mass of the copolymer (A). TIFF2026059410000006.tif30153

Description

Technical Field

[0001] The present invention relates to a resin composition, a fuel cell gasket, and a molded body.

Background Art

[0002] Ethylene-α-olefin copolymer elastomers such as ethylene-propylene copolymer (EPM, EPR) and ethylene-propylene-diene copolymer (EPDM) do not have unsaturated bonds in the main chain of their molecular structure. Therefore, compared with general-purpose conjugated diene rubbers, they are excellent in heat aging resistance, weather resistance, and ozone resistance, and are widely used in applications such as automotive parts, wire materials, electronic and electrical parts, building and civil engineering materials, and industrial material parts.

[0003] It is known to obtain a rubber molded body for sealing using EPDM (for example, Patent Document 1). The seal packing, which is a rubber molded body for sealing, is used in various applications such as automobiles, industrial machines, and electronic parts. Since automobiles and industrial machines are used even in cold regions, the seal packing is required to have low-temperature characteristics in addition to mechanical strength at normal temperature.

[0004] Further, in Patent Documents 2 and 3, as an ethylene copolymer composition for a fuel cell gasket capable of forming a seal packing having both low-temperature characteristics and mechanical strength (strength and elongation), a structural unit derived from ethylene [A], a structural unit derived from an α-olefin [B] having 4 to 20 carbon atoms, and a fuel cell gasket containing an ethylene-α-olefin-non-conjugated polyene copolymer containing a structural unit derived from a non-conjugated polyene [C] has been proposed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] Fuel cell gaskets in fuel cell vehicles (FCVs) are rubber components that prevent leakage of hydrogen, oxygen, and water within the FC stack. They require excellent mechanical properties and durability, and in recent years, the performance requirements for resin compositions used in fuel cell gaskets have been increasing. For example, there is a need to improve tensile elongation at fracture and tensile stress while maintaining excellent tensile fracture stress.

[0007] The objective of the present invention is to obtain a resin composition that exhibits excellent heat aging resistance, has excellent tensile fracture stress, and has improved tensile fracture elongation and tensile stress. [Means for solving the problem]

[0008] The inventors diligently studied to solve the aforementioned problems. As a result, they found that the aforementioned problems can be solved by the following configuration, and thus the present invention was concluded. The following are examples of the configuration of the present invention.

[0009] [1] An ethylene-α-olefin-non-conjugated polyene copolymer (A) having a structural unit derived from ethylene [A1], a structural unit derived from α-olefin [A2] having 4 to 20 carbon atoms, and a structural unit derived from a non-conjugated polyene [A3] containing a total of two or more substructures selected from the group consisting of the following general formulas (I) and (II) in the molecule, and satisfying the following requirements (1) to (3), Carbon Black (B), Anti-aging agent (C), Organic peroxides (D), and Contains crosslinking agent (E), A resin composition comprising 100 parts by mass of the copolymer (A), 5 to 150 parts by mass of the carbon black (B), 0.5 to 7.0 parts by mass of the antioxidant (C), and 1.0 to 30 parts by mass of the organic peroxide (D):

[0010] [ka]

[0011] Requirement (1): The molar ratio [[A1] / [A2]] of structural units derived from ethylene [A1] to structural units derived from α-olefins [A2] with 4 to 20 carbon atoms is 40 / 60 to 90 / 10; Requirement (2): The content of structural units derived from non-conjugated polyene [A3] is 0.1 to 6.0 mol%, with the total of structural units derived from [A1], [A2], and [A3] being 100 mol%; Requirement (3): The B value, represented by the following formula (i), is 1.20 or greater. B value = ([EX]+2[Y]) / 〔2×[E]×([X]+[Y])〕 ...Equation (i) [Here, [E], [X], and [Y] represent the mole fractions of structural units derived from ethylene [A1], α-olefins with 4 to 20 carbon atoms [A2], and non-conjugated polyenes [A3], respectively, and [EX] represents the ethylene [A1]-α-olefins with 4 to 20 carbon atoms [A2] dyad chain fraction.]

[0012] [2] The resin composition according to [1], wherein the crosslinking aid (E) is contained in an amount of 0.01 to 3.0 moles per mole of the organic peroxide (D).

[0013] [3] The resin composition according to [1] or [2], wherein the amount of the crosslinking aid (E) is 0.01 moles or more and less than 0.5 moles per mole of the organic peroxide (D).

[0014] [4] The resin composition according to any one of [1] to [3], wherein the crosslinking aid (E) has a methacrylate structure.

[0015] [5] The resin composition according to any one of [1] to [4], wherein the Mooney viscosity ML(1+4)100 °C of the copolymer (A) is 5 to 60.

[0016] [6] The resin composition according to any one of [1] to [5], wherein the copolymer (A) satisfies one or more of the following requirements (4) to (6): Requirement (4): The weight average molecular weight (Mw) of the copolymer (A), 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 (ii); 4.5 ≦ Mw × [weight fraction of A3] / 100 / [molecular weight of A3] ≦ 60 … Formula (ii) Requirement (5): The complex viscosity η * (ω=0.1) (Pa·sec) at a frequency ω = 0.1 rad / s and the complex viscosity η * (ω=100) (Pa·sec) at a frequency ω = 100 rad / s, and the ratio P (η * (ω=0.1) / η * (ω=100) ), the intrinsic viscosity [η] of the copolymer (A), and the weight fraction of the [A3] satisfy the following formula (iii); P / ([η] 2.9 ) ≦ [weight fraction of A3] × 6 … Formula (iii) Requirement (6): The complex viscosity η * (ω=0.01) (Pa·sec) at a frequency ω = 0.01 rad / s and the complex viscosity η * (ω=10) (Pa·sec) at a frequency ω = 10 rad / s, and the apparent iodine value derived from the non-conjugated polyene [A3] satisfy the following formula (vi). Log{η* (ω=0.01)} / log{η * (ω=10)}≦0.0753 × {Apparent iodine value derived from unconjugated polyene [A3]} + 1.42 …Equation (vi)

[0017] [7] The resin composition according to any one of [1] to [6], wherein the structural units derived from the α-olefin [A2] having 4 to 20 carbon atoms in the copolymer (A) include structural units derived from 1-butene.

[0018] [8] The resin composition according to any one of [1] to [7], wherein the structural units derived from the non-conjugated polyene [A3] in the copolymer (A) include structural units derived from 5-vinyl-2-norbornene.

[0019] [9] A resin composition for fuel cell gaskets, as described in any of [1] to [8].

[0020]

[10] A fuel cell gasket obtained using the resin composition described in [9].

[0021]

[11] A molded article obtained using any of the resin compositions described in [1] to [8]. [Effects of the Invention]

[0022] According to the present invention, a resin composition can be obtained that has excellent heat aging resistance and excellent tensile fracture stress, and in which tensile fracture elongation and tensile stress are improved. [Modes for carrying out the invention]

[0023] <Ethylene-α-olefin-nonconjugated polyene copolymer (A)> The ethylene-α-olefin-non-conjugated polyene copolymer (A) (hereinafter also referred to as "Copolymer (A)"), which is one of the components of the resin composition of the present invention (hereinafter also referred to as "this composition"), has structural units derived from ethylene [A1], structural units derived from α-olefin [A2] having 4 to 20 carbon atoms, and structural units derived from non-conjugated polyene [A3] containing a total of two or more substructures selected from the group consisting of the following general formulas (I) and (II) in the molecule, and satisfies the following requirements (1) to (3).

[0024] [ka]

[0025] Requirement (1): The molar ratio [[A1] / [A2]] of structural units derived from ethylene [A1] to structural units derived from α-olefins [A2] with 4 to 20 carbon atoms is 40 / 60 to 90 / 10. Requirement (2): The content of structural units derived from non-conjugated polyene [A3] is 0.1 to 6.0 mol%, with the total of structural units derived from [A1], [A2], and [A3] being 100 mol%. Requirement (3): The B value, represented by the following formula (i), is 1.20 or greater. B value = ([EX]+2[Y]) / 〔2×[E]×([X]+[Y])〕 ...Equation (i) [Here, [E], [X], and [Y] represent the mole fractions of structural units derived from ethylene [A1], α-olefins with 4 to 20 carbon atoms [A2], and unconjugated polyenes [A3], respectively, and [EX] represents the ethylene [A1]-α-olefins with 4 to 20 carbon atoms [A2] dyad chain fraction.]

[0026] Examples of α-olefins [A2] having 4 to 20 carbon atoms include 1-butene, 1-nonene, 1-decene, 1-nonadecene, 1-eicosene, etc., which have a straight chain structure without a side chain; and 4-methyl-1-pentene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc., which have a side chain.

[0027] These α-olefins [A2] can be used individually or in combination of two or more. Among these, it is preferable to include an α-olefin having 4 to 10 carbon atoms, more preferably 1-butene, 1-hexene, or 1-octene, even more preferably 1-butene, and particularly preferably 1-butene.

[0028] Ethylene-propylene-non-conjugated polyene copolymers, where the α-olefin is propylene, have insufficient rubber elasticity at low temperatures, which can limit their applications. On the other hand, copolymer (A) has structural units derived from α-olefin [A2] with 4 to 20 carbon atoms, and therefore tends to exhibit superior rubber elasticity at low temperatures.

[0029] Non-conjugated polyenes [A3] containing a total of two or more substructures selected from the group consisting of the above general formulas (I) and (II) include 5-vinyl-2-norbornene (VNB), norbornadiene, 1,4-hexadiene, 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, and 5-(1-methyl-4- Examples include pentenyl)-2-norbornene, 5-(2-ethyl-3-butenyl)-2-norbornene, 5-(6-heptenyl)-2-norbornene, 5-(3-methyl-5-hexenyl)-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-(1,2,3-trimethyl-4-pentenyl)-2-norbornene, and dicyclopentadiene. Among these, it is preferable that the non-conjugated polyene [A3] contains VNB, and more preferably that the non-conjugated polyene [A3] is VNB, because it is readily available, crosslinks well with organic peroxides, and the heat resistance of the copolymer composition is easily improved. The non-conjugated polyene [A3] may be used alone or in combination of two or more types.

[0030] The copolymer (A) according to the present invention may, to the extent that it does not impair the effects of the present invention, further contain structural units derived from ethylene [A1], α-olefins having 4 to 20 carbon atoms [A2], and the non-conjugated polyene [A3], as well as structural units derived from a non-conjugated polyene [A4] that contains only one substructure selected from the group consisting of general formulas (I) and (II) in the molecule.

[0031] Examples of such non-conjugated polyenes [A4] include 5-ethylidene-2-norbornene (ENB), 5-methylene-2-norbornene, 5-(2,3-dimethyl-3-butenyl)-2-norbornene, 5-(3,4-dimethyl-4-pentenyl)-2-norbornene, 5-(5-ethyl-5-hexenyl)-2-norbornene, and 5-(2-methyl-1-propenyl)-2-norbornene. Of these, ENB is preferred because it is readily available, the crosslinking rate during crosslinking with organic peroxides is easy to control, and good mechanical properties are easily obtained. Non-conjugated polyenes [A4] may be used alone or in combination of two or more.

[0032] Copolymer (A) may contain at least one constituent unit derived from biomass-derived monomers (ethylene [A1], α-olefins with 4 to 20 carbon atoms [A2], non-conjugated polyenes [A3], non-conjugated polyenes [A4]). The biomass-derived monomers used as raw materials for copolymer (A) may be biomass-derived ethylene, biomass-derived α-olefins, or biomass-derived non-conjugated polyenes. Examples of biomass-derived α-olefins include biomass-derived propylene. Examples of biomass-derived non-conjugated polyenes include biomass-derived 5-ethylidene-2-norbornene and biomass-derived 5-vinyl-2-norbornene. The monomers used as raw materials for copolymer (A) may contain only biomass-derived monomers, or they may contain both biomass-derived monomers and fossil fuel-derived monomers. Biomass-derived monomers such as biomass-derived ethylene, biomass-derived α-olefins, and biomass-derived non-conjugated polyenes can be obtained by known methods. It is preferable from the viewpoint of reducing environmental impact that the copolymer (A) contains constituent units derived from biomass-derived monomers.

[0033] Copolymer (A) may contain at least one constituent unit derived from chemically recycled monomers. The chemically recycled monomers that serve as raw materials for copolymer (A) may be chemically recycled ethylene, chemically recycled α-olefins, or chemically recycled non-conjugated polyenes. Furthermore, the monomers that serve as raw materials for copolymer (A) may consist solely of chemically recycled monomers, or may consist of both chemically recycled monomers and fossil fuel-derived monomers. Chemically recycled monomers such as chemically recycled ethylene, chemically recycled α-olefins, and chemically recycled non-conjugated polyenes can be obtained by known methods. It is preferable from the viewpoint of reducing environmental impact (mainly waste reduction) that the copolymer (A) contains constituent units derived from chemically recycled monomers.

[0034] 《Requirement (1)》 The molar ratio [[A1] / [A2]] of structural units derived from ethylene [A1] to structural units derived from α-olefins [A2] having 4 to 20 carbon atoms is 40 / 60 to 90 / 10. Copolymer (A) with a molar ratio within this range exhibits an excellent balance between rubber elasticity at low temperatures and tensile strength at room temperature.

[0035] The lower limit of the molar ratio [[A1] / [A2]] is preferably 45 / 55, more preferably 50 / 50, even more preferably 55 / 45, and particularly preferably 60 / 40. The upper limit of the molar ratio [[A1] / [A2]] is preferably 80 / 20, more preferably 75 / 25, and even more preferably 70 / 30.

[0036] Requirements (2) The content of structural units derived from non-conjugated polyene [A3] is 0.1 to 6.0 mol%, with the total of structural units derived from ethylene [A1], α-olefins with 4 to 20 carbon atoms [A2], and non-conjugated polyene [A3] being 100 mol%. Copolymer (A) with this content within the above range has sufficient crosslinkability and flexibility. In this specification, the content of each structural unit in the resin can be measured by NMR spectroscopy or the like.

[0037] The lower limit of the content of structural units derived from non-conjugated polyene [A3] is preferably 0.2 mol%, more preferably 0.3 mol%. The upper limit of the content of structural units derived from non-conjugated polyene [A3] is preferably 4.0 mol%, more preferably 3.0 mol%, even more preferably 2.0 mol%, and particularly preferably 1.0 mol%. When the content of structural units derived from non-conjugated polyene [A3] is within the above range, a copolymer (A) with sufficient crosslinkability and flexibility is obtained.

[0038] 《Requirement (3)》 The B value represented by formula (i) above is 1.20 or greater. The B value is preferably in the range of 1.20 to 1.80, more preferably 1.22 to 1.60, even more preferably 1.24 to 1.50, and particularly preferably 1.30 to 1.45. Ethylene copolymers with a B value of less than 1.20 exhibit high compression set at low temperatures, which may prevent the creation of ethylene copolymers with a good balance between rubber elasticity at low temperatures and tensile strength at room temperature.

[0039] The B value is an indicator of the randomness of the copolymer monomer chain distribution in copolymer (A), and in formula (i) above, [E], [X], [Y], and [EX] are 13 The 1C-NMR spectrum can be measured and determined based on reports by J. C. Sandall [Macromolecules, 15, 353 (1982)], J. Ray [Macromolecules, 10, 773 (1977)], et al.

[0040] Copolymer (A) has a Mooney viscosity ML(1+4)100°C preferably in the range of 5 to 60, more preferably 20 to 50, even more preferably 25 to 40, and particularly preferably 30 to 35. When the Mooney viscosity ML(1+4) at 100°C is within the aforementioned range, a copolymer (A) is obtained that exhibits excellent roll processability even with a high-hardness, oil-free formulation, as well as good post-treatment properties (ribbon handling properties) and excellent rubber properties.

[0041] The copolymer (A) preferably satisfies one or more of the following requirements (4) to (6). More preferably, the copolymer (A) satisfies two or more of the requirements (4) to (6), and even more preferably satisfies all of the requirements (4) to (6).

[0042] Requirements (4) The weight-average molecular weight (Mw) of copolymer (A), the weight fraction of structural units derived from non-conjugated polyene [A3] (weight fraction of [A3] (weight%)), and the molecular weight of non-conjugated polyene [A3] (molecular weight of [A3]) satisfy the following formula (ii). 4.5 ≤ Mw × weight fraction of [A3] / 100 / molecular weight of [A3] ≤ 60 ...Formula (ii)

[0043] If copolymer (A) satisfies requirement (4), the content of structural units derived from non-conjugated polyenes [A3] such as VNB is appropriate, and it exhibits sufficient crosslinking performance. Furthermore, when a crosslinked molded article is produced using copolymer (A), it exhibits excellent crosslinking speed, and the molded article after crosslinking shows excellent mechanical properties.

[0044] The copolymer (A) more preferably satisfies the following formula (ii-1). 4.5 ≤ Mw × weight fraction of [A3] / 100 / molecular weight of [A3] ≤ 35 ...Formula (ii-1)

[0045] The weight-average molecular weight (Mw) of copolymer (A) can be determined as a polystyrene-converted value measured by gel permeation chromatography (GPC). Specifically, in this specification, it was determined using 3D-GPC as described in the examples below.

[0046] The copolymer (A) has an appropriate degree of crosslinking when the "Mw × weight fraction of [A3] / 100 / molecular weight of [A3]" satisfies formula (ii) or (ii-1). By using this copolymer, it is possible to produce molded articles with a good balance of mechanical properties and heat aging resistance. If the aforementioned "Mw × weight fraction of [A3] / 100 / molecular weight of [A3]" is too small, the crosslinking ability may be insufficient and the crosslinking rate may be slow. Conversely, if it is too large, excessive crosslinking may occur, leading to a deterioration of mechanical properties.

[0047] Requirements (5) The complex viscosity η at frequency ω = 0.1 rad / s was 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) Ratio P[η] (Pa·sec) * (ω=0.1) / η * (ω=100) The intrinsic viscosity [η] of copolymer (A) and the weight fraction of [A3] satisfy the following formula (iii). P / ([η] 2.9 ) ≤ [A3] weight fraction × 6 …Equation (iii)

[0048] Here, the complex viscosity η at frequency ω = 0.1 rad / s is given. * (ω=0.1) And the complex viscosity η at frequency ω = 100 rad / s * (ω=100) The ratio P[η] * (ω=0.1) / η * (ω=100) ] represents the frequency dependence of viscosity and corresponds to the left side of equation (iii) above, 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.

[0049] Generally, in ethylene-α-olefin-non-conjugated polyene copolymers, the more structural units derived from non-conjugated polyenes they tend to contain, the more long-chain branching they have. However, copolymer (A) is thought to satisfy formula (iii) above because it has fewer long-chain branching units than conventionally known ethylene-α-olefin-non-conjugated polyene copolymers.

[0050] In this invention, the P value is determined by the ratio (η) between the complex viscosity at 0.1 rad / s and the complex viscosity at 100 rad / s, obtained by measuring under conditions of 190°C, 1.0% strain, and varying frequency using a viscoelasticity measuring device Ares (manufactured by Rheometric Scientific). * This is the calculation of the ratio.

[0051] The copolymer (A) preferably satisfies the following formula (iii-1). P / ([η] 2.9 ) ≤ [A3] weight fraction × 5.7 …Equation (iii-1) The intrinsic viscosity [η] of copolymer (A) refers to the value measured in decalin at 135°C. The intrinsic viscosity [η] of copolymer (A) is preferably 2.5 dl / g or less, more preferably 2.0 dl / g or less, even more preferably 1.85 dl / g or less, and particularly preferably 1.75 dl / g or less. There is no particular limitation on the lower limit of the intrinsic viscosity [η], but for example, it is 1.00 dl / g or more.

[0052] 《Requirement (6)》 The complex viscosity η at frequency ω = 0.01 rad / s was 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) It is preferable that (Pa·sec) and the apparent iodine value derived from the unconjugated polyene [A3] satisfy the following formula (vi). Log{η * (ω=0.01)} / log{η * (ω=10)}≦0.0753 × {Apparent iodine value derived from unconjugated polyene [A3]} + 1.42 …Equation (vi) Here, complex viscosity η * (ω=0.01) and complex viscosity η * (ω=10) The complex viscosity η in requirement (5) is * (ω=0.1) and complex viscosity η * (ω=100) The same method can be used to determine the other parameters, except for the measurement frequency.

[0053] Furthermore, the apparent iodine value derived from non-conjugated polyenes [A3] can be calculated using the following formula. The apparent iodine value derived from [A3] = weight fraction of [A3] × 253.81 / molecular weight of [A3]

[0054] In formula (vi), 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 polyene [A3] that was not consumed as long-chain branching during polymerization. If requirement (6) is met and formula (vi) is satisfied, it is preferable because the degree of long-chain branching is not too high. On the other hand, if formula (vi) is not satisfied, it indicates that a large proportion of the copolymerized unconjugated polyene [A3] was consumed for the formation of long-chain branching.

[0055] <Method for producing copolymer (A)> Copolymer (A) can be obtained by various known production methods, for example, by conventionally known production methods using a metallocene catalyst that uses a metallocene compound as one component of the catalyst. Examples of the metallocene catalyst and the production method using the catalyst can be adopted, for example, from the example described in International Publication No. 2015 / 122415, particularly paragraphs

[0249] to

[0320] of the said publication. Specifically, as described in the examples below, it can be obtained by copolymerizing at least ethylene [A1], a carbon-4 to carbon-20 α-olefin [A2], and a non-conjugated polyene [A3] in the presence of a metallocene catalyst.

[0056] <Resin composition> This composition comprises a copolymer (A), carbon black (B) (hereinafter also referred to as "component (B)"), an antioxidant (C) (hereinafter also referred to as "component (C)"), an organic peroxide (D) (hereinafter also referred to as "component (D)"), and a crosslinking aid (E) (hereinafter also referred to as "component (E)"), wherein the composition contains 5 to 150 parts by mass, preferably 10 to 100 parts by mass, and more preferably 20 to 80 parts by mass of component (B) per 100 parts by mass of copolymer (A). The composition comprises, more preferably 30 to 70 parts by mass, particularly preferably 40 to 60 parts by mass, component (C) in an amount of 0.5 to 7.0 parts by mass, preferably 1.0 to 6.0 parts by mass, more preferably 2.0 to 5.0 parts by mass, even more preferably 2.5 to 4.0 parts by mass, and component (D) in an amount of 1.0 to 30 parts by mass, preferably 1.5 to 10 parts by mass, more preferably 2.0 to 5.0 parts by mass, even more preferably 2.5 to 4.0 parts by mass.

[0057] This composition contains copolymer (A), as well as components (B), (C), and (D) in the aforementioned ranges, resulting in a fast vulcanization rate, excellent productivity, and superior heat aging resistance, low compression set at high and low temperatures, and excellent low-temperature properties (e.g., low-temperature elastic recovery (TR) properties, Gehman torsion properties).

[0058] Furthermore, the content of component (E) in this composition is preferably 0.01 to 3.0 moles, more preferably 0.05 to 0.65 moles, even more preferably 0.10 to 0.60 moles, particularly preferably 0.15 moles or more and less than 0.5 moles, and most preferably 0.20 to 0.30 moles per mole of component (D). By having the amount of component (E) within the aforementioned range, it is possible to improve the tensile elongation at fracture and tensile stress of the resulting molded article while maintaining its excellent tensile fracture stress. Furthermore, from an economic standpoint, it is preferable to use less component (E), and if the amount of component (E) used is within the aforementioned range, it can be said that the amount used has been sufficiently reduced from an economic standpoint, which is also preferable.

[0059] <Carbon Black (B) (Component (B))> Carbon black (B), one of the components of this composition, is a known type of rubber reinforcing agent used in rubber compositions and is an inorganic substance commonly referred to as carbon black.

[0060] Component (B) specifically includes, for example, SRF, GPF, FEF, MAF, HAF, ISAF, SAF, FT, and MT. The surface of the carbon black may be treated with a silane coupling agent. Examples of commercially available carbon blacks include the product names "Asahi #55G", "Asahi #50HG", "Asahi #60G", and "Asahi #60UG" (manufactured by Asahi Carbon Co., Ltd.), and the product names "Seast V" and "Seast SO" (manufactured by Tokai Carbon Co., Ltd.). Component (B) may be used alone or in combination of two or more types.

[0061] <Anti-aging agent (C) (Ingredient (C))> The antioxidant (C), which is one of the components of this composition, is a conventionally known antioxidant, such as an amine-based antioxidant, a phenol-based antioxidant, or a sulfur-based antioxidant.

[0062] Component (C) specifically includes aromatic 2-amine antioxidants such as phenylbutylamine and N,N-di-2-naphthyl-p-phenylenediamine; phenolic antioxidants such as dibutylhydroxytoluene and tetrakis[methylene(3,5-di-tert-butyl-4-hydroxy)hydrocinnamate]methane (trade name: Irganox 1010, manufactured by BASF); and bis[2-methyl-4-(3-n-alkylthiopropionyloxy)- These include thioether-based antioxidants such as 5-tert-butylphenyl sulfide; dithiocarbamate-based antioxidants such as nickel dibutyldithiocarbamate; and sulfur-based antioxidants such as 2-mercaptobenzoylimidazole (trade name: Sandant MB, manufactured by Sanshin Chemical Industry Co., Ltd.), 2-mercaptobenzoimidazole, zinc salt of 2-mercaptobenzoimidazole, dilaurylthiodipropionate, and distearylthiodipropionate. Component (C) may be used alone or in combination of two or more types.

[0063] <Organic peroxide (D) (component (D))> One of the components of this composition, the organic peroxide (D), is a type of crosslinking agent. Specifically, examples 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.

[0064] Of these, dicumyl peroxide (DCP), 2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyn-3, 1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, and n-butyl-4,4-bis(tert-butylperoxy)valerate are preferred, with dicumyl peroxide (DCP) being more preferred. Component (D) may be used alone or in combination of two or more components.

[0065] <Crosslinking agent (E) (Component (E))> The crosslinking aid (E), one of the components of this composition, when used in combination with component (D), can improve the tensile elongation at fracture and modulus of the resulting molded article while maintaining the tensile fracture stress.

[0066] Examples of crosslinking agents include sulfur; quinone dioxime crosslinking agents such as p-quinone dioxime; methacrylic crosslinking agents such as ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and zinc dimethacrylate; allyl crosslinking agents such as diallyl phthalate and triallyl isocyanurate; maleimide crosslinking agents; divinylbenzene; or mixtures thereof.

[0067] Among these, crosslinking aids having a methacrylate structure are preferred, and specifically, methacrylic crosslinking aids such as ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and zinc dimethacrylate are examples. Component (E) may be used alone or in combination of two or more types.

[0068] <Other ingredients> Depending on the purpose, this composition may contain at least one other component selected from, for example, other polymers other than copolymer (A), vulcanization accelerators, vulcanization aids, softeners, inorganic fillers, processing aids, activators, hygroscopic agents, heat stabilizers, weather stabilizers, antistatic agents, colorants, lubricants, thickeners, foaming agents, and foaming aids. Each additive may be used alone or in combination of two or more.

[0069] <Other polymers> This composition may contain polymers other than copolymer (A). Other polymers that require crosslinking include, for example, crosslinkable rubbers such as natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, acrylic rubber, silicone rubber, fluororubber, and urethane rubber.

[0070] Other polymers that do not require crosslinking include, for example, styrene-butadiene block copolymers (SBS), polystyrene-poly(ethylene-butylene)-polystyrene (SEBS), polystyrene-poly(ethylene-propylene)-polystyrene (SEPS), and other styrene-based thermoplastic elastomers (TPS), such as olefin-based thermoplastic elastomers (TPO), vinyl chloride-based elastomers (TPVC), ester-based thermoplastic elastomers (TPC), amide-based thermoplastic elastomers (TPA), urethane-based thermoplastic elastomers (TPU), and other thermoplastic elastomers (TPZ).

[0071] The other polymer can be blended in an amount of typically 100 parts by mass or less, preferably 80 parts by mass or less, per 100 parts by mass of copolymer (A).

[0072] <Softener> Examples of softening agents include petroleum-based softening agents such as process oil, lubricating oil, paraffin oil, liquid paraffin, petroleum asphalt, and petrolatum; coal tar-based softening agents such as coal tar; fatty oil-based softening agents 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 softening agents such as dioctyl phthalate and dioctyl adipate; and others such as microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, hydrocarbon-based synthetic lubricating oil, tall oil, and sub(factis). Of these, petroleum-based softening agents are preferred, and process oil is particularly preferred.

[0073] If this composition contains a softening agent, the amount of softening agent is usually 100 parts by mass or less, preferably 80 parts by mass or less, per 100 parts by mass of copolymer (A).

[0074] <Inorganic fillers> Examples of inorganic fillers include light calcium carbonate; heavy calcium carbonate; talc; clay; and metal oxides such as zinc oxide, magnesium oxide, and activated zinc oxide. Among these, metal oxides such as zinc oxide and activated zinc oxide are preferred.

[0075] If this composition contains an inorganic filler, the amount of inorganic filler is usually 1 to 50 parts by mass, preferably 2 to 30 parts by mass, more preferably 3 to 10 parts by mass, and even more preferably 4 to 8 parts by mass, per 100 parts by mass of copolymer (A). When the amount of inorganic filler is within the above range, the composition has excellent kneadability and a molded article with excellent mechanical properties can be obtained.

[0076] <Processing aids> As processing aids, for example, those commonly used as processing aids in rubber can be widely used. Specific examples of processing aids include fatty acids such as ricinoleic acid, stearic acid, palmitic acid, and lauric acid, fatty acid salts such as barium stearate, zinc stearate, and calcium stearate, and esters. Of these, stearic acid is preferred.

[0077] If the composition contains a processing aid, the amount of the processing aid is usually 10 parts by mass or less, preferably 8.0 parts by mass or less, more preferably 6.0 parts by mass or less, even more preferably 4.0 parts by mass or less, and particularly preferably 2.0 parts by mass or less, per 100 parts by mass of the copolymer (A). There is no particular lower limit, but for example, it is 0.1 parts by mass or more.

[0078] <Activating agent> Examples of activators include amines such as di-n-butylamine, dicyclohexylamine, and monoelanolamine; activators such as diethylene glycol, polyethylene glycol, lecithin, triaryl merilate, and zinc compounds of aliphatic or aromatic carboxylic acids; zinc peroxide moduloides; kutadecyltrimethylammonium bromide, synthetic hydrotalcite, and special quaternary ammonium compounds.

[0079] If the composition contains an activator, the amount of activator is usually 0.2 to 10 parts by mass, preferably 0.3 to 5 parts by mass, per 100 parts by mass of the copolymer (A).

[0080] <Desiccant> Examples of desiccants include calcium oxide, silica gel, sodium sulfate, molecular sieves, zeolite, and white carbon. If the composition contains a desiccant, the amount of desiccant is usually 0.5 to 15 parts by mass, preferably 1.0 to 12 parts by mass, per 100 parts by mass of the copolymer (A).

[0081] <Foaming agents and foaming aids> The molded article formed using this composition may be non-foamed or foamed. If the molded article is foamed, it is preferable that this composition contains a foaming agent.

[0082] Any commercially available foaming agent can be suitably used as a foaming agent. Examples of such foaming agents include inorganic foaming agents such as sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, and ammonium nitrite; nitroso compounds such as N,N'-dinitrosoterephthalamide and N,N'-dinitrosopentamethylenetetramine; azo compounds such as azodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, azodiaminobenzene, and barium azodicarboxylate; sulfonyl hydrazide compounds such as benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, and p,p'-oxybis(benzenesulfonyl hydrazide)diphenylsulfon-3,3'-disulfonyl hydrazide; and azide compounds such as calcium azide, 4,4'-diphenyldisulfonyl azide, and p-toluenemalfonyl azide. Among these, azo compounds, sulfonyl hydrazide compounds, and azide compounds are preferred.

[0083] If the composition contains a blowing agent, the amount of blowing agent is appropriately selected depending on the performance required of the molded article produced from the composition, but is usually used in a ratio of 0.1 to 30 parts by mass, preferably 0.2 to 20 parts by mass, per 100 parts by mass of copolymer (A).

[0084] Additionally, foaming aids may be used in combination with the foaming agent as needed. The addition of foaming aids is effective in regulating the decomposition temperature of the foaming agent and homogenizing the bubbles. Specific examples of foaming aids include organic acids such as salicylic acid, phthalic acid, stearic acid, and oxalic acid, as well as urea and its derivatives.

[0085] If this composition contains a foaming agent, the amount of foaming agent used is usually 1 to 100 parts by mass, preferably 2 to 80 parts by mass, per 100 parts by mass of the foaming agent.

[0086] <Method for producing resin compositions> This composition can be prepared by kneading the copolymer (A), component (B), component (C), component (D), and component (E), along with other components as needed, at a desired temperature using a kneading machine such as a mixer, kneader, or roll.

[0087] Specifically, the composition can be prepared by kneading using conventionally known kneading machines such as mixers and kneaders at a predetermined temperature and time, for example, 80 to 200°C for 3 to 30 minutes, then adding other components as needed to the resulting mixture, and kneading using rolls at a predetermined temperature and time, for example, a roll temperature of 30 to 80°C for 1 to 30 minutes.

[0088] <Uses of resin compositions> This composition is suitable for use in fuel cell gaskets. By using this composition, it is possible to obtain a fuel cell gasket with superior low-temperature flexibility compared to that using conventional EPDM, and a fuel cell gasket with superior cold resistance compared to that using silicone rubber.

[0089] <Fuel cell gasket> The fuel cell gasket of the present invention is formed from the composition described above. A method for producing a fuel cell gasket from this composition includes, for example, molding the composition into a desired fuel cell gasket shape and performing a crosslinking treatment on the composition simultaneously with or after the molding.

[0090] Examples of crosslinking methods include crosslinking the resin composition for fuel cell gaskets by heating it, and crosslinking the resin composition for fuel cell gaskets by irradiating it with an electron beam.

[0091] Specifically, the fuel cell gasket of the present invention can be prepared by forming the composition into the desired shape using a molding machine such as an extrusion machine, calender roll, press, injection molding machine, or transfer molding machine, and then crosslinking the composition simultaneously with the molding, or by introducing the molded product into a vulcanizing tank and heating it at 120 to 270°C for 1 to 30 minutes, or by irradiating it with an electron beam.

[0092] When crosslinking, a mold may be used, or it may be carried out without a mold. If a mold is not used, the molding and crosslinking processes are usually carried out continuously. As for heating methods in the vulcanization tank, hot air, glass bead fluidized bed, UHF (ultra-high frequency electromagnetic waves), steam, etc., can be used.

[0093] When using an electron beam instead of a crosslinking agent as the crosslinking method, the composition, which has been molded into a predetermined shape, should be irradiated with an electron beam having an energy of typically 0.1 to 10 MeV, preferably 0.3 to 2 MeV, so that the absorbed dose is typically 0.5 to 35 Mrad, preferably 0.5 to 10 Mrad.

[0094] The fuel cell gasket of the present invention can be preferably used as a fuel cell gasket in a hydrogen line. At hydrogen stations that supply hydrogen to fuel cell vehicles (FCVs) and the like, there are many hydrogen lines through which hydrogen passes. The fuel cell gasket of the present invention can be used as a fuel cell gasket in such a hydrogen line.

[0095] Hydrogen refueling stations require high-pressure storage of large quantities of hydrogen in compressors. Furthermore, supplying hydrogen from these stations requires high-pressure, high-speed delivery, which increases the hydrogen's temperature. To prevent excessive temperature increases in hydrogen tanks in fuel cell vehicles, hydrogen stations must store hydrogen at low temperatures, such as around -40°C. Therefore, fuel cell gaskets used in hydrogen lines require excellent sealing performance at low temperatures. The fuel cell gasket of the present invention achieves both low-temperature characteristics and mechanical strength (strength and elongation), making it suitable for use in hydrogen lines.

[0096] [Molded body] The molded articles of the present invention are formed from the aforementioned composition. The resulting molded articles (e.g., crosslinked molded articles and crosslinked foams) can be used for a variety of applications.

[0097] Specific applications of the molded articles of the present invention include tire rubber, O-rings, industrial rolls, packings (e.g., condenser packings), gaskets, belts (e.g., heat-insulating belts, copier belts), hoses (e.g., water hoses, brake reservoir hoses, radiator hoses), protective rubber, 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 all-solid-state batteries.

[0098] One method for producing a molded article of the present invention is to mold the composition (uncrosslinked composition) into a desired shape, and then crosslink the composition simultaneously with or after the molding process.

[0099] In the molding process described above, the composition is molded into a desired shape using an extrusion molding machine, calender roll, press molding machine, injection molding machine, transfer molding machine, etc. An example of the molded shape is a plate. [Examples]

[0100] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" refers to "parts by mass".

[0101] The physical properties of the copolymers used in the examples and comparative examples were measured according to the following procedure. (1) Weight fraction (weight %) and molar ratio The weight fraction (weight %) of each structural unit of the copolymer, and the molar ratio of each structural unit, 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.

[0102] (2) Intrinsic viscosity [η] The intrinsic viscosity [η] (dl / g) was measured using a fully automatic intrinsic viscometer manufactured by Rigosha Co., Ltd., at a temperature of 135°C and using decalin as the solvent.

[0103] (3) Weight average molecular weight (Mw) The weight-average molecular weight (Mw) is a polystyrene-converted value measured using a 3D high-temperature GPC instrument (PL-GPC220 model, manufactured by Polymer Laboratories). The measurement equipment and conditions are as follows: Measurements were taken. The main measurement conditions are as follows. The dn / dc value required to determine the absolute molecular weight was calculated for each sample using the dn / dc value of standard polystyrene (molecular weight 190,000) of 0.053 and the response intensity of the differential refractometer per unit injection mass. • Detector: Differential refractometer / GPC device built-in 2-angle light scattering photometer PD2040 type (manufactured by Precison Detectors) • Column: TSKgel GMH HR -H(S)HT x 2 bottles + TSKgel GMH HR - M(S) x 1 piece (each piece has an inner diameter of 7.8 mmφ x length of 300 mm, manufactured by Tosoh Corporation) Column 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.

[0104] (4) Mooney viscosity The Mooney viscosity ML(1+4) at 100°C of the copolymer was measured using a Mooney viscometer (SMV-301, manufactured by Shimadzu Corporation) in accordance with JIS K 6300-1 (2013).

[0105] (5) Complex viscosity η * and p-value 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 complex viscosity η at frequency ω = 100 rad / s * (ω=100) (All measurements were taken in Pa·sec units.)

[0106] Furthermore, from the results obtained, η * (ω=0.1) and η * (ω=100) The P value (η) is the ratio of the complex viscosity to (η) * (ω=0.1) / η * (ω=100) ) was calculated.

[0107] [Ethylene-α-olefin-non-conjugated polyene copolymer (A)] In the following examples and comparative examples, copolymer (A) was the copolymer (A-1) obtained in Production Example 1 below.

[0108] <Manufacturing Example 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.

[0109] Hexane (feed rate: 30.5 L / h) was used as the polymerization solvent, and each component was continuously supplied to the polymerizer so that the feed rates were 5.3 kg / h for ethylene, 21.5 kg / h for 1-butene, 566 g / h for VNB, and 10 NL / h for hydrogen.

[0110] While maintaining a polymerization pressure of 1.6 MPaG and a polymerization temperature of 95°C, each component was continuously supplied to the polymerizer so that the feed rate of di(p-tolyl)methylene(cyclopentadienyl)(octamethyloctahydrodibenzofluorenyl)zirconium dichloride as the main catalyst was 0.00903 mmol / h, the feed rate of (C6H5)3CB(C6F5)4 as the co-catalyst was 0.045 mmol / h, and the feed rate of triisobutylaluminum (TIBA) as the organoaluminum compound was 30 mmol / h.

[0111] 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.

[0112] Through the above procedure, ethylene-1-butene-VNB copolymer (A-1) was obtained at a rate of 8.5 kg per hour. The structure and properties of the obtained copolymer (A-1) were measured using the method described above. The results are shown in Table 1.

[0113] [Table 1]

[0114] [Example 1] Preparation of resin compositions Using a MIXTRON BB MIXER (manufactured by Kobe Steel, Ltd., BB-4 type, volume 2.95L, rotor 4WH), 100 parts ethylene-1-butene-VNB copolymer (A-1), 5 parts activated zinc oxide (product name: META-Z 102, manufactured by Inoue Lime Industry Co., Ltd.) as an inorganic filler, and 1 part stearic acid (manufactured by NOF Corporation, powdered stearic acid) as a processing aid. Composition 1 was obtained by mixing and kneading the following: Sakura, 50 parts Asahi #60UG (manufactured by Asahi Carbon Co., Ltd., grade: FEF) as carbon black (B), 2 parts 2-mercaptobenzimidazole (trade name: Sandant MB, manufactured by Sanshin Chemical Industry Co., Ltd.) as antioxidant (C), and 1 part tetrakis[methylene(3,5-di-tert-butyl-4-hydroxy)hydrocinnamate]methane (trade name: Irganox 1010, manufactured by BASF) as antioxidant (C). The kneading conditions were a rotor speed of 50 rpm and a floating weight pressure of 3 kg / cm². 2 The mixing time was 5 minutes, and the mixing discharge temperature was 150°C.

[0115] Next, after confirming that the temperature of formulation 1 reached 40°C, formulation 2 was obtained by kneading formulation 1 with a 6-inch roll. The kneading conditions were as follows: roll temperature front / rear roll = 50°C / 50°C, roll peripheral speed front / rear roll = 18 rpm / 15 rpm, roll gap = 3 mm, kneading time 5 minutes.

[0116] Evaluation of the physical properties of vulcanized materials (crosslinked materials) Compound 2 was crosslinked using a press molding machine at 180°C for 10 minutes to prepare a 2 mm thick sheet (vulcanized product (crosslinked product)). The obtained sheets were subjected to hardness tests, tensile tests, and heat aging tests using the following methods.

[0117] [Hardness test: Hardness (Durometer-A; HA (shore-A))] The hardness of the aforementioned sheet was measured in accordance with the description of "hardness test" in Section 7 of "Physical test methods for thermosetting polyurethane elastomer molded articles" in JIS K 7312:1996 and the description of test type A of "durometer hardness test" in Section 6 of "vulcanized rubber and thermoplastic rubber - method for determining hardness" in JIS K 6253:2006.

[0118] [Tensile test: Modulus, tensile stress at fracture, tensile elongation at fracture] The modulus, tensile stress at fracture, and tensile elongation at fracture of the aforementioned sheet were measured by the following method. The aforementioned sheet was punched out to prepare a Type 3 dumbbell test specimen as described in JIS K 6251:2023. Using this test specimen, a tensile test was performed under the conditions of a measurement temperature of 25°C and a tensile speed of 500 mm / min, according to the method specified in Section 13 of JIS K 6251. The tensile stress (25% modulus (M25)) when the elongation was 25%, the tensile stress (50% modulus (M50)) when the elongation was 50%, the tensile stress (100% modulus (M100)) when the elongation was 100%, the tensile stress (200% modulus (M100)) when the elongation was 200%, the tensile stress at the breaking point (TB), and the tensile elongation at the breaking point (EB) were measured.

[0119] [Heat aging test] The aforementioned sheets were subjected to a heat aging test in accordance with JIS K 6257:2017, by holding them at 150°C for 168 hours and 336 hours. After the heat aging test, the hardness, tensile stress at fracture, and tensile elongation at fracture of the sheets were measured using the same methods as for the items described in [Hardness (Durometer-A)] and [Modulus, Tensile Stress at Fracture, Tensile Elongation at Fracture] above.

[0120] The difference in hardness [AH] between the hardness of the sheet before the heat aging test (Durometer-A) was calculated by subtracting the hardness of the sheet before the heat aging test (Durometer-A) from the hardness of the sheet after the heat aging test (Durometer-A). Furthermore, the percentage change in tensile fracture stress (TB) [Ac(TB)] and the percentage change in tensile fracture elongation (EB) [Ac(EB)] before and after the heat aging test were calculated according to the following formulas. Ac(TB)(%) = (Tensile breaking point stress (TB) after heat aging test - Tensile breaking point stress (TB) before heat aging test) / Tensile breaking point stress (TB) before heat aging test × 100 Ac(EB)(%) = (Tensile breaking point stress after heat aging test (EB) - Tensile breaking point stress before heat aging test (EB)) / Tensile breaking point stress before heat aging test (EB) × 100 For example, the Ac(TB)(%) in Example 1 was determined as follows. Ac(TB)(%) of Example 1 =(14.02-13.03) / 13.03×100≈7.60

[0121] [Example 2] The procedure was the same as in Example 1, except that the amount of crosslinking aid (E-1) used was changed from 2.0 parts to 1.7 parts (0.499 moles per mole of organic peroxide (D)). The results are shown in Table 2.

[0122] [Example 3] The procedure was carried out in the same manner as in Example 1, except that the crosslinking aid (E-1) used in Example 1 was replaced with 2.0 parts of a mixture of zinc dimethacrylate (hereinafter also referred to as "crosslinking aid (E-2)") and zinc oxide (hereinafter also referred to as "product containing crosslinking aid (E-2)") (product name: ACTOR ZMA, manufactured by Kawaguchi Chemical Industry Co., Ltd., mixture of zinc dimethacrylate / zinc oxide = 66~74% / 26~34%, 0.0557~0.625 moles of zinc dimethacrylate per mole of organic peroxide (D)). The results are shown in Table 2.

[0123] [Example 4] The procedure was the same as in Example 1, except that the amount of crosslinking aid (E-2) used in Example 3 was changed from 2.0 parts to 0.9 parts (0.251 to 0.281 moles of zinc dimethacrylate per mole of organic peroxide (D)). The results are shown in Table 2.

[0124] [Comparative Example 1] The procedure was the same as in Example 1, except that the crosslinking agent (E-1) used in Example 1 was not used. The results are shown in Table 2.

[0125] [Table 2]

Claims

1. An ethylene-α-olefin-non-conjugated polyene copolymer (A) having a structural unit derived from ethylene [A1], a structural unit derived from an α-olefin [A2] having 4 to 20 carbon atoms, and a structural unit derived from a non-conjugated polyene [A3] containing a total of two or more substructures selected from the group consisting of the following general formulas (I) and (II) in the molecule, and satisfying the following requirements (1) to (3): Carbon Black (B), Anti-aging agent (C), Organic peroxides (D), and Contains crosslinking agent (E), A resin composition comprising 100 parts by mass of the copolymer (A), 5 to 150 parts by mass of the carbon black (B), 0.5 to 7.0 parts by mass of the antioxidant (C), and 1.0 to 30 parts by mass of the organic peroxide (D): 【Chemistry 1】 Requirement (1): The molar ratio [[A1] / [A2]] of structural units derived from ethylene [A1] to structural units derived from α-olefins [A2] having 4 to 20 carbon atoms is 40 / 60 to 90 / 10; Requirement (2): The content of structural units derived from non-conjugated polyene [A3] is 0.1 to 6.0 mol%, with the total of structural units derived from [A1], [A2], and [A3] being 100 mol%; Requirement (3): The B value, expressed by the following formula (i), is 1.20 or greater. B value = ([EX]+2[Y]) / [2×[E]×([X]+[Y])] ...Equation (i) [Here, [E], [X], and [Y] represent the mole fractions of structural units derived from ethylene [A1], α-olefins with 4 to 20 carbon atoms [A2], and non-conjugated polyenes [A3], respectively, and [EX] represents the ethylene [A1]-α-olefins with 4 to 20 carbon atoms [A2] dyad chain fraction.]

2. The resin composition according to claim 1, wherein the crosslinking aid (E) is contained in an amount of 0.01 to 3.0 moles per mole of the organic peroxide (D).

3. The resin composition according to claim 1, wherein the amount of the crosslinking aid (E) is 0.01 moles or more and less than 0.5 moles per mole of the organic peroxide (D).

4. The resin composition according to claim 1, wherein the crosslinking aid (E) has a methacrylate structure.

5. The resin composition according to claim 1, wherein the Mooney viscosity ML(1+4) at 100°C of the copolymer (A) is 5 to 60.

6. The resin composition according to claim 1, wherein the copolymer (A) satisfies one or more of the following requirements (4) to (6): Requirement (4): The weight-average molecular weight (Mw) of copolymer (A), the weight fraction of structural units derived from non-conjugated polyene [A3] (weight fraction of [A3] (weight%)), and the molecular weight of non-conjugated polyene [A3] (molecular weight of [A3]) satisfy the following formula (ii); 4.5 ≤ Mw × weight fraction of [A3] / 100 / molecular weight of [A3] ≤ 60 ...Formula (ii) Requirement (5): Complex viscosity η at frequency ω = 0.1 rad / s, obtained by linear viscoelastic 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] of copolymer (A) and the weight fraction of [A3] satisfy the following formula (iii): P / ([η] 2.9 ) ≤ weight fraction of [A3] × 6... Equation (iii) Requirement (6): Complex viscosity η at frequency ω = 0.01 rad / s, obtained by linear viscoelastic 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 [A3] satisfy the following equation (vi). Log{η} * (ω=0.01) } / Log{η * (ω=10) } ≤ 0.0753 × {Apparent iodine value derived from unconjugated polyene [A3]} + 1.42 …Equation (vi)

7. The resin composition according to claim 1, wherein the structural units derived from the α-olefin [A2] having 4 to 20 carbon atoms in the copolymer (A) include structural units derived from 1-butene.

8. The resin composition according to claim 1, wherein the structural units derived from the non-conjugated polyene [A3] in the copolymer (A) include structural units derived from 5-vinyl-2-norbornene.

9. A resin composition according to any one of claims 1 to 8, which is a fuel cell gasket composition.

10. A fuel cell gasket obtained using the resin composition described in claim 9.

11. A molded article obtained using the resin composition described in any one of claims 1 to 8.

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