Compositions for sponges, crosslinked materials, foams, and weatherstrip sponges

Abstract

The present invention provides a sponge composition that exhibits low compression set at low temperatures and excellent door closing performance. [Solution] A sponge composition comprising 25 to 75 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (P) having structural units derived from ethylene [A1], structural units derived from α-olefin [A2] having 3 to 20 carbon atoms, and structural units derived from non-conjugated polyene [A3], and satisfying specific requirements (1) and (2); and 25 to 75 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (Q) having structural units derived from ethylene [B1], structural units derived from α-olefin [B2] having 3 to 20 carbon atoms, and structural units derived from non-conjugated polyene [B3], and satisfying specific requirements (3) and (4) (wherein the total of copolymer (P) and copolymer (Q) is 100 parts by mass).

Description

[Technical Field]

[0001] The present invention relates to sponge compositions, crosslinked materials, foams, and weatherstrip sponges. [Background technology]

[0002] Ethylene-α-olefin rubbers, such as ethylene-propylene copolymer rubber (EPR) and ethylene-propylene-diene copolymer rubber (EPDM), do not have unsaturated bonds in the main chain of their molecular structure. As a result, they offer superior heat aging resistance, weather resistance, and ozone resistance compared to general-purpose conjugated diene rubbers, and are widely used in applications such as automotive parts, wire materials, electrical and electronic components, construction and civil engineering materials, and industrial parts.

[0003] When a composition containing ethylene-α-olefin rubber is used as a weatherstrip sponge for automotive parts, it is required that the compression set be small in order to improve the sponge's resilience and seal the gap between the door and the vehicle body (for example, Patent Documents 1-3). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2001-270957 [Patent Document 2] Japanese Patent Publication No. 2007-153953 [Patent Document 3] Japanese Patent Publication No. 2016-029136 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, conventionally known compositions containing ethylene-α-olefin rubber have the problem that their compression set tends to increase in low-temperature environments such as winter or cold regions. Furthermore, compositions containing ethylene-α-olefin rubber are required to have superior door closing performance from the viewpoint of better sealing the gap between the door and the vehicle body.

[0006] Therefore, the present invention aims to provide a sponge composition that exhibits low compression set at low temperatures and excellent door closing performance. [Means for solving the problem]

[0007] The inventors of the present invention have diligently studied to solve the above problems and have found that the above problems can be solved according to the following embodiments, and have completed the present invention. Embodiments of the present invention are shown below.

[0008] [1] 25 to 75 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (P) having structural units derived from ethylene [A1], structural units derived from at least one C3-20 α-olefin [A2], and structural units derived from at least one non-conjugated polyene [A3], and satisfying the following requirements (1) and (2), and 25 to 75 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (Q) having structural units derived from ethylene [B1], structural units derived from at least one C3-20 α-olefin [B2], and structural units derived from at least one non-conjugated polyene [B3], and satisfying the following requirements (3) and (4) (however, the total of the ethylene-α-olefin-non-conjugated polyene copolymer (P) and the ethylene-α-olefin-non-conjugated polyene copolymer (Q) is 100 parts by mass). A sponge composition containing the following: Requirement (1): The ratio ([a1] / [a2]) of the mole fraction [a1] of structural units derived from ethylene [A1] to the mole fraction [a2] of structural units derived from α-olefins with 3 to 20 carbon atoms is 40 / 60 to 90 / 10 (provided that the sum of the mole fractions of structural units derived from [A1], [A2], and [A3] is 100 mol%). Requirement (2): The intrinsic viscosity [η] measured in decalin at 135°C is 4.0 to 7.0 dl / g. Requirement (3): The ratio of the mole fraction [b1] of structural units derived from ethylene [B1] to the mole fraction [b2] of structural units derived from α-olefins with 3 to 20 carbon atoms [B2] ([b1] / [b2]) is 40 / 60 to 90 / 10 (provided that the sum of the mole fractions of structural units derived from [B1], [B2], and [B3] is 100 mol%). Requirement (4): The intrinsic viscosity [η] measured in decalin at 135°C is 0.5 to 3.0 dl / g.

[0009] [2] The sponge composition according to item [1], wherein the 3-20 carbon α-olefin [A2] of the ethylene-α-olefin-non-conjugated polyene copolymer (P) has 4-20 carbon atoms.

[0010] [3] The sponge composition according to item [1] or [2], wherein the 3-20 carbon α-olefin [A2] of the ethylene-α-olefin-non-conjugated polyene copolymer (P) is 1-butene.

[0011] [4] The sponge composition according to any one of items [1] to [3], wherein the ethylene-α-olefin-non-conjugated polyene copolymer (P) satisfies the following requirement (5). Requirement (5): The mole fraction [a3] of structural units derived from non-conjugated polyene [A3] is 0.1 to 6.0 mol% (provided that the sum of the mole fractions of structural units derived from [A1], [A2], and [A3] is 100 mol%).

[0012] [5] The sponge composition according to any one of items [1] to [4], wherein the ethylene-α-olefin-non-conjugated polyene copolymer (P) satisfies the following requirement (6). Requirement (6): The B value, represented by the following formula (i), is 1.20 or greater. B value=([EX]+2[Y]) / [2×[E]×([X]+[Y])]···(i) (where [E], [X] and [Y] each represent the mole fractions of ethylene [A1], an α-olefin having 3 to 20 carbon atoms [A2], and a non-conjugated polyene [A3], respectively, and [EX] represents the ethylene [A1]-α-olefin [A2] dyad chain fraction having 3 to 20 carbon atoms.)

[0013] [6] The composition for a sponge according to any one of items [1] to [5], wherein the non-conjugated polyenes [A3] and [B3] are 5-ethylidene-2-norbornene (ENB).

[0014] [7] The composition for a sponge according to any one of items [1] to [6], which is a composition for a weatherstrip sponge.

[0015] [8] A crosslinked product of the composition for a sponge according to any one of items [1] to [7].

[0016] [9] A foam of the composition for a sponge according to any one of items [1] to [7].

[0017]

[10] A weatherstrip sponge formed of the foam according to item [9]. Effects of the Invention

[0018] According to the present invention, it is possible to provide a composition for a sponge that has a small compression set at low temperatures and is excellent in door closing performance. Mode for Carrying Out the Invention

[0019] Hereinafter, the present invention will be described in detail. <Composition for Sponge> The sponge composition of the present invention (hereinafter also referred to as "this composition") contains 25 to 75 parts by mass of ethylene-α-olefin-nonconjugated polyene copolymer (P) (hereinafter also referred to as "polymer (P)") and 25 to 75 parts by mass of ethylene-α-olefin-nonconjugated polyene copolymer (Q) (hereinafter also referred to as "polymer (Q)"). However, the total of the ethylene-α-olefin-nonconjugated polyene copolymer (P) and the ethylene-α-olefin-nonconjugated polyene copolymer (Q) is 100 parts by mass. The content of copolymer (P) is preferably 30 to 72 parts by mass, more preferably 35 to 70 parts by mass, and even more preferably 40 to 68 parts by mass, based on 100 parts by mass of the total of copolymer (P) and copolymer (Q). The content of copolymer (Q) is preferably 28 to 70 parts by mass, more preferably 30 to 65 parts by mass, and even more preferably 32 to 60 parts by mass, based on 100 parts by mass of the total of copolymer (P) and copolymer (Q). When the content of copolymer (P) and copolymer (Q) is within the above range, it is preferable in that the compression set at low temperatures is small and the door closing performance is excellent.

[0020] <Ethylene-α-olefin-nonconjugated polyene copolymer (P)> The copolymer (P) has structural units derived from ethylene [A1], structural units derived from at least one α-olefin [A2] having 3 to 20 carbon atoms, and structural units derived from at least one non-conjugated polyene [A3], and satisfies the following requirements (1) and (2). The copolymer (P) can be used alone or in combination of two or more types.

[0021] <Requirement (1)> The ratio [a1] of the mole fraction of structural units derived from ethylene [A1] to the mole fraction [a2] of structural units derived from α-olefins having 3 to 20 carbon atoms [A2] is 40 / 60 to 90 / 10, preferably 45 / 55 to 90 / 10, more preferably 50 / 50 to 85 / 15, even more preferably 55 / 45 to 80 / 20, and particularly preferably 60 / 40 to 75 / 25. However, the sum of the mole fractions of structural units derived from [A1], [A2], and [A3] is 100 mol%.

[0022] When the ratio [a1] of the mole fraction of structural units derived from ethylene [A1] to the mole fraction [a2] of structural units derived from α-olefins having 3 to 20 carbon atoms [A2] is within the above range, it is preferable in that it provides an excellent balance between compression set at low temperatures and mechanical properties.

[0023] <Requirement (2)> The intrinsic viscosity [η] measured in decalin at 135°C is 4.0 to 7.0 dl / g, preferably 4.5 to 6.5 dl / g, more preferably 5.0 to 6.3 dl / g, and particularly preferably 5.3 to 6.0 dl / g. The measurement conditions described in the examples below can be used. When the intrinsic viscosity [η] is within the above range, it is preferable in terms of excellent mechanical properties and oil retention of the copolymer (P).

[0024] The copolymer (P) is preferably further satisfied with at least one of the following requirements (5) and (6).

[0025] <Requirement (5)> The mole fraction [a3] of structural units derived from non-conjugated polyene [A3] is preferably 0.1 to 6.0 mol%, more preferably 0.3 to 4.0 mol%, even more preferably 0.5 to 3.0 mol%, particularly preferably 0.7 to 2.0 mol%, and most preferably 1.0 to 1.5 mol% (provided that the sum of the mole fractions of structural units derived from [A1], [A2], and [A3] is 100 mol%).

[0026] It is preferable that the mole fraction [a3] of structural units derived from non-conjugated polyene [A3] falls within the above range, as this results in superior rubber properties when crosslinked.

[0027] In requirements (1) and (5) above, the mole fractions ([a1], [a2], [a3]) of structural units derived from ethylene [A1], structural units derived from α-olefin [A2], and structural units derived from non-conjugated polyene [A3] are: 1 It can be determined by measuring the intensity of the 1H-NMR spectrum.

[0028] <Requirement (6)> The B value represented by the following formula (i) is preferably 1.20 or higher, more preferably 1.20 to 1.80, and even more preferably 1.22 to 1.40. B value=([EX]+2[Y]) / [2×[E]×([X]+[Y])]···(i) Here, [E], [X], and [Y] represent the mole fractions of structural units derived from ethylene [A1], α-olefins with 3 to 20 carbon atoms [A2], and non-conjugated polyenes [A3], respectively, and [EX] represents the ethylene [A1]-α-olefins with 3 to 20 carbon atoms [A2] dyad chain fraction. Furthermore, α-olefins [A2] and non-conjugated polyenes [A3] having 3 to 20 carbon atoms may be used individually or in combination of two or more types.

[0029] Furthermore, when the B value is within the aforementioned range, it is preferable because the alternation of monomer units constituting the ethylene-α-olefin-non-conjugated polyene copolymer (P) is high and the crystallinity is low, resulting in a smaller compression set at low temperatures.

[0030] Furthermore, the B value specified in requirement (6) is an indicator of the randomness of the chain distribution of copolymer monomers in the ethylene-α-olefin-non-conjugated polyene copolymer (P), and in formula (i) above, [E], [X], [Y], and [EX] are, 13The 1C-NMR spectrum can be measured and determined based on reports such as J. C. Sandall Macromolecules, 15, 353 (1982) and J. Ray Macromolecules, 10, 773 (1977).

[0031] [α-olefin[A2]] Examples of α-olefins with 3 to 20 carbon atoms include those with a straight chain structure without side chains, such as 1-propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, and 1-decene, as well as 1-nonadecene with 19 carbon atoms and 1-eicosene with 20 carbon atoms, and those with side chains, such as 4-methyl-1-pentene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene. As for α-olefins having 3 to 20 carbon atoms, from the viewpoint of having excellent low-temperature characteristics, for example, low compression set at low temperatures, α-olefins having 4 to 20 carbon atoms are preferred, more preferably α-olefins having 4 to 10 carbon atoms, even more preferably 1-butene, 1-hexene, 1-octene, and particularly preferably 1-butene.

[0032] [Non-conjugated polyenes [A3]] Specific examples of non-conjugated polyenes [A3] include the linear non-conjugated dienes such as 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 7-methyl-1,6-octadiene, and the cyclic non-conjugated dienes such as cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene (ENB), 5-methylene-2-norbornene, and 5- Examples include isopropylidene-2-norbornene and 6-chloromethyl-5-isopropenyl-2-norbornene, and trienes such as 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,5-norbornadiene, 1,3,7-octatriene, 1,4,9-decatriene, 4,8-dimethyl-1,4,8-decatriene, and 4-ethylidene-8-methyl-1,7-nonadien.

[0033] These non-conjugated polyenes [A3] can be used individually or in combination of two or more types. Among these, linear non-conjugated dienes such as 1,4-hexadiene and cyclic non-conjugated dienes such as 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are preferred, with cyclic non-conjugated dienes being more preferred, 5-ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene being even more preferred, and 5-ethylidene-2-norbornene (ENB) being particularly preferred.

[0034] In the present invention, it is preferable that the non-conjugated polyene [A3] contains only one substructure in total per molecule, which is represented by a structural formula selected from the group consisting of the following substructure formulas (I) and (II), from the viewpoint of being readily available and having excellent crosslinking properties with sulfur. An example of such a non-conjugated polyene [A3] is 5-ethylidene-2-norbornene (ENB).

[0035] [ka]

[0036] Examples of the copolymer (P) include ethylene·1-butene·1,4-hexadiene copolymer, ethylene·1-butene·1-octene·1,4-hexadiene copolymer, ethylene·1-butene·5-ethylidene-2-norbornene copolymer, ethylene·1-butene·1-octene·5-ethylidene-2-norbornene copolymer, ethylene·1-butene·5-ethylidene-2-norbornene·5-vinyl-2-norbornene copolymer, and ethylene·1-butene·1-octene·5-ethylidene-2-norbornene·5-vinyl-2-norbornene copolymer.

[0037] The copolymer (P) may contain structural units derived from at least one monomer selected from the group consisting of ethylene [A1], α-olefins having 3 to 20 carbon atoms [A2], and non-conjugated polyenes [A3], including units derived from biomass-derived monomers and / or chemically recycled monomers.

[0038] The copolymer (P) may contain at least one structural unit derived from biomass-derived monomers. The biomass-derived monomer used as a raw material for copolymer (P) may be biomass-derived ethylene, biomass-derived α-olefin, or biomass-derived non-conjugated polyene. An example of a biomass-derived α-olefin is biomass-derived 1-propylene. An example of a biomass-derived non-conjugated polyene is biomass-derived 5-ethylidene-2-norbornene or biomass-derived 5-vinyl-2-norbornene. The monomer used as a raw material for copolymer (P) may contain only biomass-derived monomers, or it may contain both biomass-derived monomers and fossil fuel-derived monomers. Biomass-derived monomers such as biomass-derived ethylene, biomass-derived α-olefin, and biomass-derived non-conjugated polyene can be obtained by known methods. It is preferable for copolymer (P) to contain structural units derived from biomass-derived monomers from the viewpoint of reducing environmental impact.

[0039] The copolymer (P) may contain at least one structural unit derived from chemically recycled monomers. The chemically recycled monomer used as a raw material for copolymer (P) may be chemically recycled ethylene, chemically recycled α-olefin, or chemically recycled non-conjugated polyene. Furthermore, the monomer used as a raw material for copolymer (P) may contain only chemically recycled monomers, or it may contain both chemically recycled monomers and fossil fuel-derived monomers. Chemically recycled monomers such as chemically recycled ethylene, chemically recycled α-olefin, and chemically recycled non-conjugated polyene can be obtained by known methods. It is preferable from the viewpoint of reducing environmental impact (mainly waste reduction) that the copolymer (P) contains structural units derived from chemically recycled monomers.

[0040] <Method for producing ethylene-α-olefin-nonconjugated polyene copolymer (P)> The ethylene-α-olefin-non-conjugated polyene copolymer (P) can be produced, for example, by employing a production method using a metallocene catalyst as described in International Publication No. 2015 / 122415.

[0041] <Ethylene-α-olefin-nonconjugated polyene copolymer (Q)> The copolymer (Q) has structural units derived from ethylene [B1], structural units derived from at least one C3-C20 α-olefin [B2], and structural units derived from at least one non-conjugated polyene [B3], and satisfies the following requirements (3) and (4). The copolymer (Q) can be used alone or in combination of two or more types.

[0042] <Requirement (3)> The ratio [[b1] / [b2]] of the mole fraction [b1] of structural units derived from ethylene [B1] to the mole fraction [b2] of structural units derived from α-olefins having 3 to 20 carbon atoms is 40 / 60 to 90 / 10, preferably 45 / 55 to 90 / 10, more preferably 50 / 50 to 85 / 15, even more preferably 55 / 45 to 80 / 20, and particularly preferably 55 / 45 to 75 / 25. However, the sum of the mole fractions of structural units derived from [B1], [B2], and [B3] is 100 mol%.

[0043] When the ratio [[b1] / [b2]] of the mole fraction [b1] of structural units derived from ethylene [B1] to the mole fraction [b2] of structural units derived from α-olefins having 3 to 20 carbon atoms [B2] is within the above range, it is preferable in that it provides an excellent balance between compression set at low temperatures and mechanical properties.

[0044] <Requirement (4)> The intrinsic viscosity [η] measured in decalin at 135°C is 0.5 to 3.0 dl / g, preferably 0.6 to 2.7 dl / g, more preferably 0.8 to 2.4 dl / g, and particularly preferably 1.0 to 2.0 dl / g. The measurement conditions described in the examples below can be used. When the intrinsic viscosity [η] is within the above range, it is preferable in terms of excellent mechanical properties and oil retention of the copolymer (Q).

[0045] The copolymer (Q) is preferably further satisfied with at least one of the following requirements (7) and (8).

[0046] <Requirement (7)> The mole fraction [b3] of structural units derived from non-conjugated polyene [B3] is preferably 0.1 to 6.0 mol%, more preferably 0.5 to 4.0 mol%, and even more preferably 1.0 to 3.0 mol% (provided that the sum of the mole fractions of structural units derived from [B1], [B2], and [B3] is 100 mol%).

[0047] It is preferable that the mole fraction [b3] of structural units derived from non-conjugated polyene [B3] is within the above range, as this results in superior rubber properties when crosslinked.

[0048] In requirements (3) and (7) above, the mole fractions ([b1], [b2], [b3]) of structural units derived from ethylene [B1], structural units derived from α-olefin [B2], and structural units derived from non-conjugated polyene [B3] are: 1 It can be determined by measuring the intensity of the 1H-NMR spectrum.

[0049] <Requirement (8)> The B value, represented by the following formula (ii), is preferably 1.20 or higher, more preferably 1.20 to 1.80, and even more preferably 1.22 to 1.40. B value=([EX]+2[Y]) / [2×[E]×([X]+[Y])]···(ii) Here, [E], [X], and [Y] represent the mole fractions of structural units derived from ethylene [B1], α-olefins with 3 to 20 carbon atoms [B2], and non-conjugated polyenes [B3], respectively, and [EX] represents the ethylene [B1]-α-olefins with 3 to 20 carbon atoms [B2] dyad chain fraction. Furthermore, α-olefins [B2] and non-conjugated polyenes [B3] having 3 to 20 carbon atoms may be used individually or in combination of two or more types.

[0050] Furthermore, when the B value is within the aforementioned range, the alternation of monomer units constituting the ethylene-α-olefin-non-conjugated polyene copolymer (Q) is high and the crystallinity is low, which is preferable because it results in a small compression set at low temperatures.

[0051] Furthermore, the B value specified in requirement (8) is an indicator of the randomness of the chain distribution of copolymer monomers in the ethylene-α-olefin-non-conjugated polyene copolymer (Q), and in formula (ii) above, [E], [X], [Y], and [EX] are, 13The 1C-NMR spectrum can be measured and determined based on reports such as J. C. Sandall Macromolecules, 15, 353 (1982) and J. Ray Macromolecules, 10, 773 (1977).

[0052] [α-olefin[B2]] Examples of α-olefins with 3 to 20 carbon atoms include those with a straight chain structure without side chains, such as 1-propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, and 1-decene, as well as 1-nonadecene with 19 carbon atoms and 1-eicosene with 20 carbon atoms, and those with side chains, such as 4-methyl-1-pentene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene. The α-olefin having 3 to 20 carbon atoms is preferably an α-olefin having 3 to 10 carbon atoms, more preferably 1-propylene, 1-butene, 1-hexene, 1-octene, and even more preferably 1-propylene.

[0053] [Non-conjugated polyenes [B3]] Specific examples of non-conjugated polyenes [B3] include the linear non-conjugated dienes such as 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 7-methyl-1,6-octadiene, and the cyclic non-conjugated dienes such as cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene (ENB), 5-methylene-2-norbornene, and 5- Examples include isopropylidene-2-norbornene and 6-chloromethyl-5-isopropenyl-2-norbornene, and trienes such as 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,5-norbornadiene, 1,3,7-octatriene, 1,4,9-decatriene, 4,8-dimethyl-1,4,8-decatriene, and 4-ethylidene-8-methyl-1,7-nonadien.

[0054] These non-conjugated polyenes [B3] can be used individually or in combination of two or more types. Among these, linear non-conjugated dienes such as 1,4-hexadiene and cyclic non-conjugated dienes such as 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are preferred, with cyclic non-conjugated dienes being more preferred, and 5-ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene being even more preferred.

[0055] In the present invention, from the viewpoint of being readily available and having excellent crosslinking properties with sulfur, it is preferable that the non-conjugated polyene [B3] contains only one substructure in total per molecule, which is represented by a structural formula selected from the group consisting of the following substructure formulas (I) and (II). An example of such a non-conjugated polyene [A3] is 5-ethylidene-2-norbornene (ENB).

[0056] [ka]

[0057] Examples of the copolymer (Q) include ethylene·1-butene·1,4-hexadiene copolymer, ethylene·1-butene·1-octene·1,4-hexadiene copolymer, ethylene·1-butene·5-ethlylidene-2-norbornene copolymer, ethylene·1-butene·1-octene·5-ethlylidene-2-norbornene copolymer, ethylene·1-butene·5-ethlylidene-2-norbornene·5-vinyl-2-norbornene copolymer, and ethylene·1-butene·1-octene·5-ethlylidene-2-norbornene·5-vinyl-2-norbornene copolymer.

[0058] The copolymer (Q) may contain structural units derived from at least one monomer selected from the group consisting of ethylene [B1], α-olefins having 3 to 20 carbon atoms [B2], and non-conjugated polyenes [B3], including units derived from biomass-derived monomers and / or chemically recycled monomers.

[0059] The copolymer (Q) may contain at least one structural unit derived from a biomass-derived monomer. The biomass-derived monomer used as a raw material for the copolymer (Q) may be biomass-derived ethylene, biomass-derived α-olefin, or biomass-derived non-conjugated polyene. An example of a biomass-derived α-olefin is biomass-derived 1-propylene. An example of a biomass-derived non-conjugated polyene is biomass-derived 5-ethylidene-2-norbornene or biomass-derived 5-vinyl-2-norbornene. The monomer used as a raw material for the copolymer (Q) may contain only biomass-derived monomers, or it may contain both biomass-derived monomers and fossil fuel-derived monomers. Biomass-derived monomers such as biomass-derived ethylene, biomass-derived α-olefin, and biomass-derived non-conjugated polyene can be obtained by known methods. It is preferable for the copolymer (Q) to contain structural units derived from a biomass-derived monomer from the viewpoint of reducing environmental impact.

[0060] The copolymer (Q) may contain at least one structural unit derived from chemically recycled monomers. The chemically recycled monomer used as a raw material for copolymer (Q) may be chemically recycled ethylene, chemically recycled α-olefin, or chemically recycled non-conjugated polyene. Furthermore, the monomer used as a raw material for copolymer (Q) may contain only chemically recycled monomers, or it may contain both chemically recycled monomers and fossil fuel-derived monomers. Chemically recycled monomers such as chemically recycled ethylene, chemically recycled α-olefin, and chemically recycled non-conjugated polyene can be obtained by known methods. It is preferable from the viewpoint of reducing environmental impact (mainly waste reduction) that the copolymer (Q) contains structural units derived from chemically recycled monomers.

[0061] <Method for producing ethylene-α-olefin-nonconjugated polyene copolymer (Q)> The copolymer (Q) can be produced, for example, by employing a production method using a metallocene catalyst as described in International Publication No. 2015 / 122415.

[0062] <Other ingredients> Depending on the purpose, this composition may further contain at least one component other than the copolymer (P) and copolymer (Q) (hereinafter also referred to as "other components"), for example, selected from crosslinking agents, crosslinking aids, vulcanization accelerators, vulcanization aids, carbon black, softeners, inorganic fillers, antioxidants, processing aids, surfactants, hygroscopic agents, antistatic agents, colorants, lubricants, and thickeners. This composition may further contain polymers other than copolymer (P) and copolymer (Q) (hereinafter also referred to as "other polymers"), for example, elastomers and / or rubbers. Each component described below may be used alone or in combination of two or more.

[0063] <Crosslinking agent> Examples of crosslinking agents include organic peroxides, phenolic resins, sulfur-based crosslinking agents, hydrosilicone compounds, amino resins, quinones or their derivatives, amine compounds, azo compounds, epoxy compounds, and isocyanate compounds, which are commonly used when crosslinking rubber. Among these, organic peroxides and sulfur-based crosslinking agents (hereinafter also referred to as "vulcanizing agents") are preferred.

[0064] <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, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide.

[0065] <Crosslinking agent> When using an organic peroxide as a crosslinking agent, it is preferable to use a crosslinking aid in combination. Examples of crosslinking aids include sulfur; quinone dioxime crosslinking aids such as p-quinone dioxime; acrylic crosslinking aids such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate; allyl crosslinking aids such as diallyl phthalate and triallyl isocyanurate; maleimide crosslinking aids; divinylbenzene; zinc oxide (e.g., ZnO#1 and zinc oxide types 2 (JIS K1410 (2006), manufactured by Hakusui Tech Co., Ltd.)), zinc oxide (e.g., "META-Z102" (product name; manufactured by Inoue Lime Industry Co., Ltd.)); and metal oxides such as magnesium oxide.

[0066] The amount of crosslinking aid added is usually 0.01 to 10 parts by mass, preferably 0.05 to 7 parts by mass, and more preferably 0.075 to 5 parts by mass, per 1 part by mass of organic peroxide.

[0067] <Sulfur-based crosslinking agent> Examples of sulfur-based crosslinking agents include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, and selenium dithiocarbamate.

[0068] <Vulcanization promoter> When using a sulfur-based crosslinking agent, it is preferable to use a vulcanization accelerator in combination. Examples of vulcanization accelerators include N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazole sulfenamide, N,N'-diisopropyl-2-benzothiazole sulfenamide, 2-mercaptobenzothiazole (e.g., Sunceller M (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), 2-(4-morpholinodithio)benzothiazole (e.g., Noxellar MDB-P (trade name; manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)), 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-di Thiazole-based vulcanization accelerators such as ethyl-4-morpholinothio)benzothiazole and dibenzothiadyl disulfide (e.g., Suncellar DM (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)); guanidine-based vulcanization accelerators such as diphenylguanidine, triphenylguanidine and diorthotrylguanidine; aldehydeamine-based vulcanization accelerators such as acetaldehyde-aniline condensate and butyraldehyde-aniline condensate; imidazoline-based vulcanization accelerators such as 2-mercaptoimidazoline; tetramethylthiuram monosulfide (e.g., Suncellar DM (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)); Thiuram-based vulcanization accelerators such as Ra TS (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.), tetramethyl thiuram disulfide (e.g., Suncellar TT (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetraethyl thiuram disulfide (e.g., Suncellar TET (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetrabutyl thiuram disulfide (e.g., Suncellar TBT (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), and dipentamethylenethiuram tetrasulfide (e.g., Suncellar TRA (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)); zinc dimethyldithiocarbamate, diethyldithio Examples of dithioate-based vulcanization accelerators include zinc carbamate, zinc dibutyldithiocarbamate (e.g., Suncellar PZ, Suncellar BZ, and Suncellar EZ (product names; manufactured by Sanshin Chemical Industry Co., Ltd.)), and tellurium diethyldithiocarbamate; thiourea-based vulcanization accelerators include ethylenethiourea (e.g., Suncellar BUR (product name; manufactured by Sanshin Chemical Industry Co., Ltd.), Suncellar 22-C (product name; manufactured by Sanshin Chemical Industry Co., Ltd.)), N,N'-diethylthiourea, and N,N'-dibutylthiourea); and xantate-based vulcanization accelerators such as zinc dibutylxatonate.

[0069] When using vulcanization accelerators, the amount of these vulcanization accelerators in the copolymer composition is usually 0.1 to 20 parts by mass, preferably 0.2 to 15 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the total of copolymer (P) and copolymer (Q). When using sulfur-based crosslinking agents, vulcanization aids can be used in combination.

[0070] <Vulcanization aid> Sulfurization aids are sometimes used when sulfur-based crosslinking agents are used, and examples include zinc oxide (e.g., "ZnO#1 Zinc Oxide Type 2" (product name; manufactured by Hakusui Tech Co., Ltd.), "META-Z102" (product name; manufactured by Inoue Lime Industry Co., Ltd.)) and magnesium oxide.

[0071] The amount of vulcanization aid added is typically 1 to 20 parts by mass per 100 parts by mass of the total of the ethylene-α-olefin-non-conjugated polyene copolymer (P), copolymer (Q), and other polymers requiring crosslinking (such as rubber) as needed.

[0072] <Carbon Black> Examples of carbon black include 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 black include "Asahi #50G", "Asahi #50HG", "Asahi #60UG", "Asahi #65", "Asahi #70" (product names; manufactured by Asahi Carbon Co., Ltd.) and "Seasto SO" (product name; manufactured by Tokai Carbon Co., Ltd.).

[0073] The amount of carbon black added is preferably 5 to 150 parts by mass, more preferably 10 to 100 parts by mass, based on 100 parts by mass of the total amount of copolymer (P) and copolymer (Q).

[0074] The specific surface area of ​​carbon black is preferably 100 m². 2 / g or less, more preferably 5-50m 2 / g, more preferably 8-45m 2 / g, most preferably 10-45m 2It is / g.

[0075] <Softener> Specific examples of softeners include petroleum-based softeners such as paraffin oil (e.g., paraffinic process oil), naphthenic process oil, lubricating 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; fatty acids or their salts such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, and calcium stearate; 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). Among these, petroleum-based softeners are preferred, and paraffin oil is particularly preferred.

[0076] The amount of softening agent is generally 5 to 200 parts by mass, preferably 50 to 200 parts by mass, per 100 parts by mass of the total of the ethylene-α-olefin-non-conjugated polyene copolymer (P), copolymer (Q), and optionally added polymer (elastomer, rubber, etc.) components.

[0077] <Inorganic fillers> Specific examples of inorganic fillers include one or more types such as light calcium carbonate, heavy calcium carbonate, talc, and clay. Of these, heavy calcium carbonate such as "Whiteon SB" (product name; Shiraishi Calcium Co., Ltd.) and "Hakuenka CC" (product name; Shiraishi Kogyo Co., Ltd.) is preferred.

[0078] The amount of inorganic filler added is usually 2 to 100 parts by mass, preferably 5 to 100 parts by mass, relative to 100 parts by mass of the total of the ethylene-α-olefin-non-conjugated polyene copolymer (P), copolymer (Q), and other polymers (elastomers, rubber, etc.). When the amount added is within this range, the copolymer composition exhibits excellent kneadability, and a molded article with excellent mechanical properties can be obtained.

[0079] <Anti-aging agent (stabilizer)> By incorporating an antioxidant (stabilizer) into this composition, the lifespan of the molded article to be formed can be extended. Examples of such antioxidants include conventionally known antioxidants such as amine-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants.

[0080] These antioxidants can be used individually or in combination of two or more types. The amount added is typically 0.3 to 10 parts by mass, preferably 0.5 to 7.0 parts by mass, per 100 parts by mass of the total amount of ethylene-α-olefin-non-conjugated polyene copolymer (P), copolymer (Q), and other polymers (elastomers, rubber, etc.). By keeping the amount within this range, blooming on the surface of the molded article obtained from the copolymer composition is eliminated, and the occurrence of vulcanization inhibition can be suppressed.

[0081] <Processing aid> As processing aids, those commonly used in rubber processing can be widely used.

[0082] The amount of processing aid added is usually 10 parts by mass or less, preferably 8.0 parts by mass or less, based on 100 parts by mass of the total amount of ethylene-α-olefin-non-conjugated polyene copolymer (P), copolymer (Q), and other polymers (elastomers, rubber, etc.) contained in the copolymer composition.

[0083] <Activating agent> Specific examples of surfactants include amines such as di-n-butylamine, dicyclohexylamine, and monoelanolamine; diethylene glycol, polyethylene glycol (e.g., PEG #4000 (trade name; manufactured by NOF Corporation)), lecithin, triaryl merilate, zinc compounds of aliphatic or aromatic carboxylic acids; zinc peroxide preparations; octadecyltrimethylammonium bromide, synthetic hydrotalcite, and special quaternary ammonium compounds.

[0084] If an activator is included, the amount is usually 0.2 to 10 parts by mass, preferably 0.3 to 5 parts by mass, based on 100 parts by mass of the total of copolymer (P), copolymer (Q), and other polymers (elastomer, rubber, etc.).

[0085] <Other polymers> This composition may contain other polymers besides copolymer (P) (e.g., elastomers, rubber). If other polymers are included, their amount is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, based on 100 parts by mass of the total of copolymer (P) and copolymer (Q). This composition may also contain ethylene-propylene-non-conjugated diene copolymer as another polymer.

[0086] <Preparation of Composition> This composition can be prepared by kneading copolymer (P), copolymer (Q), and other components as needed at a desired temperature (e.g., 80°C to 200°C) using a kneading machine such as a mixer, kneader, or roll. Since copolymer (P) and copolymer (Q) have excellent kneadability, the preparation of this composition can be carried out smoothly.

[0087] <Molded body> Molded articles can be obtained using this composition, and specifically include crosslinked articles obtained by crosslinking this composition and foamed articles obtained by crosslinking and foaming this composition.

[0088] The molded article has a specific gravity of 1.00 or less, preferably in the range of 0.20 to 0.80, and a tensile breaking strength (TB) of 0.1 MPa or more, preferably in the range of 1.0 to 5.0 MPa.

[0089] The molded article can be obtained by molding the composition by extrusion molding, transfer molding, injection molding, die molding, or press molding. Specifically, the sponge composition obtained by the above method can be extruded into a product shape using a rubber extruder, then introduced into a vulcanization tank, and prepared by vulcanization and foaming by heating with hot air, a fluidized bed, a molten salt tank (LCM), a PCM (Powder Curing Medium or Powder Curing Method), or a microwave or far-infrared heater heating furnace. Preferably, it can be obtained by continuously vulcanizing and foaming using a hot air vulcanization tank (HAV), LCM, PCM, far-infrared heater heating furnace, or continuous extrusion using HAV and decimeter waves (UHF).

[0090] The crosslinking temperature is typically 140 to 400°C, preferably 150 to 350°C, and more preferably 150 to 300°C. The crosslinking time is typically 0.5 to 30 minutes, preferably 0.5 to 20 minutes, and more preferably 0.5 to 15 minutes.

[0091] The crosslinked foam of the present invention can also be obtained by pre-forming the composition by the molding method described above and irradiating it with an electron beam. In this case, an electron beam having an energy of 0.1 to 10 MeV should be irradiated so that the absorbed dose is typically 0.5 to 35 Mrad, preferably 0.5 to 20 Mrad, and more preferably 1 to 10 Mrad.

[0092] <Application> Specifically, the molded articles are suitably used in automobile parts, ship parts, civil engineering and construction parts, medical parts, electrical and electronic equipment parts, transport and leisure equipment parts, hoses (radiator hoses, heater hoses, etc.), vibration-damping rubber, sheets, various belts, various packings, sealing materials, potting materials, coating materials, and adhesives.

[0093] Examples of automotive parts include glass run channels, weatherstrip sponges, door opening trims, sealing members, grommets, gaskets for automotive engines, sealing materials for electrical components or oil filters; potting materials for igniter HID or automotive hybrid ICs; coating materials for automotive bodies, automotive windows, and engine control boards; gaskets for oil pans or timing belt covers, moldings, headlamp lenses, sunroof seals, and adhesives for mirrors. Examples of weatherstrip sponges include door weatherstrips, trunk weatherstrips, luggage weatherstrips, roof side rail weatherstrips, sliding door weatherstrips, ventilator weatherstrips, sliding roof weatherstrips, front window weatherstrips, rear window weatherstrips, quarter window weatherstrips, lock pillar weatherstrips, door glass outer weatherstrips, and door glass inner weatherstrips. [Examples]

[0094] The present invention will be described in more detail below based on examples, but the present invention is not limited in any way to these examples.

[0095] The following copolymers were used in the examples and comparative examples.

[0096] <Copolymer Manufacturing> <Ethylene-α-olefin-nonconjugated polyene copolymer (P)> [Manufacturing Example 1] A polymerization vessel with a volume of 300 L equipped with a stirring blade was used to continuously carry out the polymerization reaction of ethylene, 1-butene, and 5-ethylidene-2-norbornene (ENB) at 75°C.

[0097] Hexane was used as the polymerization solvent (feed amount: 46.5 L / h), and the mixture was continuously fed into the polymerization vessel such that the ethylene feed amount was 4.2 kg / h, the 1-butene feed amount was 9.8 kg / h, the ENB feed amount was 612 g / h, and the hydrogen feed amount was 3.4 NL / h.

[0098] While maintaining the polymerization pressure at 1.7 MPaG and the polymerization temperature at 75°C, [bis(4-methoxyphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -2,3,6,7-tetramethylfluorenyl)] hafnium dimethyl was used as the main catalyst, and was continuously fed into the polymerization vessel at a feed amount of 0.006 mmol / h. Further, triphenylcarbenium tetrakis(pentafluorophenyl)borate as a cocatalyst was continuously fed into the polymerization vessel at a feed amount of 0.038 mmol / h, and triisobutylaluminum as an organoaluminum compound was continuously fed into the polymerization vessel at a feed amount of 13 mmol / h, respectively.

[0099] In this way, a solution containing 5.7% by mass of an ethylene·1-butene·ENB copolymer formed from ethylene, 1-butene, and ENB was obtained. A small amount of methanol was added to the solution withdrawn from the lower part of the polymerization vessel to terminate the polymerization reaction. 75 parts by mass of paraffin oil (manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process Oil PW-100) was added to 100 parts by mass of the ethylene·1-butene·ENB copolymer, and after separating the ethylene·1-butene·ENB copolymer (P-1) from the solvent by steam stripping, the product was dried under reduced pressure at 80°C overnight.

[0100] Through the above procedure, ethylene-1-butene-ENB copolymer (P-1), formed from ethylene, butene, and ENB, was obtained at a rate of 2.5 kg per hour. Its intrinsic viscosity [η] was 6.0 g / dl.

[0101] <Composition and physical properties of ethylene-1-butene-ENB copolymer (P-1)> Structural units derived from ethylene: 70.2 mol% (The total of structural units derived from ethylene and structural units derived from 1-butene is considered to be 100% by mass.) Structural units derived from 1-butene: 29.8 mol% (The total of structural units derived from ethylene and structural units derived from 1-butene is considered to be 100% by mass.) Content of structural units derived from 5-ethylidene-2-norbornene (ENB): 3.8% by mass (with ethylene-1-butene-ENB copolymer (P-1) being 100% by mass). Mole fraction of structural units derived from 5-ethylidene-2-norbornene (ENB) [a3]: 1.2 mol% (with ethylene·1-butene·ENB copolymer (P-1) as 100 mol%). Mooney Viscosity ML (1+4) 100℃: Not measurable Intrinsic viscosity [η]:6.0dl / g B value: 1.3

[0102] <Ethylene-α-olefin-nonconjugated polyene copolymer (Q)> As the ethylene-α-olefin-non-conjugated polyene copolymer (Q), the following ethylene-propylene-ENB copolymer (Q-1) was used. Product name: Mitsui EPT 8120E (manufactured by Mitsui Chemicals, Inc.), Content of structural units derived from ethylene: 56% by mass, Content of structural units derived from 5-ethylidene-2-norbornene (ENB): 9.5% by mass (2.7 mol%), % Mooney viscosity (ML) (1+4) 150℃):61, [b1] / [b2]=70.9 / 29.1, intrinsic viscosity [η]=2.7

[0103] As the ethylene-α-olefin-non-conjugated polyene copolymer (Q), the following ethylene-propylene-ENB copolymer (Q-2) was used. Product name: Mitsui EPT 8030M (manufactured by Mitsui Chemicals, Inc.), Content of structural units derived from ethylene: 47% by mass, Content of structural units derived from 5-ethylidene-2-norbornene (ENB): 9.5% by mass (2.8 mol%), Mooney viscosity (ML) (1+4) 100℃):32, [b1] / [b2]=61.8 / 38.2, intrinsic viscosity [η]=1.6

[0104] As the ethylene-α-olefin-non-conjugated polyene copolymer (Q), the following ethylene-propylene-ENB copolymer (Q-3) was used. Product name: Mitsui EPT 4045M (manufactured by Mitsui Chemicals, Inc.), Content of structural units derived from ethylene: 45% by mass, Content of structural units derived from 5-ethylidene-2-norbornene (ENB): 7.6% by mass (2.3 mol%), Mooney viscosity (ML) (1+4) 100℃): 45, [b1] / [b2]=58.7 / 41.3, intrinsic viscosity [η]=1.6

[0105] As the ethylene-α-olefin-non-conjugated polyene copolymer (Q), the following ethylene-propylene-ENB copolymer (Q-4) was used. Product name: Mitsui EPT X-4010M (manufactured by Mitsui Chemicals, Inc.), Content of structural units derived from ethylene: 54% by mass, Content of structural units derived from 5-ethylidene-2-norbornene (ENB): 7.6% by mass (2.2 mol%), Mooney viscosity (ML) (1+4) 100℃):8, [b1] / [b2]=67.8 / 32.2, intrinsic viscosity [η]=1.0

[0106] [Example 1] Using a 6L pressurized kneader (Toshin Co., Ltd., TD6-15MDX model, volume 6.5L), 51 parts by mass of ethylene-1-butene-ENB copolymer (P-1), 49 parts by mass of ethylene-1-butene-ENB copolymer (Q-2), 8 parts by mass of "Meta Z102" (product name; manufactured by Inoue Lime Industry Co., Ltd.) as a vulcanization aid, 2 parts by mass of stearic acid and 3 parts by mass of "Actiplast" (registered trademark; manufactured by LANXESS) as processing aids, 1 part by mass of "PEG#4000" (product name; manufactured by NOF Corporation) as an activator, and "Asahi#50HG" (product name; manufactured by Asahi Carbon Co., Ltd., carbon black, specific surface area; 22m²) as a reinforcing material. 2 95 parts by mass of (1 / g), "Whiteon SB" (product name; manufactured by Shiraishi Industries Co., Ltd., calcium carbonate), 0.3 parts by mass of "Sumiriser GM" (product name; manufactured by Sumitomo Chemical Co., Ltd.) as an antioxidant, and 75 parts by mass of "Diana Process Oil PS-430" (product name; manufactured by Idemitsu Kosan Co., Ltd.) as a softening agent were kneaded together. 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.

[0107] After allowing the aforementioned mixture to cool and confirming that its temperature had dropped to 40°C or below, the mixture was kneaded using a 14-inch double-roll kneader with the following additions: 2.0 parts by mass of "Suncellar M" (product name; manufactured by Sanshin Chemical Industry Co., Ltd.) as a vulcanization accelerator, 1.0 part by mass of "Suncellar TRA" (product name; manufactured by Sanshin Chemical Industry Co., Ltd.), 1.0 part by mass of "Suncellar 22-C" (product name; manufactured by Sanshin Chemical Industry Co., Ltd.), and 0.5 parts by mass of "Suncellar TE" (product name; manufactured by Sanshin Chemical Industry Co., Ltd.) as vulcanization accelerators; 2.0 parts by mass of sulfur (manufactured by Kanto Chemical Co., Ltd.) as a vulcanizing agent; 3.0 parts by mass of "NeoCelbon N1000SW" (product name; manufactured by Eiwa Chemical Industry Co., Ltd., 4,4'-oxybis(benzenesulfonyl hydrazide)) as a foaming agent; and 8.0 parts by mass of "Vesta 18" (product name; manufactured by Inoue Lime Industry Co., Ltd.) as a dehydrating agent. The mixing conditions were as follows: roll temperature 60°C / 55°C for the front roll and 13 rpm for the front roll and 11.5 rpm for the rear roll, and the mixture was separated into ribbons.

[0108] Next, the obtained sponge composition was extruded into a tube shape using a 50 mmφ extruder equipped with a tubular die (inner diameter: height 13 mm x width 12 mm, wall thickness 1.5 mm) under conditions of die temperature 80°C and cylinder temperature 60°C. This molded body was introduced into a linear hot air vulcanizing apparatus (HAV) set to 230°C and heated for 3 minutes to perform crosslinking and foaming, obtaining a tubular foam. This foam was cut out, test pieces were punched out, and measurements and evaluations were performed using these test pieces. The results are shown in Table 1.

[0109] [Example 2] A tubular foam was produced in the same manner as in Example 1, except that the amount of ethylene-α-olefin-nonconjugated polyene copolymer (P-1) used in Example 1 was changed to 48 parts by mass, and ethylene-α-olefin-nonconjugated polyene copolymer (Q-2) was replaced with ethylene-α-olefin-nonconjugated polyene copolymer (Q-3), with the amount changed to 52 parts by mass.

[0110] [Example 3] A tubular foam was produced in the same manner as in Example 1, except that the amount of ethylene-α-olefin-non-conjugated polyene copolymer (P-1) used in Example 1 was changed to 66 parts by mass, ethylene-α-olefin-non-conjugated polyene copolymer (Q-2) was changed to ethylene-α-olefin-non-conjugated polyene copolymer (Q-4) and its amount was changed to 34 parts by mass, the amount of Suncellar M was changed to 1.75 parts by mass, and 0.25 parts by mass of "Suncellar HM" (product name; manufactured by Sanshin Chemical Industry Co., Ltd.) was added as a vulcanization accelerator.

[0111] [Comparative Example 1] A tubular foam was produced in the same manner as in Example 1, except that the ethylene-α-olefin-non-conjugated polyene copolymer (P-1) and (Q-2) used in Example 1 were not included, 120 parts by mass of ethylene-α-olefin-non-conjugated polyene copolymer (Q-1) was included, the amount of Suncellar M was changed to 1.2 parts by mass, and 0.8 parts by mass of "Noxellar MDB" (product name; manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) was included as a vulcanization accelerator.

[0112] [Comparative Example 2] Production was carried out in the same manner as in Example 1, except that the ethylene·α-olefin·non-conjugated polyene copolymer (Q-2) used in Example 1 was not blended, and 100 parts by mass of the ethylene·α-olefin·non-conjugated polyene copolymer (P-1) was blended. However, a tubular foam could not be obtained due to high viscosity.

[0113] <<Measurement Method>> <Molar fraction of structural units derived from ethylene, structural units derived from α-olefin, and structural units derived from non-conjugated polyene> Using o-dichlorobenzene-d4 as the measurement solvent, under the measurement conditions of a measurement temperature of 120°C, a spectral width of 20 ppm, a pulse repetition time of 7.0 seconds, and a pulse width of 5.00 μs (500 MHz, AVANCEIII cryo-500 nuclear magnetic resonance spectrometer manufactured by Bruker Biospin) 1 1H-NMR spectrum was measured and calculated.

[0114] <Intrinsic viscosity [η] (dl / g)> For measurement of the intrinsic viscosity [η] (dl / g) of the copolymer, after shredding 1 g of the copolymer, Soxhlet extraction was performed using methyl ethyl ketone at 80°C for 3 hours, and then the copolymer that had been dried under reduced pressure at 80°C for a whole day and night was used. The intrinsic viscosity [η] (dl / g) 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.

[0115] Using o-dichlorobenzene-d4 / benzene-d6 (4 / 1 [v / v]) as the measurement solvent, at a measurement temperature of 120°C, 13 13C-NMR spectrum (125 MHz, AVANCEIII cryo-500 nuclear magnetic resonance spectrometer manufactured by Bruker Biospin) was measured, and the B value was calculated based on the following formula (i). B value = ([EX] + 2[Y]) / [2 × [E] × ([X] + [Y])] ···(i) [Here, [E], [X], and [Y] represent the mole fractions of structural units derived from ethylene [A1], α-olefins with 3 to 20 carbon atoms [A2], and non-conjugated polyenes [A3], respectively, and [EX] represents the ethylene [A1]-α-olefins with 3 to 20 carbon atoms [A2] dyad chain fraction.]

[0116] <Moony viscosity> Mooney viscosity (ML) (1+4) 100℃ and ML (1+4) The viscosity (125°C) was measured using a Mooney viscometer (Shimadzu Corporation, SMV202 model) in accordance with JIS K6300 (1994). Here, the measurement temperature is ML (1+4) At 100℃, 100℃, ML (1+4) 125℃ was used as the temperature.

[0117] <Mooney Coach> The minimum viscosity (Vm) and scorch time (t5) at 125°C were measured under 125°C conditions using a Mooney viscometer (SMV202, manufactured by Shimadzu Corporation) in accordance with JIS K6300.

[0118] <Specific gravity> A 1g sample of tubular foam was cut off to prepare a test specimen. The test specimen was attached to an automatic hydrometer (Toyo Seiki Seisakusho: M-1 model) at 25°C, and its specific gravity was measured from the difference in mass between air and pure water.

[0119] <Tensile Test: Modulus, Tensile Stress at Breaking Point, Tensile Elongation at Breaking Point> The modulus, tensile stress at fracture, and tensile elongation at fracture of a 2mm thick tubular foam sheet were measured using the following method. The aforementioned sheet was punched out to prepare a Type 3 dumbbell test specimen as described in JIS K6251 (2017). Using this specimen, a tensile test was performed according to the method specified in Section 3 of JIS K6251, under the conditions of a measurement temperature of 23°C and a tensile speed of 500 mm / min. The tensile stress (25% modulus (M25)), tensile stress at fracture (TB), and tensile elongation at fracture (EB) were measured when the elongation was 25%.

[0120] <Door closing performance (M25 / specific gravity)> Door closing performance is evaluated by the tensile stress (25% modulus (M25)) / specific gravity when the elongation rate is 25%. The smaller the M25 / specific gravity value, the higher the flexibility and the better it can seal the gap between the door and the vehicle body, resulting in superior door closing performance.

[0121] <Compression permanent set> A tubular foam was cut 30 mm lengthwise, and the resulting specimen was mounted in a compression set measurement mold. The specimen was compressed so that its height was half of its height before loading, and the mold was placed in a -30°C low-temperature incubator for 22 hours. Next, the specimen was removed from the mold, allowed to stand for 30 minutes, and then its height was measured. The compression set (CS) (%) was calculated using the following formula. Compression set (CS) (%) = {(t0-t1) / (t0-t2)} × 100 t0: Height of the test specimen before testing. t1: Height after processing the test specimen and allowing it to stand for 30 minutes. t2: Height of the test specimen when it is attached to the measuring mold.

[0122] [Table 1]

Claims

1. 25 to 75 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (P) having structural units derived from ethylene [A1], structural units derived from at least one C3-20 α-olefin [A2], and structural units derived from at least one non-conjugated polyene [A3], and satisfying the following requirements (1) and (2), and 25 to 75 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (Q) having structural units derived from ethylene [B1], structural units derived from at least one C3-20 α-olefin [B2], and structural units derived from at least one non-conjugated polyene [B3], and satisfying the following requirements (3) and (4) (however, the total of the ethylene-α-olefin-non-conjugated polyene copolymer (P) and the ethylene-α-olefin-non-conjugated polyene copolymer (Q) is 100 parts by mass). A sponge composition containing the following: Requirement (1): The ratio of the mole fraction [a1] of structural units derived from ethylene [A1] to the mole fraction [a2] of structural units derived from α-olefins [A2] having 3 to 20 carbon atoms ([a1] / [a2]) is 40 / 60 to 90 / 10 (provided that the sum of the mole fractions of structural units derived from [A1], [A2], and [A3] is 100 mol%). Requirement (2): The intrinsic viscosity [η] measured in decalin at 135°C is 4.0 to 7.0 dl / g. Requirement (3): The ratio of the mole fraction [b1] of structural units derived from ethylene [B1] to the mole fraction [b2] of structural units derived from α-olefins [B2] having 3 to 20 carbon atoms ([b1] / [b2]) is 40 / 60 to 90 / 10 (provided that the sum of the mole fractions of structural units derived from [B1], [B2], and [B3] is 100 mol%). Requirement (4): The intrinsic viscosity [η] measured in decalin at 135°C is 0.5 to 3.0 dl / g.

2. The sponge composition according to claim 1, wherein the 3-20 carbon α-olefin [A2] of the ethylene-α-olefin-non-conjugated polyene copolymer (P) has 4-20 carbon atoms.

3. The sponge composition according to claim 1, wherein the 3-20 carbon α-olefin [A2] of the ethylene-α-olefin-non-conjugated polyene copolymer (P) is 1-butene.

4. The sponge composition according to claim 1, wherein the ethylene-α-olefin-non-conjugated polyene copolymer (P) satisfies the following requirement (5). Requirement (5): The mole fraction [a3] of structural units derived from non-conjugated polyene [A3] is 0.1 to 6.0 mol% (provided that the sum of the mole fractions of structural units derived from [A1], [A2], and [A3] is 100 mol%).

5. The sponge composition according to claim 1, wherein the ethylene-α-olefin-non-conjugated polyene copolymer (P) satisfies the following requirement (6). Requirement (6): The B value, expressed by the following formula (i), is 1.20 or greater. B value = ([EX]+2[Y]) / [2×[E]×([X]+[Y])]...(i) (Here, [E], [X], and [Y] represent the mole fractions of ethylene [A1], α-olefins with 3 to 20 carbon atoms [A2], and unconjugated polyenes [A3], respectively, and [EX] represents the ethylene [A1]-α-olefins with 3 to 20 carbon atoms [A2] dyad chain fraction.)

6. The sponge composition according to claim 1, wherein the non-conjugated polyenes [A3] and [B3] are 5-ethylidene-2-norbornene (ENB).

7. The sponge composition according to claim 1, which is a weatherstrip sponge composition.

8. A crosslinked sponge composition according to any one of claims 1 to 7.

9. A foamed sponge composition according to any one of claims 1 to 7.

10. A weatherstrip sponge made of the foam described in claim 9.

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