Copolymer composition, gasket, and molded article

Abstract

To provide a copolymer composition which has a high crosslinking rate, is excellent in productivity and processability, and gives a crosslinked molded article excellent in physical properties (for example, hardness, tensile stress at break, tensile elongation at break, and compression set).SOLUTION: A polymer (0dL) having an intrinsic viscosity [η] (in decalin at 135 °C.) of 2. 0dL / g or more and less than 4. S1 / g, a polymer (S2) having an intrinsic viscosity [η] (in decalin at 135 °C.) of 0. 5dL / g or more and less than 2. 0dL / g, a specific hydrosilyl group-containing compound (Y), S2, each of the copolymers (S1) and (S2) has a structural unit derived from ethylene (A), a structural unit derived from an α - olefin (B) having 3 to 20 carbon atoms, and a structural unit derived from a non-conjugated polyene (C).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a copolymer composition, a gasket, and a molded article. [Background technology]

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

[0003] Among ethylene-α-olefin copolymer elastomers, rubber moldings for sealing that use EPDM are known (for example, Patent Document 1). Packings and gaskets, which are rubber moldings for sealing, are used in a variety of applications, including automobiles, industrial machinery, and electronic components.

[0004] In EPDM molded articles, it has been proposed to incorporate a reinforcing agent such as carbon black to ensure strength (e.g., Patent Document 2). Generally, methods for crosslinking EPDM include sulfur vulcanization and peroxide crosslinking. However, crosslinked products obtained using sulfur tend to have a strong odor and insufficient heat aging resistance. Crosslinked products obtained using organic peroxides also tend to have a strong odor, and because peroxides cannot be handled in air, they require special equipment for handling organic peroxides. In recent years, hydrosilicone crosslinking using hydrosilyl group-containing compounds (e.g., Patent Document 3) has attracted attention because crosslinking is difficult to occur at relatively low temperatures of 50 to 130°C during kneading and molding, resulting in a sufficient scorch time, while crosslinking can occur in a short time at crosslinking temperatures of 150 to 200°C. Crosslinked products obtained using hydrosilyl group-containing compounds tend to have a low odor and excellent heat aging resistance, and can be handled in air.

[0005] However, the EPDM crosslinked molded articles obtained by hydrosilicone crosslinking, as disclosed in Patent Document 3, did not have sufficient physical properties such as strength. Furthermore, when a reinforcing agent such as carbon black was added in an attempt to improve strength, the viscosity of the uncrosslinked compound increased, resulting in a problem of reduced processability of the compound. For example, Patent Document 4 proposes an ethylene-α-olefin-non-conjugated polyene copolymer composition that not only has excellent processability but also produces excellent physical properties in the crosslinked molded articles obtained. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2000 / 59962 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-52032 [Patent Document 3] Japanese Patent Application Publication No. 2018-131527 [Patent Document 4] Japanese Patent Publication No. 2024-32012 Summary of the Invention [Problem to be solved by the invention]

[0007] For example, rubber moldings for sealing, such as gaskets and packings, typified by fuel cell gaskets for fuel cell vehicles (FCVs), are required to have sufficient physical properties such as strength. In recent years, compositions that can be used for rubber moldings for sealing have been required not only to satisfy both the above physical properties and processability, but also to shorten the vulcanization time in order to further improve productivity.

[0008] An object of the present invention is to provide a copolymer composition which has a high crosslinking rate, excellent productivity, and excellent processability, and which produces crosslinked molded articles which are excellent in physical properties (e.g., hardness, tensile stress at break, tensile elongation at break, and compression set). [Means for solving the problem]

[0009] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved by the following configuration, thereby achieving the present invention. An example of the configuration of the present invention is as follows.

[0010] [1] A copolymer (S1), A copolymer (S2), a hydrosilyl group-containing compound (Y) which is an organohydrogenpolysiloxane represented by the following formula (a) and which has at least one silicon-bonded aralkyl group and at least two silicon-bonded hydrogen atoms in the molecule; A platinum-based catalyst; A reaction inhibitor; Carbon black and a polyolefin resin (F) (however, the copolymer (S1) and the copolymer (S2) are different from each other); Including, The copolymer (S1) and the copolymer (S2) each have a structural unit derived from ethylene (A), a structural unit derived from an α-olefin (B) having 3 to 20 carbon atoms, and a structural unit derived from a non-conjugated polyene (C) containing, in one molecule, two or more partial structures in total, each of which is at least one type of partial structure selected from the group consisting of the following formula (I) and the following formula (II): The copolymer (S1) has an intrinsic viscosity [η] (in decalin at 135°C) of 2.0 dL / g or more and less than 4.0 dL / g, A copolymer composition, wherein the copolymer (S2) has an intrinsic viscosity [η] (in decalin at 135°C) of 0.5 dL / g or more and less than 2.0 dL / g.

[0011] [ka] (In formula (a), n and p are each independently 0 or a positive number, m is a number ranging from 1 to 20, and the sum of n, m, and p is 5 to 50. 1 and R 2 are each independently a monovalent alkyl group, and a plurality of R 1 and R 2may be the same or different. a is an aralkyl group, and R is R 1 , R 2 , hydrogen atoms, and R a and the two R's may be the same or different. However, when n=1, at least one of R's is a hydrogen atom, and when n=0, both R's are hydrogen atoms.

[0012] [2] The copolymer composition according to [1], wherein the content of the polyolefin resin (F) is 1 to 50 parts by mass when the total mass of the copolymers (S1) and (S2) is 100 parts by mass.

[0013] [3] The copolymer composition according to [1] or [2], wherein the polyolefin resin (F) has a melting point of 120° C. or lower as measured in accordance with the measurement method of JIS K 7121.

[0014] [4] The copolymer composition according to any one of [1] to [3], wherein the polyolefin resin (F) contains a resin or rubber having a structural unit derived from ethylene.

[0015] [5] The copolymer composition according to any one of [1] to [4], wherein the polyolefin resin (F) contains a crystalline olefin polymer.

[0016] [6] The copolymer composition according to any one of [1] to [5], wherein the mass fraction of the copolymer (S1) in the total mass of the copolymers (S1) and (S2) is more than 50 mass% and less than 100 mass%.

[0017] [7] The copolymer composition according to any one of [1] to [6], wherein the carbon black is contained in an amount of 10 to 300 parts by mass when the total mass of the copolymers (S1) and (S2) is taken as 100 parts by mass.

[0018] [8] The copolymer composition according to any one of [1] to [7], comprising 0.1 to 100 parts by mass of the hydrosilyl group-containing compound (Y) and 0.00001 to 0.3 parts by mass of the platinum catalyst, when the total mass of the copolymers (S1) and (S2) is 100 parts by mass.

[0019] [9] The copolymer composition according to any one of [1] to [8], wherein the reaction inhibitor is contained in an amount of 0.001 to 10 parts by mass when the total mass of the copolymers (S1) and (S2) is 100 parts by mass.

[0020]

[10] The copolymer composition according to any one of [1] to [9], wherein the copolymer (S1) and the copolymer (S2) both satisfy the following requirements (1) and (2): Requirement (1): The ratio [A] / [B] of the number of moles of structural units derived from ethylene (A) to the number of moles [B] of structural units derived from an α-olefin having 3 to 20 carbon atoms is 40 / 60 to 90 / 10; Requirement (2): The mass fraction (mass %) of the structural units derived from the non-conjugated polyene (C) is 0.07 to 10 mass % based on the total structural units constituting the copolymer.

[0021]

[11] The copolymer composition according to any one of [1] to

[10] , wherein the copolymer (S1) and the copolymer (S2) both satisfy at least one of the following requirements (3) to (5): Requirement (3): the weight average molecular weight (Mw), the mass fraction of the structural unit derived from the non-conjugated polyene (C) (mass fraction (mass%) of (C)), and the molecular weight of the non-conjugated polyene (C) (molecular weight of (C)) satisfy the following formula (ii); 4.5≦Mw×(C) mass fraction / 100 / (C) molecular weight≦80 … (ii) Requirement (4): Complex viscosity η at a frequency of ω = 0.1 rad / s obtained by linear viscoelasticity measurement (190 ° C) using a rheometer * (ω=0.1) (Pa·sec) and the complex viscosity η at frequency ω=100rad / s* (ω=100) (Pa·sec) and the ratio P〔η * (ω=0.1) / η * (ω=100) ], the intrinsic viscosity [η] of the copolymer (A), and the mass fraction of the copolymer (C) satisfy the following formula (iii): P / ([η] 2.9 )≦(C) weight fraction × 6 …(iii) Requirement (5): The number of long chain branches (LCB) per 1000 carbon atoms obtained using 3D-GPC 1000C ) and the natural logarithm of the weight average molecular weight (Mw) [Ln(Mw)] satisfy the following formula (iv). LCB 1000C ≦1−0.07×Ln(Mw) …(iv)

[0022]

[12] The copolymer composition according to any one of [1] to

[11] , wherein at least one of the copolymers (S1) and (S2) contains a structural unit derived from 5-vinyl-2-norbornene as a structural unit derived from the non-conjugated polyene (C).

[0023]

[13] The copolymer composition according to any one of [1] to

[12] , which is a composition for gaskets.

[0024]

[14] A gasket obtained using the copolymer composition according to

[13] .

[0025]

[15] A molded article formed using the copolymer composition according to any one of [1] to

[12] .

[0026]

[16] The copolymer composition according to any one of [1] to

[12] , which is a composition for packing.

[0027]

[17] A packing obtained using the copolymer composition according to

[16] . [Effects of the Invention]

[0028] The copolymer composition of the present invention containing the ethylene-α-olefin-non-conjugated polyene copolymer has excellent processability, and the crosslinked molded article obtained by crosslinking the copolymer composition also has excellent physical properties. Furthermore, the copolymer composition of the present invention has a high crosslinking rate and excellent productivity. Molded articles formed using the copolymer composition of the present invention can be suitably used as rubber molded articles for sealing purposes, such as gaskets and packings. DETAILED DESCRIPTION OF THE INVENTION

[0029] [Copolymer composition] The copolymer composition according to the present invention (hereinafter also referred to as "the composition") contains a copolymer (S1), a copolymer (S2), a hydrosilyl group-containing compound (Y), a platinum catalyst, a reaction inhibitor, carbon black, and a polyolefin resin (F). In this specification and claims, "parts by mass" refers to parts by mass converted into solid content excluding solvent. Furthermore, a numerical range expressed by "to" means a numerical range in which the numbers before and after "to" are the lower and upper limits.

[0030] [Copolymer (S1) and Copolymer (S2)] The copolymer component (S) of this composition comprises a copolymer (S1) and a copolymer (S2). The copolymers (S1) and (S2) have different intrinsic viscosities [η] (in decalin at 135°C). Both the copolymers (S1) and (S2) have structural units derived from ethylene (A), structural units derived from an α-olefin (B) having 3 to 20 carbon atoms, and structural units derived from a non-conjugated polyene (C) containing, in one molecule, two or more partial structures selected from the group consisting of the following formulas (I) and (II):

[0031] [ka]

[0032] In each of the copolymers (S1) and (S2), the total mass fraction of the structural units derived from ethylene (A), the structural units derived from the α-olefin (B) having 3 to 20 carbon atoms, and the structural units derived from the non-conjugated polyene (C) relative to all structural units is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 92% by mass or more, and particularly preferably 100% by mass.

[0033] Examples of the α-olefin (B) having 3 to 20 carbon atoms (hereinafter simply referred to as "α-olefin (B)") include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene. Among these, α-olefins having 3 to 8 carbon atoms, such as propylene, 1-butene, 1-hexene, and 1-octene, are preferred, with propylene being particularly preferred. Such α-olefins are preferred because they are relatively inexpensive in terms of raw material cost, the resulting copolymer compositions exhibit excellent mechanical properties, and molded articles having rubber elasticity can be obtained. These α-olefins may be used alone or in combination of two or more.

[0034] Examples of the non-conjugated polyene (C) containing two or more partial structures selected from the group consisting of the formula (I) and the following formula (II) in a molecule 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, 5-(1-methyl-3-butenyl)-2-norbornene, 5-(2-ethyl-4-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, dicyclopentadiene, and the like. Among these, it is preferable to use VNB as the non-conjugated polyene (C), and it is more preferable that the non-conjugated polyene (C) is VNB, since it is easily available, crosslinks well with the hydrosilyl-containing compound (Y) described later, and the heat resistance of the copolymer composition is likely to be improved. The non-conjugated polyene (C) may be used alone or in combination of two or more.

[0035] At least one of the copolymers (S1) and (S2) preferably contains VNB as the non-conjugated polyene (C), more preferably both contain VNB as the non-conjugated polyene (C), and even more preferably both contain VNB as the non-conjugated polyene (C).

[0036] Each of the copolymers (S1) and (S2) may further contain, in addition to the structural units derived from ethylene (A), α-olefin (B), and non-conjugated polyene (C), a structural unit derived from non-conjugated polyene (CX) containing only one partial structure selected from the group consisting of general formulas (I) and (II) in one molecule, within the range that does not impair the effects of the present invention.

[0037] Examples of the non-conjugated polyene (CX) 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.

[0038] Among these, ENB is preferred because it is readily available, the crosslinking rate during crosslinking with a hydrosilyl-containing compound is easily controlled, and good mechanical properties are easily obtained. The non-conjugated polyene (CX) may be used alone or in combination of two or more. When each of the copolymers (S1) and (S2) contains a structural unit derived from the non-conjugated polyene (CX), the content thereof is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 0.01 to 8% by mass, based on the total structural units constituting each copolymer.

[0039] The copolymers (S1) and (S2) may each contain at least one biomass-derived monomer (e.g., ethylene (A), α-olefin (B), non-conjugated polyene (C), and non-conjugated polyene (CX)), or at least one chemically recycled monomer (e.g., ethylene (A), α-olefin (B), non-conjugated polyene (C), and non-conjugated polyene (CX)). The same type of monomer constituting each copolymer may consist solely of biomass-derived monomers, solely of chemically recycled monomers, solely of fossil fuel-derived monomers, or may contain biomass-derived monomers and / or chemically recycled monomers and / or fossil fuel-derived monomers. It is preferable that the copolymers (S1) and / or (S2) contain structural units derived from biomass-derived monomers from the viewpoint of reducing the environmental impact. It is preferable that the copolymers (S1) and / or (S2) contain structural units derived from chemically recycled monomers from the viewpoint of reducing the environmental impact (mainly waste reduction).

[0040] The mass fraction of copolymer (S1) relative to the total mass of copolymers (S1) and (S2) is preferably greater than 50% by mass but less than 100% by mass, more preferably 55 to 95% by mass, even more preferably 60 to 90% by mass, and particularly preferably 65 to 85% by mass. The mass fraction of copolymer (S2) relative to the total mass of copolymers (S1) and (S2) is preferably greater than 0% by mass but less than 50% by mass, more preferably 5 to 45% by mass, even more preferably 10 to 40% by mass, and particularly preferably 15 to 35% by mass. When the mass fraction of copolymer (S1) is equal to or greater than the lower limit, a molded article having better physical properties is easily obtained. When the mass fraction of copolymer (S1) is equal to or less than the upper limit, a copolymer composition having better processability is easily obtained.

[0041] The intrinsic viscosity [η] of the copolymer (S1) (in decalin at 135°C) is 2.0 dL / g or more and less than 4.0 dL / g. The intrinsic viscosity [η] of the copolymer (S1) (in decalin at 135°C) is preferably 2.1 dL / g or more and 3.8 dL / g or less, more preferably 2.2 dL / g or more and 3.6 dL / g or less, even more preferably 2.4 dL / g or more and 3.3 dL / g or less, and particularly preferably 2.6 dL / g or more and 3.0 dL / g or less.

[0042] The intrinsic viscosity [η] of the copolymer (S2) (in decalin at 135°C) is 0.5 dL / g or more and less than 2.0 dL / g. The intrinsic viscosity [η] of the copolymer (S2) (in decalin at 135°C) is preferably 0.6 dL / g or more and 1.9 dL / g or less, more preferably 0.7 dL / g or more and 1.8 dL / g or less, even more preferably 0.8 dL / g or more and 1.7 dL / g or less, and particularly preferably 1.0 dL / g or more and 1.7 dL / g or less. The intrinsic viscosity [η] (in decalin at 135° C.) of each of the copolymers (S1) and (S2) can be adjusted by the amount of hydrogen fed during polymerization.

[0043] Furthermore, the intrinsic viscosity [η] (in decalin at 135°C) of the copolymer component (S) (copolymers (S1) and (S2)) in the composition is preferably greater than 0.5 dL / g and not greater than 3.0 dL / g, more preferably 0.6 to 2.9 dL / g, and even more preferably 0.7 to 2.8 dL / g. When the intrinsic viscosity [η] (in decalin at 135°C) of the copolymer component (S) is equal to or greater than the lower limit, a molded article having better physical properties is more easily obtained. When the intrinsic viscosity [η] (in decalin at 135°C) of the copolymer component (S) is equal to or less than the upper limit, a copolymer composition having better processability is more easily obtained.

[0044] The intrinsic viscosity [η] (in decalin at 135°C) of the copolymer component (S) can be adjusted by the intrinsic viscosity [η] (in decalin at 135°C) of each of the copolymers (S1) and (S2) or the content ratio of the copolymers (S1) and (S2). The intrinsic viscosities [η] (in decalin at 135°C) of the copolymer (S1), copolymer (S2) and copolymer component (S) are all values ​​measured in decalin at 135°C.

[0045] The weight average molecular weight (Mw) of the copolymer (S1) is preferably from 50,000 to 700,000, more preferably from 200,000 to 600,000, even more preferably from 300,000 to 550,000, and still more preferably from 400,000 to 500,000. The weight average molecular weight (Mw) of the copolymer (S2) is preferably from 10,000 to 300,000, more preferably from 30,000 to 200,000, still more preferably from 50,000 to 150,000, and particularly preferably from 70,000 to 100,000.

[0046] The weight average molecular weight (Mw) of the copolymer component (S) is preferably 10,000 to 700,000, more preferably 30,000 to 600,000, and even more preferably 50,000 to 500,000. When the weight average molecular weight (Mw) of the copolymer component (S) is equal to or greater than the lower limit, better physical properties are likely to be obtained. When the weight average molecular weight (Mw) of the copolymer component (S) is equal to or less than the upper limit, better processability is likely to be obtained.

[0047] The weight average molecular weight (Mw) of the entire copolymer component (S) can be adjusted by the weight average molecular weight (Mw) of each of the copolymers (S1) and (S2) and the content ratio of the copolymers (S1) and (S2). The weight average molecular weight (Mw) of the copolymer (S1), the copolymer (S2), and the copolymer component (S) can all be measured by 3D-GPC using the apparatus and conditions described in the Examples section.

[0048] The Mooney viscosity ML(1+4)100°C of the copolymer (S2) at 100°C is preferably 5-60, more preferably 6-40, even more preferably 7-30, and particularly preferably 8-15. When the Mooney viscosity ML(1+4)100°C is within the above range, a copolymer can be obtained which has excellent roll processability even in high-hardness oil-less formulations, and which also exhibits good post-treatment (ribbon handling properties) and has excellent rubber physical properties.

[0049] The Mooney viscosity ML(1+4)125°C of the copolymer (S1) at 125°C is preferably 10-100, more preferably 30-90, still more preferably 50-80, and particularly preferably 65-75. When the Mooney viscosity ML(1+4)125°C is within the above range, a copolymer having excellent roll processability even in a high-hardness oil-less compound, good post-treatment (ribbon handling properties) and excellent rubber physical properties can be obtained.

[0050] The glass transition temperature (Tg) of the copolymers (S1) and (S2) measured by differential scanning calorimetry (DSC) is −50° C. or lower, preferably −53° C. or lower, more preferably −55° C. or lower, and particularly preferably −57° C. or lower. When Tg is within the above range, the obtained molded article has excellent low-temperature properties. Specifically, Tg can be determined by the method described in the Examples below.

[0051] It is preferable that both copolymers (S1) and (S2) satisfy the following requirements (1) and (2). It is more preferable that both copolymers (S1) and (S2) satisfy one or more of the following requirements (3) to (5), it is even more preferable that both copolymers (S1) and (S2) satisfy two or more of the following requirements (3) to (5), and it is particularly preferable that both copolymers (S1) and (S2) satisfy all of the following requirements (1) to (5). All of requirements (3) to (5) are indicators related to the content of long chain branches in the copolymer.

[0052] Requirement (1): The ratio [A] / [B] of the number of moles of structural units derived from ethylene (A) to the number of moles [B] of structural units derived from an α-olefin having 3 to 20 carbon atoms is 40 / 60 to 90 / 10.

[0053] Requirement (2): The mass fraction of the structural units derived from the non-conjugated polyene (C) is 0.07 to 10 mass % of all structural units constituting the copolymer.

[0054] Requirement (3): The weight-average molecular weight (Mw), the mass fraction of the constitutional unit derived from the non-conjugated polyene (C) (mass fraction (mass%) of (C)), and the molecular weight of the non-conjugated polyene (C) (molecular weight of (C)) satisfy the following formula (ii): 4.5≦Mw×mass fraction of (C) / 100 / molecular weight of (C)≦80 … Formula (ii)

[0055] Requirement (4): Complex viscosity η at a frequency of ω = 0.1 rad / s obtained by linear viscoelasticity measurement (190 °C) using a rheometer * (ω=0.1) (Pa·sec) and the complex viscosity η at frequency ω=100rad / s * (ω=100) (Pa·sec) and the ratio P〔η * (ω=0.1) / η * (ω=100) ], the intrinsic viscosity [η] of the copolymer (A), and the mass fraction of (C) satisfy the following formula (iii). P / ([η] 2.9 ) ≦ weight fraction of (C) × 6 … formula (iii)

[0056] Requirement (5): The number of long-chain branches per 1,000 carbon atoms (LCB1000C) and the natural logarithm of the weight-average molecular weight (Mw) [Ln(Mw)], obtained using 3D-GPC, satisfy the following formula (iv): LCB1000C≦1-0.07×Ln(Mw) …Formula (iv)

[0057] Requirement (1) In the copolymer (S1) or (S2), the ratio [A] / [B] of the number of moles of structural units derived from ethylene (A) to the number of moles [B] of structural units derived from an α-olefin (B) having 3 to 20 carbon atoms is preferably 40 / 60 to 90 / 10, more preferably 50 / 50 to 85 / 15, even more preferably 60 / 40 to 80 / 20, and particularly preferably 65 / 35 to 75 / 25. When the copolymer (S1) and the copolymer (S2) each satisfy the requirement (1), the molded article obtained by crosslinking the copolymer component (S) with a hydrosilyl-containing compound exhibits excellent rubber elasticity and is excellent in mechanical strength and flexibility. The ratio [A] / [B] of each of the copolymers (S1) and (S2) is: 13 It can be determined by C-NMR.

[0058] Requirement (2) The mass fraction of the structural units derived from the non-conjugated polyene (C) in the copolymer (S1) or (S2) is preferably 0.07 to 10 mass%, more preferably 0.1 to 8.0 mass%, even more preferably 0.5 to 5.0 mass%, and particularly preferably 1.0 to 3.0 mass%, relative to 100 mass% of the total of all structural units (structural units derived from ethylene (A), structural units derived from α-olefin (B), structural units derived from the non-conjugated polyene (C), and structural units derived from the non-conjugated polyene (CX)) constituting the copolymer (copolymer (S1) or (S2)). When copolymer (S1) and copolymer (S2) each satisfy requirement (2), the crosslinked molded article obtained from the composition has sufficient hardness and excellent mechanical properties. Furthermore, when copolymer component (S) is crosslinked with a hydrosilyl-containing compound, the crosslinking rate is high, allowing for efficient production of crosslinked molded articles. The mass fraction of the constitutional unit derived from the non-conjugated polyene (C) in each of the copolymers (S1) and (S2) is 13 It can be determined by C-NMR.

[0059] Furthermore, it is preferable that the mass fraction of the structural unit derived from the non-conjugated polyene (C) (mass fraction of (C)) (mass%) and the natural logarithm (Ln(Mw)) of the weight average molecular weight (Mw) of the copolymer satisfy the following formula (i): 6-0.45 × Ln(Mw) ≦ (C) mass fraction ≦ 10 … Equation (i)

[0060] Requirement (3) In the copolymer (S1) or (S2), it is preferable that the weight average molecular weight (Mw) of the copolymer, the mass fraction of the structural unit derived from the non-conjugated polyene (C) (mass fraction (mass%) of (C)), and the molecular weight of the non-conjugated polyene (C) (molecular weight of (C)) satisfy the following formula (ii): 4.5≦Mw×mass fraction of (C) / 100 / molecular weight of (C)≦80 … Formula (ii) The weight average molecular weight (Mw) of each of the copolymers (S1) and (S2) can be determined as a polystyrene-equivalent value measured by 3D-GPC.

[0061] The "Mw × mass fraction of (C) / 100 / molecular weight of (C)" is the number of constitutional units derived from the non-conjugated polyene (C) per Mw of the copolymer (n C ), more preferably 4.5 or more and 80 or less, and further preferably 4.5 or more and 78 or less. c When the ratio is equal to or greater than the lower limit, a sufficient crosslinking rate is easily obtained when crosslinking with a hydrosilyl-containing compound, and when the ratio is equal to or less than the upper limit, excessive crosslinking is unlikely to occur, and the resulting crosslinked molded article exhibits better mechanical properties.

[0062] When the copolymers (S1) and (S2) each satisfy the requirement (3), the content of long chain branches in each copolymer falls within an appropriate range, resulting in a high crosslinking rate when crosslinked with a hydrosilyl-containing compound, an excellent balance of physical properties such as mechanical properties of the resulting crosslinked molded article, and a resistance to post-crosslinking, particularly excellent heat aging resistance.

[0063] When the copolymer contains the structural unit (CX), it is preferable that the weight average molecular weight (Mw) of the copolymer, the mass fraction (mass%) of (C), the molecular weight of (C), the mass fraction of the structural unit derived from the non-conjugated polyene (CX) (mass fraction (mass%) of (C)), and the molecular weight of the non-conjugated polyene (CX) (molecular weight of (C)) satisfy the following formula (ii'): 4.5≦Mw×[{mass fraction of (C) / 100} / molecular weight of (C)+{mass fraction of (CX) / 100} / molecular weight of (CX)]≦80 ... Formula (ii') The "Mw × [{mass fraction of (C) / 100} / molecular weight of (C) + {mass fraction of (CX) / 100} / molecular weight of (CX)]" is the total number (n C+CX ), more preferably 4.5 or more and 80 or less, and further preferably 4.5 or more and 78 or less.

[0064] Requirement (4) The complex viscosity η of copolymer (S1) or (S2) at a frequency of ω = 0.1 rad / s was obtained by linear viscoelasticity measurement (190 °C) using a rheometer. * (ω=0.1) (Pa·sec) and the complex viscosity η at frequency ω=100rad / s * (ω=100) (Pa·sec) and the ratio P〔η * (ω=0.1) / η * (ω=100) ], the intrinsic viscosity [η] of the copolymer, and the mass fraction of (C) preferably satisfy the following formula (iii): P / ([η] 2.9 ) ≦ (C) mass fraction × 6 … formula (iii) The P value was calculated by measuring the complex viscosity at 0.1 rad / s and the complex viscosity at 100 rad / s using a viscoelasticity measuring device, Ares (manufactured by Rheometric Scientific), at 190°C, 1.0% strain, and various frequencies. The P value was calculated by calculating the ratio (η * The intrinsic viscosity [η] of the copolymer is the value measured in decalin at 135°C.

[0065] Furthermore, it is more preferable that the copolymer (S1) or (S2) satisfies the following formula (iii-1). P / ([η] 2.9 ) ≦ Weight fraction of [A3] × 5.7 … Formula (iii-1) Here, the complex viscosity η at frequency ω=0.1 rad / s * (ω=0.1) and the complex viscosity η at frequency ω=100rad / 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 the formula (iii) or (iii-1), P / ([η] 2.9 ) tends to show high values ​​when there are many long chain branches, although it is affected by factors such as short chain branches and molecular weight.

[0066] Generally, in an ethylene-α-olefin-non-conjugated polyene copolymer, the more structural units derived from non-conjugated polyenes the copolymer contains, the more long-chain branches it tends to contain. However, it is believed that copolymer (A) can satisfy the above formula (iii) or (iii-1) because it has fewer long-chain branches than conventionally known ethylene-α-olefin-non-conjugated polyene copolymers.

[0067] Requirement (5) The number of long chain branches (LCB) per 1000 carbon atoms of copolymers (S1) and (S2) was determined using 3D-GPC. 1000C ) and the natural logarithm of the weight average molecular weight (Mw) (Ln(Mw)) preferably satisfy the following formula (iv): LCB 1000C ≦1-0.07×Ln(Mw) …Formula (iv)

[0068] The formula (iv) specifies the upper limit of the long-chain branch content per unit carbon number of the copolymer. That is, requirement (5) means that the copolymer has a low proportion of long-chain branches. When copolymer (S1) and copolymer (S2) each satisfy requirement (5), they exhibit excellent curing properties when crosslinked with hydrosilicone. Furthermore, crosslinked molded articles obtained using them exhibit excellent heat aging resistance. It is more preferable that the copolymer (S1) or (S2) satisfies the following formula (iv-1). LCB 1000C ≦1-0.071×Ln(Mw) …Formula (iv-1) In the formula (iv) and the formula (iv-1), Mw and LCB 1000Cis a value determined by a structural analysis method using 3D-GPC, specifically, by the method described in the Examples below.

[0069] It is also preferable that the copolymers (S1) and (S2) further satisfy the following requirement (6). Requirement (6): Complex viscosity η at a frequency of ω = 0.01 rad / s obtained by linear viscoelasticity measurement (190 °C) using a rheometer * (ω=0.01) (Pa·sec) and the complex viscosity η at frequency ω=10 rad / s * (ω=10) (Pa·sec) and the apparent iodine value derived from the non-conjugated polyene (C) satisfy the following formula (v). Log{η * (ω=0.01)} / Log{η * (ω=10)}≦0.0753×{apparent iodine value derived from non-conjugated polyene (C)}+1.42 …Equation (v)

[0070] Complex viscosity η * (ω=0.01) and complex viscosity η * (ω=10) is the complex viscosity η in requirement (4) * (ω=0.1) and complex viscosity η * (ω=100) and can be obtained in the same way except for the measurement frequency. The apparent iodine value derived from the non-conjugated polyene (C) can be calculated by the following formula: Apparent iodine value derived from (C) = mass fraction of (C) × 253.81 / molecular weight of (C)

[0071] In the formula (v), the left side represents the shear rate dependency, which is an index of the amount of long chain branches, and the right side represents an index of the content of non-conjugated polyene (C) that is not consumed as long chain branches during polymerization. When the formula (v) is satisfied, the degree of long chain branching is not too high, which is preferable. On the other hand, when the formula (v) is not satisfied, this indicates that a large proportion of the copolymerized non-conjugated polyene (C) is consumed in the formation of long chain branches.

[0072] The copolymer (S1) and the copolymer (S2) may each contain two or more types of copolymers. For example, two or more types of copolymers (S1) and / or copolymers (S2) may be contained. For example, two or more types of copolymers (S1) and / or copolymers (S2) having different molar ratios of ethylene / α-olefin having 3 to 20 carbon atoms, two or more types of copolymers (S1) and / or copolymers (S2) having different iodine values, or two or more types of copolymers (S1) and / or copolymers (S2) having different intrinsic viscosities [η] (in decalin at 135°C) may be mixed and used.

[0073] <Method for producing copolymers (S1) and (S2)> The method for producing the copolymers (S1) and (S2) is not particularly limited, and they can be obtained by various known production methods, for example, a conventionally known production method using a metallocene catalyst in which a metallocene compound is used as one component of the catalyst. Examples of metallocene catalysts and production methods using such catalysts include those described in WO 2015 / 122415, particularly paragraphs

[0249] to

[0320] of the publication.

[0074] <Hydrosilyl Group-Containing Compound (Y)> The hydrosilyl group-containing compound (Y), one of the components of the present composition, is represented by the following formula (a), and is an organohydrogenpolysiloxane having at least one silicon-bonded aralkyl group and at least two silicon-bonded hydrogen atoms in the molecule. The hydrosilyl group-containing compound (Y) may be contained alone or in combination with two or more different compounds.

[0075] [ka]

[0076] In formula (a), n and p are each independently 0 or a positive number, m is a number ranging from 1 to 20, and the sum of n, m, and p is 5 to 50. 1 and R 2 are each independently a monovalent alkyl group, and a plurality of R1 and R 2 may be the same or different. a is an aralkyl group, and R is R 1 , R 2 , hydrogen atoms, and R a and the two R's may be the same or different, provided that when n=1, at least one of R's is a hydrogen atom, and when n=0, both R's are hydrogen atoms.

[0077] The hydrosilyl group-containing compound (Y) is an organohydrogenpolysiloxane with a linear structure that has a relatively low degree of siloxane polymerization and has at least one silicon-bonded aralkyl group and at least two silicon-bonded hydrogen atoms in each molecule.

[0078] In formula (a), m is the number of diorganosiloxy units having silicon-bonded aralkyl groups, and is 1 to 20, preferably 2 to 10, more preferably 2 to 8, and even more preferably 3 to 6.

[0079] In formula (a), n is the number of organohydrogensiloxy units having silicon-bonded hydrogen atoms. n can be 0 or 1, but when n=1, at least one of the two Rs is a hydrogen atom, and when n=0, both Rs are hydrogen atoms. In other words, the organohydrogenpolysiloxane represented by formula (Y1) has a structure containing at least two silicon-bonded hydrogen atoms per molecule. Note that even if n is a number other than 0 or 1, one or both of the Rs at both ends of the molecular chain can be silicon-bonded hydrogen atoms.

[0080] n is preferably a number other than 0 or 1, and more preferably a number satisfying n≧m. n is preferably 3-10, more preferably 3-9, and even more preferably 5-9.

[0081] In formula (a), p is the number of diorganosiloxy units that do not contain aralkyl groups or silicon-bonded hydrogen atoms. p may be 0, or may be the number obtained by subtracting the values ​​of n and m from the total degree of polymerization of siloxy units, which is represented by the sum of n, m, and p, as described below. p is preferably 0 to 12, more preferably 0 to 10, even more preferably 0 to 5, and particularly preferably 0 to 2.

[0082] In the organohydrogenpolysiloxane represented by formula (a), the diorganosiloxy unit (-[O-Si(R 1 )(R 2 )]-), organohydrogensiloxy units having silicon-bonded hydrogen atoms (-[O-Si(R 1 )H]-), and diorganosiloxy units that do not contain aralkyl groups or silicon-bonded hydrogen atoms (-[O-Si(R 1 )(R 2 The siloxy units such as (a)-(a) may be arranged in a block form or randomly, i.e., the order of arrangement of the siloxy units in formula (a) is not particularly limited.

[0083] The hydrosilyl group-containing compound (Y) has a relatively low degree of siloxane polymerization. In formula (Y1), the sum of the values ​​of n, m, and p is 5 to 50, preferably 5 to 20, and more preferably 5 to 15. In formula (Y1), it is preferable that m is 3 to 6, n is 5 to 9, and p is 0 to 2.

[0084] In formula (a), R is R 1 , R 2 , hydrogen atoms, and R a However, when n=0 or 1, both or one of R is a hydrogen atom. R in the formula 1 and R 2 R are monovalent alkyl groups, which may be the same or different, and some of the carbon atom-bonded hydrogen atoms may be substituted with halogen atoms. 1 and R 2The number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 1 to 10, still more preferably 1 to 5, and particularly preferably 1 to 3. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group, with a methyl group being particularly preferred.

[0085] In formula (a), R a The number of carbon atoms in the aralkyl group in R is preferably 7 to 20, more preferably 7 to 15. Examples of the aralkyl group include a benzyl group, a phenylethyl group, a phenylpropyl group, and a phenylbutyl group. a As R, an aralkyl group containing at least one branching unit represented by -CH(CH3)- in the alkanediyl group between the aryl group such as a phenyl group and the silicon atom is preferred. a As the alkyl group, an aralkyl group represented by —CH2—CH(CH3)—C6H5 is particularly preferred.

[0086] The aralkyl group is a characteristic functional group that confers usefulness as a crosslinking agent to the hydrosilyl group-containing compound (Y). In particular, the presence of an aralkyl group together with a silicon-bonded hydrogen atom in the compound (Y) having n, m, and p within the above ranges tends to significantly improve the physical properties of the resulting crosslinked product. By applying the hydrosilyl group-containing compound (Y) to the copolymer component (S) and then crosslinking it, it is possible to obtain a molded product that is particularly excellent in physical properties such as scorch resistance, moldability, elongation at break, and compression set.

[0087] In the present composition, the amount of the hydrosilyl group-containing compound (Y) per 100 parts by mass of the total of the copolymer (S1) and the copolymer (S2) (100 parts by mass of the copolymer component (S)) is preferably 0.1 to 100 parts by mass, more preferably 2.0 to 30 parts by mass, even more preferably 2.5 to 20 parts by mass, and particularly preferably 3.0 to 10 parts by mass.

[0088] <Platinum catalyst> The platinum catalyst, one of the components of this composition, is an addition reaction catalyst, and any catalyst can be used without particular limitation, as long as it promotes the addition reaction (hydrosilylation reaction of an alkene) between the alkenyl group in the copolymer component (S) and the hydrosilyl group in the hydrosilyl group-containing compound (Y). Platinum catalysts for hydrosilylation crosslinking are widely used for the hydrosilylation crosslinking reaction, which involves the addition of silicon-bonded hydrogen atoms to carbon-carbon double bonds. The platinum catalyst may be contained alone or in combination of two or more.

[0089] Examples of platinum catalysts include platinum itself (platinum black), chloroplatinic acid, platinum-olefin complexes, platinum-alcohol complexes, and platinum supported on a carrier such as alumina or silica.

[0090] Examples of platinum-based catalysts include the fine powder metal platinum catalysts described in U.S. Pat. No. 2,970,150 and the like, the chloroplatinic acid catalysts described in U.S. Pat. No. 2,823,218 and the like, the complex compounds of platinum and hydrocarbons described in U.S. Pat. Nos. 3,159,601 and 159,662 and the like, the complex compounds of chloroplatinic acid and olefins described in U.S. Pat. No. 3,516,946 and the like, and the complex compounds of platinum and vinylsiloxanes described in U.S. Pat. Nos. 3,775,452 and 3,814,780 and the like.

[0091] Specific examples of platinum catalysts include platinum itself (platinum black); platinum complexes such as chloroplatinic acid, platinum-hydrocarbon complexes, platinum-vinylsiloxane complexes, platinum-alcohol complexes, chloroplatinic acid-olefin complexes, and chloroplatinic acid-vinylsiloxane complexes. Among these, platinum-vinylsiloxane complexes are preferred due to their high catalytic activity. Examples of platinum-vinylsiloxane complexes include 1,1,3,3-tetramethyl-1,3-divinyldisiloxane platinum complexes. The platinum-based catalyst may be supported on a carrier such as alumina or silica.

[0092] In this composition, the amount of platinum-based catalyst to be blended per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)) is preferably 0.00001 to 0.3 parts by mass, more preferably 0.0001 to 0.15 parts by mass, even more preferably 0.0005 to 0.09 parts by mass, and particularly preferably 0.001 to 0.03 parts by mass.

[0093] <Reaction inhibitor> The reaction inhibitor, one of the components of this composition, is a compound that has the function of suppressing the crosslinking reaction (hydrosilylation addition reaction to alkene) between the alkenyl group of the copolymer component (S) and the hydrosilyl group of the hydrosilyl group-containing compound (Y). The addition of a reaction inhibitor is preferable in that it stabilizes the processability of the composition during kneading and molding. The reaction inhibitor may be contained alone or in combination of two or more kinds.

[0094] Specific examples of the reaction inhibitor include benzotriazole; acetylene alcohols such as 1-hexyn-3-ol, 3-methyl-1-butyn-3-ol, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 1-ethynylcyclohexanol, and 3,5-dimethyl-1-hexyn-3-ol; acrylonitrile; amide compounds such as N,N-diallylacetamide, N,N-diallylbenzamide, N,N,N',N'-tetraallyl-o-phthalic acid diamide, N,N,N',N'-tetraallyl-m-phthalic acid diamide, and N,N,N',N'-tetraallyl-p-phthalic acid diamide; and others, sulfur, phosphorus, nitrogen, amine compounds, sulfur compounds, phosphorus compounds, tin, tin compounds, and tetramethyltetravinylcyclotetrasiloxane. Among these compounds, 3,5-dimethyl-1-hexyn-3-ol is particularly preferred.

[0095] In the present composition, the amount of the reaction inhibitor to be blended per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)) is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 5.0 parts by mass, even more preferably 0.05 to 3.0 parts by mass, and even more preferably 0.10 to 1.0 part by mass.

[0096] <Carbon black> Carbon black, one of the components of the present composition, is a type of known rubber reinforcing agent compounded in rubber compositions, and is an inorganic substance commonly referred to as carbon black. Carbon black functions as a reinforcing agent, and by including carbon black, the processability of the copolymer composition can be improved, and further, a copolymer composition having improved mechanical properties such as tensile strength, tear strength, and abrasion resistance can be obtained. The carbon black may be contained alone or in combination of two or more kinds.

[0097] Examples of the 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 those sold under the trade names "Asahi #55G," "Asahi #50HG," "Asahi #60G," "Asahi #60UG," and "Asahi #70" (manufactured by Asahi Carbon Co., Ltd.), and those sold under the trade names "Seast SVH," "Seast V," and "Seast G-SO" (manufactured by Tokai Carbon Co., Ltd.).

[0098] In this composition, the amount of carbon black to be blended per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)) is preferably 10 to 300 parts by mass, more preferably 30 to 200 parts by mass, even more preferably 60 to 150 parts by mass, and even more preferably 80 to 130 parts by mass. If the amount of carbon black to be blended is within the above range, a copolymer composition excellent in dynamic magnification (dynamic modulus / static modulus), processability, mechanical properties, etc. can be obtained.

[0099] <Polyolefin resin (F)> This composition contains a polyolefin resin (F) that is different from the copolymers (S1) and (S2). The polyolefin resin (F) is a resin or rubber other than the copolymers (S1) and (S2). The inclusion of the polyolefin resin (F) in this composition significantly improves the crosslinking rate. This is presumably because the improved fluidity of the composition facilitates physical association between the catalyst, crosslinking agent, and copolymer, and also because it allows for a reduction in the amount of added carbon black, which contains sulfur and is a catalyst poisoning substance. The polyolefin resin (F) may be contained alone or in combination of two or more.

[0100] Resins or rubbers other than copolymer (S1) and copolymer (S2) include general-purpose resins such as polyethylene, polypropylene, and polystyrene; and rubbers such as silicone rubber, ethylene-propylene random copolymer rubber (EPR), natural rubber, styrene-butadiene rubber, isoprene rubber, butadiene rubber, and chloroprene rubber.

[0101] In one embodiment, the polyolefin resin (F) preferably contains a resin or rubber having structural units derived from ethylene, and more preferably contains an ethylene-based (co)polymer having ethylene-derived structural units in an amount of more than 50 mol% of all structural units of the resin or rubber.

[0102] When the polyolefin resin (F) contains an ethylene (co)polymer, the content of structural units derived from ethylene is preferably 50 mol% or more, more preferably 60 mol% or more (however, the total of structural units derived from ethylene and structural units derived from α-olefins other than ethylene is 100 mol%). The upper limit of the content of structural units derived from ethylene is, for example, 100 mol%. When the content of structural units derived from ethylene is within the above range, a copolymer composition having excellent compatibility with the copolymer component (S) can be obtained.

[0103] The α-olefin copolymerized with ethylene is preferably an α-olefin having 3 to 20 carbon atoms, specifically propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc. Among them, propylene, 1-butene, 1-hexene, 1-octene, etc. are preferably used, and 1-butene is more preferably used. These α-olefins may be used alone or in combination of two or more.

[0104] In another embodiment, the polyolefin resin (F) preferably contains a crystalline olefin polymer. The crystalline olefin polymer is a crystalline homopolymer or copolymer of an α-olefin having 2 to 20 carbon atoms. In the present invention, a crystalline polymer is a polymer having a melting point.

[0105] Specific examples of the α-olefin constituting the crystalline olefin polymer include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 5-methyl-1-hexene. The crystalline olefin polymers may be used alone or in combination of two or more kinds.

[0106] Specific examples of crystalline olefin polymers include the following (co)polymers: In these (co)polymers, "mol %" refers to the proportion when the total of all monomers is 100 mol %. (1) Ethylene-based polymers such as ethylene homopolymers and copolymers of ethylene with 10 mol% or less of other α-olefins having 3 to 20 carbon atoms or vinyl monomers such as vinyl acetate and ethyl acrylate. More specifically, high-pressure low-density polyethylene (HP-LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene, high-density polyethylene (HDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer, etc. (2) Propylene-based polymers such as propylene homopolymers, random copolymers of propylene with 10 mol% or less of other α-olefins having 2 or 4 to 20 carbon atoms, and block copolymers of propylene with 30 mol% or less of other α-olefins. These propylene-based polymers are generally also called homo-, random-, or block-type polypropylenes. (3) 1-butene polymers such as homopolymers of 1-butene and random copolymers of 1-butene with 10 mol % or less of other α-olefins having 2 to 3 carbon atoms or 5 to 20 carbon atoms. (4) 4-methyl-1-pentene polymers such as homopolymers of 4-methyl-1-pentene and random copolymers of 4-methyl-1-pentene with 20 mol % or less of other α-olefins. Among the crystalline olefin polymers, the ethylene polymers (1) above are preferred, and linear low-density polyethylene (LLDPE) is particularly preferred.

[0107] The melting point of the polyolefin resin (F), measured in accordance with JIS K 7121, is preferably 120° C. or lower, more preferably 115° C. or lower, and even more preferably 112° C. or lower. The lower limit of the melting point is not particularly limited, but is usually 0° C. When the melting point of the polyolefin resin (F) is within the above range, unmelted polyolefin resin (F) is less likely to remain, and a molded article having a particularly small mold shrinkage rate and excellent abrasion resistance can be obtained. The melting point was measured using a differential scanning calorimeter (DSC) in accordance with JIS K 7121. Specifically, pellets of polyolefin resin (F) were heated at 230°C for 10 minutes, then cooled to 30°C at a rate of 10°C / min, held at that temperature for 1 minute, and then heated at a rate of 10°C / min. The temperature at which the maximum amount of heat absorption was measured in the DSC curve was taken as the melting point.

[0108] The MFR of the polyolefin resin (F) at 190°C and 2.16 kg, measured in accordance with ASTS D 1238, is preferably 0.1 to 50 g / 10 min, more preferably 0.2 to 30.0 g / 10 min, even more preferably 0.5 to 10 g / 10 min, and particularly preferably 1.0 to 5.0 g / 10 min. When the MFR is within the above range, a copolymer composition having a small mold shrinkage and excellent processability can be obtained.

[0109] The polyolefin resin (F) is preferably solid at a temperature of from room temperature to 100°C, preferably at a temperature of 90°C.

[0110] The density of the polyolefin resin (F) measured in accordance with ASTM D1505 is preferably 840 to 930 kg / m 3 and more preferably 850 to 930 kg / m 3 and more preferably 860 to 925 kg / m 3 Particularly preferably, it is 860 to 922 kg / m 3 When the density is within the above range, a molded article having a small molding shrinkage rate and excellent strength characteristics and abrasion resistance can be obtained.

[0111] In the present composition, the content of polyolefin resin (F) is preferably 1 to 50 parts by mass, more preferably 5 to 40 parts by mass, even more preferably 10 to 35 parts by mass, and particularly preferably 20 to 30 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)). Within this range, the hardness of a molded article formed from the composition can be adjusted, and the compound viscosity at processing temperatures can be reduced, thereby further improving processability. In addition, the composition can be handled as a thermoplastic elastomer, which broadens the range of handling and kneading techniques.

[0112] <Other ingredients> The composition may contain at least one other component selected from the group consisting of organic peroxides, crosslinking aids, antioxidants, antioxidants, vulcanization accelerators, vulcanization aids, reinforcing agents, softeners (plasticizers), processing aids, activators, moisture absorbers, fillers, foaming agents, foaming aids, heat stabilizers, weather stabilizers, antistatic agents, colorants, lubricants, thickeners, and tackifiers, depending on the purpose. Each additive may be used alone or in combination of two or more.

[0113] <Organic peroxide> The composition may contain an organic peroxide, which is a type of crosslinking agent. Specific 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)hexyne-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-butyl peroxybenzoate, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide.

[0114] The organic peroxide used is preferably one whose decomposition products produced during crosslinking are low molecular weight compounds with sufficiently high vapor pressure, as this makes it difficult for odors to remain in the resulting crosslinked molded article.

[0115] When the composition contains an organic peroxide, the amount of the organic peroxide is preferably 0.1 to 8 parts by mass, more preferably 0.2 to 7 parts by mass, and even more preferably 0.3 to 6 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)). When the amount of the organic peroxide is within the above range, there is no blooming on the surface of the obtained molded article, and the copolymer composition exhibits excellent crosslinking properties.

[0116] When the present composition contains an organic peroxide, the total amount of the hydrosilyl group-containing compound (Y) and the organic peroxide is preferably 0.2 to 108 parts by mass, more preferably 2.2 to 37 parts by mass, and even more preferably 2.8 to 26 parts by mass, per 100 parts by mass of the total of the copolymer (S1) and the copolymer (S2) (100 parts by mass of the copolymer component (S)).

[0117] When the present composition contains an organic peroxide, the mass ratio of the hydrosilyl group-containing compound (Y) to the organic peroxide [Y / organic peroxide] is preferably 23 / 77 to 99 / 1, more preferably 47 / 53 to 99 / 1.

[0118] <Crosslinking aid> When the composition contains an organic peroxide, 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 / zinc oxide type 2 (compliant with JIS K 1410) (manufactured by Hakusui Tech Co., Ltd.) and activated zinc oxide "META-Z102" (manufactured by Inoue Lime Industry Co., Ltd.)); and metal oxides such as magnesium oxide.

[0119] When the present composition contains an organic peroxide, the amount of the crosslinking aid added is usually 0.5 to 10 mol, preferably 0.5 to 7 mol, more preferably 1 to 6 mol, per 1 mol of the organic peroxide.

[0120] <Antioxidants> The composition may contain an antioxidant. A hindered phenol-based antioxidant is preferred as the antioxidant. By including a hindered phenol-based antioxidant, the composition can produce a crosslinked molded article with higher water absorption and excellent compression set.

[0121] Examples of hindered phenol-based antioxidants include 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)mesitylene (manufactured by ADEKA Corporation, trade name: Adekastab AO-330, melting point: 243 to 245°C), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione ( ADEKA CORPORATION, trade name: ADK STAB AO-20, melting point: 220-222°C), 4,4'-butylidenebis(6-tert-butyl-m-cresol) (ADEKA CORPORATION, trade name: ADK STAB AO-40, melting point: 210-214°C), N,N'-bis{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl}hydrazine (BASF, trade name: Irganox Examples of suitable hydroxytoluenes include methyl acrylate (MD1024, melting point: 224 to 229°C), pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (manufactured by BASF, trade name: Irganox1010, melting point: 110 to 130°C), dibutylhydroxytoluene, and 2,5-di-tert-butylhydroquinone (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name: Nocrac NS-7, melting point: 200°C or higher).

[0122] When the present composition contains an antioxidant, the amount of the antioxidant is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 10 parts by mass, still more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 8 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)).

[0123] <Anti-aging agent> The composition may contain an antioxidant. Examples of the antioxidant include conventionally known antioxidants, such as amine-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants. In order to maintain heat aging resistance for a long period of time at high temperatures, it is preferable to use two or more of these antioxidants in combination.

[0124] Specific examples include aromatic secondary amine-based antioxidants such as phenylbutylamine and N,N-di-2-naphthyl-p-phenylenediamine; thioether-based antioxidants such as bis[2-methyl-4-(3-n-alkylthiopropionyloxy)-5-tert-butylphenyl]sulfide; dithiocarbamate-based antioxidants such as nickel dibutyldithiocarbamate; and sulfur-based antioxidants such as 2-mercaptobenzoylimidazole, 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, dilaurylthiodipropionate, and distearylthiodipropionate.

[0125] When the composition contains an antioxidant, the amount of antioxidant is preferably 0.3 to 10 parts by mass, more preferably 0.5 to 7.0 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)). By adjusting the amount within this range, blooming on the surface of a crosslinked molded article obtained from the copolymer composition can be suppressed, and further, crosslinking inhibition can be suppressed.

[0126] <Reinforcing agent> The composition may contain a reinforcing agent to improve physical properties such as tensile stress at break and tensile elongation at break. The reinforcing agent is a known rubber reinforcing agent compounded in rubber compositions, and specific examples include silica, calcium carbonate, activated calcium carbonate, finely divided talc, and differential silicic acid. Among these, silica is preferred. The inclusion of silica improves the elongation of the copolymer composition, thereby improving its mold release properties.

[0127] Examples of silica include hydrophilic silica and hydrophobic silica. Hydrophilic silica refers to silica that does not have hydrophobic groups on its surface, and typically includes the well-known dry silica and wet silica typically used in the rubber industry. An example of a commercially available hydrophilic silica product is Nipsil ER (registered trademark) (manufactured by Tosoh Silica Corporation). Hydrophobic silica is silica particles whose surface has been treated with a hydrophobizing agent. Examples of hydrophobizing agents include organosilicon compounds such as methyltrichlorosilane, dimethyldichlorosilane, hexamethyldisilazane, hexamethylcyclotrisiloxane, and octamethylcyclotetrasiloxane. Examples of commercially available hydrophobic silica products include RX50, RX200, RX300, R8200, and NX90S from the AEROSIL series manufactured by Nippon Aerosil Co., Ltd.

[0128] When the present composition contains a reinforcing agent, the amount of the reinforcing agent to be blended is preferably 10 to 80 parts by mass, more preferably 15 to 60 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)).

[0129] <Softener (plasticizer)> The composition may also include an emollient. The softener may be any known softener that is compounded in rubber compositions.Specific examples include petroleum-based softeners such as process oil, lubricating oil, paraffin oil, liquid paraffin, petroleum asphalt, and Vaseline; coal tar-based softeners such as coal tar; fatty oil-based softeners such as castor oil, linseed oil, rapeseed oil, soybean oil, and coconut oil; waxes such as beeswax and carnauba wax; naphthenic acid, pine oil, rosin or its derivatives; synthetic polymers such as terpene resin, petroleum resin, and coumarone-indene resin; ester-based softeners such as dioctyl phthalate and dioctyl adipate; and other softeners such as microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, hydrocarbon-based synthetic lubricating oil, tall oil, and sub(factice).Among these, petroleum-based softeners are preferred, and process oil is particularly preferred.

[0130] When the composition contains a softener, the amount of the softener is preferably 5 to 150 parts by mass, more preferably 10 to 150 parts by mass, and particularly preferably 10 to 120 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)). When the amount of the softener is within the above range, a copolymer composition can be obtained that has little tack and is excellent in processability, heat aging resistance, mechanical properties, etc.

[0131] <Moisture absorbent> Examples of moisture absorbents include calcium oxide, silica gel, sodium sulfate, molecular sieves, zeolite, and white carbon.

[0132] When the composition contains a moisture absorbent, the amount of the moisture absorbent is preferably 0.5 to 15 parts by mass, more preferably 1.0 to 12 parts by mass, and even more preferably 1.0 to 10 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)).

[0133] <Filler> The composition may contain a filler to reduce formulation costs. Examples of fillers include light calcium carbonate, heavy calcium carbonate, talc, and clay. Of these, heavy calcium carbonate such as "Whiten SB" (product name, manufactured by Shiraishi Calcium Co., Ltd.) is preferred.

[0134] When the composition contains a filler, the amount of filler is preferably 1 to 500 parts by mass, more preferably 1 to 400 parts by mass, and even more preferably 1 to 300 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)). When the amount of filler is within the above range, the mechanical properties such as tensile strength, tear strength, and abrasion resistance of the resulting molded article can be improved.

[0135] <Processing aids> As the processing aid, for example, a wide range of processing aids that are generally compounded in rubber can be 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, etc. Of these, stearic acid is preferred.

[0136] When the composition contains a processing aid, the amount of the processing aid can be appropriately blended in an amount of preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)). When the amount of the processing aid is within the above range, the composition exhibits excellent processability, such as kneading processability, extrusion processability, and injection moldability.

[0137] <Activator> Examples of the surfactant include amines such as di-n-butylamine, dicyclohexylamine, and monoelanolamine; surfactants such as diethylene glycol, polyethylene glycol, lecithin, triaryl methylate, and zinc compounds of aliphatic or aromatic carboxylic acids; zinc peroxide preparations; octadecyltrimethylammonium bromide, synthetic hydrotalcite, and special quaternary ammonium compounds.

[0138] When the present composition contains an activator, the amount of the activator to be blended is preferably 0.2 to 15 parts by mass, more preferably 0.3 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)).

[0139] <Foaming agent> The gasket or packing formed using the present composition may be a non-foamed or foamed product. When the gasket or packing is a foamed product, the present composition preferably contains a foaming agent.

[0140] Examples of blowing agents include physical blowing agents such as carbon dioxide, nitrogen, air, and water; inorganic blowing agents such as sodium bicarbonate (baking soda), sodium carbonate, ammonium bicarbonate, ammonium carbonate, and ammonium nitrite; nitroso compounds such as N,N'-dimethyl-N,N'-dinitrosoterephthalamide and N,N'-dinitrosopentamethylenetetramine (DPT); azodicarbonamide (ADCA), azobisisobutyronitrile, azocyclohexylnitrile, and azodiaminobenzene. Examples of suitable foaming agents include azo compounds such as benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, p,p'-oxybis(benzenesulfonyl hydrazide), diphenylsulfone-3,3'-disulfonyl hydrazide, and 4,4'-oxybisbenzenesulfonyl hydrazide (OBSH); and azide compounds such as calcium azide, 4,4-diphenyldisulfonyl azide, and p-toluenesulfonyl azide. Among these, inorganic foaming agents are preferred, and sodium bicarbonate is more preferred, as they can lower the specific gravity and increase the crosslink density of foamed molded articles.

[0141] When the composition contains a foaming agent, the amount of foaming agent is appropriately selected depending on the performance required of the gasket or packing produced from the composition, but is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 10 parts by mass, even more preferably 0.1 to 10 parts by mass, and particularly preferably 0.2 to 10 parts by mass, per 100 parts by mass of the total of copolymer (S1) and copolymer (S2) (100 parts by mass of copolymer component (S)).

[0142] <Foaming aid> If necessary, a foaming aid may be used in combination with the foaming agent. The addition of the foaming aid is effective in adjusting the decomposition temperature of the foaming agent and uniforming the bubbles. Specific examples of the foaming aid include organic acids such as salicylic acid, phthalic acid, stearic acid, and oxalic acid, as well as urea and its derivatives.

[0143] When the present composition contains a foaming aid, the amount of the foaming aid is usually 1 to 100 parts by mass, preferably 2 to 80 parts by mass, per 100 parts by mass of the foaming agent.

[0144] <Method of manufacturing the present composition> The composition can be prepared in the same manner as in the preparation of known general rubber compositions. Specifically, the method is as follows. For example, it is also preferable to masticate or knead (first kneading) the copolymer (S1), the copolymer (S2), the hydrosilyl group-containing compound (Y), and, if necessary, other components, and then add the platinum catalyst, the reaction inhibitor, and, if necessary, other components to the resulting masticated or kneaded product, and then masticate or knead (second kneading).When an organic peroxide is used, it is preferably added during the second kneading. Specifically, copolymer (S1), copolymer (S2), hydrosilyl group-containing compound (Y), and other components, if necessary, are masticated or kneaded (first kneading) at 130 to 170°C for 1 to 10 minutes, preferably at 130 to 150°C for 3 to 8 minutes, and then a platinum catalyst and a reaction inhibitor, as well as other components, are added to the resulting masticated or kneaded product, followed by mastication or kneading (second kneading) at 30 to 80°C for 1 to 10 minutes, preferably at 50 to 80°C for 3 to 7 minutes, and then fractionation. In this way, a copolymer composition in the form of a ribbon or sheet is usually obtained.

[0145] When adding a reinforcing agent, softener, etc., they may be added during either the first kneading or the second kneading, but are preferably added during the first kneading. When adding other components such as a moisture absorbent, antioxidant, filler, processing aid, activator, plasticizer, thickener, tackifier, etc., they are preferably added during the first kneading, and crosslinking aids, crosslinking accelerators, and foaming agents are preferably added during the second kneading.

[0146] The kneading device used in the first kneading may be any known kneading device capable of high-temperature processing, such as a Banbury mixer, a kneader, or an extruder. Examples of the kneading device used in the second kneading include a roll, a kneader, and an extruder, which are easy to control the temperature of.

[0147] By dividing the kneading of each component into the first kneading and the second kneading, the kneading time can be shortened compared to when all components are kneaded without being divided. In addition, since the progress of crosslinking during the first kneading can be suppressed, the temperature during the first kneading can be increased, and moisture can be removed in a shorter time.

[0148] <Uses of this composition> The composition is suitable for use in sealing rubber moldings such as gaskets and packings. By using this composition, it is possible to obtain gaskets and packings that have a high crosslinking rate, excellent productivity, and excellent processability, and that have excellent physical properties in the crosslinked molded articles obtained, compared to when conventional rubber compositions are used. The gaskets and packings of the present invention are formed from the above-mentioned present composition.

[0149] Examples of gaskets include fuel cell gaskets, automotive gaskets, industrial gaskets, and construction gaskets, and the gaskets are preferably used as fuel cell gaskets.

[0150] [gasket] A method for producing a gasket from the present composition includes, for example, molding the present composition into the desired gasket shape and crosslinking the present composition simultaneously with or after molding.

[0151] Examples of the crosslinking method include a method in which the present composition is crosslinked by heating it, and a method in which the present composition is crosslinked by irradiating it with an electron beam.

[0152] Specifically, the gasket of the present invention can be produced by molding the composition into the intended shape using a molding machine such as an extrusion molding machine, a calendar roll, a press, an injection molding machine, or a transfer molding machine, and crosslinking the composition by heating at 120 to 270°C for 1 to 30 minutes during molding or by introducing the molded product into a vulcanization tank, or by irradiating it with an electron beam.

[0153] Crosslinking may be carried out using a mold or without a mold. When a mold is not used, the molding and crosslinking steps are usually carried out continuously. Heating methods that can be used in the vulcanization tank include hot air, a glass bead fluidized bed, UHF (ultra-high frequency electromagnetic waves), and steam.

[0154] When an electron beam is used as the crosslinking method without using a crosslinking agent, the composition formed into a predetermined shape is 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.

[0155] The gasket of the present invention can be preferably used as a fuel cell gasket used in a hydrogen line. At a hydrogen station that supplies hydrogen to fuel cell vehicles (FCVs) and the like, there are many hydrogen lines through which hydrogen passes.

[0156] [rubber seal] A method for producing a packing from the present composition of the present invention includes, for example, molding the present composition into a desired seal packing shape and crosslinking the composition simultaneously with or after molding.

[0157] Examples of the crosslinking method include a method in which a composition containing a crosslinking agent is used as the present composition and crosslinked by heating, and a method in which the present composition is crosslinked by irradiating it with an electron beam.

[0158] That is, the packing of the present invention can be prepared by molding the present composition into an intended shape using a molding machine such as an extruder, a calendar roll, a press, an injection molding machine, or a transfer molding machine, and crosslinking the composition by heating at 120 to 270°C for 1 to 30 minutes during molding or by introducing the molded product into a vulcanization tank, or by irradiating it with an electron beam.

[0159] Crosslinking may be carried out using a mold or without a mold. When a mold is not used, the molding and crosslinking steps are usually carried out continuously. Heating methods that can be used in the vulcanization tank include hot air, a glass bead fluidized bed, UHF (ultra-high frequency electromagnetic waves), and steam.

[0160] When an electron beam is used as the crosslinking method without using a crosslinking agent, the composition formed into a predetermined shape is 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.

[0161] The packing of the present invention can be suitably used as a packing part for automobiles, a sealing part for machines, a packing part for electronic and electric parts, a construction gasket, and a packing part for civil engineering and building materials.

[0162] Specific examples of the packing of the present invention include a cup for a brake master cylinder in a hydraulic brake, a cup for a brake wheel cylinder, a seal packing for controlling brake fluid pressure, and an O-ring for a brake, a cup for a clutch cylinder in a clutch, a condenser packing, and a hydrogen seal packing.

[0163] [Molded body] The molded article of the present invention is formed from copolymer component (S), crosslinked copolymer component (S), or a composition containing copolymer component (S). The obtained molded article (e.g., crosslinked molded article, crosslinked foam, etc.) has excellent physical properties, and the composition has a fast crosslinking rate, excellent productivity, and excellent processability, and can be used for a variety of applications.

[0164] Specific applications of the molded article of the present invention include tire rubber, O-rings, industrial rolls, packing (e.g., condenser packing), gaskets, belts (e.g., heat insulation belts, copier belts), hoses (e.g., water hoses, brake reservoir hoses, radiator hoses), waterproof rubber, sponges (e.g., weatherstrip sponges, heat insulation sponges, protect sponges, micro-foam sponges), cables (ignition cables, cab tire cables, high tension cables), electric wire coating materials (high voltage wire coating materials, low voltage electric wire coating materials, marine electric wire coating materials), glass run channels, color skin materials, paper feed rolls, roofing sheets, all-solid-state batteries, etc.

[0165] The molded article of the present invention can be produced, for example, by preforming the copolymer component (S) or the present composition (uncrosslinked composition) into a desired shape by molding using various molding machines such as an extruder, a calendar roll, a press molding machine, an injection molding machine, or a transfer molding machine, and then, simultaneously with molding, introducing the molded article into a crosslinking tank and heating it to crosslink it. When the copolymer composition of the present invention contains a foaming agent, foaming proceeds simultaneously with crosslinking, resulting in a foamed crosslinked molded article (foamed molded article).

[0166] Any known heating method can be used without limitation, but it is particularly preferred to heat at a temperature of 150 to 200°C for 1 to 30 minutes using a heating bath such as a far-infrared heating furnace, hot air, a glass bead fluidized bed, UHF (ultra-high frequency electromagnetic waves), steam, or LCM (molten salt bath). Molding and crosslinking may or may not require the use of a mold. When a mold is not used, the rubber composition is usually molded and crosslinked continuously.

[0167] It is also preferable to press-mold the composition to perform primary crosslinking, remove the composition from the mold to obtain a primary molded article, and then subject the resulting primary molded article to secondary crosslinking in a heat medium. Specifically, the composition is press-molded at 120 to 200°C for 1 to 20 minutes, preferably 150 to 200°C for 10 to 18 minutes, to perform primary crosslinking, and then remove the composition from the mold to obtain a primary molded article. The resulting primary molded article is then subjected to secondary crosslinking in a heat medium at 120 to 160°C for 10 to 24 hours, preferably 140 to 160°C for 15 to 20 minutes. Examples of heat mediums used for secondary crosslinking include air, steam, paraffin-based process oil, and molten salt.

[0168] When primary crosslinking is performed by press molding, the crosslinked body does not become hot due to shear heating. This makes it possible to suppress the generation of low molecular weight siloxanes and polymer degradation. Furthermore, when press molding is performed in a sealed state, a certain amount of low molecular weight siloxanes are generated and remain inside the crosslinked body. However, by subsequently performing secondary crosslinking in a heat medium, the low molecular weight siloxanes are volatilized, making it possible to obtain a crosslinked body with a low amount of low molecular weight siloxanes. [Example]

[0169] 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" means "parts by mass."

[0170] The physical properties of each copolymer used in the examples and comparative examples were measured as follows. (1) Mass fraction (mass%) and mole number (mol%) of constituent units The mass fraction (mass%) of each structural unit in the copolymer and the number of moles (mol%) of each structural unit are: 13 The measurements were obtained by C-NMR using an ECX400P nuclear magnetic resonance spectrometer (manufactured by JEOL Ltd.), with a measurement temperature of 120°C, a measurement solvent of orthodichlorobenzene / deuterated benzene = 4 / 1, and an accumulation number of 8000. 13 The C-NMR spectrum was obtained.

[0171] (2) Number of long chain branches (LCB) 1000C Copolymer long chain branching number LCB 1000C was calculated by structural analysis from the absolute molecular weight distribution and intrinsic viscosity obtained using 3D-GPC (3D-high temperature GPC apparatus PL-GPC220, Polymer Laboratories). The main measurement conditions are as follows. The dn / dc value (the differential value of refractive index n with respect to concentration c) required to determine the absolute molecular weight was calculated for each sample from the dn / dc value of standard polystyrene (molecular weight 190,000) of 0.053 and the response intensity of the differential refractometer per unit injected mass. Detector: Differential refractometer / GPC device built-in 2-angle light scattering photometer PD2040 type (manufactured by Precison Detectors) Bridge-type viscometer PL-BV400 (Polymer Laboratories) Column: TSKgel GMH HR -H(S)HT x 2 + TSKgel GMH HR -M(S) x 1 (inner diameter 7.8mmφ x length 300mm, 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: Filtration through a sintered filter with a pore size of 1.0 μm

[0172] The long chain branching parameter g'i for each eluted component was calculated from the relationship between the intrinsic viscosity obtained from the viscometer and the absolute molecular weight obtained from the light scattering photometer using the following formula (v-1).

[0173]

number

[0174] where [η]=KM vThe relational equation of v = 0.725 was applied. This equation is called the Mark-Houwink-Sakurada equation, where K is the solvent constant and M is the average molecular weight. Further, the average values ​​of g' were calculated from the following formulas (v-2), (v-3), and (v-4): A trendline assuming only short chain branches was determined for each sample.

[0175]

number

[0176] Furthermore, using g'w, the number of branch points per molecular chain, BrNo, and the number of long chain branches per 1000 carbon atoms, LCB, are calculated. 1000C The branching degree λ per unit molecular weight was calculated. BrNo was calculated using the following Zimm-Stockmayer formula (v-5): 1000C The following formulas (v-6) and (v-7) were used to calculate λ. Here, g is the long chain branching parameter calculated from the radius of gyration Rg, and the following simple correlation is established between g' calculated from the intrinsic viscosity: g=g' (1 / ε) (ε(structure factor)=0.5~1.5) Various values ​​have been proposed for ε in the formula depending on the shape of the molecule. Here, the calculation was performed assuming ε = 1 (i.e., g' = g).

[0177]

number

[0178] (3) Intrinsic viscosity [η] The intrinsic viscosity [η] (dl / g) of the copolymer was measured using a fully automatic intrinsic viscometer manufactured by Rigo Co., Ltd. at a temperature of 135° C. and in decalin as a measurement solvent.

[0179] (4) Weight average molecular weight (Mw) The weight average molecular weight (Mw) of the copolymer was determined using 3D-GPC (3D-high temperature GPC apparatus PL-GPC220, manufactured by Polymer Laboratories) under the same measurement conditions as in (2) above.

[0180] (5) Mooney viscosity ML(1+4) 100℃ The Mooney viscosity ML(1+4)100°C of the copolymer was measured at 100°C using a Mooney viscometer (SMB-301RT model manufactured by Shimadzu Corporation) in accordance with JIS K 6300-1:2013.

[0181] (6) Mooney viscosity ML (1+4) 125℃ The Mooney viscosity ML(1+4)125°C of the copolymer was measured at 125°C using a Mooney viscometer (SMB-301RT model manufactured by Shimadzu Corporation) in accordance with JIS K 6300-1:2013.

[0182] (7) Complex viscosity η * and P value The rheometer used was a viscoelasticity measuring device, Ares (manufactured by Rheometric Scientific), and the complex viscosity η was measured at a frequency of ω = 0.01 rad / s under the conditions of 190°C and 1.0% strain. * (ω=0.01) , complex viscosity η at frequency ω=0.1rad / s * (ω=0.1) , complex viscosity η at frequency ω=10 rad / s * (ω=10) and the complex viscosity η at frequency ω = 100 rad / s * (ω=100) (All units are Pa·sec)

[0183] In addition, from the obtained results, η * (ω=0.1) and η * (ω=100) The P value (η * (ω=0.1) / η * (ω=100)) was calculated.

[0184] [Copolymer component (S)] In the following examples and comparative examples, copolymers (S1-1) and (S2-1) obtained in the following Production Examples 1 and 2 were used as the copolymer component (S).

[0185] [Manufacturing Example 1] A 300-L polymerization reactor equipped with a stirring blade was continuously fed with 58.3 L / hr of dehydrated and purified hexane solvent through line 1, and 4.5 mmol / hr of triisobutylaluminum (TiBA), 0.150 mmol / hr of (C6H5)3CB(C6F5)4, and 0.030 mmol / hr of di(p-tolyl)methylene(cyclopentadienyl)(octamethyloctahydrodibenzofluorenyl)zirconium dichloride through line 2. Simultaneously, 6.6 kg / hr of ethylene, 9.3 kg / hr of propylene, 18 L / hr of hydrogen, and 340 g / hr of VNB were continuously fed into the polymerization reactor through separate lines, and copolymerization was carried out under the conditions of a polymerization temperature of 87°C, a total pressure of 1.6 MPaG, and a residence time of 1.0 hour. In this way, a solution containing 20% ​​by mass of ethylene-propylene-VNB copolymer formed from ethylene, propylene, and VNB was obtained. A small amount of methanol was added to the polymerization reaction mixture withdrawn from the bottom of the polymerization reactor to terminate the polymerization reaction. The ethylene-propylene-VNB copolymer was separated from the solvent by steam stripping and then dried under reduced pressure at 80°C overnight. By the above procedure, ethylene-propylene-VNB copolymer (S1-1) was obtained. The physical properties of the obtained copolymer (S1-1) were measured by the methods described above. The results are shown in Table 1.

[0186] [Manufacturing Example 2] A 300-L polymerization reactor equipped with a stirring blade was continuously fed with 25.4 L / hr of dehydrated and purified hexane solvent through line 1, and 12 mmol / hr of triisobutylaluminum (TiBA), 0.120 mmol / hr of (C6H5)3CB(C6F5)4, and 0.060 mmol / hr of di(p-tolyl)methylene(cyclopentadienyl)(octamethyloctahydrodibenzofluorenyl)zirconium dichloride through line 2. Simultaneously, 4.7 kg / hr of ethylene, 4.2 kg / hr of propylene, 220 L / hr of hydrogen, and 240 g / hr of VNB were continuously fed into the polymerization reactor through separate lines, and copolymerization was carried out under the conditions of a polymerization temperature of 110°C, a total pressure of 1.6 MPaG, and a residence time of 1.0 hour. In this way, a solution containing 20% ​​by mass of ethylene-propylene-VNB copolymer formed from ethylene, propylene, and VNB was obtained. A small amount of methanol was added to the polymerization reaction mixture withdrawn from the bottom of the polymerization reactor to terminate the polymerization reaction. The ethylene-propylene-VNB copolymer was separated from the solvent by steam stripping and then dried under reduced pressure at 80°C overnight. By the above procedure, ethylene-propylene-VNB copolymer (S2-1) was obtained. The physical properties of the obtained copolymer (S2-1) were measured by the methods described above. The results are shown in Table 1.

[0187] [Table 1]

[0188] [Hydrosilyl group-containing compound (Y)] In the following examples and comparative examples, the compound (Y-1) obtained in the following Production Example 3 was used as the hydrosilyl group-containing compound (Y).

[0189] [Manufacturing Example 3] A reactor was charged with 536 g of methylhydrogenpolysiloxane represented by the following formula (a-1-1) and heated to 40°C while stirring under a nitrogen flow. 0.4 g of a toluene solution of platinum-1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane complex (Pt concentration 0.3 wt%) was added, and 265 g of α-methylstyrene was added dropwise while maintaining the reaction temperature at 40 to 90°C.

[0190] [ka]

[0191] After the dropwise addition was completed, stirring was continued for 2 hours at 85°C, and then 0.5 g of the reaction solution was sampled, and the reaction rate of the Si-H group was confirmed to be approximately 36% by an alkali decomposition gas generation method (the remaining Si-H group was decomposed with an ethanol / aqueous solution of KOH, and the reaction rate of the Si-H group was calculated from the volume of the generated hydrogen gas). The reaction solution was then heated to 135°C under reduced pressure for 2 hours to distill off low boiling points, yielding 673 g of crosslinking agent (Y-1), a hydrosilyl group-containing compound. The resulting crosslinking agent (Y-1) was 29 The resulting crosslinking agent (Y-1) was confirmed to be a compound represented by the following formula (a-1) by Si-NMR. The viscosity of the resulting crosslinking agent (Y-1) was measured at 25°C using an Ubbelohde viscometer according to JIS Z 8803. 2 / s.

[0192] [ka]

[0193] In the following examples and comparative examples, the raw materials other than the copolymer component (S) and the hydrosilyl group-containing compound (Y) are as follows. Carbon black: Asahi #60UG, manufactured by Asahi Carbon Co., Ltd. Reaction inhibitor: ETCH (1-ethynyl-1-cyclohexanol), manufactured by Nissin Chemical Industry Co., Ltd. Platinum catalyst: SRX212 Catalyst manufactured by Dow Toray Industries, Inc. (a catalyst solution containing 1% by mass or more and less than 3% by mass of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane platinum complex). Polyolefin resin (F-1): ENEOS NUC Corporation, DND2450 (high-pressure low-density polyethylene, MFR = 1.30, density = 920 kg / m 3 , melting point (according to JIS K 7121) = 111°C). Polyolefin resin (F-2): Mitsui Chemicals, Inc., Toughmer DF640 (ethylene-1-butene copolymer, MFR = 3.6, density = 864 kg / m 3 , melting point (according to JIS K 7121) = less than 50°C). Filler: Whiten SB (heavy calcium carbonate) manufactured by Shiraishi Calcium Co., Ltd. Softener: Idemitsu Kosan Co., Ltd., Diana (registered trademark) Process PW-380 (paraffin-based process oil).

[0194] [Example 1] <<Preparation of Copolymer Composition>> In the first stage, the raw materials shown in Raw Material 1 in Table 2 were mixed at 140°C for 2 minutes using a BB-L1800 Banbury mixer (manufactured by Kobe Steel, Ltd.). After that, the ram was raised and cleaned, and the mixture was mixed for another minute and then discharged at approximately 150°C to obtain the first stage compound. Next, in the second step, the compound obtained in the first step was wound around an 8-inch roll (manufactured by Nippon Roll Co., Ltd.; front roll surface temperature 50°C, rear roll surface temperature 50°C, front roll rotation speed 16 rpm, rear roll rotation speed 18 rpm), and the raw material shown in raw material 2 in Table 2 was added thereto and kneaded for 10 minutes to obtain an uncrosslinked copolymer composition.

[0195] <Evaluation of uncrosslinked rubber properties> [Mooney viscosity ML(1+4) 125℃] The Mooney viscosity ML(1+4)125°C of the uncrosslinked copolymer composition was measured at 125°C using a Mooney viscometer (SMB-301RT model manufactured by Shimadzu Corporation) in accordance with JIS K 6300-1:2013. When the Mooney viscosity ML(1+4)125°C of the uncrosslinked rubber copolymer composition is 30 or less, it can be said that the processability is excellent.

[0196] <Crosslinking (vulcanization) speed evaluation> The following values ​​were determined from the crosslinking curves measured using an uncrosslinked copolymer composition after heating at 125°C for 60 minutes or at 180°C for 10 minutes in accordance with JIS K 6300-2:2001. MDR2000 (manufactured by ALPHA TECHNOLOGIES) was used for the measurements. · S'Max (dNm): Maximum torque. · S'Min(dNm): Minimum torque value. · S'Max-Min (dNm): The difference between S'Max and S'Min. ·TS1(min): The time it takes for the torque value to increase by 1dNm from S'Min, based on the start of measurement. tC90 (min): The time it takes for the torque value of the measured sample to reach 90%, with the minimum torque value S'Min being 0% and the maximum torque value S'Max being 100%. The smaller the tC90, the faster the vulcanization rate (crosslinking rate).

[0197] <Evaluation of physical properties of vulcanized (crosslinked) products> The uncrosslinked copolymer composition was crosslinked for 10 minutes at 180° C. using a press molding machine to prepare a sheet (vulcanized product (crosslinked product)) having a thickness of 2 mm. The obtained sheet was subjected to a hardness test and a tensile test by the following methods, and the results are shown in Table 2.

[0198] [Hardness test: Hardness (Durometer-A; HA)] The uncrosslinked copolymer composition was press-molded in a mold at 180°C for 10 minutes using a press molding machine to obtain a 2 mm-thick crosslinked sheet-shaped molded product. Six flat portions of the resulting crosslinked sheet-shaped molded product were stacked to form a test piece approximately 12 mm thick, and the hardness (Durometer-A, HA) was measured in accordance with JIS K 6253-3:2012. However, test pieces containing foreign matter, bubbles, or scratches were not used. The dimensions of the test piece's measurement surface were such that measurements could be made with the tip of the indenter at least 12 mm away from the edge of the test piece. The results are shown in Table 2.

[0199] [Tensile test: tensile stress at break, tensile elongation at break] The uncrosslinked copolymer composition was press-molded in a mold at 180°C for 10 minutes using a press molding machine to obtain a 2mm-thick crosslinked sheet-shaped molded product. The resulting crosslinked sheet-shaped molded product was punched out to prepare a dumbbell-shaped No. 3 test piece described in JIS K 6251:2023. Using this test piece, a tensile test was performed according to the method specified in JIS K 6251 at a measurement temperature of 25°C and a tensile speed of 500mm / min to measure the tensile stress at break (TB) and tensile elongation at break (EB). The results are shown in Table 2.

[0200] Separately, an uncrosslinked copolymer composition was vulcanized at 180°C for 15 minutes using a press molding machine equipped with a cylindrical mold to prepare a right cylindrical test piece having a thickness of 12.7 mm and a diameter of 29 mm, thereby obtaining a test piece (vulcanizate) for a compression set (CS) test. The compression set (CS) test specimens thus obtained were used to evaluate the compression set according to the following method. The results are shown in Table 2.

[0201] [Compression set (CS) test: Compression set] For the test pieces for compression set (CS) measurement, the compression set was measured after heat treatment at 100°C for 22 hours according to JIS K 6262:2013. Specifically, the test pieces were compressed by 25% from their height (12.7 mm) before applying the load, and then placed in a gear oven at 100°C together with the spacer and heat-treated for 22 hours. The test pieces were then removed and left at room temperature for 30 minutes, after which the height of the test pieces was measured and the compression set (%) was calculated using the following formula: Compression set (CS;%) = {(t0-t1) / (t0-t2)} x 100 t0: Height of the specimen before the test. t1: Height after the test piece is heat-treated under the above conditions and then left at room temperature for 30 minutes. t2: Height of the test specimen when attached to the measuring mold.

[0202] [Example 2, Comparative Examples 1 and 2] The same procedure as in Example 1 was carried out, except that raw materials 1 and 2 in Table 2 used in Example 1 were changed to the types and amounts shown in Table 2. The results are shown in Table 2.

[0203] [Table 2]

[0204] As shown in Table 2, in Examples 1 and 2, which used a copolymer (S1-1) having an intrinsic viscosity [η] (in decalin at 135°C) of 2.0 dL / g or more, a copolymer (S2-1) having an intrinsic viscosity [η] of less than 2.0 dL / g, and a polyolefin resin additive, crosslinking proceeded at a faster rate than in Comparative Examples 1 and 2. Furthermore, the Mooney viscosity (ML(1+4)125°C) of the uncrosslinked copolymer compositions of Examples 1 and 2 was sufficiently low, and the crosslinked molded articles obtained from these copolymer compositions had a large tensile stress at break, sufficient rigidity, and a small compression set, demonstrating that the copolymer compositions of Examples 1 and 2 maintained good processability while possessing excellent mechanical properties as crosslinked molded articles.

Claims

1. Copolymer (S1), Copolymer (S2), a hydrosilyl group-containing compound (Y) which is an organohydrogenpolysiloxane represented by the following formula (a) and which has at least one silicon-bonded aralkyl group and at least two silicon-bonded hydrogen atoms in the molecule; A platinum-based catalyst; A reaction inhibitor; Carbon black and a polyolefin resin (F) (however, different from the copolymer (S1) and the copolymer (S2)); Including, Both the copolymer (S1) and the copolymer (S2) have a structural unit derived from ethylene (A), a structural unit derived from an α-olefin (B) having 3 to 20 carbon atoms, and a structural unit derived from a non-conjugated polyene (C) containing, in one molecule, two or more partial structures in total, each of which is at least one type of partial structure selected from the group consisting of the following formula (I) and the following formula (II): The copolymer (S1) has an intrinsic viscosity [η] (in decalin at 135°C) of 2.0 dL / g or more and less than 4.0 dL / g, The copolymer composition, wherein the copolymer (S2) has an intrinsic viscosity [η] (in decalin at 135°C) of 0.5 dL / g or more and less than 2.0 dL / g. 【Chemistry 1】 (In formula (a), n and p are each independently 0 or a positive number, m is a number ranging from 1 to 20, and the sum of n, m, and p is 5 to 50. １ and R ２ are each independently a monovalent alkyl group, and a plurality of R １ and R ２ may be the same or different. ａ is an aralkyl group, and R is R １ , R ２ , a hydrogen atom, and R ａ and the two R's may be the same or different. However, when n=1, at least one of R's is a hydrogen atom, and when n=0, both R's are hydrogen atoms.

2. 2. The copolymer composition according to claim 1, wherein the content of the polyolefin resin (F) is 1 to 50 parts by mass when the total mass of the copolymers (S1) and (S2) is 100 parts by mass.

3. The copolymer composition according to claim 1, wherein the polyolefin resin (F) has a melting point of 120°C or lower, as measured in accordance with the measurement method of JIS K 7121.

4. The copolymer composition according to claim 1 , wherein the polyolefin resin (F) comprises a resin or rubber having structural units derived from ethylene.

5. The copolymer composition according to claim 1 , wherein the polyolefin resin (F) comprises a crystalline olefin polymer.

6. 2. The copolymer composition according to claim 1, wherein the mass fraction of the copolymer (S1) relative to the total mass of the copolymers (S1) and (S2) is more than 50 mass% and less than 100 mass%.

7. 2. The copolymer composition according to claim 1, wherein the carbon black is contained in an amount of 10 to 300 parts by mass when the total mass of the copolymers (S1) and (S2) is 100 parts by mass.

8. 2. The copolymer composition according to claim 1, wherein the copolymer composition comprises 0.1 to 100 parts by mass of the hydrosilyl group-containing compound (Y) and 0.00001 to 0.3 parts by mass of the platinum-based catalyst, relative to 100 parts by mass of the total mass of the copolymers (S1) and (S2).

9. 9. The copolymer composition according to claim 8, wherein the reaction inhibitor is contained in an amount of 0.001 to 10 parts by mass when the total mass of the copolymers (S1) and (S2) is 100 parts by mass.

10. The copolymer composition according to claim 1, wherein the copolymer (S1) and the copolymer (S2) both satisfy the following requirements (1) and (2): Requirement (1): The ratio [A] / [B] of the number of moles of structural units derived from ethylene (A) to the number of moles [B] of structural units derived from an α-olefin having 3 to 20 carbon atoms is 40 / 60 to 90 / 10; Requirement (2): The mass fraction (mass %) of the structural units derived from the non-conjugated polyene (C) is 0.07 to 10 mass % based on the total mass of all structural units constituting the copolymer.

11. The copolymer composition according to claim 1, wherein the copolymer (S1) and the copolymer (S2) both satisfy at least one of the following requirements (3) to (5): Requirement (3): The weight average molecular weight (Mw), the mass fraction of the constituent unit derived from the non-conjugated polyene (C) (mass fraction (mass%) of (C)), and the molecular weight of the non-conjugated polyene (C) (molecular weight of (C)) satisfy the following formula (ii): 4.5≦Mw×mass fraction of (C) / 100 / molecular weight of (C)≦80...Formula (ii) Requirement (4): Complex viscosity η at a frequency ω = 0.1 rad / s obtained by linear viscoelasticity measurement (190 ° C) using a rheometer * (ω=0.1) (Pa sec) and the complex viscosity η at a frequency ω = 100 rad / s * (ω=100) (Pa sec) and the ratio P [η * (ω=0.1) / η * (ω=100) ], the intrinsic viscosity [η] of the copolymer (A), and the mass fraction of the copolymer (C) satisfy the following formula (iii): P / ([η] 2.9 )≦weight fraction of (C)×6 ... formula (iii) Requirement (5): The number of long chain branches (LCB) per 1,000 carbon atoms obtained using 3D-GPC １０００Ｃ ) and the natural logarithm of the weight average molecular weight (Mw) [Ln(Mw)] satisfy the following formula (iv). LCB １０００Ｃ ≦1-0.07×Ln(Mw) …Formula (iv)

12. 2. The copolymer composition according to claim 1, wherein at least one of the copolymers (S1) and (S2) contains a structural unit derived from 5-vinyl-2-norbornene as the structural unit derived from the non-conjugated polyene (C).

13. The copolymer composition according to any one of claims 1 to 12, which is a gasket composition.

14. A gasket obtained using the copolymer composition according to claim 13.

15. A molded article formed using the copolymer composition according to any one of claims 1 to 12.

16. The copolymer composition according to any one of claims 1 to 12, which is a composition for packing.

17. A packing obtained using the copolymer composition according to claim 16.

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