Copolymer composition, crosslinked molded article, and weather strip sponge

Abstract

To provide a copolymer composition capable of obtaining a molded article excellent in balance of water absorption, surface roughness and compression set.SOLUTION: A copolymer (S) having a structural unit derived from ethylene (A), a structural unit derived from an α - olefin having 3 to 20 carbon atoms (B), and a structural unit derived from a non-conjugated polyene (C), a hydrosilyl group-containing compound (Y) represented by the formula (a) which is an organohydrogenpolysiloxane having at least one silicon-bonded aralkyl group and at least two silicon-bonded hydrogen atoms in a molecule, a platinum-based catalyst, a reaction inhibitor, carbon black, a sodium bicarbonate-based foaming agent (F1), and a microcapsule-based foaming agent (F2); To provide a copolymer composition, a crosslinked molded product of the composition, and a weather strip sponge.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] EPDM crosslinked moldings, obtained by crosslinking ethylene-α-olefin-non-conjugated polyene random copolymers (hereinafter sometimes referred to as "EPDM"), have no double 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. In particular, EPDM foam, obtained by simultaneously crosslinking and foaming EPDM, is widely used in various fields, including indoor products such as home appliances, outdoor products such as automobiles, and buildings such as houses, as it has excellent cushioning properties, compressibility, and other properties, and is therefore used as cushioning materials, padding materials, sealing materials for airtightness and waterproofing, heat insulation materials, soundproofing materials, and other applications.

[0003] Patent Document 1, for example, discloses an ethylene-α-olefin-non-conjugated polyene copolymer composition that is excellent in terms of the physical properties and processability of the resulting molded article. The copolymer composition comprises: a copolymer (S) that has 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 specific non-conjugated polyene (C) and satisfies requirements (i) and (ii); a hydrosilyl group-containing compound (Y) that is an organohydrogenpolysiloxane having at least one silicon-bonded aralkyl group and at least two silicon-bonded hydrogen atoms in the molecule; and a platinum-based catalyst for hydrosilyl crosslinking. (i) [A] / [B] is 40 / 60 to 99.9 / 0.1. (ii) The mass percent concentration of the constitutional units derived from the non-conjugated polyene (C) is 0.07 to 10 mass %.

[0004] Automotive weatherstrip sponges, one of the typical applications of EPDM foam, are attached to the body, doors, trunk, etc. of the vehicle to prevent water, noise, and dust from entering the interior of the vehicle, cushion the impact when opening and closing the door, and prevent door vibration while driving. Patent Document 2, for example, discloses an ethylene-α-olefin-non-conjugated polyene copolymer composition that is excellent in processability and in which the resulting crosslinked molded article has excellent physical properties, and a weatherstrip sponge obtained from this copolymer composition. The copolymer composition contains a copolymer (S), a hydrosilyl group-containing compound (Y), a platinum catalyst, a reaction inhibitor, and carbon black. Furthermore, Patent Document 3, for example, discloses an ethylene copolymer composition that has excellent heat aging resistance and good compression set and is suitable for use in seal sponges and the like used in opening and closing parts of automobiles, building materials, home appliances, etc., and that contains an ethylene-α-olefin-non-conjugated polyene copolymer (A), 0.1 to 15 parts by mass of a blowing agent (B), and 0.5 to 20 parts by mass of calcium oxide (C) that has been surface-treated with a fatty acid and / or an oil, per 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2023 / 136287 [Patent Document 2] Japanese Patent Publication No. 2024-032012 [Patent Document 3] Patent Publication No. 2021-147464 Summary of the Invention [Problem to be solved by the invention]

[0006] Ethylene-α-olefin-non-conjugated polyene copolymers are usually crosslinked to improve elasticity and modulus. Sulfur or organic peroxides are commonly used as crosslinking agents. 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 require special equipment to handle them, as peroxides cannot be handled in air. Crosslinked products obtained using hydrosilicone compounds tend to have little odor and excellent resistance to heat aging, and can be handled in air. Patent Documents 1 and 2 describe ethylene-α-olefin-non-conjugated polyene copolymers containing hydrosilyl group-containing compounds, and Patent Document 3 uses an OBSH (4,4'-oxybisbenzenesulfonylhydrazide) blowing agent. However, both require further improvement in terms of the balance between water absorption, surface roughness, and compression set.

[0007] As a result of extensive research, the inventors have found that when a sodium bicarbonate-based blowing agent and a microcapsule-type blowing agent are used in combination as blowing agents in hydrosilicone crosslinking using a hydrosilyl group-containing compound, a better balance of water absorption, surface roughness, and compression set is achieved compared to when either agent is used alone. The problem to be solved by one embodiment of the present invention is to provide a copolymer composition that can give a molded article having an excellent balance of water absorption, surface roughness, and compression set. Another problem to be solved by one embodiment of the present invention is to provide a crosslinked molded article and a weatherstrip sponge having an excellent balance of water absorption, surface roughness, and compression set. [Means for solving the problem]

[0008] The means for solving the above problems include the following aspects. <1> a copolymer (S) having 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 selected from the following formula (I) and the following formula (II); a hydrosilyl group-containing compound (Y) represented by the following formula (a), which is an organohydrogenpolysiloxane having 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 Sodium bicarbonate foaming agent (F1) and a microcapsule-type blowing agent (F2); A copolymer composition comprising:

[0009] [ka]

[0010] [ka]

[0011] (In formula (a), n and p are each independently 0 or a positive number, m is 1 to 20, the sum of n, m, and p is 5 to 50, and a plurality of R 1 and R 2 are each independently a monovalent alkyl group, and R a is an aralkyl group, and two R are each independently R 1 , R 2 , hydrogen atoms, and R a -[O-Si(R 1 )(R a )]-, -[O-Si(R 1 )H]- and -[O-Si(R 1 )(R 2The structural units represented by (n) )- may be arranged in a block form or randomly. However, when n=1, at least one of the two R's is a hydrogen atom, and when n=0, both of the two R's are hydrogen atoms. <2> the content of the sodium bicarbonate-based blowing agent (F1) is 0.1 to 20 parts by mass relative to 100 parts by mass of the copolymer (S); <1> The copolymer composition according to claim 1. <3> the content of the microcapsule-type blowing agent (F2) is 0.1 to 20 parts by mass relative to 100 parts by mass of the copolymer (S); <1> or <2> The copolymer composition according to claim 1. <4> the ratio of the content of the sodium bicarbonate-based blowing agent (F1) to the total content of the sodium bicarbonate-based blowing agent (F1) and the microcapsule-type blowing agent (F2) is 5 to 95% by mass (provided that the total content of the sodium bicarbonate-based blowing agent (F1) and the microcapsule-type blowing agent (F2) is 100% by mass); <1> ~ <3> 10. The copolymer composition according to claim 9, wherein the copolymer composition is a copolymer of a hydroxybenzoate and a hydroxybenzoate. <5> the content of the carbon black is 10 to 300 parts by mass, the content of the platinum-based catalyst is 0.001 to 10 parts by mass, and the content of the reaction inhibitor is 0.05 to 5 parts by mass, relative to 100 parts by mass of the copolymer (S); <1> ~ <4> 10. The copolymer composition according to claim 9, wherein the copolymer composition is a copolymer of a hydroxybenzoate and a hydroxybenzoate. <6> The copolymer (S) has an intrinsic viscosity [η] measured in decalin at 135°C of 2.0 dL / g or more and less than 4.0 dL / g. <1> ~ <5> 10. The copolymer composition according to claim 9, wherein the copolymer composition is a copolymer of a hydroxybenzoate and a hydroxybenzoate. <7> The copolymer (S) satisfies the following requirements (1) and (2): <1> ~ <6> 10. The copolymer composition according to claim 9, wherein the copolymer composition is a copolymer of a hydroxybenzoate and a hydroxybenzoate. Requirement (1): The ratio ([A] / [B]) of the number of moles [A] 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 40 / 60 to 99.9 / 0.1; Requirement (2): The mass fraction of the structural units derived from the non-conjugated polyene (C) is 0.07 to 10 mass % based on the total mass of the structural units constituting the copolymer (S). <8> The copolymer (S) satisfies at least one of the following requirements (3) to (5): <1> ~ <7> 10. The copolymer composition according to claim 9, wherein the copolymer composition is a copolymer of a hydroxybenzoate and a hydroxybenzoate. Requirement (3): The weight average molecular weight (Mw) of the copolymer (S), 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 [A3] (molecular weight of (C)) satisfy the following formula (ii); 4.5≦[Mw×mass fraction (mass%) of (C)] / 100 / molecular weight of (C)≦80 Formula (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 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 (S) and the mass fraction of the structural units derived from the non-conjugated polyene (C) satisfy the following formula (iii): P / ([η]2.9)≦mass fraction of non-conjugated polyene (C)×6 (iii) Requirement (5): The number of long-chain branches per 1000 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) <9> The structural units derived from the non-conjugated polyene (C) include structural units derived from 5-vinyl-2-norbornene. <1> ~ <8> 10. The copolymer composition according to claim 9, wherein the copolymer composition is a copolymer of a hydroxybenzoate and a hydroxybenzoate. <10> The composition further contains a plasticizer, and the content of the plasticizer is 50 to 150 parts by mass per 100 parts by mass of the copolymer (S). <1> ~ <9> 10. The copolymer composition according to claim 9, wherein the copolymer composition is a copolymer of a hydroxybenzoate and a hydroxybenzoate. <11> <1> ~ <10> 1. A crosslinked molded article comprising the copolymer composition according to any one of the above items. <12> <1> ~ <10> A weatherstrip sponge comprising the copolymer composition according to any one of the above items. [Effects of the Invention]

[0012] According to one embodiment of the present invention, there is provided a copolymer composition that can give a molded article having an excellent balance of water absorption, surface roughness, and compression set. Also, according to one embodiment of the present invention, there are provided a crosslinked molded article and a weatherstrip sponge having an excellent balance of water absorption, surface roughness, and compression set. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below. The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. 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. Furthermore, in this specification, when referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, it means the total amount of the multiple substances present in the composition, unless otherwise specified. As used herein, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, unless otherwise specified, each component in the composition or each structural unit in the polymer may be contained alone or in combination of two or more types. The present invention will be described in detail below.

[0014] <Copolymer composition> The copolymer composition according to the present invention comprises a copolymer (S) having 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, per molecule, two or more partial structures selected from the following formula (I) and the following formula (II): a hydrosilyl group-containing compound (Y) represented by the following formula (a) and which is an organohydrogenpolysiloxane having, per molecule, at least one silicon-bonded aralkyl group and at least two silicon-bonded hydrogen atoms; a platinum catalyst; a reaction inhibitor; carbon black; a sodium bicarbonate blowing agent (F1); and a microcapsule-type blowing agent (F2). The copolymer composition according to the present invention, having the above-described structure, produces molded articles with an excellent balance of water absorption, surface roughness, and compression set. While the reason for this is unclear, the following mechanism is presumed. The microencapsulated blowing agent (F2) forms fine foam cells in the molded article when crosslinked, which can reduce the water absorption of the molded article. However, the microencapsulated agent also reduces the surface roughness of the molded article, making it prone to compression set. On the other hand, it is presumed that a composition containing the microencapsulated blowing agent (F2) in combination with a hydrosilyl group-containing compound (Y) having a specific structure exhibits a high crosslinking rate when the composition is crosslinked, resulting in a high crosslink density on the surface of the molded article, thereby improving surface roughness. Furthermore, because the hydrosilyl group-containing compound (Y) has a higher bond energy than sulfur vulcanization, the resulting molded article exhibits improved compression set and excellent recovery force upon compression, leading to excellent sealing performance. A molded article having an excellent balance of water absorption, surface roughness, and compression set means that the obtained molded article has low water absorption and small values ​​of surface roughness and compression set. The water absorption, surface roughness, and compression set can be evaluated by the methods described in the examples below. Each component contained in the copolymer composition will be described below.

[0015] [Copolymer (S)] The copolymer (S) has 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 following formula (I) and the following formula (II):

[0016] <<α-Olefin (B)>> Examples of the α-olefin (B) having 3 to 20 carbon atoms (hereinafter sometimes 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, as the α-olefin (B), 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 the raw material costs are relatively low, the resulting copolymer (S) exhibits excellent mechanical properties, and a molded article having rubber elasticity can be obtained. These α-olefins may be used alone or in combination of two or more.

[0017] <<Non-conjugated polyene (C)>> The non-conjugated polyene (C) contains at least one partial structure selected from the following formula (I) and the following formula (II) in a total of two or more per molecule.

[0018] [ka]

[0019] Examples of the non-conjugated polyene (C) include 5-vinyl-2-norbornene (VNB), norbornadiene, 1,4-hexadiene, and dicyclopentadiene. Among these, it is preferable that the structural unit derived from the non-conjugated polyene (C) contains a structural unit derived from 5-vinyl-2-norbornene (VNB), because it is easily available, exhibits good hydrosilicone crosslinking, and is likely to improve the heat resistance of the copolymer composition, and it is more preferable that the structural unit derived from the non-conjugated polyene (C) is a structural unit derived from 5-vinyl-2-norbornene (VNB). The non-conjugated polyene (C) may be used alone or in combination of two or more.

[0020] 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) 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, based on all structural units constituting the copolymer (S).

[0021] (Non-conjugated polyene (CX)) The copolymer (S) may further contain a structural unit derived from a non-conjugated polyene (CX) (hereinafter, sometimes simply referred to as "non-conjugated polyene (CX)") containing only one partial structure selected from the group consisting of the general formulas (I) and (II) in one molecule, within the scope that does not impair the effects of the present invention. Examples of such non-conjugated polyenes (CX) include 5-ethylidene-2-norbornene (ENB), 5-methylene-2-norbornene, 5-(2-propenyl)-2-norbornene, 5-(3-butenyl)-2-norbornene, 5-(1-methyl-2-propenyl)-2-norbornene, 5-(4-pentenyl)-2-norbornene, 5-(1-methyl-3-butenyl)-2-norbornene, 5-(5-hexenyl)-2-norbornene, 5-(1-methyl-4-pentenyl)-2-norbornene, 5-(2,3-dimethyl-3-butenyl)-2-norbornene, 5-(2-ethyl-3- butenyl)-2-norbornene, 5-(6-heptenyl)-2-norbornene, 5-(3-methyl-5-hexenyl)-2-norbornene, 5-(3,4-dimethyl-4-pentenyl)-2-norbornene, 5-(3-ethyl-4-pentenyl)-2-norbornene, 5-(7-octenyl)-2-norbornene, 5-(2-methyl-6-heptenyl)-2-norbornene, 5-(1,2-dimethyl-5-hexenyl)-2-norbornene, 5-(5-ethyl-5-hexenyl)-2-norbornene, 5-(1,2,3-trimethyl-4-pentenyl)-2-norbornene, and the like.

[0022] Among these, 5-ethylidene-2-norbornene (ENB) is preferred as the non-conjugated polyene (CX) because it is readily available, the crosslinking rate during hydrosilicone crosslinking can be easily controlled, and good mechanical properties can be easily obtained.

[0023] When the copolymer (S) contains a structural unit derived from a non-conjugated polyene (CX), the mass fraction of the structural unit derived from the non-conjugated polyene (CX) is preferably 0 to 20 mass%, more preferably 0 to 10 mass%, and even more preferably 0.01 to 8.0 mass%, based on all structural units constituting the copolymer (S). The non-conjugated polyene (CX) may be used alone or in combination of two or more.

[0024] The copolymer (S) may contain, as a constituent unit derived from at least one monomer selected from the aforementioned ethylene (A), the α-olefin (B) having 3 to 20 carbon atoms, the non-conjugated polyene (C), and the non-conjugated polyene (CX), a constituent unit derived from a biomass-derived monomer and / or a chemically recycled monomer.

[0025] The copolymer (S) may contain a structural unit derived from at least one biomass-derived monomer. The biomass-derived monomer used as a raw material for the copolymer (S) may be biomass-derived ethylene, biomass-derived α-olefin, or biomass-derived non-conjugated polyene. An example of a biomass-derived α-olefin is biomass-derived propylene. Examples of biomass-derived non-conjugated polyenes include biomass-derived 5-ethylidene-2-norbornene and biomass-derived 5-vinyl-2-norbornene. The monomers used as raw materials for the copolymer (S) may contain only biomass-derived monomers, or may contain both biomass-derived monomers and fossil fuel-derived monomers. Note that biomass-derived monomers such as biomass-derived ethylene, biomass-derived α-olefins, and biomass-derived non-conjugated polyenes can be obtained by known methods. It is preferable from the viewpoint of reducing the environmental load that the copolymer (S) contains a structural unit derived from a biomass-derived monomer.

[0026] The copolymer (S) may contain a constituent unit derived from at least one chemically recycled monomer. The chemically recycled monomer used as the raw material for the copolymer (S) may be ethylene derived from chemical recycling, an α-olefin derived from chemical recycling, or a non-conjugated polyene derived from chemical recycling. Furthermore, the monomer used as the raw material for the copolymer (S) may contain only a chemically recycled monomer, or may contain both a chemically recycled monomer and a fossil fuel-derived monomer. Chemically recycled monomers such as ethylene derived from chemical recycling, an α-olefin derived from chemical recycling, and a non-conjugated polyene derived from chemical recycling can be obtained by known methods. It is preferable that the copolymer (S) contains a structural unit derived from a chemically recycled monomer from the viewpoint of reducing the environmental load (mainly reducing waste).

[0027] The copolymer (S) preferably satisfies the following requirements (1) and (2): Furthermore, the copolymer (S) preferably satisfies at least one of the following requirements (3) to (5). In addition to the following requirements (1) and (2), it is more preferable to satisfy the following requirements (3) and (4), and it is even more preferable to satisfy the following requirement (5). The requirements (4) and (5) are both indicators related to the content of long chain branches in the copolymer (S).

[0028] <<Requirement (1)>> In the copolymer (S), the ratio ([A] / [B]) of the number of moles [B] of structural units derived from an α-olefin (B) having 3 to 20 carbon atoms to the number of moles [A] of structural units derived from ethylene (A) is 40 / 60 to 99.9 / 0.1, preferably 50 / 50 to 90 / 10, more preferably 55 / 45 to 85 / 15, even more preferably 60 / 40 to 78 / 22, and particularly preferably 65 / 35 to 75 / 25. When copolymer (S) satisfies requirement (1), the molded article obtained by hydrosilicone crosslinking of copolymer (S) exhibits excellent rubber elasticity and is excellent in mechanical strength and flexibility, which is desirable. The ratio ([A] / [B]) of the number of moles of structural units derived from ethylene (A) to the number of moles of structural units derived from α-olefin (B) in the copolymer (S) is determined by the method described in the Examples below. 13 It can be determined by C-NMR.

[0029] <<Requirement (2)>> In the copolymer (S), the mass fraction of the structural units derived from the non-conjugated polyene (C) is 0.07 to 10 mass%, preferably 0.1 to 8.0 mass%, more preferably 0.5 to 5.0 mass%, and even more preferably 1.0 to 3.0 mass%, based on all structural units constituting the copolymer (S). Copolymer (S) is preferred because it satisfies requirement (2), and crosslinked molded articles obtained from the copolymer composition have sufficient hardness and excellent mechanical properties. Furthermore, when copolymer (S) is crosslinked with hydrosilicone, it is preferred because it exhibits a fast crosslinking rate, allowing crosslinked molded articles to be produced efficiently. The mass fraction of the structural units derived from the non-conjugated polyene (C) in the copolymer (S) is determined by the formula (1) in the Examples below. 13 It can be determined by C-NMR.

[0030] When the proportion of the structural units derived from the non-conjugated polyene (C) in the copolymer (S) is expressed as an iodine value, it is preferably from 0.14 to 20, more preferably from 0.2 to 16, and even more preferably from 1.0 to 10. When the proportion of the structural units derived from the non-conjugated polyene (C) is within the preferred iodine value range, good rubber elasticity can be obtained. The iodine value can be determined by the measurement method described in the Examples.

[0031] The mass fraction of the structural unit derived from the non-conjugated polyene (C) (mass fraction (mass %) of (C)) and the weight average molecular weight (Mw) of the copolymer (S) preferably satisfy the following formula (V). 6-0.45 × Ln(Mw) ≦ mass fraction of (C) ≦ 10 ··· Equation (V)

[0032] <<Requirement (3)>> The weight average molecular weight (Mw) of the copolymer (S), 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 [A3] (molecular weight of (C)) satisfy the following formula (ii): 4.5≦Mw×[mass fraction of (C) (mass %)] / 100 / molecular weight of (C)≦80 Formula (ii) In formula (ii), (Mw) is the weight average molecular weight of the copolymer (S), the mass fraction of (C) is the mass fraction (mass%) of the constituent units derived from the non-conjugated polyene (C), and the molecular weight of (C) is the molecular weight of the non-conjugated polyene (C).

[0033] The weight average molecular weight (Mw) refers to a value measured by 3D-GPC (Triple Detection Gel Permeation Chromatography). The value calculated from the formula "Mw × [mass fraction of (C)] / 100 / molecular weight of (C)" (hereinafter, sometimes referred to as "(nC)") is preferably 4.5 or more and 78 or less, and more preferably 4.5 or more and 75 or less.

[0034] (nC) represents the number of constitutional units derived from the non-conjugated polyene (C) per weight average molecular weight (Mw) of the copolymer (S). When (nC) is 4.5 or more, it is easy to obtain a sufficient crosslinking rate during hydrosilicone crosslinking, and when (nC) is 80 or less, excessive crosslinking is unlikely to occur, and the resulting crosslinked molded article exhibits superior mechanical properties.

[0035] When copolymer (S) satisfies requirement (3), the content of long chain branches in the copolymer falls within an appropriate range, which is preferable because it results in a fast hydrosilicone crosslinking rate, an excellent balance of physical properties such as the mechanical properties of the resulting crosslinked molded article, and resistance to post-crosslinking, particularly excellent heat aging resistance.

[0036] When the copolymer (S) contains the above-mentioned structural unit (CX), (n C+cx ) is preferably 4.5 to 80, more preferably 4.5 to 78, and even more preferably 4.5 to 75. (n C+cx ) = (Mw) × [{mass fraction of (C) / 100} / molecular weight of (C) + {mass fraction of (CX) / 100} / molecular weight of (CX)] (1')

[0037] (n C+cx ) is the total number of constitutional units derived from the non-conjugated polyene (C) and the number of constitutional units derived from the non-conjugated polyene (CX) per weight average molecular weight (Mw) of the copolymer (S).

[0038] <<Requirement (4)>> The copolymer (S) was measured by linear viscoelasticity measurement (190°C) using a rheometer, and the complex viscosity η at a frequency of ω = 0.1 rad / s was * (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 (S), and the mass fraction (mass fraction of C) of the structural unit derived from the non-conjugated polyene (C) satisfy the following formula (iii): P / ([η] 2.9 ) ≦ (C) mass fraction × 6 Equation (iii)

[0039] The rheometer used for linear viscoelasticity measurement in requirement (4) is the Ares viscoelasticity measuring device (manufactured by Rheometric Scientific), and the complex viscosity η * (ω=0.1) (Pa·sec) is measured at 190°C and 1.0% strain while changing the frequency. The intrinsic viscosity [η] is a value measured in decalin at 135°C.

[0040] The copolymer (S) more preferably satisfies the following formula (iii-2). P / ([η] 2.9 ) ≦ (C) mass fraction × 5.7 Equation (iii-2)

[0041] ratio P(η * (ω=0.1) / η * (ω=100) ) represents the frequency dependence of viscosity, and is the left side of the equation (iii) and the equation (iii-2), 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.

[0042] 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, the copolymer (S) according to the present invention has fewer long-chain branches than conventionally known ethylene-α-olefin-non-conjugated polyene copolymers, and is therefore considered to be able to satisfy the above formula (iii).

[0043] <<Requirement (5)>> The copolymer (S) was analyzed by 3D-GPC to determine the number of long chain branches (LCB) per 1000 carbon atoms. 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)

[0044] The upper limit of the long chain branch content per unit carbon number of the copolymer (S) is specified by the above formula (iv). That is, requirement (5) means that the proportion of long chain branches in the copolymer (S) is low. By satisfying requirement (5), the copolymer (S) exhibits excellent curing properties when subjected to hydrosilicone crosslinking, and the crosslinked molded articles obtained using the copolymer exhibit excellent heat aging resistance.

[0045] The copolymer (S) more preferably satisfies the following formula (iv-2). LCB 1000C ≦1-0.071×Ln(Mw)...Formula (iv-2)

[0046] Mw and (LCB 1000C ) are values ​​determined by structural analysis using 3D-GPC. Specifically, Mw and (LCB 1000C ) can be determined by the method described in the Examples below.

[0047] The long chain branching parameter g for each eluted component was calculated from the relationship between the intrinsic viscosity [η] measured in decalin at 135°C using a viscometer and the absolute molecular weight obtained using a light scattering photometer. ’i was calculated using the following formula (v-1).

[0048]

number

[0049] Here, the intrinsic viscosity [η] = KM v The equation used was v = 0.726, known as the Mark-Houwink-Sakurada equation, where K is the solvent constant, M is the absolute molecular weight, and v is the conformation of the polymer chain (i.e., the molecular shape, degree of bending, and other molecular extensions) in the measurement solvent at the measurement temperature. Furthermore, 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.

[0050]

number

[0051] Furthermore, the weight average long chain branching parameter g' represented by the above formula (v-3) w The number of branch points per molecular chain: BrNo, and the number of long chain branches per 1000 carbon atoms: LCB 1000C The branching degree per unit molecular weight: λ was calculated. BrNo was calculated using the Zimm-Stockmayer formula (v-5) shown below. 1000C The calculation of and λ was performed using the following equations (v-6) and (v-7).

[0052] 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) Various values ​​have been proposed for ε in the above formula depending on the shape of the molecule. Here, the calculation was performed assuming ε = 1 (i.e., g' = g).

[0053]

number

[0054] λ=BrNo / M (V-6) LCB 1000C =λ×14000 (V-7) In formula (V-7), 14,000 represents the molecular weight of 1,000 methylene (CH2) units.

[0055] The intrinsic viscosity [η] of the copolymer (S) measured in decalin at 135°C is preferably 2.0 dL / g or more and less than 4.0 dL / g, more preferably 2.0 to 3.5 dL / g, and even more preferably 2.5 to 3.0 dL / g.

[0056] It is also preferable that the copolymer (S) satisfies the requirement (6) represented by the following formula (vi). <<Requirement (6)>> Log{η * (ω=0.01)} / Log{η * (ω=10)}≦0.0753 × {apparent iodine value derived from non-conjugated polyene (C)} + 1.42 Formula (vi)

[0057] In formula (vi), η * (ω=0.01) is the complex viscosity η at a frequency of ω = 0.01 rad / s obtained by linear viscoelasticity measurement (190 °C) using a rheometer. * (Pa·sec). Also, η * (ω=10) is the complex viscosity η at a frequency of ω = 10 rad / s obtained by linear viscoelasticity measurement (190 °C) using a rheometer * (Pa·sec). where η * (ω=0.01) and 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.

[0058] In the formula (vi), the apparent iodine value derived from the non-conjugated polyene (C) is calculated by the following formula. Apparent iodine value derived from (C) = mass fraction of (C) × 253.81 / molecular weight of (C)

[0059] In the above formula (vi), 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. If the copolymer (S) satisfies the requirement (6), it is preferable because the degree of long chain branching is not too high. If the copolymer (S) does not satisfy the requirement (6), it means that a large proportion of the copolymerized non-conjugated polyene (C) is consumed in the formation of long chain branches.

[0060] The weight average molecular weight (Mw) of the copolymer (S) is preferably from 10,000 to 800,000, more preferably from 30,000 to 700,000, still more preferably from 50,000 to 600,000, and particularly preferably from 100,000 to 500,000. When the weight average molecular weight (Mw) of the copolymer (S) is equal to or greater than the lower limit of the preferred range, it is easy to obtain better physical properties. When the weight average molecular weight (Mw) is equal to or less than the upper limit of the preferred range, it is easier to shape the copolymer (S) into any desired shape by hand, etc.

[0061] The copolymer composition may contain two or more types of copolymers (S). For example, two or more types of the copolymers (S) differing in (a) molar ratio of ethylene / α-olefin having 3 to 20 carbon atoms, (b) iodine value, or (c) in intrinsic viscosity [η] may be mixed and used. In particular, in the case of (c), a mixture of a low intrinsic viscosity component and a high intrinsic viscosity component may be used.

[0062] The method for producing the copolymer (S) is preferably a method for copolymerizing monomers in the presence of a metallocene compound, more preferably a method for copolymerizing monomers in the presence of a catalyst system containing a metallocene compound. Specifically, the copolymer (S) can be produced, for example, by the method described in WO 2015 / 122495.

[0063] [Hydrosilyl group-containing compound (Y)] The hydrosilyl group-containing compound (Y) 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 copolymer composition may contain one kind of hydrosilyl group-containing compound (Y) alone, or may contain two or more kinds of hydrosilyl group-containing compounds (Y).

[0064] [ka]

[0065] In formula (a), n and p are each independently 0 or a positive number, m is a number ranging from 1 to 20, the sum of n, m, and p is 5 to 50, and R 1 and R 2 are each independently a monovalent alkyl group, and R a is an aralkyl group, and two R are each independently R 1 , R 2 , hydrogen atoms and R a -[O-Si(R 1 )(R a )]-, -[O-Si(R 1 )H]- and -[O-Si(R 1 )(R 2 The structural units represented by n)- may be arranged in a block form or randomly, provided that when n=1, at least one of R is a hydrogen atom, and when n=0, both R are hydrogen atoms.

[0066] Such a 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 the molecule.

[0067] By selectively using the hydrosilyl group-containing compound (Y) in combination with the copolymer (S), 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 molding strain, and the applicability to weatherstrip sponges, etc. is particularly improved.

[0068] In formula (a), m is the number of diorganosiloxane units having silicon-bonded aralkyl groups, and is a number in the range of 1 to 20, may be a number in the range of 2 to 10, and is particularly preferably a number in the range of 3 to 6.

[0069] In formula (a), n is the number of organohydrogenpolysiloxane units having silicon-bonded hydrogen atoms in the side chain and may be 0 or 1. When n=1, at least one of R is a hydrogen atom, and when n=0, both R are hydrogen atoms, resulting in a structure having at least two silicon-bonded hydrogen atoms in the molecule.

[0070] When n is a positive number other than 0 or 1, one or both of the R at both molecular chain terminals may be a silicon-bonded hydrogen atom. Furthermore, n is preferably a positive number other than 0 or 1, and more preferably a positive number satisfying n≧m. More specifically, n may be a number in the range of 3 to 10, and particularly preferably a number in the range of 3 to 9.

[0071] In formula (a), p is the number of diorganosiloxane units that do not contain aralkyl groups or silicon-bonded hydrogen atoms, and may be 0 or may be a number within the range obtained by dividing the values ​​of n and m from the total degree of polymerization of diorganosiloxane units, which is represented by the sum of n, m, and p, as described below. For example, p may be a number within the range of 0 to 12, 0 to 10, 0 to 5, or 0 to 2. P is preferably a number within the above range.

[0072] The hydrosilyl group-containing compound (Y) has a relatively low degree of siloxane polymerization, and the sum of the above values ​​of n, m and p is 5-50, preferably 5-20, and more preferably 5-15. In the hydrosilyl group-containing compound (Y), m is particularly preferably a number in the range of 3 to 6, n is a number in the range of 3 to 9, and p is a number in the range of 0 to 2.

[0073] 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 ,R 2are monovalent alkyl groups, which may be the same or different, and in which some of the carbon atom-bonded hydrogen atoms may be substituted with halogen atoms. Such alkyl groups may be alkyl groups having 1 to 20 carbon atoms, and industrially may be methyl groups.

[0074] In formula (a), R a is an aralkyl group, preferably an aralkyl group having 7 to 20 carbon atoms, more preferably an aralkyl group having 7 to 15 carbon atoms. Examples of such an aralkyl group include a benzyl group, a phenylethyl group, a phenylpropyl group, and a phenylbutyl group. In particular, R a It is preferable that the alkylene structure between the aryl group such as a phenyl group and the silicon atom contains at least one branching unit represented by -CH(CH3)-. R a is more preferably an aralkyl group represented by -CH2-CH(CH3)-C6H5.

[0075] R a When n, m, and p are the above-mentioned aralkyl groups, the hydrosilyl group-containing compound (Y) can be made useful as a crosslinking agent. In particular, when the aralkyl group is present together with a hydrogen atom bonded to a silicon atom in the hydrosilyl group-containing compound (Y) in which n, m, and p are within the above-mentioned ranges, it is presumed that the physical properties of the resulting molded product are significantly improved.

[0076] In the copolymer composition, the content of the hydrosilyl group-containing compound (Y) relative to 100 parts by mass of the copolymer (S) is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, even more preferably 1.0 to 30 parts by mass, and particularly preferably 3.0 to 10 parts by mass. The hydrosilyl group-containing compound (Y) may be contained either alone or in combination of two or more.

[0077] [Platinum-based catalyst] The platinum catalyst is an addition reaction catalyst, and any catalyst can be used without particular limitation, as long as it promotes the addition reaction between the alkenyl group of the copolymer (S) and the hydrosilyl group of the hydrosilyl group-containing compound (Y) (hydrosilylation reaction of an alkene). Examples of platinum catalysts include platinum alone (platinum black), chloroplatinic acid, platinum-olefin complexes, platinum-alcohol complexes, and platinum supported on a carrier such as alumina or silica.

[0078] Specific platinum catalysts may be any known platinum catalyst typically used in addition curing, such as the fine powder platinum metal catalyst described in U.S. Pat. No. 2,970,150, the chloroplatinic acid catalyst described in U.S. Pat. No. 2,823,218, the complex compounds of platinum and hydrocarbons described in U.S. Pat. Nos. 3,159,601 and 159,662, the complex compounds of chloroplatinic acid and olefins described in U.S. Pat. No. 3,516,946, and the complex compounds of platinum and vinylsiloxanes described in U.S. Pat. Nos. 3,775,452 and 3,814,780.

[0079] Among these, from the viewpoint of high catalytic activity, a platinum-vinylsiloxane complex compound is preferred as the platinum-based catalyst, such as 1,1,3,3-tetramethyl-1,3-divinyldisiloxane platinum complex. The platinum-based catalyst may be supported on a carrier such as alumina or silica.

[0080] The platinum-based catalyst preferably contains a platinum complex at a concentration of 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, and particularly preferably 1.0% by mass or more, relative to the total mass of the catalyst.

[0081] In the copolymer composition, the content of the platinum catalyst relative to 100 parts by mass of the copolymer (S) is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 5 parts by mass, even more preferably 0.01 to 3 parts by mass, and particularly preferably 0.05 to 1.0 part by mass. When the content of the platinum-based catalyst is equal to or greater than the lower limit, crosslinking at room temperature is promoted. When the content of the platinum-based catalyst is equal to or less than the upper limit, the physical properties of the resulting molded body tend to be good. When the content of the platinum-based catalyst is within the above range, the molded body is less likely to harden and has excellent handleability even before being molded into any shape. The platinum catalyst may be contained alone or in combination of two or more.

[0082] The platinum complex content of commercially available platinum-based catalysts varies depending on the lot, so it is preferable to adjust the specific content so that the difference in copolymer composition [S'max - S'min] and tc50, which will be described later, are within appropriate ranges.

[0083] [Reaction inhibitor] The copolymer composition contains a reaction inhibitor. The reaction inhibitor is not particularly limited as long as it is a compound that has the function of inhibiting the crosslinking reaction (hydrosilylation addition reaction to alkene) between the alkenyl group in the copolymer (S) and the hydrosilyl group in the hydrosilyl group-containing compound (Y). By including the reaction inhibitor in the copolymer composition, the processability of the composition during kneading and molding is made more stable.

[0084] The reaction inhibitor is not particularly limited, and examples thereof 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-ethynyl-1-cyclohexanol, and 3,5-dimethyl-1-hexyn-3-ol; acrylonitrile; and N,N-diallyl. amide compounds such as acetamide, 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 such as sulfur, phosphorus, nitrogen, amine compounds, sulfur compounds, phosphorus compounds, tin, tin compounds, and tetramethyltetravinylcyclotetrasiloxane. Among these compounds, 1-ethynyl-1-cyclohexanol or 3,5-dimethyl-1-hexyn-3-ol is preferred as the reaction inhibitor, and 1-ethynyl-1-cyclohexanol is more preferred.

[0085] In the copolymer composition, the content of the reaction inhibitor relative to 100 parts by mass of the copolymer (S) is preferably 0.05 to 5 parts by mass, more preferably 0.08 to 3 parts by mass, even more preferably 0.1 to 2 parts by mass, and particularly preferably 0.2 to 1 part by mass. The reaction inhibitor may be contained either as a single type or as a combination of two or more types.

[0086] [Carbon black] The copolymer composition contains carbon black. Carbon black functions as a reinforcing agent, so by including carbon black in the copolymer composition, the processability of the copolymer composition is improved, and a copolymer composition having improved mechanical properties such as tensile strength, tear strength, and abrasion resistance can be obtained. Carbon black may also be used as a colorant, as described below.

[0087] Examples of carbon black include Asahi #50HG, Asahi #55G, and Asahi #60UG (all manufactured by Asahi Carbon Co., Ltd.), Seast SVH, Seast V, and Seast G-SO (all manufactured by Tokai Carbon Co., Ltd.). The carbon black may be surface-treated with a silane coupling agent or the like.

[0088] In the copolymer composition, the content of carbon black is preferably 10 to 300 parts by mass, more preferably 30 to 250 parts by mass, still more preferably 50 to 200 parts by mass, and particularly preferably 80 to 150 parts by mass, per 100 parts by mass of copolymer (S). When the carbon black content is within the above range, a copolymer composition excellent in dynamic modulus (dynamic modulus / static modulus), processability, mechanical properties, etc. is likely to be obtained. Carbon black may be used alone or in combination of two or more types.

[0089] The copolymer composition may contain a reinforcing agent other than carbon black to improve physical properties such as tensile stress at break and tensile elongation at break, within a range that does not impair the effects of the present invention. Examples of reinforcing agents other than carbon black include silica, calcium carbonate, activated calcium carbonate, finely divided talc, and finely divided silicic acid. The reinforcing agents other than carbon black may be used alone or in combination of two or more.

[0090] From the viewpoint of easily obtaining a molded product having an excellent balance of water absorption, surface roughness, and compression set, the content of the carbon black is preferably 10 to 300 parts by mass (more preferably 30 to 250 parts by mass, even more preferably 50 to 200 parts by mass, and particularly preferably 80 to 150 parts by mass), the content of the platinum-based catalyst is 0.001 to 10 parts by mass (more preferably 0.005 to 5 parts by mass, even more preferably 0.01 to 3 parts by mass, and particularly preferably 0.05 to 1.0 part by mass), and the content of the reaction inhibitor is 0.05 to 5 parts by mass (more preferably 0.08 to 3 parts by mass, even more preferably 0.1 to 2 parts by mass, and particularly preferably 0.2 to 1 part by mass), relative to 100 parts by mass of the copolymer (S).

[0091] [Sodium bicarbonate foaming agent (F1)] The sodium bicarbonate-based foaming agent is not particularly limited as long as it is a foaming agent containing sodium bicarbonate (that is, sodium bicarbonate), and any conventionally known foaming agent can be used. A suitable example of the sodium bicarbonate foaming agent is a mixture containing a foam nucleating agent and sodium bicarbonate (that is, sodium bicarbonate containing a foam nucleating agent). Examples of foam nucleating agents include calcium carbonate, clay, talc, silica, magnesium oxide, zinc oxide, carbon black, silicon dioxide, titanium oxide, plastic microspheres, orthoboric acid, alkaline earth metal salts of fatty acids, citric acid, etc. Among these foam nucleating agents, citric acid is preferred.

[0092] Examples of foam nucleating agent-containing sodium bicarbonate containing a foam nucleating agent such as citric acid include Hydrocellol CF, Hydrocellol BIT, and Hydrocellol BIF manufactured by CLARIANT, and Celvon FE-507, Celvon SC-P, Celvon SC-K, and Celvon SC-850 manufactured by Eiwa Chemical Industry Co., Ltd.

[0093] The content of the sodium bicarbonate-based blowing agent (F1) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, even more preferably 2 to 6 parts by mass, and particularly preferably 3 to 5 parts by mass, relative to 100 parts by mass of the copolymer (S). The foaming agents may be used alone or in combination of two or more.

[0094] The foam nucleating agent-containing sodium bicarbonate may be prepared by separately blending the foam nucleating agent and sodium bicarbonate into the composition.

[0095] When the foam nucleating agent and sodium bicarbonate are contained separately, the content ratio (mass ratio) of the foam nucleating agent to sodium bicarbonate is usually 0.1 / 99.9 to 90 / 10, preferably 0.5 / 99.5 to 80 / 20, and more preferably 1 / 99 to 70 / 30.

[0096] [Microcapsule type foaming agent (F2)] The microcapsule type blowing agent (F2) refers to a blowing agent having a core-shell structure, and is composed of a shell containing a resin and a core containing a volatile material encapsulated within the shell. Specifically, a suitable example is a thermally expandable microcapsule-type blowing agent having a core-shell structure. When heat is applied to the thermally expandable microcapsule-type blowing agent, the resin that constitutes the shell softens and the volatile material in the core vaporizes, causing the volume to expand and inflate like a balloon.

[0097] The resin forming the shell is preferably a thermoplastic resin, and examples thereof include polystyrene, styrene-acrylic acid ester copolymer, polyamide resin, polyacrylic acid ester, polyvinylidene chloride, polyacrylonitrile, polymethyl methacrylate, vinylidene chloride-acrylonitrile, methacrylic acid ester-acrylic acid copolymer, vinylidene chloride-acrylic acid copolymer, and vinylidene chloride-acrylic acid ester copolymer.

[0098] Volatile materials include low molecular weight hydrocarbons such as ethane, ethylene, propane, propene, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, heptane, and petroleum ether; chlorofluorocarbons such as CClF, CClF, CClF, and CClF-CClF; and tetraalkylsilanes such as tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, and trimethyl-n-propylsilane. Among these, low molecular weight hydrocarbons with a molecular weight of 120 or less are preferred.

[0099] The thermally expandable microcapsule-type blowing agent preferably has an average diameter of 5 to 30 μm before expansion and a maximum expansion ratio in air of 5 to 15 times.

[0100] The microcapsule type blowing agent may be obtained by synthesis or may be a commercially available product. Examples of commercially available products include Neoslen HM50B (Eiwa Chemical Industry Co., Ltd.), Matsumoto Microsphere (registered trademark) F, FN series (Matsumoto Yushi Pharmaceutical Co., Ltd.), and the like.

[0101] The content of the microcapsule-type blowing agent (F2) is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, even more preferably 1 to 5 parts by mass, and particularly preferably 1.5 to 4.5 parts by mass, relative to 100 parts by mass of the copolymer (S). The microcapsule type blowing agent may be used alone or in combination of two or more kinds.

[0102] The ratio of the content of the sodium bicarbonate-based blowing agent (F1) to the total content of the sodium bicarbonate-based blowing agent (F1) and the microcapsule-type blowing agent (F2) (F1 / (F1+F2)) is preferably 5 to 95 mass%, more preferably 30 to 80 mass%, and even more preferably 50 to 70 mass%, provided that the total content of the sodium bicarbonate-based blowing agent (F1) and the microcapsule-type blowing agent (F2) is 100 mass%. When the content of the sodium bicarbonate-based blowing agent (F1) relative to the total content of the sodium bicarbonate-based blowing agent (F1) and the microcapsule-type blowing agent (F2) (F1 / (F1+F2)) is within the above range, a molded product having an excellent balance of water absorption, surface roughness, and compression set is likely to be obtained.

[0103] [Other ingredients] The copolymer composition may contain components other than the hydrosilyl group-containing compound (Y), the platinum-based catalyst, the reaction inhibitor, carbon black, the sodium bicarbonate-based blowing agent (F1), and the microcapsule-type blowing agent (F2) (hereinafter, these may be simply referred to as "other components"), as long as the object of the present invention is not impaired. Examples of other components include antioxidants, colorants other than carbon black, antioxidants, processing aids, activators, moisture absorbers, organic peroxides, and crosslinking aids, as well as known and commonly used rubber compounding agents such as metal salts of α,β-unsaturated organic acids, crosslinking accelerators, and tackifiers.

[0104] [Antioxidants] The copolymer composition may contain an antioxidant, preferably a hindered phenol-based antioxidant. By including a hindered phenol-based antioxidant, the copolymer composition of this embodiment can give a crosslinked molded article having a high water absorption rate and excellent compression set. The antioxidant may be contained alone or in combination of two or more kinds.

[0105] 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: Adeka STAB 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 (manufactured by ADEKA Corporation, trade name: Adeka STAB AO-20, melting point: 220 to 222°C), and 4,4'-butylidenebis(6-tert-butyl-m-cresol). (manufactured by ADEKA Corporation, trade name: Adekastab AO-40, melting point: 210 to 214°C), N,N'-bis{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl}hydrazine (manufactured by BASF Japan Ltd., trade name: Irganox MD1024, melting point: 224 to 229°C), pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (manufactured by BASF Japan Ltd., trade name: Irganox 1010, melting point: 110 to 130°C), dibutylhydroxytoluene, 2,5-di-tert-butylhydroquinone (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name: Nocrac NS-7, melting point: 200°C or higher), and the like.

[0106] When the copolymer composition contains an antioxidant, the content of the antioxidant relative to 100 parts by mass of the copolymer (S) 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 0.5 to 8 parts by mass.

[0107] [Coloring agent] The copolymer composition may contain pigments other than carbon black, which is usually used as a colorant in rubber, and dyes for the purpose of enhancing design properties, etc. The pigment may be either an organic pigment or an inorganic pigment. Inorganic pigments other than carbon black, which are usually used as a reinforcing agent for rubber, may also be blended.

[0108] Examples of organic pigments include azo pigments such as azo lake pigments, insoluble monoazo pigments, insoluble disazo pigments, condensed azo pigments, and chelate azo pigments; polycyclic pigments such as phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments; dye chelates such as basic dye chelates and acid dye chelates; and nitro pigments and nitroso pigments.

[0109] Specific examples of organic pigments include Pigment Yellow 1 (Color Index (hereinafter referred to as CI) 11680), Pigment Yellow 3 (CI 11710), Pigment Yellow 14 (CI 21095), Pigment Yellow 17 (CI 21105), Pigment Yellow 42 (CI 77492), Pigment Yellow 74 (CI 11741), Pigment Yellow 83 (CI 21108), Pigment Yellow 93 (CI 20710), and Pigment Yellow 98 (CI 11727). ), Pigment Yellow 109 (CI 56284), Pigment Yellow 110 (CI 56280), Pigment Yellow 128 (CI 20037), Pigment Yellow 138 (CI 56300), Pigment Yellow 139 (CI 56298), Pigment Yellow 147 (CI 60645), Pigment Yellow 154 (CI 11781), Pigment Yellow 155 (CI -), Pigment Yellow 180 (CI 21290), Pigment Yellow 185 (CI 56290), Pigment Orange 5 (CI 12075), Pigment Orange 13 (CI 21110), Pigment Orange 16 (CI 21160), Pigment Orange 34 (CI 21160), Pigment Orange 43 (CI 71105), Pigment Orange 61 (CI 11265), Pigment Orange 71 (CI 56120), Pigment Red 5 (CI 12490), Pigment Red 8 (CI 12335), Pigment Red 17 (CI 12390), Pigment Red 22 (CI 12315), Pigment Red 48:2 (CI 15865:2), Pigment Red 112 (CI 12370), Pigment Red 122 (CI 73915), Pigment Red 177 (CI 65300), Pigment Red 202 (CI 73907), Pigment Red 254 (CI 56110), Pigment Violet 19 (CI 46500), Pigment Violet 23 (CI 51319), Pigment Blue 15:1 (CI 74160), Pigment Blue 15:3 (CI74160), Pigment Blue 15:4 (CI 74160), Pigment Blue 60 (CI 69800), Pigment Green 7 (CI 74260), Pigment Green 36 (CI 74265), etc.

[0110] Examples of inorganic pigments include titanium oxide, iron oxide yellow, iron oxide brown, chromium oxide, Prussian blue, ultramarine, molybdenum red, iron oxide black, lead yellow, composite oxide pigments, and carbon black, as well as pigments commonly referred to as inorganic reinforcing agents, such as silica, activated calcium carbonate, finely divided talc, finely divided silicic acid, light calcium carbonate, heavy calcium carbonate, talc, kaolin, and clay.

[0111] Specific examples of inorganic pigments other than carbon black include Pigment Yellow 42 (CI 77492), Pigment Yellow 74 (CI 11741), Pigment Yellow 109 (CI 56284), Pigment Yellow 110 (CI 56280), Pigment Yellow 128 (CI 20037), Pigment Yellow 155 (CI -), Pigment Yellow 180 (CI 21290), Pigment Red 122 (CI 73915), Pigment Red 202 ( Pigment Blue 15:1 (CI 74160), Pigment Blue 15:3 (CI 74160), Pigment Blue 15:4 (CI 74160), Pigment Blue 60 (CI 69800), Pigment Blue 27 (CI 77510), Pigment Blue 29 (CI 77007), Pigment White 6 (CI 77891), Pigment Black 7 (CI 77266), etc.

[0112] Among colorants, isoindolinone pigments, quinacridone pigments, condensed azo pigments, phthalocyanine pigments, quinophthalone pigments, and anthraquinone pigments are preferred because of their excellent light-shielding properties.

[0113] [Plasticizer] The copolymer composition may include a plasticizer. The plasticizer is a known plasticizer that is compounded in rubber compositions.Specific examples include petroleum-based plasticizers such as paraffin-based process oil, lubricating oil, paraffin oil, liquid paraffin, petroleum asphalt, and Vaseline; coal tar-based plasticizers such as coal tar; fatty oil-based plasticizers such as castor oil, linseed oil, rapeseed oil, soybean oil, and palm 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 plasticizers such as dioctyl phthalate and dioctyl adipate; and other plasticizers such as microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, hydrocarbon-based synthetic lubricating oil, tall oil, and sub(factice).Among these, petroleum-based plasticizers are preferred, and paraffin-based process oil is particularly preferred. The copolymer composition may contain two or more plasticizers.

[0114] When the copolymer composition contains a plasticizer, the content of the plasticizer is preferably 50 to 150 parts by mass, more preferably 60 to 100 parts by mass, and even more preferably 80 to 100 parts by mass, per 100 parts by mass of copolymer (S). When the content of the plasticizer 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.

[0115] [Anti-aging agent] The copolymer composition may include an antioxidant. As the antioxidant, known antioxidants used in general rubber compositions can be used, specifically, phenol-based antioxidants, amine-based antioxidants, etc. The antioxidants may be used alone, but are preferably used in combination of two or more kinds in order to maintain heat aging resistance for a long period of time at high temperatures.

[0116] When the copolymer composition contains a phenolic antioxidant, it can be used in an amount of preferably 0.2 to 5 parts by mass, more preferably 0.5 to 4 parts by mass, and particularly preferably 0.5 to 3 parts by mass, per 100 parts by mass of the copolymer (S). When the phenolic antioxidant is used in the above range, the effect of improving heat aging resistance is significant.

[0117] When the copolymer composition contains an amine-based antioxidant, it is preferably used in an amount of 0.05 to 5 parts by mass, more preferably 0.1 to 4 parts by mass, and particularly preferably 0.2 to 3 parts by mass, per 100 parts by mass of the copolymer (S). When the amine-based antioxidant is used in the above range, the effect of improving heat aging resistance is significant.

[0118] [Processing aids] The copolymer composition may also include a processing aid. As the processing aid, a wide variety of processing aids that are generally compounded in rubber can be used. Specific examples include ricinoleic acid, stearic acid, palmitic acid, lauric acid, barium stearate, zinc stearate, calcium stearate, zinc laurate, and esters thereof. Among these, stearic acid is preferred as the processing aid.

[0119] The processing aid may be used alone or in combination of two or more kinds. When the copolymer composition contains a processing aid, the content of the processing aid is preferably 1 to 3 parts by mass per 100 parts by mass of the copolymer (S). When the content of the processing aid is within this range, contamination of the surface of the crosslinked molded article due to bloom is reduced.

[0120] [Activator] The copolymer composition may include an active agent. Examples of surfactants 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.

[0121] The active agent may be one kind alone or two or more kinds. When the copolymer composition contains an activator, the content of the activator is preferably 0.2 to 10 parts by mass, more preferably 0.3 to 5 parts by mass, per 100 parts by mass of the copolymer (S). When the content of the activator is within the above range, good physical properties can be obtained.

[0122] [Moisture absorbent] The copolymer composition may also include a moisture absorbent. Examples of moisture absorbents include calcium oxide, silica gel, sodium sulfate, molecular sieves, zeolite, and white carbon. Among these, calcium oxide is preferred as the moisture absorbent. The content of the moisture absorbent is preferably 1 to 20 parts by mass, more preferably 5 to 17 parts by mass, and even more preferably 8 to 15 parts by mass, per 100 parts by mass of the copolymer (S). The copolymer composition may contain one or more types of moisture absorbents.

[0123] [Organic peroxide] The copolymer composition may contain an organic peroxide. Examples of organic peroxides include dicumyl peroxide (DCP), di-tert-butyl peroxide, 2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)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, ert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide.

[0124] When the copolymer composition contains an organic peroxide, the content of the organic peroxide per 100 parts by mass of the copolymer (S) is preferably 0.2 to 6 parts by mass, more preferably 0.2 to 4.8 parts by mass, and even more preferably 0.2 to 4 parts by mass. The total content of the hydrosilyl group-containing compound (Y) and the organic peroxide relative to 100 parts by mass of the copolymer (S) is preferably 0.01 to 0.15 equivalents, more preferably 0.01 to 0.1 equivalents, and even more preferably 0.02 to 0.1. The equivalent ratio [Y / Z] of the content of the hydrosilyl group-containing compound (Y) to the content of the organic peroxide (Z) is preferably 23 / 77 to 99 / 1, more preferably 47 / 53 to 99 / 1.

[0125] [Crosslinking aid] The copolymer composition may contain a crosslinking coagent. Specific examples of the crosslinking aid include sulfur, quinone dioxime compounds such as p-quinone dioxime, methacrylate compounds such as polyethylene glycol dimethacrylate, allyl compounds such as diallyl phthalate and triallyl cyanurate, maleimide compounds, divinylbenzene, etc. Such a crosslinking aid is preferably used in an amount of 0.5 to 2 moles, more preferably about equimolar, per mole of the hydrosilyl group-containing compound (Y) used.

[0126] [Other resins] The copolymer composition may contain a resin and / or rubber other than the copolymer (S) within a range that does not impair the effects of the present invention. The content of the resin and rubber other than the copolymer (S) is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of the copolymer (S). It is preferable that the copolymer composition is substantially free of such resin and rubber.

[0127] Examples of resins other than the copolymer (S) include general-purpose resins such as polyethylene, polypropylene, and polystyrene. Examples of rubber include silicone rubber, ethylene-propylene random copolymer rubber (EPR), natural rubber, styrene-butadiene rubber, isoprene rubber, butadiene rubber, and chloroprene rubber.

[0128] [Physical properties of copolymer composition] The copolymer composition preferably has a difference [S'max-S'min] between the maximum torque value S'max and the minimum torque value S'min measured at a crosslinking temperature of 25°C and a crosslinking time of 60 minutes of 3 dNm or more. The difference [S'max-S'min] is preferably 3 to 20 dNm, more preferably 3 to 15 dNm, and even more preferably 3 to 10 dNm.

[0129] When the difference [S'max - S'min] is equal to or greater than the preferred lower limit, sufficient crosslinking can be achieved at room temperature. When the difference [S'max - S'min] is equal to or less than the preferred upper limit, the shape can be easily maintained during molding. The difference [S'max-S'min] can be appropriately adjusted by the content of the hydrosilyl group-containing compound (Y).

[0130] When the crosslinking temperature was 25°C and the crosslinking time was 60 minutes, the copolymer composition had a torque value corresponding to 90% of the difference [S'max-S'min] from the minimum torque value S'min and a torque value corresponding to the minimum torque value S' min It is preferable that tc90, which is the time required to reach a torque value corresponding to the sum of Under the above conditions, tc90 is preferably 1 to 30 minutes, more preferably 2 to 20 minutes, and even more preferably 3 to 10 minutes.

[0131] When tc90 is equal to or greater than the preferable lower limit, it is easy to ensure time for molding. Furthermore, by ensuring that tc90 is equal to or less than the preferred upper limit, the time required for sufficient crosslinking after molding can be shortened. The tc90 can be adjusted by the content of the platinum complex contained in the platinum catalyst and the amount of the platinum catalyst used in the copolymer composition.

[0132] [Production of copolymer composition] The method for producing the copolymer composition is not particularly limited, and examples thereof include the same methods as those for producing known general rubber compositions. Specifically, the method is as follows. For example, the copolymer (S) and other components are kneaded for 3 to 10 minutes (first kneading) using an internal mixer such as a Banbury mixer, kneader, or intermix at a temperature of 80 to 170°C, followed by adding the hydrosilyl group-containing compound (Y), platinum catalyst, reaction inhibitor, carbon black, sodium bicarbonate blowing agent (F1), microcapsule-type blowing agent (F2), and, if necessary, other compounding agents such as reinforcing agents and plasticizers, as well as other rubbers and resins, and then kneading for 5 to 30 minutes (second kneading) using rolls such as open rolls or a kneader at a roll temperature of 50 to 80°C, followed by dispensing. In this way, a copolymer composition typically in the form of a ribbon or sheet is obtained.

[0133] To obtain the copolymer composition, it is preferable to knead the copolymer (S), the hydrosilyl group-containing compound (Y), carbon black, and, if necessary, other components (first kneading), and then add the platinum-based catalyst, the reaction inhibitor, the sodium bicarbonate-based blowing agent (F1), the microcapsule-type blowing agent (F2), and, if necessary, other components to the resulting kneaded mixture and knead them (second kneading). When an organic peroxide is added, it may be added during the second kneading.

[0134] Specifically, the copolymer (S), the hydrosilyl group-containing compound (Y), carbon black, and other components as required are kneaded at 80 to 150°C for 1 to 10 minutes, preferably at 110 to 150°C for 3 to 8 minutes (first kneading), and then the platinum catalyst, reaction inhibitor, sodium bicarbonate blowing agent (F1), microcapsule-type blowing agent (F2), and other components as required are added to the resulting kneaded mixture, and the mixture is kneaded at 10 to 100°C for 1 to 10 minutes, preferably at 20 to 80°C for 3 to 7 minutes (second kneading).

[0135] A colorant such as carbon black may be added during either the first kneading or the second kneading, but is preferably added during the first kneading. The same applies when reinforcing agents, plasticizers, etc. other than carbon black are added. When other rubber compounding agents, such as metal salts of α,β-unsaturated organic acids, moisture absorbents, antioxidants, fillers, processing aids, activators, and tackifiers are added, they are preferably added during the first kneading, and crosslinking aids and crosslinking accelerators are preferably added during the second kneading.

[0136] 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.

[0137] <Crosslinked molded body> The crosslinked molded article according to the present invention is a crosslinked molded article made of the copolymer composition described above. The crosslinked molded article is obtained by crosslinking the copolymer composition described above. The crosslinked molded article can be obtained by preforming the copolymer composition of the present invention into a desired shape by a molding method 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. Since the copolymer composition contains a foaming agent, foaming proceeds simultaneously with crosslinking, resulting in a foamed crosslinked molded article (foamed molded article).

[0138] When crosslinking by heating, any known method can be used without limitation as the heating method, 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). Molten molding and crosslinking may or may not be performed using a mold. When a mold is not used, the copolymer composition is usually molded and crosslinked continuously.

[0139] It is also preferred to press-mold the copolymer composition to perform primary crosslinking, remove the primary molded article from the mold, and then perform secondary crosslinking in a heat medium. Specifically, the copolymer composition is press-molded at 120 to 200°C for 1 to 20 minutes, preferably at 150 to 200°C for 10 to 18 minutes, to perform primary crosslinking, and then removed from the mold to obtain a primary molded article.Then, the obtained primary molded article is subjected to secondary crosslinking in a heat medium at 120 to 160°C for 10 to 24 hours, preferably at 140 to 160°C for 15 to 20 minutes. Examples of the heat medium used for the secondary crosslinking include air, steam, paraffin-based process oil, and molten salt.

[0140] When primary crosslinking is performed by press molding, the crosslinked body is less likely to reach high temperatures due to shear heating, which makes it possible to prevent the generation of low-molecular-weight siloxanes and polymer degradation. Furthermore, in press molding in which crosslinking is performed in a sealed state, a certain amount of generated low molecular weight siloxane remains inside the crosslinked body, but by subsequently performing secondary crosslinking in a heat medium, the low molecular weight siloxane can be volatilized, making it possible to obtain a crosslinked body with a low amount of low molecular weight siloxane.

[0141] The crosslinked molded article can be used in a variety of applications. Specific examples include tire rubber, O-rings, industrial rolls, packing (e.g., condenser packing), gaskets, belts (e.g., heat-insulating belts, copier belts, and conveyor belts), hoses such as automotive hoses (e.g., water hoses, brake reservoir hoses, radiator hoses, and air hoses), vibration-isolating rubber, vibration-insulating or vibration-damping materials (e.g., engine mounts and motor mounts), muffler hangers, sponges (e.g., weatherstrip sponges, heat-insulating sponges, protective sponges, and micro-foam sponges), cables (ignition cables, cab-tire cables, and high-tension cables), electric wire coating materials (high-voltage wire coating materials, low-voltage electric wire coating materials, and marine electric wire coating materials), glass run channels, color skin materials, paper feed rolls, and roofing sheets. Among these, the crosslinked molded article is particularly suitable for use as a weatherstrip sponge.

[0142] [Weatherstrip sponge] The weatherstrip sponge according to the present invention is a crosslinked product of the copolymer composition. Examples of weatherstrip sponges include door sponges, opening trim sponges, hood seal sponges, and trunk seal sponges. Weatherstrip sponge has sufficient rigidity despite its low specific gravity, making it lightweight and providing excellent door closing performance. The specific gravity of the weatherstrip sponge is preferably 0.3 to 0.5, more preferably 0.3 to 0.45. The low extension stress (σ25) of the weatherstrip sponge is preferably 0.15 to 0.35 MPa, more preferably 0.15 to 0.30 MPa. [Example]

[0143] The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples. The physical properties of the copolymer (S), uncrosslinked copolymer composition (copolymer composition immediately after the second stage kneading described below, the same applies hereinafter) and crosslinked molded article of each example were measured and evaluated by the following methods.

[0144] <Measurement method> [Composition of copolymer (S)] The content of each structural unit in the copolymer (S) is: 13 The C-NMR spectrum of the copolymer (S) was calculated using an ECX400P nuclear magnetic resonance spectrometer (manufactured by JEOL Ltd.) under the conditions of a measurement temperature of 120°C, a measurement solvent of orthodichlorobenzene / deuterated benzene = 4 / 1, and an accumulation number of 8000. 13 C-NMR spectrum was measured.

[0145] [Iodine value of copolymer (S)] The iodine value of the copolymer (S) was determined by titration. Specifically, it was measured by the following method. 0.5 g of copolymer (S) was dissolved in 60 mL of carbon tetrachloride, a small amount of Wiss's reagent and 20% by mass potassium iodide solution were added, and the solution was titrated with 0.1 mol / L sodium thiosulfate solution. Near the end point, starch indicator was added, and the solution was titrated with thorough stirring until the pale purple color disappeared. The amount of halogen consumed per 100 g of sample was calculated as the number of grams of iodine.

[0146] [3D-GPC measurement conditions] The weight average molecular weight (Mw) and the number of long chain branches (LCB) per 1000 carbon atoms of the copolymer (S) 1000C ) is a value determined by structural analysis using 3D-GPC. Specifically, the absolute molecular weight distribution was determined using a 3D-high temperature GPC device (PL-GPC220, manufactured by Polymer Laboratories), and the intrinsic viscosity in decalin at 135°C was simultaneously determined using a viscometer. The main measurement conditions are as follows:

[0147] 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)

[0148] Column: TSKgel GMHHR-H(S)HT x 2 + TSKgel GMHHR-M(S) x 1 (inner diameter 7.8mmφ x length 300mm per piece) 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

[0149] The dn / dc value (differential value of refractive index n with respect to concentration c) required to determine the absolute molecular weight was determined 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. Long chain branches per 1000 carbon atoms (LCB) 1000C ) was calculated using the method described above.

[0150] [Intrinsic viscosity [η] of copolymer (S)] The intrinsic viscosity [η] of the copolymer (S) was measured using a fully automatic intrinsic viscometer (manufactured by Rigo Co., Ltd.) under the conditions of a temperature of 135° C. and a measurement solvent of decalin.

[0151] [P value of copolymer (S)] 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 = 0.1 rad / s under the conditions of 190 °C and 1.0% strain. * (ω=0.1) , and the complex viscosity η at frequency ω=100 rad / s * (ω=100) (All units are Pa·sec) were measured. * (ω=0.1) and η * (ω=100) The P value of the copolymer (η * (ω=0.1) / η * (ω=100) ) was calculated.

[0152] [Mooney viscosity (ML (1+4) 125℃)] Mooney viscosity (ML) of uncrosslinked copolymer composition at 100°C (1+4) The viscosity (viscosity) was measured at 100°C using a Mooney viscometer (Shimadzu Corporation, Model SMV202) in accordance with JIS K6300.

[0153] [Crosslinking behavior of copolymer composition] The following values ​​were determined from crosslinking curves measured at the crosslinking temperatures and crosslinking times shown in each table in accordance with JIS K6300-2 using the uncrosslinked copolymer compositions of Examples 1 to 3 and Comparative Examples 1 and 2. A Premier MDR (manufactured by Alpha Technologies) was used for the measurements. "tcx1" (min) represents the time required to reach a torque value equivalent to the sum of the minimum torque value S'min and a torque value equivalent to x1% of "S'max-S'min". "tc90" in Table 2 means the time it takes to reach the torque value corresponding to the sum of the minimum torque value S'min and the torque value corresponding to 90% of "S'max-S'min".

[0154] [Compression set] The tubular sponge was cut into 30 mm lengths, and the resulting test specimens were attached to a compression set measurement mold. The test specimens were compressed to half their original height before the load was applied, and then placed together with the mold in a gear oven set to 70°C for 197 hours. The test piece was then removed from the mold and allowed to cool for 30 minutes, after which the height of the test piece was measured and the compression set [CS] (%) was calculated using the following formula: The smaller the compression set [CS] value, the better the recovery force when compressed, and the better the sealing performance of the resulting molded product (sponge). Compression set [CS] (%) = {(t0-t1) / (t0-t2)} x 100 t0: Height of the specimen before the test t1: Height of the test piece after heat treatment and cooling for 30 minutes t2: Height of the test piece attached to the measurement mold

[0155] [specific gravity] The top of the tubular sponge was punched out to a size of 20 mm x 20 mm, and the dirt on the surface of the obtained test piece was wiped off with alcohol. The test piece was attached to an automatic hydrometer (M-1 model, manufactured by Toyo Seiki Seisakusho Co., Ltd.) in an atmosphere of 25°C, and the mass of the test piece measured in air and the mass of the test piece measured in pure water were measured, and the specific gravity of the test piece was calculated from the difference between these masses.

[0156] [Water absorption rate] A 20mm x 20mm test piece was punched out of the tubular sponge, and surface dirt was wiped off with alcohol. The test piece was then depressurized to 635mmHg at a position 50mm below the water surface and held there for 1 minute. The pressure was then returned to atmospheric pressure, and after 3 minutes, the mass of the water-absorbed test piece was measured, and the water absorption rate was calculated using the following formula. A water absorption rate of 40% or less is considered to be low, and is also preferred because it results in denser foam cells in a molded product (sponge) with low water absorption rate. Wa={(W2-W1) / W1} W1: Mass before immersion (g) W2: Mass after immersion (g)

[0157] [Surface roughness] The surface roughness of the tubular sponge was expressed by quantifying the irregularities on the top surface of the tubular sponge using a stylus surface roughness measuring instrument. Measurements were taken on a sponge cut to a length of 50 mm, and the reference length specified by JIS B 0601:1994 and JIS B 0031:1994 was extracted from the roughness curve in the direction of the mean line. The surface roughness (μm) of the tubular sponge was calculated by subtracting the sum of the heights of the convex parts from the maximum to the 10th value (h1) from the sum of the heights of the concave parts from the minimum to the 10th smallest value (h2) and dividing this value (h1-h2) by 10. The smaller the value of the surface roughness (μm), the smoother the surface of the resulting molded product (sponge) will be, which is preferable.

[0158] <Copolymer (S)> The copolymer (S) used in each example was produced by the method of the following production example.

[0159] [Ethylene-propylene-VNB copolymer] [Production Example 1: Production of Copolymer (S-1)] A 300-liter polymerization reactor 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. Ethylene was continuously fed through separate lines at 6.6 kg / hr, 9.3 kg / hr of propylene, 18 L / hr of hydrogen, and 340 g / hr of 5-vinyl-2-norbornene (VNB), 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. The physical properties of the resulting ethylene-propylene-VNB copolymer (copolymer (S-1)) were measured by the methods described above. The results are shown in Table 1.

[0160] [Table 1]

[0161] Example 1 [Preparation of Uncrosslinked Copolymer Composition] In the first stage, the raw materials shown in Raw Material 1 in Table 2 were mixed for 2 minutes at 140°C using a Banbury mixer (manufactured by Kobe Steel, Model BB-L1800). 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 materials shown in raw material 2 in Table 2 were added thereto and kneaded for 10 minutes to obtain an uncrosslinked copolymer composition for each example. The Mooney viscosity and crosslinking behavior of the uncrosslinked copolymer compositions were determined by the above-mentioned measurement methods. The results are shown in Table 2.

[0162] [Preparation of cross-linked tubular sponge body] The obtained uncrosslinked copolymer composition was extruded into a tube using a 50 mm diameter extruder equipped with a tubular die (inner diameter: height 13 mm × width 11 mm, wall thickness: 1.5 mm) at a die temperature of 80°C and a cylinder temperature of 50°C. Simultaneously with molding, this molded body was introduced into a vulcanization tank and heated at 250°C for 3 minutes for crosslinking and foaming treatment, yielding a tubular sponge. The physical properties of the resulting tubular sponge were measured by the above-mentioned methods, and the results are shown in Table 2.

[0163] <Examples 2 and 3> An uncrosslinked copolymer composition was prepared in the same manner as in Example 1, except that the raw materials shown in Table 2 were used in Example 1. In addition, a tubular sponge was produced in the same manner as in Example 1, except that the obtained uncrosslinked copolymer composition was used, and the physical properties of the obtained tubular sponge were determined. The results are shown in Table 2.

[0164] <Comparative Example 1> [Preparation of tubular sponge crosslinked molding (comparative example)] An uncrosslinked copolymer composition was prepared in the same manner as in Example 1, except that the raw materials shown in Table 2 were used instead. The uncrosslinked copolymer composition obtained was heated for 3 minutes to crosslink and foam in the same manner as described in [Example 8] of WO 2009 / 072503, to produce a tubular sponge, and the physical properties of the resulting tubular sponge were determined. The results are shown in Table 2.

[0165] <Comparative Example 2> An uncrosslinked copolymer composition was prepared in the same manner as in Example 1, except that the raw materials shown in Table 2 were used in Example 1. In addition, a tubular sponge was produced in the same manner as in Comparative Example 1, except that the obtained uncrosslinked copolymer composition was used, and the physical properties of the obtained tubular sponge were determined. The results are shown in Table 2.

[0166] [Table 2]

[0167] The details of each component in Table 2 are as follows: In Table 2, "-" means that the corresponding component is not included. <Crosslinking agent> Hydrosilyl group-containing compound (Y-1-1): A compound represented by the following formula (a-1) was synthesized and used according to the method described in paragraphs

[0322] to

[0324] of WO 2023 / 136287.

[0168] [ka]

[0169] <Other ingredients> Carbon black: Asahi #50HG manufactured by Asahi Carbon Co., Ltd. Plasticizer: Diana Process Oil PS-430, manufactured by Idemitsu Kosan Co., Ltd. Dehydrating agent: Vesta C-80N, manufactured by Inoue Lime Industry Co., Ltd. Sodium bicarbonate foaming agent (F1): Eiwa Chemical Industry Co., Ltd., Celbon SC-850 Microcapsule type foaming agent (F2): Neoslen HM50B, manufactured by Eiwa Chemical Industry Co., Ltd. Reaction inhibitor: 1-ethynyl-1-cyclohexanol, manufactured by Nissin Chemical Industry Co., Ltd. Platinum catalyst: SRX212 Catalyst, manufactured by Dow Toray Industries, Inc., a complex salt of chloroplatinic acid and 1,3-divinyltetramethyldisiloxane

[0170] As shown in Table 2, the crosslinked molded articles of Examples 1 to 3 are superior to the crosslinked molded articles of Comparative Examples 1 and 2 in terms of the balance of water absorption, surface roughness, and compression set.

Claims

1. a copolymer (S) having 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 selected from the following formula (I) and the following formula (II); a hydrosilyl group-containing compound (Y) represented by the following formula (a), which is an organohydrogenpolysiloxane having 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 sodium bicarbonate-based foaming agent (F1); a microcapsule-type blowing agent (F2); A copolymer composition comprising: 【Chemistry 1】 【Chemistry 2】 (In formula (a), n and p are each independently 0 or a positive number, m is 1 to 20, the sum of n, m, and p is 5 to 50, and a plurality of R １ and R ２ are each independently a monovalent alkyl group, and R ａ is an aralkyl group, and two R are each independently R １ , R ２ , a hydrogen atom, and R ａ is selected from the group consisting of —[O—Si(R １ ) (R ａ )]-,-[O-Si(R １ )H]- and -[O-Si(R １ ) (R ２ ))]- may be arranged in a block form or randomly. However, when n=1, at least one of the two R's is a hydrogen atom, and when n=0, both of the two R's are hydrogen atoms.

2. 2. The copolymer composition according to claim 1, wherein the content of the sodium bicarbonate-based blowing agent (F1) is 0.1 to 20 parts by mass relative to 100 parts by mass of the copolymer (S).

3. 2. The copolymer composition according to claim 1, wherein the content of the microcapsule-type blowing agent (F2) is 0.1 to 20 parts by mass based on 100 parts by mass of the copolymer (S).

4. 2. The copolymer composition according to claim 1, wherein the ratio of the content of the sodium bicarbonate-based blowing agent (F1) to the total content of the sodium bicarbonate-based blowing agent (F1) and the microcapsule-type blowing agent (F2) is 5 to 95% by mass (provided that the total content of the sodium bicarbonate-based blowing agent (F1) and the microcapsule-type blowing agent (F2) is 100% by mass).

5. 2. The copolymer composition according to claim 1, wherein the content of the carbon black is 10 to 300 parts by mass, the content of the platinum-based catalyst is 0.001 to 10 parts by mass, and the content of the reaction inhibitor is 0.05 to 5 parts by mass, relative to 100 parts by mass of the copolymer (S).

6. The copolymer composition according to claim 1, wherein the copolymer (S) has an intrinsic viscosity [η] measured in decalin at 135°C of 2.0 dL / g or more and less than 4.0 dL / g.

7. The copolymer composition according to claim 1, wherein the copolymer (S) satisfies the following requirements (1) and (2): Requirement (1): The ratio ([A] / [B]) of the number of moles [A] 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 40 / 60 to 99.9 / 0.1; Requirement (2): The mass fraction of the structural units derived from the non-conjugated polyene (C) is 0.07 to 10 mass % based on the total mass of the structural units constituting the copolymer (S).

8. The copolymer composition according to claim 1, wherein the copolymer (S) satisfies at least one of the following requirements (3) to (5): Requirement (3): The weight average molecular weight (Mw) of the copolymer (S), 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 [A3] (molecular weight of (C)) satisfy the following formula (ii): 4.5≦[Mw×mass fraction (mass%) 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 complex viscosity η at 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 (S), and the mass fraction of the structural unit derived from the non-conjugated polyene (C) satisfy the following formula (iii): P / ([η] ２．９ )≦mass fraction of non-conjugated polyene (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)] satisfies the following formula (iv). LCB １０００Ｃ ≦1-0.07×Ln(Mw) ・・・Formula (iv)

9. 2. The copolymer composition according to claim 1, wherein the structural units derived from the non-conjugated polyene (C) include structural units derived from 5-vinyl-2-norbornene.

10. 2. The copolymer composition according to claim 1, further comprising a plasticizer, wherein the content of the plasticizer is 50 to 150 parts by mass per 100 parts by mass of the copolymer (S).

11. A crosslinked molded article comprising the copolymer composition according to any one of claims 1 to 10.

12. A weatherstrip sponge comprising the copolymer composition according to any one of claims 1 to 10.

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