Copolymer composition and its uses

Abstract

Provided is a copolymer rubber composition from which a crosslinked molded article having well-balanced and excellent properties in terms of low hardness, small compression set at low temperatures, and high abrasion resistance can be obtained. [Solution] The copolymer composition comprises 100 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (P) having structural units derived from ethylene [A1], structural units derived from an α-olefin [A2] having 4 to 20 carbon atoms, and structural units derived from a non-conjugated polyene [A3], wherein the [A2] contains 1-butene, and satisfies the following (1) and (2): (1) the ratio [[e] / [x]] of the molar fraction [e] of the structural units derived from ethylene [A1] to the molar fraction [x] of the structural units derived from the α-olefin [A2] having 4 to 20 carbon atoms is 40 / 60 to 90 / 10; and (2) the intrinsic viscosity [η] measured in decalin at 135°C is 5.0 to 7.0 dl / g.

Description

[Technical Field]

[0001] The present invention relates to a copolymer composition and its use. [Background technology]

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

[0003] It is known that carbon black is added to copolymer rubber such as EPDM in order to obtain a rubber compound with excellent abrasion resistance (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-151958 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-153773 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while crosslinked molded articles obtained from conventional copolymer rubber compositions containing carbon black have excellent abrasion resistance, there is room for further improvement in terms of lowering hardness and reducing compression set at low temperatures.

[0006] Therefore, an object of the present invention is to provide a copolymer rubber composition from which a crosslinked molded article having well-balanced and excellent properties in terms of low hardness, small compression set at low temperatures, and high abrasion resistance can be obtained. [Means for solving the problem]

[0007] As a result of extensive research aimed at solving the above problems, the present inventors have found that the above problems can be solved by the following embodiments, and have completed the present invention.

[0008] [1] A polymer having a structural unit derived from ethylene [A1], a structural unit derived from an α-olefin having 4 to 20 carbon atoms [A2], and a structural unit derived from a non-conjugated polyene [A3], the α-olefin [A2] having 4 to 20 carbon atoms includes 1-butene, 100 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (P) that satisfies the following requirements (1) and (2), and 5 to 150 parts by mass of carbon black (D) A copolymer composition comprising: Requirement (1): The ratio [e] / [x] of the molar fraction [e] of structural units derived from ethylene [A1] to the molar fraction [x] of structural units derived from an α-olefin [A2] having 4 to 20 carbon atoms is 40 / 60 to 90 / 10 (provided that the sum of the molar fractions of structural units derived from [A1], [A2] and [A3] is 100 mol %). Requirement (2): The intrinsic viscosity [η] measured in decalin at 135°C is 5.0 to 7.0 dl / g.

[0009] [2] The copolymer composition according to item [1], wherein the ethylene-α-olefin-non-conjugated polyene copolymer (P) satisfies the following requirement (3): Requirement (3): The molar fraction [y] of the structural unit derived from the non-conjugated polyene [A3] is 0.1 to 6.0 mol %.

[0010] [3] The copolymer composition according to item [1] or [2], wherein the ethylene-α-olefin-non-conjugated polyene copolymer (P) satisfies the following requirement (4): Requirement (4): The B value represented by the following formula (i) is 1.20 or more. B value=([EX]+2[Y]) / [2×[E]×([X]+[Y])]···(i) (Here, [E], [X], and [Y] represent the mole fractions of structural units derived from ethylene [A1], α-olefin [A2] having 4 to 20 carbon atoms, and non-conjugated polyene [A3], respectively, and [EX] represents the fraction of ethylene [A1]-α-olefin [A2] having 4 to 20 carbon atoms dyad chains.)

[0011] [4] The copolymer composition according to any one of items [1] to [3], wherein the non-conjugated polyene [A3] contains only one partial structure represented by a structural formula selected from the group consisting of the following partial structural formulas (I) and (II) in one molecule: [ka]

[0012] [5] The copolymer composition according to any one of items [1] to [4], wherein the non-conjugated polyene [A3] contains 5-ethylidene-2-norbornene.

[0013] [6] The copolymer composition according to any one of items [1] to [5], comprising 5 to 200 parts by mass of a softener per 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (P) and any polymer components other than the ethylene-α-olefin-non-conjugated polyene copolymer (P), which are optionally blended.

[0014] [7] The specific surface area of ​​the carbon black (D) is 100 m 2 The copolymer composition according to any one of items [1] to [6], wherein the copolymer composition has a viscosity of 1000 MPa or less.

[0015] [8] The copolymer composition according to any one of items [1] to [7], which contains a sulfur-based crosslinking agent (J).

[0016] [9] A crosslinked product of the copolymer composition according to any one of items [1] to [8].

[0017]

[10] A roll comprising the crosslinked body according to item [9].

[0018]

[11] A sheet comprising the crosslinked product according to item [9]. [Effects of the Invention]

[0019] The present invention can provide a copolymer rubber composition that can give a crosslinked molded article having well-balanced and excellent properties in terms of low hardness, small compression set at low temperatures, and high abrasion resistance. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be described in detail below.

[0021] <Copolymer composition> The copolymer composition of the present invention is characterized by containing an ethylene-α-olefin-non-conjugated polyene copolymer (P) (hereinafter also referred to as "copolymer (P)"), and 5 to 150 parts by mass of carbon black (D) per 100 parts by mass of the copolymer (P).

[0022] <Ethylene-α-olefin-non-conjugated polyene copolymer (P)> The ethylene-α-olefin-non-conjugated polyene copolymer (P) has a structural unit derived from ethylene [A1], a structural unit derived from an α-olefin having 4 to 20 carbon atoms [A2], and a structural unit derived from a non-conjugated polyene [A3], the structural units derived from the α-olefin [A2] having 4 to 20 carbon atoms include structural units derived from 1-butene, And meet the following requirements (1) and (2).

[0023] <Requirement (1)> The ratio [e] / [x] of the molar fraction [e] of structural units derived from ethylene [A1] to the molar fraction [x] of structural units derived from an α-olefin [A2] having 4 to 20 carbon atoms is 40 / 60 to 90 / 10, preferably 45 / 55 to 90 / 10, more preferably 50 / 50 to 85 / 15, even more preferably 55 / 45 to 80 / 20, and particularly preferably 60 / 40 to 75 / 25 (wherein the sum of the molar fractions of structural units derived from [A1], [A2], and [A3] is 100 mol %).

[0024] It is preferable that the ratio [e] / [x] of the molar fraction [e] of structural units derived from ethylene [A1] to the molar fraction [x] of structural units derived from α-olefin [A2] is within the above range, in that a good balance between small compression set at low temperatures and mechanical properties is achieved.

[0025] <Requirement (2)> The intrinsic viscosity [η] measured in decalin at 135°C is 5.0 to 7.0 dL / g, preferably 5.5 to 6.5 dL / g, more preferably 5.6 to 6.3 dL / g, and particularly preferably 5.6 to 6.0 dL / g. The measurement conditions can be those in the examples described later. The intrinsic viscosity [η] within the above range is preferable in terms of excellent mechanical properties and oil retention of the copolymer (P).

[0026] The ethylene-α-olefin-non-conjugated polyene copolymer (P) preferably further satisfies at least one of the following requirements (3) and (4):

[0027] <Requirement (3)> The molar fraction [y] of the structural units derived from the non-conjugated polyene [A3] is preferably 0.1 to 6.0 mol %, more preferably 0.3 to 4.0 mol %, even more preferably 0.5 to 3.0 mol %, particularly preferably 0.7 to 2.0 mol %, and even more preferably 1.0 to 1.5 mol % (wherein the sum of the molar fractions of the structural units derived from [A1], [A2] and [A3] is 100 mol %).

[0028] It is preferable that the molar fraction [y] of the structural unit derived from the non-conjugated polyene [A3] is within the above range, since excellent rubber properties are obtained when crosslinked.

[0029] In the above requirements (1) and (3), the mole fractions ([e], [x], and [y]) of the structural units derived from ethylene [A1], the structural units derived from α-olefin [A2], and the structural units derived from non-conjugated polyene [A3] are: 1 It can be determined by measuring the H-NMR spectrum and measuring the intensity.

[0030] <Requirement (4)> The B value represented by the following formula (i) is preferably 1.20 or more, more preferably 1.20 to 1.80, and even more preferably 1.22 to 1.40. B value=([EX]+2[Y]) / [2×[E]×([X]+[Y])]···(i) Here, [E], [X], and [Y] represent the molar fractions of structural units derived from ethylene [A1], α-olefins having 4 to 20 carbon atoms [A2], and non-conjugated polyenes [A3], respectively, and [EX] represents the ethylene [A1]-α-olefins having 4 to 20 carbon atoms [A2] dyad chain fraction. The α-olefin [A2] having 4 to 20 carbon atoms and the non-conjugated polyene [A3] may each be used alone or in combination of two or more.

[0031] Furthermore, if the B value is within the above range, the monomer units constituting the ethylene-α-olefin-non-conjugated polyene copolymer (P) have high alternation and low crystallinity, which is preferable in that the compression set at low temperatures is small.

[0032] The B value specified in requirement (4) is an index showing the randomness of the sequence distribution of the copolymerization monomers in the ethylene-α-olefin-non-conjugated polyene copolymer (P), and [E], [X], [Y], and [EX] in the above formula (i) are 13The C-NMR spectrum can be measured and determined based on reports such as J.C.Randall Macromolecules, 15, 353 (1982) and J. Ray Macromolecules, 10, 773 (1977).

[0033] [α-Olefin [A2]] The ethylene-α-olefin-non-conjugated polyene copolymer (P) contains 1-butene as the α-olefin [A2] having 4 to 20 carbon atoms, and may further contain, in some cases, at least one or more α-olefins having 5 to 20 carbon atoms. The proportion of 1-butene in the α-olefin [A2] having 4 to 20 carbon atoms is preferably 50 mol % or more, more preferably 70 mol % or more, and even more preferably 90 mol % or more, with the upper limit being, for example, 100 mol %. It is preferable that the ethylene-α-olefin-non-conjugated polyene copolymer (P) contains structural units derived from 1-butene, since the copolymer composition has an excellent balance of low hardness, compression set at low temperature, and abrasion resistance.

[0034] Examples of α-olefins having 5 to 20 carbon atoms that may be used in combination include 1-pentene, 1-hexene, 1-octene, 1-nonene, and 1-decene, which have a straight-chain structure without a side chain, as well as 1-nonadecene having 19 carbon atoms and 1-eicosene having 20 carbon atoms, and 4-methyl-1-pentene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene, which have a side chain. As the α-olefin having 5 to 20 carbon atoms that may be used in combination, an α-olefin having 5 to 10 carbon atoms is preferred, and 1-hexene, 1-octene, and the like are particularly preferred.

[0035] [Non-conjugated polyene [A3]] In the present invention, the non-conjugated polyene [A3] preferably contains only one partial structure represented by a structural formula selected from the group consisting of the following partial structural formulas (I) and (II) in one molecule:

[0036] [ka]

[0037] Specific examples of the non-conjugated polyene [A3] include linear non-conjugated dienes such as 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 7-methyl-1,6-octadiene, and cyclic non-conjugated dienes such as cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene (ENB), 5-methylene-2-norbornene, and 5- isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, and the trienes 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,5-norbornadiene, 1,3,7-octatriene, 1,4,9-decatriene, 4,8-dimethyl-1,4,8-decatriene, and 4-ethylidene-8-methyl-1,7-nonadiene.

[0038] These non-conjugated polyenes [A3] can be used singly or in combination of two or more. Among these, linear non-conjugated dienes such as 1,4-hexadiene, and cyclic non-conjugated dienes such as 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are preferred, and cyclic non-conjugated dienes are more preferred, with 5-ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene being even more preferred.

[0039] Examples of the ethylene-α-olefin-non-conjugated polyene copolymer (P) include ethylene-1-butene-1,4-hexadiene copolymer, ethylene-1-butene-1-octene-1,4-hexadiene copolymer, ethylene-1-butene-5-ethylidene-2-norbornene copolymer, ethylene-1-butene-1-octene-5-ethylidene-2-norbornene copolymer, ethylene-1-butene-5-ethylidene-2-norbornene-5-vinyl-2-norbornene copolymer, and ethylene-1-butene-1-octene-5-ethylidene-2-norbornene-5-vinyl-2-norbornene copolymer.

[0040] The copolymer (P) may contain structural units derived from one or more biomass-derived monomers (biomass-derived ethylene [A1], C4-20 α-olefin [A2], and non-conjugated polyene [A3]). The copolymer (P) may contain structural units derived from one or more chemically recycled monomers (chemically recycled ethylene [A1], C4-20 α-olefin [A2], and non-conjugated polyene [A3]).

[0041] <Method for producing ethylene-α-olefin-non-conjugated polyene copolymer (P)> The ethylene-α-olefin-non-conjugated polyene copolymer (P) can be produced, for example, by employing the production method using a metallocene catalyst described in WO 2015 / 122415.

[0042] <Carbon black (D)> The content of carbon black (D) is 5 to 150 parts by mass, preferably 10 to 100 parts by mass, more preferably 20 to 80 parts by mass, and even more preferably 30 to 60 parts by mass, relative to 100 parts by mass of the copolymer (P). When the content of carbon black (D) is within the above range, the copolymer composition has an appropriately low hardness and can maintain a certain level of mechanical strength, which is preferable. Examples of carbon black (D) include SRF, GPF, FEF, MAF, HAF, ISAF, SAF, FT, and MT. The surface of the carbon black may be treated with a silane coupling agent. Commercially available carbon blacks include "Asahi #50G," "Asahi #60UG," "Asahi #65," and "Asahi #70" (trade names, manufactured by Asahi Carbon Co., Ltd.) and "Seast SO" (trade name, manufactured by Tokai Carbon Co., Ltd.).

[0043] The specific surface area of ​​the carbon black (D) is preferably 100 m 2 / g or less, more preferably 5 to 50m 2 / g, more preferably 8 to 45 m 2 / g, most preferably 10 to 45 m 2 When the specific surface area of ​​the carbon black (D) is within the above range, the hardness of the resulting copolymer composition is suitably low and a certain level of mechanical strength can be maintained, which is preferable. The composition of the present invention may contain one type of carbon black (D), or may contain two or more types of carbon black (D).

[0044] <Other ingredients> The composition of the present invention may further contain components other than the copolymer (P) and carbon black (D) (hereinafter also referred to as "other components") depending on the purpose, such as at least one selected from a crosslinking agent, a crosslinking aid, a vulcanization accelerator, a vulcanization aid, a softener, an inorganic filler, an antioxidant, a processing aid, an activator, a moisture absorbent, an antistatic agent, a colorant, a lubricant, and a thickener. The composition of the present invention may further contain a polymer other than the copolymer (P) (hereinafter also referred to as "other polymer"), such as an elastomer and / or rubber. Each of the components described below may be used alone or in combination of two or more.

[0045] <Crosslinking agent> Examples of the crosslinking agent include crosslinking agents that are generally used when crosslinking rubber, such as organic peroxides, phenolic resins, sulfur-based crosslinking agents (J), hydrosilicone compounds, amino resins, quinone or its derivatives, amine compounds, azo compounds, epoxy compounds, isocyanate compounds, etc. Among these, crosslinking agents such as organic peroxides and sulfur-based crosslinking agents (J) (hereinafter also referred to as "vulcanizing agents") are preferred.

[0046] <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, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide.

[0047] <Crosslinking aid> When an organic peroxide is used as the crosslinking agent, it is preferable to use a crosslinking aid in combination. Examples of the crosslinking aid include sulfur; quinone dioxime-based crosslinking aids such as p-quinone dioxime; acrylic crosslinking aids such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate; allyl crosslinking aids such as diallyl phthalate and triallyl isocyanurate; maleimide-based crosslinking aids; divinylbenzene; zinc oxide (e.g., ZnO#1, zinc oxide type 2 (JIS K1410 (2006), manufactured by Hakusui Tech Co., Ltd.)), zinc oxide (e.g., "META-Z102" (trade name, manufactured by Inoue Lime Industry Co., Ltd.)); and metal oxides such as magnesium oxide.

[0048] The amount of the crosslinking aid to be added is usually 0.01 to 10 parts by mass, preferably 0.05 to 7 parts by mass, and more preferably 0.075 to 5 parts by mass, per part by mass of the organic peroxide.

[0049] <Sulfur-based crosslinking agent (J)> Examples of the sulfur-based crosslinking agent (J) include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, and selenium dithiocarbamate.

[0050] <Vulcanization accelerator> When a sulfur-based crosslinking agent (J) is used as the crosslinking agent, it is preferable to use a vulcanization accelerator in combination. Examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazole sulfenamide, N,N'-diisopropyl-2-benzothiazole sulfenamide, 2-mercaptobenzothiazole (e.g., Suncerer M (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), 2-(4-morpholinodithio)benzothiazole (e.g., Noccelaer MDB-P (trade name; manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)), 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-dinitrophenyl)mercaptobenzothiazole, Thiazole-based vulcanization accelerators such as ethyl-4-morpholinothio)benzothiazole and dibenzothiazyl disulfide (e.g., Sancerer DM (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)); guanidine-based vulcanization accelerators such as diphenylguanidine, triphenylguanidine, and diorthotolylguanidine; aldehyde-amine-based vulcanization accelerators such as acetaldehyde-aniline condensation product and butyraldehyde-aniline condensation product; imidazoline-based vulcanization accelerators such as 2-mercaptoimidazoline; tetramethylthiuram monosulfide (e.g., Sancerer DM (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)); thiuram-based vulcanization accelerators such as Sancerer TS (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetramethylthiuram disulfide (e.g., Sancerer TT (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetraethylthiuram disulfide (e.g., Sancerer TET (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), tetrabutylthiuram disulfide (e.g., Sancerer TBT (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), and dipentamethylenethiuram tetrasulfide (e.g., Sancerer TRA (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)); zinc dimethyldithiocarbamate, diethyldithio Examples of such vulcanization accelerators include dithioacid salt vulcanization accelerators such as zinc carbamate, zinc dibutyldithiocarbamate (for example, Sancerar PZ, Sancerar BZ, and Sancerar EZ (trade names; manufactured by Sanshin Chemical Industry Co., Ltd.)) and tellurium diethyldithiocarbamate; thiourea-based vulcanization accelerators such as ethylenethiourea (for example, Sancerar BUR (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.), Sancerar 22-C (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.)), N,N'-diethylthiourea, and N,N'-dibutylthiourea; and xanthate-based vulcanization accelerators such as zinc dibutylxatogenate.

[0051] When a vulcanization accelerator is used, the blending amount of the vulcanization accelerator in the copolymer composition is usually 0.1 to 20 parts by mass, preferably 0.2 to 15 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the copolymer (P). When a sulfur-based crosslinking agent (J) is used, a vulcanization aid can be used in combination.

[0052] <Vulcanization aid> The vulcanization aid may be used when a sulfur-based crosslinking agent (J) is used, and examples thereof include zinc oxide (e.g., "ZnO#1 / Zinc Oxide Type 2" (trade name; manufactured by Hakusui Tech Co., Ltd.) and "META-Z102" (trade name; manufactured by Inoue Lime Industry Co., Ltd.)) and magnesium oxide.

[0053] The amount of the vulcanization aid is usually 1 to 20 parts by mass per 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (P) and other polymers (rubbers, etc.) that require crosslinking and are added as needed.

[0054] <Softener> Specific examples of softeners include petroleum-based softeners such as paraffin oil (e.g., paraffin-based process oil), naphthenic process oil, lubricating oil, liquid paraffin, petroleum asphalt, and Vaseline; coal tar-based softeners such as coal tar; fatty oil-based softeners such as castor oil, linseed oil, rapeseed oil, soybean oil, and coconut oil; waxes such as beeswax and carnauba wax; fatty acids or salts thereof such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, and calcium stearate; naphthenic acid, pine oil, rosin, and derivatives thereof; synthetic polymeric substances such as terpene resins, petroleum resins, and coumarone-indene resins; ester-based softeners such as dioctyl phthalate and dioctyl adipate; and other softeners such as microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, hydrocarbon-based synthetic lubricating oils, tall oil, and sub(factice). Of these, petroleum-based softeners are preferred, and paraffin oil is particularly preferred.

[0055] The amount of the softener to be blended is generally 5 to 200 parts by mass, preferably 50 to 200 parts by mass, per 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (P) and any polymer (elastomer, rubber, etc.) components that are optionally blended.

[0056] <Inorganic fillers> Specific examples of inorganic fillers that can be used include one or more of light calcium carbonate, heavy calcium carbonate, talc, clay, etc., and among these, heavy calcium carbonate such as "Whiten SB" (product name; Shiraishi Calcium Co., Ltd.) and "Shiraenka CC" (product name; Shiraishi Kogyo Co., Ltd.) is preferred.

[0057] The amount of inorganic filler blended is usually 2 to 100 parts by mass, preferably 5 to 100 parts by mass, per 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (P) and other polymers (elastomers, rubbers, etc.) blended as needed. When the blending amount is within the above range, the copolymer composition has excellent kneading processability, and a molded product with excellent mechanical properties can be obtained.

[0058] <Anti-aging agent (stabilizer)> The life of a molded article formed from the composition of the present invention can be extended by incorporating an antioxidant (stabilizer). Examples of such antioxidants include conventionally known antioxidants, such as amine-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants.

[0059] These antioxidants can be used alone or in combination of two or more, and the blending amount is usually 0.3 to 10 parts by mass, preferably 0.5 to 7.0 parts by mass, per 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (P) and other polymers (elastomers, rubbers, etc.). By adjusting the blending amount within this range, no bloom occurs on the surface of a molded article obtained from the resulting copolymer composition, and furthermore, vulcanization inhibition can be suppressed.

[0060] <Processing aids> As the processing aid, a wide variety of processing aids that are generally compounded in rubber can be used.

[0061] The amount of the processing aid is usually 10 parts by mass or less, and preferably 8.0 parts by mass or less, per 100 parts by mass of the total of the ethylene-α-olefin-non-conjugated polyene copolymer (P) and polymers other than the copolymer (P) (elastomers, rubbers, etc.) contained in the copolymer composition.

[0062] <Activator> Specific examples of surfactants include amines such as di-n-butylamine, dicyclohexylamine, and monoethanolamine; diethylene glycol, polyethylene glycol, lecithin, triaryl methylate, zinc compounds of aliphatic or aromatic carboxylic acids; zinc peroxide preparations; octadecyltrimethylammonium bromide, synthetic hydrotalcite, and special quaternary ammonium compounds.

[0063] When an activator is contained, the amount thereof is usually 0.2 to 10 parts by mass, preferably 0.3 to 5 parts by mass, per 100 parts by mass of the total of the ethylene-α-olefin-non-conjugated polyene copolymer (P) and other polymers (elastomers, rubbers, etc.).

[0064] <Other polymers> The composition of the present invention may contain a polymer (also referred to as "other polymer") other than the copolymer (P) (for example, an elastomer or rubber). When the composition contains other polymers, the amount of the other polymers is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, per 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (P). The composition of the present invention may contain an ethylene-propylene-non-conjugated diene copolymer as the other polymer.

[0065] <Preparation of Composition> The composition of the present invention can be prepared by kneading the ethylene-α-olefin-non-conjugated polyene copolymer (P), carbon black (D), and other components that are added as needed, at a desired temperature (e.g., 80°C to 200°C) using a kneading machine such as a mixer, kneader, or roll. The ethylene-α-olefin-non-conjugated polyene copolymer (P) has excellent kneadability, allowing for good preparation of the copolymer composition.

[0066] In order to fully utilize the improved cold resistance and roll processability of the ethylene-α-olefin-non-conjugated polyene copolymer (P) while maintaining the high strength of the copolymer, when the copolymer (P) is used as a raw material after being oil-extended, the amount of oil extension is preferably 50 to 150 parts by mass per 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (P).

[0067] <Molded body> Molded articles obtained from the composition of the present invention, such as crosslinked molded articles and crosslinked foamed articles, can be used in a variety of applications.

[0068] Specific examples of such molded articles include tire rubber, O-rings, industrial rolls, printing equipment rolls, packing (e.g., condenser packing), gaskets, belts (e.g., heat insulation belts, copier belts), hoses (e.g., water hoses, brake reservoir hoses, radiator hoses), protective rubber, sponges (e.g., weatherstrip sponges, heat insulation sponges, protect sponges, micro-foam sponges), cables (ignition cables, cab tire cables, high-tension cables), electric wire coating materials (high-voltage wire coating materials, low-voltage electric wire coating materials, marine electric wire coating materials), glass run channels, color skin materials, paper feed rolls, roofing sheets, and seismic and vibration-damping sheets, and these are used in a wide range of applications. [Example]

[0069] The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples in any way.

[0070] <Production of copolymer> [Manufacturing Example 1] A polymerization reaction of ethylene, 1-butene, and 5-ethylidene-2-norbornene (ENB) was carried out continuously at 75°C using a 300 L volume polymerization vessel equipped with a stirring blade.

[0071] Hexane (feed rate: 46.5 L / h) was used as the polymerization solvent and continuously supplied to the polymerization reactor so that the ethylene feed rate was 4.2 kg / h, the 1-butene feed rate was 9.8 kg / h, the ENB feed rate was 612 g / h, and the hydrogen feed rate was 3.4 NL / h.

[0072] The polymerization pressure was kept at 1.7 MPaG and the polymerization temperature at 75°C. 5 -cyclopentadienyl)(η 5 The resulting mixture was continuously fed to the polymerization reactor using dimethyl ether (2,3,6,7-tetramethylfluorenyl) hafnium dimethyl at a feed rate of 0.006 mmol / h. Furthermore, triphenylcarbenium tetrakis(pentafluorophenyl)borate as a cocatalyst was continuously fed to the polymerization reactor at a feed rate of 0.038 mmol / h, and triisobutylaluminum as an organoaluminum compound was continuously fed at a feed rate of 13 mmol / h.

[0073] In this way, a solution containing 5.7 mass% of ethylene-1-butene-ENB copolymer (P1) formed from ethylene, 1-butene, and ENB was obtained. A small amount of methanol was added to the solution withdrawn from the bottom of the polymerization reactor to terminate the polymerization reaction. 75 mass parts of paraffin oil (Idemitsu Kosan Co., Ltd., product name: Diana Process Oil PW-100) were added to 100 mass parts of ethylene-1-butene-ENB copolymer (P1), and the ethylene-1-butene-ENB copolymer (P1) was separated from the solvent by steam stripping and then dried under reduced pressure at 80°C overnight.

[0074] By the above procedure, ethylene-1-butene-ENB copolymer (P1) formed from ethylene, butene, and ENB was obtained at a rate of 2.5 kg / h. Its intrinsic viscosity [η] was 5.8 g / dl.

[0075] [Manufacturing Example 2] Ethylene-propylene-5-ethylidene-2-norbornene copolymer (P2) (Mitsui Chemicals, Inc., trade name: X-3042E, intrinsic viscosity [η]: 4.1 dl / g, Mooney viscosity (ML (1+4) 100°C): 37, ethylene content: 66 mass%, ENB content: 4.7 mass%, oil extension amount: 120 phr) was prepared.

[0076] [Table 1]

[0077] [Example 1] [Preparation of Uncrosslinked Composition] In the first step, a BB-L1800 Banbury mixer (manufactured by Kobe Steel, Ltd.) was used to mix 100 parts by mass of the copolymer (P1) obtained in Production Example 1, 95 parts by mass of paraffin oil, and carbon black 1 (manufactured by Asahi Carbon Co., Ltd., trade name: Asahi #60UG, specific surface area: 41 m). 2 50 parts by mass of cellulose acetate (100%) / g, 1 part by mass of lubricant (manufactured by NOF Corporation, trade name: Camellia Stearate), 5 parts by mass of zinc oxide (manufactured by Hakusui Tech Co., Ltd.), 1 part by mass of PEG#4000 (manufactured by NOF Corporation), 40 parts by mass of white filler 1 (manufactured by Shiraishi Calcium Co., Ltd., trade name: Whiten SB), and 30 parts by mass of white filler 2 (manufactured by Shiraishi Kogyo Co., Ltd., trade name: Hakuenka CC) were kneaded for 2 minutes at 140°C. The ram was then raised and cleaned, and the mixture was kneaded for another 1 minute and discharged at approximately 150°C to obtain a first-stage blend.

[0078] 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.; surface temperature of front roll: 50°C; surface temperature of rear roll: 50°C; rotation speed of front roll: 16 rpm; rotation speed of rear roll: 18 rpm), and 1.5 parts by mass of sulfur (manufactured by Junsei Chemical Co., Ltd.) and, as vulcanization accelerators, 1 part by mass of Sancerer BZ (manufactured by Sanshin Chemical Industry Co., Ltd.), 0.5 parts by mass of Sancerer M (manufactured by Sanshin Chemical Industry Co., Ltd.), 0.5 parts by mass of Sancerer TT (manufactured by Sanshin Chemical Industry Co., Ltd.), and 1.2 parts by mass of Sancerer TRA (manufactured by Sanshin Chemical Industry Co., Ltd.) were added thereto and kneaded for 10 minutes to obtain an uncrosslinked composition.

[0079] [Preparation of sheet-like crosslinked molded body] The uncrosslinked composition was pressed in a mold at 170° C. for 15 minutes using a press molding machine to obtain a crosslinked molded sheet having a thickness of 2 mm.

[0080] [Preparation of block-shaped crosslinked molded body] The uncrosslinked composition was vulcanized at 170°C for 20 minutes using a press molding machine equipped with a cylindrical mold to obtain a crosslinked molded product having a diameter of 29 mm and a height (thickness) of 12.5 mm according to JIS K6262.

[0081] [Example 2] Carbon black 1 was replaced with carbon black 2 (manufactured by Asahi Carbon Co., Ltd., product name: Asahi #50G, specific surface area 22 m 2 An uncrosslinked composition was produced in the same manner as in Example 1 except that the amount of water was changed to 1 / g). Then, a crosslinked molded article was produced.

[0082] [Comparative Examples 1 and 2] An uncrosslinked composition was produced in the same manner as in Example 1, except that the raw materials were changed as shown in Table 2, and then a crosslinked molded article was produced.

[0083] <Measurement of physical properties> [Mole fraction of structural units derived from ethylene, structural units derived from α-olefins, and structural units derived from non-conjugated polyenes] The measurement was performed using o-dichlorobenzene-d4 as the measurement solvent, under the following measurement conditions: measurement temperature 120°C, spectrum width 20 ppm, pulse repetition time 7.0 seconds, pulse width 5.00 μsec (500 MHz, Bruker Biospin, AVANCEIII cryo-500 type nuclear magnetic resonance spectrometer). 1 H-NMR spectra were measured and calculated.

[0084] [Intrinsic viscosity [η](dl / g)] To measure the intrinsic viscosity [η] (dl / g) of the copolymer, 1 g of the copolymer was shredded, and then subjected to Soxhlet extraction using methyl ethyl ketone at 80°C for 3 hours, followed by drying under reduced pressure overnight at 80°C. The intrinsic viscosity [η] (dl / g) of the copolymer was measured using a fully automatic intrinsic viscometer manufactured by Rigo Co., Ltd. at a temperature of 135°C and a measurement solvent of decalin.

[0085] [B value] The measurement solvent was o-dichlorobenzene-d4 / benzene-d6 (4 / 1 [v / v]) at a measurement temperature of 120°C. 13 C-NMR spectrum (125 MHz, Bruker Biospin, AVANCEIII cryo-500 type nuclear magnetic resonance apparatus) was measured, and the B value was calculated based on the following formula (i). B value=([EX]+2[Y]) / [2×[E]×([X]+[Y])]···(i) [Here, [E], [X], and [Y] represent the molar fractions of structural units derived from ethylene [A1], α-olefin [A2] having 4 to 20 carbon atoms, and non-conjugated polyene [A3], respectively, and [EX] represents the ethylene [A1]-α-olefin [A2] having 4 to 20 carbon atoms dyad chain fraction.]

[0086] [Mooney viscosity (ML (1+4) 100℃)] Mooney viscosity at 100°C (ML (1+4) The viscosity (100°C) was measured at 100°C using a Mooney viscometer (Shimadzu Corporation, SMB-301RT model) in accordance with JIS K6300-1 (2013).

[0087] [Crosslinking behavior of copolymer composition] Using the uncrosslinked composition in each example, the following values ​​were determined from the crosslinking curve measured at the crosslinking temperature and crosslinking time shown in each table in accordance with JIS K6300-2 (2001). MDR2000 (manufactured by Alpha Technologies) was used for the measurement. "S'max" (dNm): The maximum torque value S'max. "S'min" (dNm): The minimum torque value S'min. "S'max-S'min" (dNm): The difference between the maximum torque value S'max and the minimum torque value S'min. "tc" (min): The time required to reach a torque value corresponding to the sum of the minimum torque value S'min and a torque value corresponding to 90% of "S'max-S'min". "MCR" (dNm / min): The maximum slope of the vulcanization curve.

[0088] [Durometer A hardness] In accordance with JIS K6253-3 (2012), the sheet hardness (Type A durometer, HA) was measured using six 2 mm thick cross-linked sheets with smooth surfaces, stacked on top of each other at the flat part to a thickness of approximately 12 mm. However, specimens containing foreign matter, bubbles, or scratches were not used. The dimensions of the measurement surface of the specimen were such that measurements could be made with the tip of the indenter at least 12 mm away from the edge of the specimen.

[0089] [Modulus (MPa), Tensile stress at break (MPa), Tensile elongation at break (%)] The sheet was punched out to prepare No. 3 dumbbell test pieces as specified in JIS K6251 (2017). Using these test pieces, tensile tests were carried out according to the method specified in JIS K6251, paragraph 3, at a measurement temperature of 25°C and a tensile speed of 500 mm / min, and the modulus at 300% elongation (M300), tensile stress at break (TB), and tensile elongation at break (EB) were measured.

[0090] [Compression set (CS) of sheet-shaped molded product] The compounds obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were vulcanized at 170°C for 20 minutes using a press molding machine equipped with a cylindrical mold to prepare right cylindrical test pieces (vulcanizates) with a thickness of 12.7 mm and a diameter of 29 mm. The compression set test was carried out in accordance with JIS K6262 (2013) using the obtained right cylindrical test piece (vulcanizate) by compressing it to 25% in an atmosphere of 0°C for 22 hours, and then determining the permanent set (%) after release. The smaller the permanent set, the better the low-temperature properties.

[0091] [Taber abrasion test] According to the method specified in JIS K 6264-2 (2005), a Taber abrasion tester was used to measure the amount of wear when the abrasive wheel was rotated 1,000 times at 60 revolutions per minute in an atmosphere of 23°C using an H-18 abrasive wheel with a weight of 250 g attached.

[0092] [Tensile viscoelasticity test] Storage modulus E': Dynamic viscoelasticity was measured under nitrogen using a TA Instruments RSA-G2 for 1 mm sheets of vulcanized rubber obtained in the Examples and Comparative Examples. Here, storage modulus (E') is a component of the complex modulus, which expresses the relationship between stress and strain when a sinusoidal oscillatory strain is applied to a viscoelastic material, and is the value measured using a TA Instruments RSA-G2 in tension mode (1% strain) at a temperature range of -70°C to 100°C, at a heating rate of 4°C / min, and at a frequency of 1 Hz. Tan δ: Dynamic viscoelasticity was measured under nitrogen using a TA Instruments RSA-G2 for 1 mm sheets of vulcanized rubber obtained in the Examples and Comparative Examples. Here, tan δ is the value calculated by the formula: tan δ (0°C, 60°C) = E" / E'.

[0093] [Table 2]

Claims

1. The copolymer has a structural unit derived from ethylene [A1], a structural unit derived from an α-olefin [A2] having 4 to 20 carbon atoms, and a structural unit derived from a non-conjugated polyene [A3], the α-olefin [A2] having 4 to 20 carbon atoms includes 1-butene, 100 parts by mass of an ethylene / α-olefin / non-conjugated polyene copolymer (P) that satisfies the following requirements (1) and (2): 5 to 150 parts by mass of carbon black (D) A copolymer composition comprising: Requirement (1): The ratio [e] / [x] of the molar fraction [e] of structural units derived from ethylene [A1] to the molar fraction [x] of structural units derived from an α-olefin [A2] having 4 to 20 carbon atoms is 40 / 60 to 90 / 10 (where the sum of the molar fractions of the structural units derived from [A1], [A2], and [A3] is 100 mol %). Requirement (2): The intrinsic viscosity [η] measured in decalin at 135° C. is 5.0 to 7.0 dl / g.

2. The copolymer composition according to claim 1, wherein the ethylene / α-olefin / non-conjugated polyene copolymer (P) satisfies the following requirement (3): Requirement (3): The molar fraction [y] of the structural unit derived from the non-conjugated polyene [A3] is 0.1 to 6.0 mol %.

3. The copolymer composition according to claim 1, wherein the ethylene / α-olefin / non-conjugated polyene copolymer (P) satisfies the following requirement (4): Requirement (4): The B value represented by the following formula (i) is 1.20 or more. B value = ([EX]+2[Y]) / [2×[E]×([X]+[Y])]...(i) (Here, [E], [X], and [Y] represent the mole fractions of structural units derived from ethylene [A1], C4-C20 α-olefin [A2], and non-conjugated polyene [A3], respectively, and [EX] represents the ethylene [A1]-C4-C20 α-olefin [A2] dyad chain fraction.)

4. The copolymer composition according to claim 1, wherein the non-conjugated polyene [A3] contains only one partial structure represented by a structural formula selected from the group consisting of the following partial structural formulas (I) and (II) in total per molecule: 【Chemistry 1】

5. The copolymer composition according to claim 1, wherein the non-conjugated polyene [A3] comprises 5-ethylidene-2-norbornene.

6. The copolymer composition according to claim 1, comprising 5 to 200 parts by mass of a softener relative to a total of 100 parts by mass of the ethylene / α-olefin / non-conjugated polyene copolymer (P) and any polymer components other than the ethylene / α-olefin / non-conjugated polyene copolymer (P) that are optionally blended.

7. The specific surface area of ​​the carbon black (D) is 100 m 2 The copolymer composition according to claim 1, wherein the copolymer composition has a viscosity of 1 / g or less.

8. The copolymer composition according to claim 1, further comprising a sulfur-based crosslinking agent (J).

9. A crosslinked product of the copolymer composition according to any one of claims 1 to 8.

10. A roll comprising the crosslinked body according to claim 9.

11. A sheet comprising the crosslinked product according to claim 9.

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