Rubber composition

Abstract

To provide a rubber composition that exhibits superior balance in kneading workability, flexibility of a molded article, and tensile properties of the molded article.SOLUTION: A rubber composition is provided, wherein the rubber composition contains: at least one copolymer rubber (A) selected from ethylene-α-olefin copolymer rubbers and ethylene-α-olefin-non-conjugated polyene copolymer rubbers; a modified ethylene-α-olefin copolymer (B) satisfying specific requirements; and an organic filler (C). The content of the modified ethylene-α-olefin copolymer (B) is 1 to 100 pts.mass relative to 100 pts.mass of the copolymer rubber (A), and the content of the organic filler (C) is 1 to 200 pts.mass.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a rubber composition.

Background Art

[0002] In rubber compositions, modifiers such as softeners may be blended for the purpose of improving processability and moldability, or adjusting rubber physical properties such as hardness and flexibility (see, for example, Patent Documents 1 and 2). As the softener, mineral oil refined from crude oil or synthetic oil is used. In addition, organic fillers may be blended in rubber compositions for the purpose of improving mechanical properties.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the studies of the present inventors, in conventional rubber compositions containing an ethylene-α-olefin copolymer rubber or the like and an organic filler, there is room for improvement in the balance of kneading processability, flexibility of a molded body formed from the rubber composition, and tensile properties of the molded body. One object of the present disclosure is to provide a rubber composition excellent in the balance of kneading processability, flexibility of a molded body, and tensile properties of the molded body.

Means for Solving the Problems

[0005] One aspect of the rubber composition of the present disclosure contains one or more copolymer rubbers (A) selected from ethylene·α-olefin copolymer rubber and ethylene·α-olefin·non-conjugated polyene copolymer rubber, a modified ethylene·α-olefin copolymer (B) that satisfies specific requirements, and an organic filler (C). With respect to 100 parts by mass of the copolymer rubber (A), the content of the modified ethylene·α-olefin copolymer (B) is 1 to 100 parts by mass, and the content of the organic filler (C) is 1 to 200 parts by mass.

Advantages of the Invention

[0006] According to the present disclosure, it is possible to provide a rubber composition excellent in kneading processability, flexibility of the molded body, and balance of tensile properties of the molded body.

Embodiments for Carrying Out the Invention

[0007] In this specification, "N1~N2" indicating a numerical range means "N1 or more and N2 or less" unless otherwise specified. N1 and N2 are each any numbers satisfying the condition of N1 < N2.

[0008] In this specification, the description "(meth)acrylic" is used in the sense of including acrylic and methacrylic. That is, "(meth)acrylic" may be acrylic, may be methacrylic, or may be both acrylic and methacrylic.

[0009] [Rubber Composition and Its Manufacturing Method] The rubber composition of the present disclosure contains one or more copolymer rubbers (A) selected from ethylene·α-olefin copolymer rubber and ethylene·α-olefin·non-conjugated polyene copolymer rubber, a modified ethylene·α-olefin copolymer (B) described later, and an organic filler (C). By using a rubber composition preferably containing the copolymer rubber (A), the modified ethylene·α-olefin copolymer (B), and the organic filler (C) within the ranges described later, the rubber composition is excellent in kneading processability and can form a molded body excellent in flexibility and tensile properties (for example, tensile product which is the product of tensile strength at break and elongation at break).

[0010] The method for producing the rubber composition of the present disclosure includes a step of mixing at least one copolymer rubber (A) selected from an ethylene-α-olefin copolymer rubber and an ethylene-α-olefin-non-conjugated polyene copolymer rubber, a modified ethylene-α-olefin copolymer (B) described later, and an organic filler (C).

[0011] <Copolymer rubber (A)> The copolymer rubber (A) is at least one selected from an ethylene-α-olefin copolymer rubber and an ethylene-α-olefin-non-conjugated polyene copolymer rubber.

[0012] The copolymer rubber (A) has a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 or more carbon atoms. In the total amount of the structural units derived from the polymerizable monomers in the copolymer rubber (A), the content ratio of the structural unit derived from ethylene is preferably 40 to 90 mol%, more preferably 45 to 85 mol%, still more preferably 50 to 80 mol%, and the content ratio of the structural unit derived from an α-olefin having 3 or more carbon atoms is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably 20 to 50 mol%. The content ratio of the above structural units is 13 measured by the C-NMR method.

[0013] As the α-olefin having 3 or more carbon atoms, α-olefins having 3 to 20 carbon atoms are preferable, α-olefins having 3 to 12 carbon atoms are more preferable, and α-olefins having 3 to 8 carbon atoms are even more preferable. Examples of the above α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene. Propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene are more preferable, and propylene is particularly preferable. That is, as the copolymer rubber (A), one or more selected from ethylene-propylene copolymer rubber and ethylene-propylene-non-conjugated polyene copolymer rubber are preferable.

[0014] The ethylene-α-olefin-non-conjugated polyene copolymer rubber further has a structural unit derived from a non-conjugated polyene in addition to the structural unit derived from ethylene and the structural unit derived from an α-olefin having 3 or more carbon atoms. In the ethylene-α-olefin-non-conjugated polyene copolymer rubber, the content ratio of the structural unit derived from the non-conjugated polyene is preferably 0.1 to 5 mol%, more preferably 0.3 to 4 mol%, and even more preferably 0.5 to 4 mol%. In this case, the content ratio of the structural unit derived from ethylene is preferably 40 to 89.9 mol%, more preferably 45 to 84.7 mol%, and even more preferably 50 to 79.5 mol%, and the content ratio of the structural unit derived from an α-olefin having 3 or more carbon atoms is preferably 10 to 59.9 mol%, more preferably 15 to 54.7 mol%, and even more preferably 20 to 49.5 mol%. The content ratio of the above structural unit is 13 measured by the C-NMR method.

[0015] Examples of non-conjugated polyenes include chain 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; cyclic non-conjugated dienes such as cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, and 6-chloromethyl-5-isopropenyl-2-norbornene; and trienes such as 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,5-norbornadiene, 1,3,7-octatriene, 1,4,9-decatriene, 4,8-dimethyl-1,4,8-decatriene, and 4-ethylidene-8-methyl-1,7-nonadiene. Among these, at least one selected from 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene is preferred.

[0016] The copolymer rubber (A) has at least one structural unit derived from an α-olefin, and may have two or more structural units derived from an α-olefin. The copolymer rubber (A) may have one structural unit derived from a non-conjugated polyene, or may have two or more structural units derived from a non-conjugated polyene. Ethylene, an α-olefin having 3 or more carbon atoms, and a non-conjugated polyene, which are monomers that constitute or can constitute the copolymer rubber (A), may each be, for example, a monomer derived from fossil fuel or a monomer derived from biomass, and these monomers may be used alone or in combination of two or more.

[0017] The weight average molecular weight (Mw) of the copolymer rubber (A) determined by gel permeation chromatography (GPC) is preferably from 30,000 to 1,000,000, more preferably from 50,000 to 500,000, still more preferably from 100,000 to 300,000. Such a copolymer rubber (A) tends to be excellent in the balance between processability when kneaded with the modified ethylene·α-olefin copolymer (B) and the organic filler (C), and the tensile properties of the molded article obtained from the rubber composition.

[0018] Details of the measurement conditions of Mw are described in the Examples section.

[0019] The Mooney viscosity ML(1+4) 100°C of the copolymer rubber (A) is preferably from 10 to 100, more preferably from 20 to 90, still more preferably from 30 to 80. The Mooney viscosity is measured by a method conforming to JIS K6300-1:2013 "Unvulcanized rubbers - Physical properties - Part 1: Determination of viscosity and scorch time using a Mooney viscometer".

[0020] The rubber composition of the present disclosure may contain one kind of copolymer rubber (A) or may contain two or more kinds of copolymer rubbers (A). The content ratio of the copolymer rubber (A) in the rubber composition of the present disclosure is preferably from 20 to 90% by mass, more preferably from 30 to 80% by mass, still more preferably from 40 to 70% by mass in 100% by mass of the rubber composition. The rubber composition in such a form tends to be able to form a molded article excellent in rubber physical properties such as hardness and flexibility. In the method for producing the rubber composition of the present disclosure, the above "content ratio" is read as "blending ratio".

[0021] <Modified ethylene·α-olefin copolymer (B)> The modified ethylene·α-olefin copolymer (B) (hereinafter also referred to as "modified copolymer (B)") satisfies the requirements (b-1) to (b-3) described below. In one embodiment, the modified copolymer (B) is liquid at 23°C and 1 atm. The modified copolymer (B) has a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 or more carbon atoms.

[0022] <Requirement (b-1)> In the ethylene-α-olefin copolymer (B') before modification of the modified copolymer (B) with the carboxylic acid compound described below, the content ratio of the structural unit derived from ethylene (hereinafter also referred to as "ethylene content ratio") is 10 to 90 mol%. However, the total of the content of the structural unit derived from ethylene and the content of the structural unit derived from an α-olefin having 3 or more carbon atoms is 100 mol%.

[0023] The above copolymer (B') has a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 or more carbon atoms. In one embodiment of the modified copolymer (B), at least a part of the structural unit derived from ethylene (ethylene unit) and / or the structural unit derived from an α-olefin having 3 or more carbon atoms (α-olefin unit) is modified with the carboxylic acid compound described below. Specifically, a site derived from the carboxylic acid compound is introduced into at least a part of the structural unit.

[0024] The ethylene content ratio in the above copolymer (B') is 10 to 90 mol%, preferably 30 to 80 mol%, more preferably 35 to 65 mol%, and still more preferably 40 to 60 mol%. The copolymer (B) which is a modified product of such a copolymer (B') becomes low crystalline or amorphous, and has a composition close to that of the copolymer rubber (A) and good compatibility. Therefore, the rubber composition containing the modified copolymer (B) tends to be excellent in kneading processability, flexibility, and tensile properties.

[0025] The ethylene content ratio of the above copolymer (B') is 13 Measured by the C-NMR method, and determined by identifying and quantifying the peaks according to the method adopted in the examples described below and the method described in the "Polymer Analysis Handbook" (published by Asakura Shoten, P163-170).

[0026] Examples of α-olefins having 3 or more carbon atoms include α-olefins having 3 to 20 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicosene. Among the α-olefins, from the viewpoints such as effectively reducing the crystallinity of the copolymer and obtaining a liquid copolymer, and easily obtaining the rubber composition and molded article having the above desired effects, α-olefins having 3 to 10 carbon atoms are preferable, propylene and 1-butene are more preferable, and propylene is even more preferable. That is, as the modified copolymer (B), a modified ethylene-propylene copolymer is preferable.

[0027] The modified copolymer (B) has at least one structural unit derived from an α-olefin, and may have two or more structural units derived from an α-olefin. Ethylene and α-olefins having 3 or more carbon atoms, which are monomers constituting the modified copolymer (B), may each be, for example, a monomer derived from a fossil fuel or a monomer derived from biomass, and these monomers may be used alone or in combination of two or more.

[0028] <Requirement (b-2)> The weight average molecular weight (Mw) of the modified copolymer (B) determined by gel permeation chromatography (GPC) is 1,000 to 100,000. The Mw of the modified copolymer (B) is 1,000 to 100,000, preferably 1,500 to 50,000, more preferably 2,000 to 20,000, and even more preferably 2,500 to 15,000. Such a modified copolymer (B) tends to have an excellent balance between processability when kneaded with the copolymer rubber (A) and rubber physical properties such as flexibility and tensile properties in the molded article obtained from the rubber composition.

[0029] The ratio (Mw / Mn), which is the molecular weight distribution of the modified copolymer (B), is preferably from 1.4 to 3.0, more preferably from 1.4 to 2.9, still more preferably from 1.4 to 2.8. A rubber composition containing such a modified copolymer (B) tends to suppress a decrease in flexibility and mechanical properties of a molded article due to volatilization of low molecular weight components and / or bleed-out of low molecular weight components to the surface of the molded article when used in a high temperature environment.

[0030] Mw and Mn are determined by gel permeation chromatography (GPC). Details of the measurement conditions for Mw and Mn are described in the Examples section.

[0031] 〈Requirement (b-3)〉 The modified copolymer (B) is a modified copolymer having a site derived from one or more carboxylic acid compounds selected from unsaturated carboxylic acids containing one or more carbon-carbon unsaturated bonds and derivatives thereof, and the content ratio of the site derived from the carboxylic acid compound in 100% by mass of the modified copolymer is from 0.5 to 50% by mass. The content ratio of the site is preferably from 0.5 to 30% by mass, more preferably from 1 to 30% by mass, still more preferably from 1 to 20% by mass, and particularly preferably from 1.5 to 15% by mass. A rubber composition containing such a modified copolymer (B) tends to form a molded article excellent in tensile properties such as tensile product. Note that the position of the site derived from the carboxylic acid compound, for example, the graft position of the carboxylic acid compound, is not particularly limited.

[0032] In one embodiment, the modified copolymer (B) has an ethylene·α-olefin copolymer part (main chain part) and a graft part derived from the carboxylic acid compound. The ethylene·α-olefin copolymer part has a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 or more carbon atoms. The ethylene·α-olefin copolymer part is preferably a random copolymer chain of ethylene and an α-olefin having 3 or more carbon atoms.

[0033] The content ratio of the site derived from the carboxylic acid compound in the modified copolymer (B) is1 It is measured by the H-NMR method. Details of the measurement conditions are described in the Examples section.

[0034] The number of carbon-carbon unsaturated bonds in the unsaturated carboxylic acid is preferably 1 to 3, more preferably 1 to 2, and even more preferably 1. As the carbon-carbon unsaturated bond, a carbon-carbon unsaturated double bond is preferred.

[0035] Examples of the unsaturated carboxylic acid include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, and isocrotonic acid; and unsaturated dicarboxylic acids such as maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, and nadic acid (endo-cis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid). As the unsaturated carboxylic acid, an aliphatic unsaturated carboxylic acid is preferred.

[0036] Examples of the derivative of the unsaturated carboxylic acid include an acid anhydride, an ester, an amide, or an imide of the unsaturated carboxylic acid. Among the derivatives of the unsaturated carboxylic acid, an acid anhydride of the unsaturated carboxylic acid is preferred. Examples of the acid anhydride of the unsaturated carboxylic acid include maleic anhydride and citraconic anhydride.

[0037] Examples of the ester of the unsaturated carboxylic acid include esters and half-esters such as methyl (meth)acrylate, ethyl (meth)acrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, monomethyl itaconate, and diethyl itaconate.

[0038] Examples of the amides of unsaturated carboxylic acids include (meth)acrylamide, maleic acid monoamide, maleic acid diamide, maleic acid - N - monoethylamide, maleic acid - N,N - diethylamide, maleic acid - N - monobutylamide, maleic acid - N,N - dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid - N - monobutylamide, and fumaric acid - N,N - dibutylamide.

[0039] Examples of the imides of unsaturated carboxylic acids include maleimide, N - butylmaleimide, and N - phenylmaleimide.

[0040] Among carboxylic acid - based compounds, unsaturated dicarboxylic acids and their derivatives are preferred, and maleic acid and maleic anhydride are more preferred in terms of being less likely to produce by - products such as homopolymers in the reaction for producing the modified copolymer (B).

[0041] The number of carbon atoms of the carboxylic acid - based compound is preferably 20 or less.

[0042] The acid value of the modified copolymer (B) is preferably 5 - 300 mgKOH / g, more preferably 10 - 200 mgKOH / g, and even more preferably 15 - 150 mgKOH / g. The acid value is measured by a method in accordance with JIS K2501:2003.

[0043] The modified copolymer (B) may have one type of site derived from the above - mentioned carboxylic acid - based compound, or may have two or more types of sites derived from the above - mentioned carboxylic acid - based compound. Also, the above - mentioned carboxylic acid - based compounds may each be, for example, a monomer derived from fossil fuel or a monomer derived from biomass, and these monomers may be used alone or in combination of two or more.

[0044] The modified copolymer (B) preferably has a heat of fusion (ΔH) measured by differential scanning calorimetry (DSC) of 20 J / g or less, or the heat of fusion (ΔH) is not substantially measured by DSC. More preferably, the heat of fusion (ΔH) measured by DSC is 10 J / g or less, or the heat of fusion (ΔH) is not substantially measured by DSC. Even more preferably, the heat of fusion (ΔH) is not substantially measured by DSC. That the heat of fusion (ΔH) is not substantially measured by DSC means that no melting peak is observed in the DSC measurement, or the measured heat of fusion (ΔH) is 1 J / g or less. When the heat of fusion (ΔH) of the modified copolymer (B) is within the above range, or the heat of fusion (ΔH) is not substantially measured by DSC, the rubber composition containing the modified copolymer (B) has excellent kneading processability, and the flexibility and tensile properties of the molded article obtained from the rubber composition tend to be excellent.

[0045] The heat of fusion (ΔH) of the modified copolymer (B) can be measured by DSC, for example, as follows. Using a differential scanning calorimeter [for example, DSC220 manufactured by Seiko Instruments Inc.], about 5.0 mg of the sample is heated from 30 °C to 200 °C at a heating rate of 10 °C / min under a nitrogen atmosphere and held at that temperature for 10 minutes. Further, it is cooled to -100 °C at a cooling rate of 10 °C / min and held at that temperature for 5 minutes, and then heated to 200 °C at a heating rate of 10 °C / min to obtain a DSC curve. The heat of fusion (ΔH) can be calculated by analyzing the obtained DSC curve in accordance with JIS K7121.

[0046] By appropriately controlling the ethylene content ratio and the weight average molecular weight, the modified copolymer (B) becomes an amorphous copolymer having good fluidity, and the rubber composition tends to have good processability and flexibility. The modified copolymer (B) is a modified copolymer having a site derived from a carboxylic acid compound containing one or more carbon-carbon unsaturated bonds, and has excellent interactivity with the organic filler (C). For example, when using a filler containing cellulose as the organic filler (C), it is considered that the site derived from the carboxylic acid compound in the modified copolymer (B) and the hydroxyl group contained in the cellulose present on the filler surface form a hydrogen bond or an ester bond, whereby the modified copolymer (B) can cover the filler. Further, the ethylene-α-olefin copolymer main chain of the modified copolymer (B) has a composition similar to that of the copolymer rubber (A), and the modified copolymer (B) has excellent compatibility with the copolymer rubber (A). Therefore, when the modified copolymer (B) functions as a compatibilizer for the copolymer rubber (A) and the organic filler (C), the rubber composition has good dispersibility of the organic filler (C), and the resulting molded article is considered to tend to have excellent tensile properties such as tensile product.

[0047] The rubber composition of the present disclosure may contain one kind of modified copolymer (B) or may contain two or more kinds of modified copolymers (B). The content of the modified copolymer (B) in the rubber composition of the present disclosure is preferably 1 to 100 parts by mass, more preferably 5 to 50 parts by mass, still more preferably 10 to 50 parts by mass, and particularly preferably 15 to 40 parts by mass with respect to 100 parts by mass of the copolymer rubber (A). The rubber composition in such a mode tends to exhibit the above-described effects more favorably. In the method for producing the rubber composition of the present disclosure, the above "content" is read as "blending amount". The same applies to other parts. The content of the modified copolymer (B) in the rubber composition of the present disclosure is preferably 20 to 200 parts by mass, more preferably 30 to 160 parts by mass, and still more preferably 40 to 120 parts by mass with respect to 100 parts by mass of the organic filler (C). The rubber composition in such a mode tends to exhibit the above-described effects more favorably.

[0048] <Manufacturing method of modified copolymer (B)> The modified copolymer (B) can be produced, for example, by modifying an ethylene-α-olefin copolymer (B') having a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 or more carbon atoms as a base copolymer with the above carboxylic acid compound. Specifically, the modified copolymer (B) can be produced by various conventionally known methods described in, for example, JP-A-61-126120 and Japanese Patent No. 2593264, or by modifying the ethylene-α-olefin copolymer (B') by the following method (1) or (2). Hereinafter, the ethylene-α-olefin copolymer (B') to be modified is also referred to as "copolymer (B')".

[0049] (1) A method of charging the copolymer (B') into an extruder or a batch reactor, etc., and adding the above carboxylic acid compound to be reacted thereto to modify the copolymer (B'). (2) A method of dissolving the copolymer (B') in a solvent, adding the above carboxylic acid compound to be reacted thereto, and modifying the copolymer (B').

[0050] In any of the above methods, in order to efficiently react (preferably graft-react) the copolymer (B') with the above carboxylic acid compound, it is preferable to carry out the above reaction in the presence of a radical initiator or the like.

[0051] As the above carboxylic acid compound, one kind may be used, or two or more kinds may be used. The amount of the above carboxylic acid compound used is preferably 0.5 to 150 parts by mass, more preferably 0.5 to 60 parts by mass, and still more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the copolymer (B').

[0052] Examples of the radical initiator include organic peroxides and azo compounds. Examples of the organic peroxide include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, 2,5-dimethyl-2,5-di(peroxybenzoate)-3-hexyne, 1,4-bis(t-butylperoxyisopropyl)benzene, t-butylperoxyacetate, t-butylperoxybenzoate, t-butylperoxyphenylacetate, t-butylperoxyisobutyrate, t-butylperoxy-sec-octoate, t-butylperoxypivalate, t-butylperoxydiethylacetate, and cumylperoxypivalate. As the organic peroxide, a compound having a half-life decomposition temperature of 150 to 270°C and a half-life of 1 minute is preferable. Examples of the azo compound include azobisisobutyronitrile and dimethylazoisobutyrate.

[0053] Among these, in particular, dialkyl peroxides such as dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, and 1,4-bis(t-butylperoxyisopropyl)benzene are preferable.

[0054] One radical initiator may be used, or two or more radical initiators may be used. The amount of the radical initiator used is preferably 0.01 to 15 parts by mass, more preferably 0.05 to 10 parts by mass, and still more preferably 0.1 to 8 parts by mass with respect to 100 parts by mass of the copolymer (B').

[0055] The reaction temperature in the above modification reaction is preferably 20 to 350°C, more preferably 60 to 300°C, still more preferably 120 to 200°C, and particularly preferably 130 to 180°C. The reaction time in the above modification reaction is preferably 30 minutes to 80 hours, more preferably 1 hour to 50 hours.

[0056] The modified copolymer (B) is obtained, for example, by modifying an ethylene-α-olefin copolymer (B') having structural units derived from ethylene and structural units derived from an α-olefin having 3 or more carbon atoms with the above carboxylic acid compound (preferably by graft modification). The copolymer (B') is, for example, a random copolymer of ethylene and an α-olefin having 3 or more carbon atoms. In the copolymer (B'), as described above, the content ratio of the structural units derived from ethylene is 10 to 90 mol%, preferably 30 to 80 mol%, more preferably 40 to 60 mol%. However, the total of the content of the structural units derived from ethylene and the content of the structural units derived from an α-olefin having 3 or more carbon atoms is 100 mol%.

[0057] The copolymer (B') may further have structural units derived from at least one other monomer selected from polar group-containing monomers, aromatic vinyl compounds, and cyclic olefins. The content of the structural units derived from the above other monomers in the copolymer (B') is preferably 20 mol% or less, more preferably 10 mol% or less, still more preferably 5 mol% or less, even more preferably 1 mol% or less, particularly preferably 0.5 mol% or less, based on the total of 100 mol% of the content of the structural units derived from ethylene and the content of the structural units derived from an α-olefin having 3 or more carbon atoms. It is preferable that the copolymer (B') does not have structural units derived from the above other monomers.

[0058] Examples of the polar group-containing monomer include α,β-unsaturated carboxylic acids such as (meth)acrylic acid, fumaric acid, and maleic anhydride; metal salts such as sodium salts of the α,β-unsaturated carboxylic acids; α,β-unsaturated carboxylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, and n-propyl (meth)acrylate; vinyl esters such as vinyl acetate and vinyl propionate; and unsaturated glycidyls such as glycidyl (meth)acrylate.

[0059] Examples of the aromatic vinyl compound include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, methoxystyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylbenzyl acetate, hydroxystyrene, p-chlorostyrene, divinylbenzene, α-methylstyrene, and allylbenzene.

[0060] Examples of the cyclic olefin include cyclic olefins such as cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, and tetracyclododecene. The number of carbon atoms of the cyclic olefin is preferably 3 to 30, more preferably 3 to 20.

[0061] Examples of the method for producing the copolymer (B') include a method using a vanadium-based catalyst containing a vanadium compound and an organoaluminum compound as described in Japanese Examined Patent Publication No. 2-1163 or Japanese Examined Patent Publication No. 2-7998. As a method for producing the copolymer (B') with high polymerization activity, for example, a method using a metallocene-based catalyst containing a metallocene compound such as zirconocene and an organoaluminum oxy compound (aluminoxane) as described in Japanese Unexamined Patent Application Publication No. 61-221207, Japanese Examined Patent Publication No. 7-121969, Japanese Patent No. 2796376, or Re-Published Japanese Patent Application No. 2015-147215 is also included. This method is preferable from the viewpoints such as being able to reduce the chlorine content in the obtained copolymer and the 2,1-insertion amount of α-olefin.

[0062] The reduction of the 2,1-insertion amount of α-olefin makes it possible to further reduce the ethylene chains in the copolymer molecule and suppress the intramolecular crystallinity of ethylene. Therefore, the copolymer (B') tends to be an amorphous copolymer having good fluidity. Due to this property, a rubber composition having good processability and flexibility can be obtained. The 2,1-insertion amount of α-olefin is in accordance with the method described in Japanese Unexamined Patent Application Publication No. 7-145212 13It is determined by the analysis of the 13C-NMR measurement. The 2,1-insertion amount of the α-olefin is preferably 1% or less, more preferably 0.5% or less, and still more preferably 0.1% or less. 13 In the 13C-NMR measurement, a copolymer in which no peak is observed in the range of 15.0 to 17.5 ppm is particularly preferred.

[0063] For example, by using the following method, a copolymer (B') having a good performance balance in terms of molecular weight, molecular weight distribution, and amorphousness can be obtained. The copolymer (B') can be produced by copolymerizing ethylene and an α-olefin having 3 or more carbon atoms in the presence of an olefin polymerization catalyst. The olefin polymerization catalyst includes, for example, at least one compound (Q) selected from the group consisting of a crosslinked metallocene compound (P) represented by the formula [I], an organometallic compound (Q-1), an organoaluminum oxy compound (Q-2), and a compound (Q-3) that reacts with the crosslinked metallocene compound (P) to form an ion pair.

[0064] ((Crosslinked metallocene compound (P))) The crosslinked metallocene compound (P) is represented by the formula [I]. [Chemical formula]

[0065] Each element in the formula [I] will be described below. R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9 and R 12 are each independently a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group. R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9 and R 12A plurality of adjacent groups in [the compound] may be connected to each other to form a ring structure. R 6 and R 11 are the same group as each other, and are a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group. R 7 and R 10 are the same group as each other, and are a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group. R 6 and R 7 may be bonded to a hydrocarbon having 2 to 3 carbon atoms to form a ring structure. R 10 and R 11 may be bonded to a hydrocarbon having 2 to 3 carbon atoms to form a ring structure. R 6 , R 7 , R 10 and R 11 are not hydrogen atoms at the same time (that is, R 6 = R 7 = R 10 = R 11 = a hydrogen atom does not occur). R 13 and R 14 are each independently a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, and may be connected to each other to form a ring structure.

[0066] Examples of the hydrocarbon group include a hydrocarbon group having 1 to 20 carbon atoms. Examples of the hydrocarbon group having 1 to 20 carbon atoms include a linear saturated hydrocarbon group having 1 to 20 carbon atoms, a linear unsaturated hydrocarbon group having 2 to 20 carbon atoms, a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, and a cyclic unsaturated hydrocarbon group having 3 to 20 carbon atoms.

[0067] Examples of the chain saturated hydrocarbon groups having 1 to 20 carbon atoms include linear alkyl groups such as methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, and n-decanyl group; and branched alkyl groups such as isopropyl group, isobutyl group, s-butyl group, t-butyl group, t-amyl group, neopentyl group, 3-methylpentyl group, 1,1-diethylpropyl group, 1,1-dimethylbutyl group, 1-methyl-1-propylbutyl group, 1,1-propylbutyl group, 1,1-dimethyl-2-methylpropyl group, and 1-methyl-1-isopropyl-2-methylpropyl group. The number of carbon atoms in the chain saturated hydrocarbon group is preferably 1 to 6.

[0068] Examples of the chain unsaturated hydrocarbon groups having 2 to 20 carbon atoms include alkenyl groups such as ethenyl group (vinyl group), 1-propenyl group, 2-propenyl group (allyl group), and 1-methylethenyl group (isopropenyl group); and alkynyl groups such as ethynyl group, 1-propynyl group, and 2-propynyl group (propargyl group). The number of carbon atoms in the chain unsaturated hydrocarbon group is preferably 2 to 4.

[0069] Examples of the cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include cyclic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, norbornenyl group, 1-adamantyl group, and 2-adamantyl group, and groups in which at least one hydrogen atom of the cyclic saturated hydrocarbon group is replaced by a hydrocarbon group having 1 to 17 carbon atoms, such as 3-methylcyclopentyl group, 3-methylcyclohexyl group, 4-methylcyclohexyl group, and 4-cyclohexylcyclohexyl group. The number of carbon atoms in the cyclic saturated hydrocarbon group is preferably 5 to 11.

[0070] Examples of the cyclic unsaturated hydrocarbon group having 3 to 20 carbon atoms include cyclic unsaturated hydrocarbon groups such as phenyl group, naphthyl group, indenyl group, azulenyl group, phenanthryl group, anthracenyl group, cyclopentadienyl group, and norbornyl group; groups in which at least one hydrogen atom of the cyclic unsaturated hydrocarbon group is replaced by a hydrocarbon group having 1 to 15 carbon atoms, such as 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, biphenylyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, and 2,4,6-trimethylphenyl group; groups in which at least one hydrogen atom of the chain saturated hydrocarbon group is replaced by a cyclic unsaturated hydrocarbon group having 3 to 19 carbon atoms, such as benzyl group and cumyl group. The number of carbon atoms of the cyclic unsaturated hydrocarbon group is preferably 6 to 10.

[0071] Examples of the silicon-containing hydrocarbon group include groups in which at least one carbon atom in the above hydrocarbon group is replaced by a silicon atom, and specifically include alkylsilyl groups such as trimethylsilyl group, triethylsilyl group, t-butyldimethylsilyl group, and triisopropylsilyl group; arylsilyl groups such as dimethylphenylsilyl group, methyldiphenylsilyl group, and t-butyldiphenylsilyl group; pentamethyldisilanyl group, and trimethylsilylmethyl group. The number of carbon atoms of the alkylsilyl group is preferably 1 to 10, and the number of carbon atoms of the arylsilyl group is preferably 6 to 18.

[0072] R 13 and R 14 The bridged metallocene compound (P) in which either one or both of them are aryl groups is preferred, and R 13 and R 14 both are aryl groups, and either one of R 2 and R 3 is a saturated hydrocarbon group having 4 carbon atoms. The bridged metallocene compound (P) is more preferred. R 13 and R 14The crosslinked metallocene compound (P) in which both are aryl groups has high polymerization activity for the copolymerization of ethylene and α-olefin. By using this crosslinked metallocene compound (P), the polymerization selectively stops by introducing hydrogen to the molecular end, so the unsaturated bonds of the resulting copolymer (B') tend to decrease. Therefore, a copolymer (B') with high saturation and excellent heat resistance can be obtained only by performing a simpler hydrogenation operation or without performing a hydrogenation operation, and it also tends to be excellent in terms of cost. In addition, the copolymer (B') obtained from the compound (P) has a high random copolymerizability and thus tends to have a controlled molecular weight distribution.

[0073] Y is a carbon atom or a silicon atom, preferably a carbon atom. M is a transition metal atom, titanium (Ti), zirconium (Zr) or hafnium (Hf), and is preferably zirconium from the viewpoint of high polymerization activity.

[0074] Q is a halogen atom, a hydrocarbon group, an anionic ligand or a neutral ligand capable of coordinating with a lone pair of electrons, j is an integer of 1 to 4, preferably 2. When j is an integer of 2 or more, the plurality of Qs may be the same or different from each other.

[0075] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Details of the hydrocarbon group are as described above for R 1 and so on. When Q is a halogen atom, a chlorine atom is preferred. When Q is a hydrocarbon group, the hydrocarbon group preferably has 1 to 7 carbon atoms.

[0076] Examples of the anionic ligand include alkoxy groups such as a methoxy group and a t-butoxy group; aryloxy groups such as a phenoxy group; carboxylate groups such as acetate and benzoate; and sulfonate groups such as mesylate and tosylate.

[0077] Examples of neutral ligands capable of coordinating with lone pairs of electrons include organic phosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, and diphenylmethylphosphine; and ether compounds such as tetrahydrofuran, diethyl ether, dioxane, and 1,2-dimethoxyethane.

[0078] Specific examples of the bridged metallocene compound (P) include the compounds listed in paragraphs

[0093] and

[0094] of JP-A-2023-51117.

[0079] The bridged metallocene compound (P) may be used alone or in combination of two or more.

[0080] ((Compound (Q))) The compound (Q) is at least one compound selected from the group consisting of an organometallic compound (Q-1), an organoaluminum oxy compound (Q-2), and a compound (Q-3) that reacts with the bridged metallocene compound (P) to form an ion pair. The compound (Q) may be used alone or in combination of two or more.

[0081] Examples of the organometallic compound (Q-1) include organometallic compounds (Q-1a), (Q-1b), and (Q-1c) of Groups 1, 2, 12, and 13 of the periodic table.

[0082] (Q-1a) General formula R a m Al(OR b ) n H p X q An organoaluminum compound represented by In the formula, R a and R b may be the same or different from each other, and are hydrocarbon groups having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms. X is a halogen atom, m is a number where 0 < m ≦ 3, n is a number where 0 ≦ n < 3, p is a number where 0 ≦ p < 3, q is a number where 0 ≦ q < 3, and m + n + p + q = 3.

[0083] Examples of such compounds include tri-n-alkylaluminums such as trimethylaluminum, triethylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum; tri-branched alkylaluminums such as triisopropylaluminum, triisobutylaluminum, tri-sec-butylaluminum, tri-t-butylaluminum, tri-2-methylbutylaluminum, tri-3-methylhexylaluminum, and tri-2-ethylhexylaluminum; tricycloalkylaluminums such as tricyclohexylaluminum and tricyclooctylaluminum; triarylaluminums such as triphenylaluminum and tri(4-methylphenyl)aluminum; dialkylaluminum hydrides such as diisopropylaluminum hydride and diisobutylaluminum hydride; alkenylaluminums such as isoprenylaluminum represented by the general formula (i-C4H9) x Al y (C5H 10 ) z (wherein x, y, and z are positive numbers and z ≤ 2x); alkylaluminum alkoxides such as isobutylaluminum methoxide and isobutylaluminum ethoxide; dialkylaluminum alkoxides such as dimethylaluminum methoxide, diethylaluminum ethoxide, and dibutylaluminum butoxide; alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide; general formula R a 2.5 Al(OR b ) 0.5Partially alkoxylated alkylaluminum having an average composition represented by etc.; alkylaluminum aryloxides such as diethylaluminum phenoxide and diethylaluminum(2,6-di-t-butyl-4-methylphenoxide); dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide, and diisobutylaluminum chloride; alkylaluminum sesquihalides such as ethylaluminum sesquichloride, butylaluminum sesquichloride, and ethylaluminum sesquibromide; partially halogenated alkylaluminum such as ethylaluminum dichloride; dialkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride; alkylaluminum dihydrides such as ethylaluminum dihydride and propylaluminum dihydride and other partially hydrogenated alkylaluminum; partially alkoxylated and halogenated alkylaluminum such as ethylaluminum ethoxychloride, butylaluminum butoxychloride, and ethylaluminum ethoxybromide. Also, compounds similar to the compound represented by the above general formula R a m Al(OR b ) n H p X q can be used, for example, organoaluminum compounds in which two or more aluminum compounds are bonded via a nitrogen atom. Examples of such compounds include, for example, (C2H5)2AlN(C2H5)Al(C2H5)2.

[0084] (Q-1b) Complex alkylates of a Group 1 metal of the periodic table and aluminum, represented by the general formula M 2 AlR a 4. In the formula, M 2 is Li, Na or K, and R a is a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms.

[0085] Examples of such compounds include, for example, LiAl(C2H5)4 and LiAl(C7H 15 )4.

[0086] (Q-1c) A dialkyl compound of a Group 2 or Group 12 metal of the periodic table represented by the general formula R a R b M 3 . In the formula, R a and R b may be the same as or different from each other, and are hydrocarbon groups having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, and M 3 is Mg, Zn or Cd.

[0087] As the organoaluminum oxy compound (Q-2), conventionally known aluminoxanes can be used as they are. Specifically, compounds represented by the general formula [II] and compounds represented by the general formula [III] are mentioned.

[0088]

Chemical formula

[0089] Methylaluminoxane in which R is a methyl group and n is 3 or more, preferably 10 or more, is preferred. These aluminoxanes may contain some organoaluminum compounds.

[0090] When copolymerizing ethylene with an α-olefin having 3 or more carbon atoms at a high temperature, a benzene-insoluble organoaluminum oxy compound as exemplified in JP-A-2-78687 can also be used. Further, an organoaluminum oxy compound described in JP-A-2-167305, and an aluminoxane having two or more alkyl groups described in JP-A-2-24701 and JP-A-3-103407 can also be preferably used. The "benzene-insoluble organoaluminum oxy compound" is a compound in which the Al component soluble in benzene at 60 °C is preferably 10% or less, more preferably 5% or less, still more preferably 2% or less in terms of Al atoms, and is insoluble or hardly soluble in benzene.

[0091] Examples of the organoaluminum oxy compound (Q-2) include a modified methylaluminoxane represented by the general formula [IV].

[0092]

Chemical formula

[0093] The modified methylaluminoxane represented by the formula [IV] is prepared using trimethylaluminum and an alkylaluminum other than trimethylaluminum, as shown in, for example, US Patent No. 4,960,878 and US Patent No. 5,041,584. For example, it is prepared using trimethylaluminum and triisobutylaluminum. The aluminoxane in which Rx is an isobutyl group is commercially available under the trade names MMAO and TMAO in the form of a saturated hydrocarbon solution (see Tosoh Finechem Corporation, Tosoh Research & Technology Review, Vol 47, 55 (2003)).

[0094] Examples of the organoaluminum oxy compound (Q-2) also include a boron-containing organoaluminum oxy compound represented by the general formula [V].

[0095] [Chemical formula] In formula [V], R c is a hydrocarbon group having 1 to 10 carbon atoms, and R d may be the same as or different from each other, and is a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

[0096] Examples of the compound (Q-3) that reacts with the bridged metallocene compound (P) to form an ion pair (hereinafter also referred to as "ionized ionic compound" or simply "ionic compound") include, for example, those described in Japanese Patent Publication No. Hei 1-501950, Japanese Patent Publication No. Hei 1-502036, Japanese Patent Application Laid-Open No. Sho 3-179005, Japanese Patent Application Laid-Open No. Sho 3-179006, Japanese Patent Application Laid-Open No. Sho 3-207703, Japanese Patent Application Laid-Open No. Sho 3-207704, Japanese Patent Application Laid-Open No. 2004-51676, and U.S. Patent No. 5321106. Examples include Lewis acids, ionic compounds, borane compounds, and carborane compounds, and further include heteropoly compounds and isopoly compounds.

[0097] Examples of the ionized ionic compound include, for example, boron compounds represented by the general formula [VI].

[0098] [Chemical formula] In formula [VI], R e+ includes, for example, H + , a carbenium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptyltrienyl cation, and a ferrocenium cation having a transition metal. R f ~R i may be the same as or different from each other, and is a substituent selected from hydrocarbon groups having 1 to 20 carbon atoms, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms, and halogen-containing groups, and is preferably a substituted aryl group.

[0099] Examples of the above-mentioned carbenium cation include trisubstituted carbenium cations such as triphenylcarbenium cation, tris(4-methylphenyl)carbenium cation, and tris(3,5-dimethylphenyl)carbenium cation.

[0100] Examples of the above-mentioned ammonium cation include trialkyl-substituted ammonium cations such as trimethylammonium cation, triethylammonium cation, tri(n-propyl)ammonium cation, triisopropylammonium cation, tri(n-butyl)ammonium cation, and triisobutylammonium cation; N,N-dialkylanilinium cations such as N,N-dimethylanilinium cation, N,N-diethylanilinium cation, and N,N-2,4,6-pentamethylanilinium cation; and dialkylammonium cations such as diisopropylammonium cation and dicyclohexylammonium cation.

[0101] Examples of the above-mentioned phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tris(4-methylphenyl)phosphonium cation, and tris(3,5-dimethylphenyl)phosphonium cation.

[0102] R e+ Among the above specific examples, the carbenium cation and the ammonium cation are preferred, and the triphenylcarbenium cation, N,N-dimethylanilinium cation, and N,N-diethylanilinium cation are more preferred.

[0103] Among the ionized ionic compounds, examples of the compounds containing a carbenium cation include triphenylcarbenium tetraphenylborate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis{3,5-di-(trifluoromethyl)phenyl}borate, tris(4-methylphenyl)carbenium tetrakis(pentafluorophenyl)borate, and tris(3,5-dimethylphenyl)carbenium tetrakis(pentafluorophenyl)borate.

[0104] Among the ionized ionic compounds, examples of the compounds containing a trialkyl-substituted ammonium cation include triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri(n-butyl)ammonium tetraphenylborate, trimethylammonium tetrakis(4-methylphenyl)borate, trimethylammonium tetrakis(2-methylphenyl)borate, tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate, triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(2,4-dimethylphenyl)borate, tri(n-butyl)ammonium tetrakis(3,5-dimethylphenyl)borate, tri(n-butyl)ammonium tetrakis{4-(trifluoromethyl)phenyl}borate, tri(n-butyl)ammonium tetrakis{3,5-di(trifluoromethyl)phenyl}borate, tri(n-butyl)ammonium tetrakis(2-methylphenyl)borate, dioctadecylmethylammonium tetraphenylborate, dioctadecylmethylammonium tetrakis(4-methylphenyl)borate, dioctadecylmethylammonium tetrakis(4-methylphenyl)borate, dioctadecylmethylammonium tetrakis(pentafluorophenyl)borate, dioctadecylmethylammonium tetrakis(2,4-dimethylphenyl)borate, dioctadecylmethylammonium tetrakis(3,5-dimethylphenyl)borate, dioctadecylmethylammonium tetrakis{4-(trifluoromethyl)phenyl}borate, and dioctadecylmethylammonium tetrakis{3,5-di(trifluoromethyl)phenyl}borate.

[0105] Among the ionized ionic compounds, examples of the compounds containing an N,N-dialkylanilinium cation include N,N-dimethylanilinium tetraphenylborate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis{3,5-di(trifluoromethyl)phenyl}borate, N,N-diethylanilinium tetraphenylborate, N,N-diethylanilinium tetrakis(pentafluorophenyl)borate, N,N-diethylanilinium tetrakis{3,5-di(trifluoromethyl)phenyl}borate, N,N-2,4,6-pentamethylanilinium tetraphenylborate, and N,N-2,4,6-pentamethylanilinium tetrakis(pentafluorophenyl)borate.

[0106] Among the ionized ionic compounds, examples of the compounds containing a dialkylammonium cation include di-n-propylammonium tetrakis(pentafluorophenyl)borate and dicyclohexylammonium tetraphenylborate.

[0107] Examples of the catalyst system constitution include, for example, the following [1] to [4]. [1] Containing a bridged metallocene compound (P) and a compound (Q-2) [2] Containing a bridged metallocene compound (P), a compound (Q-1), and a compound (Q-2) [3] Containing a bridged metallocene compound (P), a compound (Q-1), and a compound (Q-3) [4] Containing a bridged metallocene compound (P), a compound (Q-2), and a compound (Q-3)

[0108] ((Support (R))) As a constituent component of the olefin polymerization catalyst, the support (R) may be used as necessary. The carrier (R) is an inorganic or organic compound and is a granular or particulate solid. Among these, as the inorganic compound, a porous oxide, inorganic chloride, clay, clay mineral or ion-exchangeable layered compound is preferable. Specific examples of the carrier (R) include, for example, the compounds or substances listed in paragraphs

[0127] to

[0131] of JP-A-2023-51117.

[0109] The usage method and addition order of each component of the polymerization catalyst are arbitrarily selected. The bridged metallocene compound (P), compounds (Q-1) to (Q-3) may be introduced into the reaction system in any order. Further, at least two or more of the components in the catalyst may be contacted in advance.

[0110] The bridged metallocene compound (P) (hereinafter also referred to as "component (P)") is used, for example, in an amount of preferably 10 -9 ~10 -1 moles, more preferably 10 -8 ~10 -2 moles per liter of the reaction volume.

[0111] The organometallic compound (Q-1) (hereinafter also referred to as "component (Q-1)") is used, for example, in an amount such that the molar ratio [(Q-1) / M] of component (Q-1) to the transition metal atom (M) in component (P) is preferably 0.01 to 50,000, more preferably 0.05 to 10,000.

[0112] The organoaluminum oxy compound (Q-2) (hereinafter also referred to as "component (Q-2)") is used, for example, in an amount such that the molar ratio [(Q-2) / M] of the aluminum atom in component (Q-2) to the transition metal atom (M) in component (P) is preferably 10 to 5,000, more preferably 20 to 2,000.

[0113] The ionic compound (Q-3) (hereinafter also referred to as "component (Q-3)") is used, for example, in an amount such that the molar ratio [(Q-3) / M] of component (Q-3) to the transition metal atom (M) in component (P) is preferably 1 to 10,000, more preferably 1 to 5,000.

[0114] The polymerization temperature is preferably -50 to 300 °C, more preferably 30 to 250 °C, still more preferably 100 °C to 250 °C, and particularly preferably 130 °C to 200 °C. The polymerization pressure is preferably normal pressure to 10 MPa gauge pressure (MPaG), more preferably normal pressure to 8 MPaG.

[0115] The polymerization reaction can be carried out by any of batch, semi-continuous, and continuous methods. Furthermore, it is also possible to continuously carry out the polymerization in two or more polymerization reactors with different reaction conditions.

[0116] The molecular weight of the obtained copolymer can be adjusted by changing the hydrogen concentration and / or the polymerization temperature in the polymerization system, and further can be adjusted by the amount of the compound (Q) used. When adding hydrogen, the amount is preferably about 0.001 to 5,000 NL per 1 kg of the copolymer to be produced.

[0117] The polymerization solvent used in the liquid phase polymerization method is preferably an inert hydrocarbon solvent, more preferably a saturated hydrocarbon having a boiling point of 50 to 200 °C under normal pressure. Specifically, as the polymerization solvent, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane can be mentioned, and particularly preferably, hexane, heptane, octane, decane, and cyclohexane can be mentioned. The α-olefin itself to be polymerized can also be used as the polymerization solvent. Aromatic hydrocarbons such as benzene, toluene, and xylene, and halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane can also be used as the polymerization solvent, but from the viewpoints of reducing the environmental load and minimizing the impact on human health, the use of these may not be preferable in some cases.

[0118] The molecular weight distribution (Mw / Mn) of the copolymer can be adjusted by removing the low molecular weight component of the copolymer by a conventionally known method such as vacuum distillation. Hydrogenation may be carried out on the obtained copolymer by a conventionally known method. If the double bonds of the obtained copolymer are reduced by hydrogenation, the oxidation stability and heat resistance are improved.

[0119] <Organic filler (C)> The rubber composition of the present disclosure contains an organic filler (C). A rubber composition containing an organic filler (C) tends to be able to form a molded body that is excellently balanced in flexibility and tensile properties.

[0120] Examples of the organic filler (C) in the present disclosure include fibrous, particulate or plate-like organic fillers. Examples of the fibrous organic filler (C) include synthetic fibers made of resin materials such as polybenzazole fibers, aramid fibers, polyparaphenylene benzoxazole fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, polyamide fibers, polyolefin fibers, polyvinyl alcohol fibers and polyarylate fibers, cellulose fibers, pulp, cotton, wool and silk and other natural fibers, as well as regenerated fibers such as proteins, polypeptide fibers and alginic acid fibers. Examples of the particulate organic filler (C) include olefin particles, acrylic particles, polystyrene particles, melamine particles, fluororesin particles and powdered cellulose.

[0121] The organic filler (C) may be a biomass-derived filler or a filler produced from fossil fuels. Examples of the biomass-derived filler include plant-derived fillers such as wood powder, wood fiber, pulp, bamboo, cotton, sugarcane, rice husk, cellulose fiber, powdered cellulose and nanocellulose fiber.

[0122] As for the wood powder, the tree species of the raw log is not limited, and wood powder and wood fibers obtained from wood waste and unused wood in the wood industry can be used. The wood powder may be wood powder obtained from one tree species, or may be a wood powder mixture composed of two or more tree species.

[0123] Since the wood powder is a material with high water absorption, it is preferable to perform a heat drying treatment in advance to reduce the water content in the wood powder. The water content is preferably 10% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less in 100% by mass of the wood powder. The heating temperature is preferably in the range of 80 to 120 °C, and the drying time is preferably 1 to 4 hours. By reducing the water content in the wood powder, good miscibility between the copolymer rubber (A) and the wood powder used as the organic filler (C) can be obtained, and a uniform rubber composition is easily obtained.

[0124] Examples of the pulp include hardwood air-dried kraft pulp and softwood air-dried kraft pulp. Hardwood air-dried kraft pulp and softwood air-dried kraft pulp are obtained, for example, by chipping wood, adding an alkaline agent, boiling under high temperature and high pressure, separating the solution, washing it, and removing impurities other than pulp.

[0125] As the cellulose fiber, for example, a lignocellulosic fiber formed from polysaccharide cellulose, hemicellulose, and high molecular compound lignin containing a plant cell wall may be used. Examples of the cellulose-based compounds contained in cellulose fibers and powdered cellulose include esterified cellulose obtained by adding a polybasic acid anhydride to the hydroxyl group contained in cellulose, esterified lignocellulose obtained by adding a polybasic acid anhydride to the hydroxyl group contained in lignocellulose, oligoesterified cellulose obtained by adding a polybasic acid anhydride and an epoxy compound to the hydroxyl group contained in cellulose, and oligoesterified lignocellulose obtained by adding a polybasic acid anhydride and an epoxy compound to the hydroxyl group contained in lignocellulose. From the viewpoints of the kneading processability of the rubber composition, the flexibility of the molded article, and the tensile properties, the cellulose-based compound is preferably unmodified.

[0126] Examples of the polybasic acid anhydride include maleic anhydride, phthalic anhydride, hexahydrophthalic anhydride, dichloromaleic anhydride, succinic anhydride, and itaconic anhydride. Examples of the epoxy compound include methyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and styrene oxide.

[0127] Examples of the filler containing nanocellulose include nanocellulose fibers, cellulose nanocrystals having a structure in which bundles of cellulose are microfibrillated, cellulose nanowhiskers, and bacterial nanofibers produced from fine bacteria.

[0128] The biomass-derived filler may be a fiber obtained from agricultural products. Examples of the fiber obtained from agricultural products include hemp, flax, manila hemp, sisal hemp, rice straw, kenaf, coir, jute, kapok, ramie, henequen, corn fiber, and nut shells.

[0129] As the organic filler (C), a biomass-derived filler is preferable from the viewpoint of reducing the environmental load. Further, as the organic filler (C), from the viewpoints of the kneading processability of the rubber composition, the flexibility of the molded article, and the tensile properties, it is preferably a filler containing a compound having a hydroxyl group, more preferably a filler containing a cellulose-based compound, still more preferably a filler containing cellulose, and particularly preferably cellulose fiber or powdered cellulose. That is, as the organic filler (C), biomass-derived cellulose fiber or biomass-derived powdered cellulose is particularly preferable.

[0130] The rubber composition of the present disclosure may contain one kind of organic filler (C) or may contain two or more kinds of organic fillers (C). The content of the organic filler (C) in the rubber composition of the present disclosure is preferably 1 to 200 parts by mass, more preferably 5 to 100 parts by mass, still more preferably 10 to 80 parts by mass, and particularly preferably 15 to 50 parts by mass with respect to 100 parts by mass of the copolymer rubber (A). The rubber composition in such a mode is excellent in kneading processability and tends to form a molded body excellent in flexibility and tensile properties.

[0131] <Other components> The rubber composition of the present disclosure may contain other components other than the copolymer rubber (A), the modified copolymer (B), and the organic filler (C) described above. Examples of other components include rubber components other than the copolymer rubber (A), plastics, crosslinking agents, crosslinking aids, softeners, plasticizers, fillers other than the organic filler (C), tackifiers, colorants, foaming agents, foaming aids, activators, reaction inhibitors, dispersants, flame retardants, lubricants, ultraviolet absorbers, heat stabilizers, antioxidants, and anti-aging agents. The rubber composition of the present disclosure may contain one kind of other component or two or more kinds of other components.

[0132] Examples of the rubber component other than the copolymer rubber (A) include natural rubber, isoprene rubber, butyl rubber, halogenated butyl rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, nitrile rubber, acrylic rubber, chloroprene rubber, fluororubber, urethane rubber, and silicone rubber. Examples of the plastic include polyolefins such as crystalline polypropylene and poly(4-methyl-1-pentene), nylon, polyester, and polycarbonate.

[0133] Examples of the crosslinking agent include organic peroxides; sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, and insoluble sulfur; sulfur compounds such as sulfur monochloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, and selenium dimethyldithiocarbamate; and metal compounds such as magnesium oxide, zinc white, and red lead.

[0134] Examples of the organic peroxides include dialkyl peroxides such as dicumyl peroxide, di-t-butyl peroxide, di-t-butyl peroxy-3,3,5-trimethylcyclohexane, t-butyl cumyl peroxide, di-t-amyl peroxide, t-butyl hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-mono(t-butylperoxy)hexane, and α,α'-bis(t-butylperoxy-m-isopropyl)benzene; peroxy esters such as t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxypivalate, t-butyl peroxymaleate, t-butyl peroxyneodecanoate, t-butyl peroxybenzoate, and di-t-butyl peroxyphtalate; and ketone peroxides such as dicyclohexanone peroxide.

[0135] As for the form of the organic peroxide, it is possible to use the organic peroxide as it is. However, due to handling problems, diluted products in which the organic peroxide is adsorbed on an inorganic filler such as calcium carbonate, or masterbatch-type diluted products for the purpose of suppressing powdering during kneading and improving dispersibility in the polymer can be preferably used. The concentration of the organic peroxide in the above diluted product is preferably 10 to 60% by mass, more preferably 20 to 50% by mass.

[0136] When the rubber composition of the present disclosure contains an organic peroxide, the content of the organic peroxide is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the copolymer rubber (A).

[0137] When the rubber composition of the present disclosure contains sulfur or a sulfur compound, the content of sulfur or the sulfur compound is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the copolymer rubber (A).

[0138] When an organic peroxide is used as a crosslinking agent, examples of the crosslinking aid include sulfur; sulfur compounds such as dipentamethylenethiuram tetrasulfide; quinonedioxime compounds such as p-quinonedioxime and p,p'-dibenzoylquinone oxime; and polyfunctional monomers. Examples of the polyfunctional monomers include (meth)acrylate compounds such as polyethylene glycol di(meth)acrylate; allyl compounds such as diallyl phthalate and triallyl cyanurate; maleimide compounds such as metaphenylenebismaleimide and toluylenebismaleimide; and divinylbenzene.

[0139] When sulfur or a sulfur compound is used as a crosslinking agent, examples of crosslinking aids include sulfenamide compounds such as N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazole sulfenamide, N-t-butyl-2-benzothiazole sulfenamide, and N,N-diisopropyl-2-benzothiazole sulfenamide; thiazole compounds such as 2-mercaptobenzothiazole, 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(4-morpholinodithio)benzothiazole, 2-(2,6-diethyl-4-morpholinothio)benzothiazole, and dibenzothiazyl disulfide; guanidine compounds such as diphenylguanidine, triphenylguanidine, diorthotolylguanidine, orthotolylbiguanide, and diphenylguanidine phthalate; aldehydeamine or aldehyde-ammonia compounds such as acetaldehyde-aniline condensate, butyraldehyde-aniline condensate, hexamethylenetetramine, and acetaldehyde ammonia; imidazoline compounds such as 2-mercaptoimidazoline; thiourea compounds such as thiocarbanilide, diethylthiourea, dibutylthiourea, trimethylthiourea, and diorthotolylthiourea; thiuram compounds such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetrakis(2-ethylhexyl)thiuram disulfide, and dipentamethylenethiuram tetrasulfide; dithiocarbamate salts such as zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, and tellurium dimethyldithiocarbamate; xanthate salts such as zinc dibutylxanthate; zinc white (zinc oxide); fatty acids such as stearic acid and other compounds.

[0140] When the rubber composition of the present disclosure contains a crosslinking aid, the content of the crosslinking aid is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, based on 100 parts by mass of the copolymer rubber (A).

[0141] Although the modified copolymer (B) can also exhibit the effect as a softening agent, a softening agent other than the modified copolymer (B) may be further used. Examples of such softening agents include petroleum-based softening agents such as mineral oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, and petrolatum; coal tar-based softening agents such as coal tar and coal tar pitch; fatty oil-based softening agents such as castor oil, linseed oil, rapeseed oil, soybean oil, and coconut oil; tall oil; rosin; waxes such as beeswax, carnauba wax, and lanolin; fatty acids and their salts such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate, and zinc laurate; and synthetic polymer substances such as petroleum resin, atactic polypropylene, and coumarone-indene resin. Among these, petroleum-based softening agents are preferred, and mineral oil is more preferred.

[0142] When the rubber composition of the present disclosure contains a softening agent other than the modified copolymer (B), the content of the softening agent is preferably 1 to 100 parts by mass, more preferably 2 to 80 parts by mass, based on 100 parts by mass of the copolymer rubber (A).

[0143] Examples of the plasticizer include phthalate ester-based, adipate ester-based, sebacate ester-based, or phosphate-based plasticizers. Examples of the tackifier include coumarone-indene resin, terpene-phenol resin, and xylene-formalin resin. Examples of the colorant include inorganic pigments and organic pigments. Examples of the foaming agent include sodium bicarbonate, ammonium carbonate, N,N'-dinitrosopentamethylenetetramine, azocarboxamide, azobisisobutyronitrile, benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, calcium amide, and paratoluenesulfonyl azide. Examples of the foaming aid include salicylic acid, phthalic acid, and urea.

[0144] Examples of the filler other than the organic filler (C) include known inorganic fillers such as rubber reinforcing agents and inorganic fillers. By containing these inorganic fillers in the rubber composition, an effect of enhancing the rubber reinforcing effect of the rubber composition and improving mechanical properties such as the tensile strength, tear strength, and abrasion resistance of the crosslinked rubber can be expected.

[0145] Examples of the rubber reinforcing agent include carbon black surface-treated with carbon black, graphite, silane coupling agent, etc.; oxide-based fillers such as fine powder silica, silica, alumina, magnesium oxide, barium oxide, and calcium oxide; hydroxide-based fillers such as aluminum hydroxide and magnesium hydroxide; sedimentary rock-based fillers such as diatomaceous earth and limestone; clay mineral-based fillers such as kaolinite and montmorillonite; magnetic-based fillers such as ferrite, iron, and cobalt; and conductive fillers such as silver, gold, copper, and alloys. Among them, carbon black and / or silica are preferable as the rubber reinforcing material.

[0146] Examples of the carbon black include SAF, ISAF, HAF, EPC, XCF, FEF, GPF, HMF, SRF, FT, and MT. These may be used alone or in combination of two or more.

[0147] Commercially available products may be used as the carbon black. Examples of commercially available carbon black products include those of Asahi Carbon Co., Ltd., Cabot Japan Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin-Nichi Kasei Carbon Co., Ltd., and Columbian Carbon Company, etc.

[0148] The silica is not particularly limited, and examples thereof include dry-process silica (anhydrous silicic acid) and wet-process silica (hydrous silicic acid). These may be used alone or in combination of two or more. Wet-process silica is preferred because of its large number of silanol groups. These silicas may be surface-treated with reactive silanes such as hexamethyldisilazane, chlorosilane, and alkoxysilane, or low molecular weight siloxane, etc.

[0149] Commercially available products may be used as the silica. Examples of commercially available silica products include those of Degussa AG, Rhodia, Tosoh Silica Corporation, Solvay Japan Ltd., and Tokuyama Corporation, etc.

[0150] The inorganic filler is not particularly limited, and examples thereof include light calcium carbonate, heavy calcium carbonate, talc, and clay. These inorganic fillers can be used alone or in combination of two or more according to the purpose.

[0151] When the rubber composition of the present disclosure contains a filler other than the organic filler (C), the content of the filler is preferably 1 to 200 parts by mass, more preferably 5 to 180 parts by mass, and still more preferably 10 to 150 parts by mass with respect to 100 parts by mass of the copolymer rubber (A).

[0152] <Manufacture of Rubber Composition> The rubber composition of the present disclosure can be produced, for example, by blending the copolymer rubber (A), the modified ethylene-α-olefin copolymer (B), and the organic filler (C), and other components as necessary, by a known method.

[0153] The production of the rubber composition, the production of the molded article, the preform for the production of the crosslinked molded article, or the crosslinked molded article may be carried out continuously. After producing the rubber composition, molding and crosslinking may be carried out separately using the rubber composition.

[0154] When producing a crosslinked molded article from the rubber composition, for example, in the same manner as when crosslinking a general rubber, an uncrosslinked rubber composition (compounded rubber) is first produced, and then this compounded rubber is molded into the intended shape and then crosslinked.

[0155] Specifically, the rubber composition can be produced by the following method. Using an internal mixer (closed mixer) such as a Banbury mixer, kneader or intermix, the copolymer rubber (A), the modified ethylene-α-olefin copolymer (B), the organic filler (C), and other components as required are kneaded at a temperature of 90 to 170°C for 1 to 20 minutes, and then, using rolls such as an open roll or a kneader, other components (crosslinking agent, crosslinking aid, foaming agent, etc.) are additionally mixed as desired and kneaded at 40 to 90°C for 5 to 30 minutes, and then separated to produce the rubber composition.

[0156] The crosslinkable rubber composition produced as described above can be molded into the intended shape by various molding methods using an extrusion molding machine, calender roll, press molding machine, injection molding machine or transfer molding machine, etc., and can be crosslinked simultaneously with molding or by introducing the obtained molded article into a crosslinking tank.

[0157] The crosslinking can preferably be carried out by heating at 100 to 270°C, more preferably at 110 to 250°C, still more preferably at 120 to 200°C, preferably for 1 to 60 minutes, more preferably for 5 to 40 minutes, still more preferably for 10 to 30 minutes. When obtaining a crosslinked molded body by crosslinking with heat in this way, it is preferable that the rubber composition contains a crosslinking agent. Further, the crosslinking can also be carried out by irradiating a predetermined amount of radiation to the uncrosslinked rubber composition molded as needed. Examples of the radiation include α-rays, β-rays, γ-rays, electron beams, neutron beams, and X-rays. When the crosslinking is carried out by irradiation with radiation such as an electron beam, the rubber composition does not necessarily have to contain a crosslinking agent. The crosslinking may be carried out using a mold, or the crosslinking may be carried out without using a mold. When not using a mold, the molding and crosslinking steps are usually carried out continuously. For heating in a crosslinking tank, for example, hot air, steam, a glass bead fluidized bed, UHF (ultra-high frequency electromagnetic wave), or LCM (hot molten salt bath) can be used.

[0158] [Use] The rubber composition or the molded body thereof of the present disclosure can be applied to products used in fields such as moving bodies (for example, automobiles, ships, airplanes, or railway vehicles, and related products thereof), construction and civil engineering, medical, electric and electronic equipment, machinery, food and cosmetics, fibers, and pulp. The molded body of the present disclosure includes the above rubber composition or a crosslinked product thereof.

[0159] Examples of automobile-related products include the following products. (1) Each part of a tire, such as a tread, carcass, sidewall, inner liner, undertread, and belt part of the tire (2) A radiator grille, side moldings, garnishes (pillar, rear, cowl top) , exterior parts such as aeroparts (air dams, spoilers), wheel covers, weather strips, cowl grills, air outlet louvers, air scoops, hood bulges, ventilation parts, anti-contact parts (over fenders, side seal panels, moldings (window, hood, door belt)), marks, etc.; weather strip sponges for doors, lights, and wipers (e.g., door weather strip, trunk weather strip, luggage weather strip, roof side rail weather strip, sliding door weather strip, ventilator weather strip, sliding roof weather strip, front window weather strip, rear window weather strip, quarter window weather strip, rocker pillar weather strip, door glass outer weather strip, door glass inner weather strip), interior window frame parts such as glass runs and glass run channels, (3) air duct hoses, radiator hoses, brake hoses, (4) lubricating oil system parts such as crankshaft seals, valve stem seals, head cover gaskets, A / T oil cooler hoses, transmission oil seals, P / S hoses, P / S oil seals, etc., (5) fuel system parts such as fuel hoses, emission control hoses, inlet filler hoses, diaphragms, etc.; anti-vibration parts such as engine mounts and in-tank pump mounts, (6) boots such as CVJ boots and rack & pinion boots, (7) air conditioning parts such as A / C hoses and A / C seals, (8) belt parts such as timing belts and accessory belts, (9) sealants such as windshield sealants, vinyl plastisol sealants, anaerobic sealants, body sealants, spot weld sealants, etc.

[0160] Examples of products for construction and civil engineering include, for example, building sealants used for joints in glass screen construction methods for commercial buildings, glass perimeter joints between window frames, interior joints in toilets, washrooms or showcases, joints around bathtubs, expansion joints for exterior walls of prefabricated houses, joints for sizing boards; sealants for multilayer glass; civil engineering sealants used for road repair; paints and adhesives for metals, glass, stone, slate, concrete or tiles; adhesive sheets, waterproof sheets, and vibration-proof sheets.

[0161] Examples of medical products include, for example, rubber stoppers for pharmaceuticals, syringe gaskets, and rubber stoppers for decompression blood vessels.

[0162] Examples of products for electrical and electronic equipment include, for example, heavy electrical components, low-voltage electrical components, sealants, potting materials, coating materials or adhesives for circuits and boards of electrical and electronic equipment; sealants for wiring connection branch boxes, electrical system components or electric wires; adhesives for electric wires or glass; repair materials for wire coatings; insulating sealants for wire joint components; rolls for OA equipment (charging rolls, transfer rolls, developing rolls, paper feed rolls); vibration absorbers; grommets; encapsulating materials for gels or capacitors.

[0163] The uses of the rubber composition or its molded body of the present disclosure partly overlap with the above uses, and further include belts, hoses, tubes, sheets, sealants, potting materials, coating materials, adhesives, and vibration damping materials.

[0164] Examples of belts include, for example, transmission belts (V-belts, flat belts, toothed belts, timing belts), conveyor belts (light conveyor belts, cylindrical belts, raft top belts, conveyor belts with flanges, conveyor belts with U-shaped guides, conveyor belts with V-shaped guides). Examples of hoses include, for example, radiator hoses, heater hoses. Examples of tubes include, for example, vacuum tubes, tire tubes. Examples of sheets include, for example, roofing sheets, waterproof sheets, rubber sheets.

[0165] Examples of the sealing material include a sealing material for a refrigerator, a freezer, a washing machine, a gas meter, a microwave oven, a steam iron, or an earth leakage circuit breaker. In various industries such as machinery, electricity, and chemistry, materials used for the purpose of water tightness and air tightness at joints and contact parts are also sealing materials in a broad sense.

[0166] Examples of the potting material include a potting material for potting a transformer high-voltage circuit, a printed circuit board, a high-voltage transformer with a variable resistor part, an electrical insulation part, a semiconductive part, a conductive part, a solar cell, or a flyback transformer for a television.

[0167] Examples of the coating material include various circuit elements such as a high-voltage thick film resistor or a hybrid IC; a HIC, an electrical insulation part; a semiconductive part; a conductive part; a module; a printed circuit; a ceramic substrate; a buffer material such as a diode, a transistor, or a bonding wire; a semiconductor element; or a coating material for coating an optical fiber for optical communication.

[0168] Examples of the adhesive include an adhesive for adhering a cathode ray tube wedge, a neck, an electrical insulation part, a semiconductive part, or a conductive part.

[0169] Examples of the vibration damping material include vibration damping rubber. Examples of the vibration damping rubber include vibration damping rubber for automobiles (engine mounts, liquid-sealed engine mounts, damper pulleys, chain dampers, carburetor mounts, torsional dampers, strut mounts, rubber bushes, bumper rubbers, helper rubbers, spring sheets, shock absorbers, air springs, body mounts, bumper guards, muffler supports, rubber couplings, center bearing supports, clutch rubbers, differential mounts, suspension bushes, slip bushes, cushion strut bars, stoppers, steering dampers, radiator supports or muffler hangers), vibration damping rubber for railways (slab mats, ballast mats or track mats), and vibration damping rubber for industrial machines (expansion joints, flexible joints, bushes, mounts).

[0170] Examples of the uses of the rubber composition or its molded article of the present disclosure partially overlap with the above uses. Further examples include cup and seal materials for automobiles (master cylinder piston cups, wheel cylinder piston cups, constant velocity joint boots, pin boots, dust covers, piston seals, packings, O-rings, diaphragms, dam windshields, brackets for door mirrors, sealed headlamps, sealed cowl tops), industrial seal materials (capacitor packings, O-rings, packings), foams (sponges for hose protection, sponges for cushioning, heat insulating sponges, insulation pipes), coated electric wires, wire joints, electrical insulation parts, semiconductive rubber parts, industrial rolls (rolls for iron making, rolls for paper making, wire rolls for printing), anode caps, plug caps, ignition cables, lamp socket covers, terminal covers, wiper blades, air springs, shoe soles, shoe heels, tire sidewalls, and fabric coatings.

[0171] The uses of the rubber composition or its molded article of the present disclosure partially overlap with the above-described uses. Furthermore, they include air-conditioning related products such as passenger car air conditioners, bus air conditioners, and refrigerators; rollers, linings, rubber conveyor belts, gloves, fenders, medical rubber (syringe gaskets, tubes, catheters); gaskets (for household appliances and construction); leisure products (swimming members such as swimming caps, diving masks, and earplugs; gel cushioning members such as sports shoes and baseball gloves); asphalt modifiers, hot melt adhesives, boots, grips, toys, shoes, sandals, keypad, gears, elastomers such as PET bottle cap liners, rubber footwear, rubber rolls, printing blankets, rubber-resin linings, conductive rubber products, urethane film waterproofing, sealing devices, extruded rubber products, sponge rubber products, fenders, construction gaskets, seismic isolation rubber, paving rubber blocks, non-metallic chains, medical and sanitary rubber products, rubber conveyor belt products, rubber-vinyl gloves, fingerprint-resistant coatings for touch panels, lubricating coatings for metal surfaces, coating materials such as primers for metal coatings, etc.

[0172] [Aspect Example] The present disclosure relates to, for example, the following [1] to

[15] . [1] A rubber composition, wherein the rubber composition contains one or more copolymer rubbers (A) selected from ethylene-α-olefin copolymer rubber and ethylene-α-olefin-non-conjugated polyene copolymer rubber, a modified ethylene-α-olefin copolymer (B) that satisfies the following requirements (b-1) to (b-3), an organic filler (C), and the content of the modified ethylene-α-olefin copolymer (B) is 1 to 100 parts by mass and the content of the organic filler (C) is 1 to 200 parts by mass with respect to 100 parts by mass of the copolymer rubber (A), a rubber composition; Requirement (b-1): The content ratio of the structural unit derived from ethylene in the ethylene-α-olefin copolymer (B') before modification is 10 to 90 mol% (provided that the total of the content of the structural unit derived from ethylene and the content of the structural unit derived from an α-olefin having 3 or more carbon atoms is 100 mol%). Requirement (b-2): The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,000 to 100,000. Requirement (b-3): The modified ethylene-α-olefin copolymer (B) is a modified copolymer having a site derived from one or more carboxylic acid compounds selected from unsaturated carboxylic acids containing one or more carbon-carbon unsaturated bonds and derivatives thereof, and the content ratio of the site derived from the carboxylic acid compound in 100% by mass of the modified copolymer is 0.5 to 50% by mass.

[0173] [2] In the above requirement (b-1), the content ratio of the structural unit derived from ethylene is 35 to 65 mol%, In the above requirement (b-2), the weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 2,000 to 20,000, In the above requirement (b-3), the content ratio of the site derived from the carboxylic acid compound in 100% by mass of the modified copolymer is 1 to 20% by mass. The rubber composition according to [1] above.

[0174] [3] With respect to 100 parts by mass of the copolymer rubber (A), the content of the modified ethylene-α-olefin copolymer (B) is 10 to 50 parts by mass, and the content of the organic filler (C) is 10 to 80 parts by mass. The rubber composition according to [1] or [2] above.

[0175] [4] In the above requirement (b-3), the carboxylic acid compound is at least one compound selected from maleic acid and maleic anhydride. The organic filler (C) is a filler derived from biomass, The rubber composition according to any one of [1] to [3].

[0176] [5] A belt containing the rubber composition according to any one of [1] to [4] or a crosslinked product thereof.

[0177] [6] A hose containing the rubber composition according to any one of [1] to [4] or a crosslinked product thereof.

[0178] [7] A tube containing the rubber composition according to any one of [1] to [4] or a crosslinked product thereof.

[0179] [8] A sealing material containing the rubber composition according to any one of [1] to [4] or a crosslinked product thereof.

[0180] [9] A vibration damping material containing the rubber composition according to any one of [1] to [4] or a crosslinked product thereof.

[0181]

[10] A method for producing a rubber composition, The production method is, One or more copolymer rubbers (A) selected from ethylene-α-olefin copolymer rubber and ethylene-α-olefin-non-conjugated polyene copolymer rubber, A modified ethylene-α-olefin copolymer (B) satisfying the following requirements (b-1) to (b-3), An organic filler (C), And a step of mixing, In the step, Based on 100 parts by mass of the copolymer rubber (A), the blending amount of the modified ethylene-α-olefin copolymer (B) is 1 to 100 parts by mass, and the blending amount of the organic filler (C) is 1 to 200 parts by mass. A method for producing a rubber composition; Requirement (b-1): The content ratio of the structural unit derived from ethylene in the ethylene-α-olefin copolymer (B') before modification is 10 to 90 mol% (provided that the total of the content of the structural unit derived from ethylene and the content of the structural unit derived from an α-olefin having 3 or more carbon atoms is 100 mol%). Requirement (b-2): The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,000 to 100,000. Requirement (b-3): The modified ethylene-α-olefin copolymer (B) is a modified copolymer having a site derived from one or more carboxylic acid compounds selected from unsaturated carboxylic acids containing one or more carbon-carbon unsaturated bonds and derivatives thereof, and the content ratio of the site derived from the carboxylic acid compound in 100% by mass of the modified copolymer is 0.5 to 50% by mass.

[0182]

[11] The method for producing the rubber composition according to

[10] , wherein the modified ethylene-α-olefin copolymer (B) is a modified copolymer obtained by modifying an ethylene-α-olefin copolymer (B') produced by the following method (α) with the carboxylic acid compound; Method (α): The crosslinked metallocene compound (P) represented by the aforementioned formula [I], At least one compound (Q) selected from the group consisting of an organometallic compound (Q-1), an organoaluminum oxy compound (Q-2), and a compound (Q-3) that reacts with the crosslinked metallocene compound (P) to form an ion pair, A method including a step of copolymerizing ethylene and an α-olefin having 3 or more carbon atoms in the presence of an olefin polymerization catalyst containing the same.

[0183]

[12] In the aforementioned formula [I], R 13 and R 14 The method for producing the rubber composition according to

[11] , wherein one or both of them are aryl groups.

[0184]

[13] In the formula [I], R 13 and R 14 are both aryl groups, and either R 2 or R 3 is a saturated hydrocarbon group having 4 carbon atoms, the method for producing the rubber composition according to the above

[11] or

[12] .

[0185]

[14] In the above step, with respect to 100 parts by mass of the copolymer rubber (A), the compounding amount of the modified ethylene·α-olefin copolymer (B) is 10 to 50 parts by mass, and the compounding amount of the organic filler (C) is 10 to 80 parts by mass. In the requirement (b-1), the content ratio of the structural unit derived from ethylene is 35 to 65 mol%. In the requirement (b-2), the weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 2,000 to 20,000. In the requirement (b-3), the content ratio of the site derived from the carboxylic acid compound in 100% by mass of the modified copolymer is 1 to 20% by mass. The method for producing the rubber composition according to any one of the above

[10] to

[13] .

[0186]

[15] In the requirement (b-3), the carboxylic acid compound is at least one compound selected from maleic acid and maleic anhydride. The organic filler (C) is a filler derived from biomass. The method for producing the rubber composition according to any one of the above

[10] to

[14] .

Examples

[0187] Hereinafter, the rubber composition of the present disclosure will be described in more detail based on examples, but the rubber composition of the present disclosure is not limited to these examples.

[0188] [Measurement methods for the structure, molecular weight, etc. of raw materials] The structures, molecular weights, etc. of each copolymer and each polyolefin wax were measured by the following methods.

[0189] <Ethylene content (mol%)> 13 The ethylene content (mol%) in each copolymer was measured by applying the following apparatus and conditions using the C-NMR method. Using a JNM-ECP500 nuclear magnetic resonance apparatus manufactured by JEOL Ltd., solvent: orthodichlorobenzene / deuterated benzene (80 vol% / 20 vol%) mixed solvent, sample concentration: 55 mg / 0.6 mL, measurement temperature: 120 °C, observed nucleus: 13 C (125 MHz), sequence: single pulse proton decoupling, pulse width: 4.7 μs (45° pulse), repetition time: 5.5 s, number of integrations: 10,000 or more, chemical shift reference value: 27.50 ppm. Based on the reports of G.J. Ray (Macromolecules, 10, 773 (1977)), J.C. Randall (Macromolecules, 15, 353 (1982)), K. Kimura (Polymer, 25, 4418 (1984)), etc., the ethylene content was determined from the 13 C-NMR spectrum.

[0190] <Number average molecular weight, weight average molecular weight, and molecular weight distribution> By gel permeation chromatography (GPC), following the procedure of universal calibration, the weight average molecular weight (Mw) and number average molecular weight (Mn) were calculated in terms of polystyrene molecular weight conversion, and the molecular weight distribution (Mw / Mn) was calculated from these values. High-speed GPC measuring device: HLC-8320GPC (manufactured by Tosoh Corporation) Separation column: TSKgel Super Multipore HZ-M (manufactured by Tosoh Corporation), 4 columns connected in series Column temperature: 40 °C Mobile phase: tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.) Mobile phase flow rate: 0.35 mL / min Sample concentration: 5.5 g / L Sample injection volume: 20 μL Detector: Differential refractometer Standard polystyrene: PStQuick MP-M (manufactured by Tosoh Corporation)

[0191] <Content ratio of the site derived from the carboxylic acid-based compound> 1 The content ratio (mass %) of the site (modified site) derived from the carboxylic acid-based compound in the modified copolymer (B) was measured by applying the following apparatus and conditions using the H-NMR method. An AVANCE III cryo-500 type nuclear magnetic resonance apparatus (500 MHz) manufactured by Bruker BioSpin Corporation was used, and the measurement was carried out under the conditions of solvent: 1,1,2,2-tetrachloroethane-d2, measurement temperature: 120 °C, spectral width: 20 ppm, pulse repetition time: 30 seconds, and pulse width: 5.00 μs. The 1 The above content ratio was determined by calculating the area ratio of the peaks characteristic of the carboxylic acid-based compound (such as the hydrogen bonded to the α-position carbon of the carbonyl group) from the H-NMR spectrum obtained as described above.

[0192] <Acid value> The acid value was measured by a method conforming to JIS K2501:2003.

[0193] <Heat of fusion (ΔH)> Using a differential scanning calorimeter [DSC220, manufactured by Seiko Instruments Inc.], about 5.0 mg of the sample was heated from 30 °C to 200 °C at a heating rate of 10 °C / min in a nitrogen atmosphere and held at that temperature for 10 minutes. Further, it was cooled to -100 °C at a cooling rate of 10 °C / min and held at that temperature for 5 minutes, and then heated to 200 °C at a heating rate of 10 °C / min to obtain a DSC curve. The heat of fusion (ΔH) was calculated by analyzing the obtained DSC curve in accordance with JIS K7121.

[0194] [Production of modified copolymer (B)] [Production Example 1] A 2-L stainless steel autoclave fully purged with nitrogen was charged with 760 mL of heptane and 120 g of propylene. After raising the temperature inside the system to 150 °C, hydrogen at 0.85 MPa and ethylene at 0.19 MPa were supplied to set the total pressure to 3 MPaG. Next, 0.4 mmol of triisobutylaluminum, 0.0002 mmol of [diphenylmethylene(η 5 -3-n-butylcyclopentadienyl)(η 5 -2,7-di-t-butylfluorenyl)]zirconium dichloride, and 0.002 mmol of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were pressured in with nitrogen, and polymerization was initiated by setting the stirring rotation speed to 400 rpm. Thereafter, only ethylene was continuously supplied to maintain the total pressure at 3 MPaG, and polymerization was carried out at 150 °C for 5 minutes. Polymerization was stopped by adding a small amount of ethanol to the system, and unreacted ethylene, propylene, and hydrogen were purged. The resulting polymerization solution was washed three times with 1000 mL of 0.2 mol / L hydrochloric acid and then three times with 1000 mL of distilled water, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The obtained polymer was dried at 80 °C under reduced pressure for 24 hours to obtain an ethylene-propylene copolymer (B1'). The ethylene content ratio of the ethylene-propylene copolymer (B1') was 49.5 mol%, Mw was 5,100, Mw / Mn was 1.7, and the heat of fusion (ΔH) was not substantially measured.

[0195] [Production Example 2] A 2-L stainless steel autoclave fully purged with nitrogen was charged with 760 mL of heptane and 120 g of propylene. After raising the temperature inside the system to 150 °C, hydrogen at 0.85 MPa and ethylene at 0.19 MPa were supplied to set the total pressure to 3 MPaG. Next, 0.4 mmol of triisobutylaluminum, 0.0002 mmol of [methylphenylmethylene(η 5 -cyclopentadienyl)(η 50.0002 mmol of bis(2,7-di-t-butylfluorenyl)zirconium dichloride and 0.002 mmol of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were pressured in with nitrogen, and the polymerization was initiated by setting the stirring speed to 400 rpm. Thereafter, only ethylene was continuously supplied to maintain the total pressure at 3 MPaG, and the polymerization was carried out at 150 °C for 5 minutes. The polymerization was stopped by adding a small amount of ethanol to the system, and then unreacted ethylene, propylene, and hydrogen were purged. The obtained polymerization solution was washed three times with 1000 mL of 0.2 mol / L hydrochloric acid and then three times with 1000 mL of distilled water, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain a crude ethylene-propylene copolymer.

[0196] 100 mL of a hexane solution of a 0.5 mass% Pd / alumina catalyst and 500 mL of a 30 mass% hexane solution of the obtained crude ethylene-propylene copolymer were added to a 1 L stainless steel autoclave. After sealing the autoclave, nitrogen substitution was performed. Then, the temperature was raised to 140 °C with stirring, the system was purged with hydrogen, and then the pressure was increased to 1.5 MPa with hydrogen and a hydrogenation reaction was carried out for 15 minutes. After filtering the reaction solution to remove the hydrogenation catalyst, the solvent was distilled off under reduced pressure and dried at 80 °C under reduced pressure for 24 hours to obtain an ethylene-propylene copolymer (B2'). The ethylene content ratio of the ethylene-propylene copolymer (B2') was 48.5 mol%, Mw was 5,200, Mw / Mn was 1.7, and the heat of fusion (ΔH) was not substantially measured.

[0197] [Modified Example 1] A 200 mL glass reactor equipped with a nitrogen blowing tube, a water-cooled condenser, a thermometer, and two dropping funnels was charged with 100 g of an unmodified ethylene-propylene copolymer (B1'). After heating up, nitrogen bubbling was started at 120 °C and the system was kept at 160 °C. Then, 6.6 g of maleic anhydride (heated to a liquid state at around 70 °C) and 1.3 g of di-t-butyl peroxide, which had been previously charged into the two dropping funnels respectively, were supplied over 5 hours, and the reaction was carried out for 1 hour after the supply was completed. Next, the temperature was further raised to 175 °C. After depressurizing the system, nitrogen was gradually purged with a vacuum pump while reducing the pressure for 1 hour to remove impurities (unreacted maleic anhydride and decomposition products of di-t-butyl peroxide). By the above operations, a maleic anhydride-modified ethylene-propylene copolymer (B-1) was obtained. The content ratio of the site derived from the carboxylic acid-based compound of the obtained modified copolymer (B-1) was 4.9 mass%, Mw was 5,600, the acid value was 52 mgKOH / g, and the heat of fusion (ΔH) was not substantially measured. This is also described below as "liquid maleic anhydride-modified copolymer (B-1)".

[0198] [Modification Example 2] The unmodified ethylene-propylene copolymer (B1’) was changed to an unmodified ethylene-propylene copolymer (B2’), the supply amount of maleic anhydride was changed to 14.1 g, the supply amount of di-t-butyl peroxide was changed to 2.8 g, and the supply time of maleic anhydride and di-t-butyl peroxide was changed to 10 hours. Otherwise, it was carried out in the same manner as in Modification Example 1. The content ratio of the site derived from the carboxylic acid-based compound of the resulting maleic anhydride-modified ethylene-propylene copolymer of the product was 10.6 mass%, Mw was 7,300, the acid value was 121 mgKOH / g, and the heat of fusion (ΔH) was not substantially measured. This is also described below as "liquid maleic anhydride-modified copolymer (B-2)".

[0199] The measurement results of the molecular weight and the like of the liquid maleic anhydride-modified copolymers (B-1) to (B-2) obtained in Modification Examples 1 to 2 are shown in Table 1.

[0200]

Table 1

[0201] [Production of Maleic Anhydride-Modified Polyethylene Wax and Maleic Anhydride-Modified Polypropylene Wax] [Production Example 3] (1) Preparation of Catalyst In a 1.5 L glass autoclave, 25 g of commercially available anhydrous magnesium chloride was suspended in 500 mL of hexane. This suspension was maintained at 30 °C, and 92 mL of ethanol was added dropwise over 1 hour while stirring. After the addition was complete, the mixture was reacted for 1 hour. After the reaction was complete, 93 mL of diethylaluminum monochloride was added dropwise over 1 hour and reacted for 1 hour after the addition was complete. After the reaction was complete, 90 mL of titanium tetrachloride was added dropwise. After the addition was complete, the temperature of the solution was raised to 80 °C and reacted for 1 hour. After the reaction was complete, the solid part was washed with hexane by decantation until no free titanium was detected. The titanium concentration in the solid part (hexane suspension) washed with hexane was quantified by titration. The hexane suspension was subjected to the following steps.

[0202] (2) Production of Polyethylene Wax (W1’) 930 mL of hexane and 70 mL of propylene were charged into a 2 L stainless steel autoclave that had been thoroughly purged with nitrogen, and hydrogen was supplied until the total pressure reached 1.96 MPaG. Next, after raising the temperature inside the system to 170 °C, 0.1 mmol of triethylaluminum, 0.4 mmol of ethylaluminum sesquichloride, and the above hexane suspension were pressured into the system with ethylene so that the amount of titanium component contained in the hexane suspension was 0.008 mmol in terms of titanium atoms, and polymerization was initiated. Thereafter, polymerization was carried out at 170 °C for 40 minutes while maintaining the total pressure at 3.92 MPaG by continuously supplying only ethylene. After stopping the polymerization by adding a small amount of ethanol to the system, unreacted ethylene and propylene were purged. The obtained polymer solution was dried under reduced pressure at 100 °C overnight to obtain polyethylene wax (W1’). The ethylene content ratio of the obtained polyethylene wax (W1’) was 97.3 mol%, Mw was 1,200, and Mw / Mn was 1.9.

[0203] (3) Production of Acid-Modified Polyethylene Wax (W-1) 500 g of the above-prepared unmodified polyethylene wax (W1’) was charged into a glass reactor and melted at 160°C under a nitrogen atmosphere. Next, 30 g of maleic anhydride and 3 g of di-t-butyl peroxide were continuously fed into the reaction system at 160°C over 5 hours. Then, after further heating and reacting for 1 hour, the melt was degassed under 10 mmHg vacuum for 0.5 hour to remove volatile components. After that, it was cooled to obtain maleic anhydride-modified polyethylene wax (W-1). The content ratio of the site derived from the carboxylic acid compound in the obtained maleic anhydride-modified polyethylene wax (W-1) was 5.2% by mass, Mw was 4,100, acid value was 60 mgKOH / g, and heat of fusion (ΔH) was 147 J / g.

[0204] [Production Example 4] (1) Production of Polypropylene Wax (W2’) 200 g of commercially available polypropylene (PP, manufactured by Prime Polymer Co., Ltd., Prime Polypro J208, MFR (230°C, 2.16 kg) 40 g / 10 min) was placed in a 1.5 L stainless steel pyrolysis apparatus equipped with a stirrer, a nitrogen inlet tube, and a condenser, and the inside of the system was sufficiently purged with nitrogen. Next, while flowing nitrogen, the pyrolysis apparatus was heated to 380°C, and after melting the polypropylene, stirring was started. Heating was carried out for 2.5 hours after the temperature of the polypropylene in the system reached 380°C to conduct pyrolysis. Then, the pyrolysis apparatus was cooled to room temperature to obtain polypropylene wax (W2’). The ethylene content ratio of the obtained polypropylene wax (W2’) was 3.0 mol%, Mw was 6,900, and Mw / Mn was 2.5.

[0205] (2) Production of Acid-Modified Polypropylene Wax (W-2) 500 g of polypropylene wax (W2’) was charged into a glass reactor and melted at 170 °C under a nitrogen atmosphere. Next, 26 g of maleic anhydride and 5.5 g of di-t-butyl peroxide were continuously fed into the reactor over 3 hours. Subsequently, the contents of the reactor were heated and reacted for 1 hour. The contents of the reactor were degassed for 0.5 hour in a vacuum of 10 mmHg while in a molten state to remove volatile components. Thereafter, the contents of the reactor were cooled to obtain maleic anhydride-modified polypropylene wax (W-2). The content ratio of the site derived from the carboxylic acid-based compound in the obtained maleic anhydride-modified polypropylene wax (W-2) was 4.0% by mass, Mw was 33,600, acid value was 46 mg KOH / g, and heat of fusion (ΔH) was 73 J / g.

[0206] [Components of rubber composition] In the following examples and the like, the following components were used. [Copolymer rubber (A)] · Ethylene·propylene·non-conjugated polyene copolymer rubber (EPDM, manufactured by Mitsui Chemicals, Inc., Mitsui EPT 4045, ML(1+4) 100 °C = 45) [Modified copolymer (B)] · Liquid maleic anhydride-modified copolymers (B-1) and (B-2) [Softening agent] · Paraffinic mineral oil (manufactured by Idemitsu Kosan Co., Ltd., Diana Process Oil PW-380) [Unmodified copolymer (B')] · Liquid ethylene·propylene copolymer (B1') [Modified copolymer] · Maleic anhydride-modified liquid isoprene rubber (manufactured by Kuraray Co., Ltd., LIR-403) [Modified polyolefin wax] · Maleic anhydride-modified polyethylene wax (W-1) · Maleic anhydride-modified polypropylene wax (W-2) [Organic filler (C)] · Powdered cellulose (manufactured by Nippon Paper Industries Co., Ltd., KC Flock W-100GK) [Product containing organic peroxide] · Kayak Mil D-40C (manufactured by KAYAK CHEMICAL NURION Co., Ltd., a product obtained by diluting dicumyl peroxide (DCP) to 40% by mass with calcium carbonate, etc.)

[0207] [Manufacture of Rubber Composition and Crosslinked Molded Body] [Example 1] Using a Laboplast Mill (manufactured by Toyo Seiki Seisakusho, model 4C150, volume 60 cc), 100 parts by mass of EPDM, 25 parts by mass of a liquid maleic anhydride-modified copolymer (B-1), and 25 parts by mass of powdered cellulose were kneaded (kneading 1). The kneading conditions were a rotor rotation speed of 50 rpm, a set temperature of 130 °C, and a kneading time of 2.5 minutes. Subsequently, the kneaded material was put into the Laboplast Mill again and kneaded with 7 parts by mass of Kayak Mil D-40C (kneading 2). The kneading conditions were a rotor rotation speed of 40 rpm, a set temperature of 40 °C, and a kneading time of 2.5 minutes. Then, the kneaded material was formed into sheets with a thickness of 1 mm × 65 mm square and a thickness of 2 mm × 65 mm square using a hot press machine (manufactured by Shindo Metal Works), and a crosslinked sheet was obtained. The crosslinking conditions were a set temperature of 180 °C and a vulcanization time of 10 minutes.

[0208] [Example 2 and Comparative Examples 1 to 5] Except for changing the blending composition of the raw materials constituting the rubber composition as described in Table 2, kneaded materials and crosslinked sheets were obtained in the same manner as in Example 1.

[0209] [Evaluation Method of Physical Properties] <Kneading Processability> The value of torque, which is the magnitude of the load applied to the rotor of the Laboplast Mill at the 100-second point after starting kneading 2, was measured. Table 2 shows the relative values of torque in each example and comparative example when the torque value of Comparative Example 1 was taken as 100. It can be judged that the smaller the relative value of torque, the better the kneading processability.

[0210] <Flexibility> The hardness (Type A durometer hardness) of a test piece obtained by stacking three crosslinked sheets with a thickness of 2 mm was measured under the conditions of a test temperature of 23°C and a measurement time of 3 seconds by a method in accordance with JIS K6253-3:2012 "Vulcanized Rubber and Thermoplastic Rubber - Methods for Determining Hardness - Part 3: Durometer Hardness". Table 2 shows the relative values of the hardness in each example and comparative example when the hardness value of Comparative Example 1 was taken as 100. It can be judged that the smaller the relative value of the hardness, the better the flexibility.

[0211] <Tensile properties> From a crosslinked sheet with a thickness of 1 mm, dumbbell-shaped No. 7 test pieces in accordance with JIS K6251:2017 "Vulcanized Rubber and Thermoplastic Rubber - Methods for Determining Tensile Properties" were prepared. The tensile strength at break (Tb) (MPa) and elongation at break (Eb) (%) of the dumbbell-shaped No. 7 test pieces were measured under the conditions of a test temperature of 23°C and a tensile speed of 200 mm / min by a method in accordance with JIS K6251:2017 "Vulcanized Rubber and Thermoplastic Rubber - Methods for Determining Tensile Properties". The tensile product was calculated by calculating the product of the obtained Tb and Eb. Table 2 shows the relative values of the tensile product in each example and comparative example when the value of the tensile product of Comparative Example 1 was taken as 100. It can be judged that the larger the relative value of the tensile product, the better the tensile properties.

[0212]

Table 2

Claims

1. A rubber composition, wherein the rubber composition comprises at least one copolymer rubber (A) selected from ethylene-α-olefin copolymer rubber and ethylene-α-olefin-non-conjugated polyene copolymer rubber, a modified ethylene-α-olefin copolymer (B) satisfying the following requirements (b-1) to (b-3), an organic filler (C), and contains wherein, based on 100 parts by mass of the copolymer rubber (A), the content of the modified ethylene-α-olefin copolymer (B) is 1 to 100 parts by mass, and the content of the organic filler (C) is 1 to 200 parts by mass; a rubber composition; Requirement (b-1): The content ratio of the structural unit derived from ethylene in the ethylene-α-olefin copolymer (B') before modification is 10 to 90 mol% (however, the total of the content of the structural unit derived from ethylene and the content of the structural unit derived from an α-olefin having 3 or more carbon atoms is 100 mol%).; Requirement (b-2): The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,000 to 100,000; Requirement (b-3): The modified ethylene-α-olefin copolymer (B) is a modified copolymer having a site derived from at least one carboxylic acid compound selected from unsaturated carboxylic acids containing one or more carbon-carbon unsaturated bonds and derivatives thereof, and the content ratio of the site derived from the carboxylic acid compound in 100% by mass of the modified copolymer is 0.5 to 50% by mass.

2. In the requirement (b-1), the content ratio of the structural unit derived from ethylene is 35 to 65 mol%, in the requirement (b-2), the weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 2,000 to 20,000, and in the requirement (b-3), the content ratio of the site derived from the carboxylic acid compound in 100% by mass of the modified copolymer is 1 to 20% by mass. The rubber composition according to Claim 1.

3. Based on 100 parts by mass of the copolymer rubber (A), the content of the modified ethylene-α-olefin copolymer (B) is 10 to 50 parts by mass, and the content of the organic filler (C) is 10 to 80 parts by mass. The rubber composition according to Claim 1.

4. In the above requirement (b-3), the carboxylic acid compound is at least one compound selected from maleic acid and maleic anhydride, the organic filler (C) is a filler derived from biomass, The rubber composition according to claim 1.

5. A belt comprising the rubber composition according to any one of claims 1 to 4 or a crosslinked product thereof.

6. A hose comprising the rubber composition according to any one of claims 1 to 4 or a crosslinked product thereof.

7. A tube comprising the rubber composition according to any one of claims 1 to 4 or a crosslinked product thereof.

8. A sealing material comprising the rubber composition according to any one of claims 1 to 4 or a crosslinked product thereof.

9. A vibration damping material comprising the rubber composition according to any one of claims 1 to 4 or a crosslinked product thereof.

10. A method for producing a rubber composition, the production method includes one or more copolymer rubbers (A) selected from ethylene-α-olefin copolymer rubber and ethylene-α-olefin-non-conjugated polyene copolymer rubber, a modified ethylene-α-olefin copolymer (B) satisfying the following requirements (b-1) to (b-3), an organic filler (C), and a step of mixing them, in the above step, with respect to 100 parts by mass of the copolymer rubber (A), the blending amount of the modified ethylene-α-olefin copolymer (B) is 1 to 100 parts by mass, and the blending amount of the organic filler (C) is 1 to 200 parts by mass, A method for producing a rubber composition; Requirement (b-1): The content ratio of the structural unit derived from ethylene in the ethylene-α-olefin copolymer (B') before modification is 10 to 90 mol% (however, the sum of the content of the structural unit derived from ethylene and the content of the structural unit derived from an α-olefin having 3 or more carbon atoms is 100 mol%).); Requirement (b-2): The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,000 to 100,000; Requirement (b-3): The modified ethylene-α-olefin copolymer (B) is a modified copolymer having a site derived from one or more carboxylic acid compounds selected from unsaturated carboxylic acids containing one or more carbon-carbon unsaturated bonds and derivatives thereof, and the content ratio of the site derived from the carboxylic acid compound in 100% by mass of the modified copolymer is 0.5 to 50% by mass.

11. The method for producing a rubber composition according to claim 10, wherein the modified ethylene-α-olefin copolymer (B) is a modified copolymer obtained by modifying an ethylene-α-olefin copolymer (B') produced by the following method (α) with the carboxylic acid compound; Method (α): A crosslinked metallocene compound (P) represented by the following formula [I], At least one compound (Q) selected from the group consisting of an organometallic compound (Q-1), an organoaluminum oxy compound (Q-2), and a compound (Q-3) that reacts with the crosslinked metallocene compound (P) to form an ion pair, A method including a step of copolymerizing ethylene and an α-olefin having 3 or more carbon atoms in the presence of an olefin polymerization catalyst containing the same. 【Chemical 1】 [In formula [I], R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9 and R 12 are each independently a hydrogen atom, a hydrocarbon group or a silicon-containing hydrocarbon group, and a plurality of adjacent groups may be linked to each other to form a ring structure. R 6 and R 11 are the same group as each other and are a hydrogen atom, a hydrocarbon group or a silicon-containing hydrocarbon group. R 7 and R 10 are the same group as each other and are a hydrogen atom, a hydrocarbon group or a silicon-containing hydrocarbon group. R 6 and R 7 may be bonded to a hydrocarbon having 2 to 3 carbon atoms to form a ring structure. R 10 and R 11 may be bonded to a hydrocarbon having 2 to 3 carbon atoms to form a ring structure. R 6 , R 7 , R 10 and R 11 are not hydrogen atoms at the same time, R 13 and R 14 are each independently a hydrogen atom, a hydrocarbon group or a silicon-containing hydrocarbon group, and may be linked to each other to form a ring structure, Y is a carbon atom or a silicon atom, M is Ti, Zr, or Hf, Q is a halogen atom, a hydrocarbon group, an anionic ligand, or a neutral ligand capable of coordinating with a lone pair of electrons, j is an integer of 1 to 4, and when j is an integer of 2 or more, a plurality of Qs may be the same as or different from each other. ]

12. In the formula [I], R 13 and R 14 The method for producing a rubber composition according to claim 11, wherein either one or both of them are aryl groups.

13. In the above formula [I], R 13 and R 14 are both aryl groups, and either R 2 or R 3 is a saturated hydrocarbon group having 4 carbon atoms, the method for producing a rubber composition according to claim 11.

14. In the above step, with respect to 100 parts by mass of the copolymer rubber (A), the blending amount of the modified ethylene-α-olefin copolymer (B) is 10 to 50 parts by mass, and the blending amount of the organic filler (C) is 10 to 80 parts by mass. In the above requirement (b-1), the content ratio of the structural unit derived from ethylene is 35 to 65 mol%. In the above requirement (b-2), the weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 2,000 to 20,000. In the above requirement (b-3), the content ratio of the site derived from the carboxylic acid compound in 100% by mass of the modified copolymer is 1 to 20% by mass. The method for producing a rubber composition according to claim 10.

15. In the above requirement (b-3), the carboxylic acid compound is at least one compound selected from maleic acid and maleic anhydride. The organic filler (C) is a filler derived from biomass. The method for producing a rubber composition according to claim 10.

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