Elastomer composition and elastomer material for tire using the same

Abstract

To provide an elastomer composition capable of having tensile stress based on 100% modulus, breaking elongation, and resistance to compressive permanent strain in good balance at a high level.SOLUTION: An elastomer composition comprising: a thioester group- and / or dithioester group-containing elastomeric polymer, the polymer having a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linkable moiety in its side chain, a side chain consisting of a thioester group and / or a side chain consisting of a dithioester group, and having a glass transition temperature of 25°C or lower; at least one filler selected from the group consisting of carbon black and silica; and at least one plasticizer selected from the group consisting of paraffinic oil, aromatic oil, naphthenic oil, and petroleum resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an elastomer composition and an elastomer material for a tire using the same. [Background technology]

[0002] Elastomer compositions are industrially very useful materials because they melt at processing temperatures during molding and can be molded using known resin molding methods. For example, International Publication No. 2017 / 047274 (Patent Document 1) discloses an example of such an elastomer composition. It includes at least one elastomer component selected from the group consisting of an elastomeric polymer (A) having a side chain (a) containing a hydrogen-bond cross-linkable moiety having a carbonyl-containing group and / or a nitrogen-containing heterocycle and having a glass transition temperature of 25°C or lower, and an elastomeric polymer (B) having a side chain containing a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linkable moiety and having a glass transition temperature of 25°C or lower, a clay content of 20 parts by mass or less per 100 parts by mass of the elastomer component, and an α-olefin resin that does not have a chemically bonded cross-linkable moiety. International Publication No. 2017 / 047274 (Patent Document 1) also discloses that carbon black can be used as a reinforcing material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 047274 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional elastomer compositions such as those described in Patent Document 1 were not necessarily sufficient in terms of having a high level of well-balanced tensile stress based on 100% modulus, elongation at break, and resistance to compression set.

[0005] The present invention has been made in view of the problems associated with the prior art, and aims to provide an elastomer composition that can have a high level of tensile stress based on 100% modulus, elongation at break, and resistance to compression set in a well-balanced manner, as well as an elastomer material for tires using the same. [Means for solving the problem]

[0006] As a result of intensive research into achieving the above-mentioned object, the present inventors have found that an elastomer composition containing a thioester group- and / or dithioester group-containing elastomeric polymer which contains a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety in its side chain, has side chains consisting of thioester groups and / or side chains consisting of dithioester groups, and has a glass transition temperature of 25°C or lower; at least one filler selected from the group consisting of carbon black and silica; and at least one plasticizer selected from the group consisting of paraffinic oils, aromatic oils, naphthenic oils, and petroleum resins can be obtained which has a good balance of high levels of tensile stress based on 100% modulus, elongation at break, and resistance to compression set, and have thus completed the present invention.

[0007] That is, the present invention provides the following aspects.

[0008] [1] A thioester group- and / or dithioester group-containing elastomeric polymer having a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linkable moiety in its side chain, a side chain consisting of a thioester group and / or a side chain consisting of a dithioester group, and a glass transition temperature of 25°C or lower; at least one filler selected from the group consisting of carbon black and silica; at least one plasticizer selected from the group consisting of paraffinic oils, aromatic oils, naphthenic oils, and petroleum resins; An elastomer composition comprising:

[0009] [2] The elastomer composition according to [1], further comprising a thioester group- and dithioester group-free elastomeric polymer, which contains a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety in its side chain, has a glass transition point of 25°C or lower, and has neither a side chain consisting of a thioester group nor a side chain consisting of a dithioester group.

[0010] [3] The elastomer composition according to [1] or [2], wherein the side chain comprising a thioester group and / or the side chain comprising a dithioester group is a side chain comprising a thioester group and / or a side chain comprising a dithiocarbamate group.

[0011] [4] The side chain comprising a thioester group and / or the side chain comprising a dithioester group is a side chain consisting of at least one thioester group selected from the group consisting of a methyl thioester group, a butyl thioester group, and a (2-ethylhexyl)hexyl thioester group; and / or a side chain consisting of a dithioester group which is at least one dithiocarbamate group selected from the group consisting of a dimethyldithiocarbamate group, a diethyldithiocarbamate group, a dibutyldithiocarbamate group, and a di(2-ethylhexyl)dithiocarbamate group; The elastomer composition according to any one of [1] to [3], wherein

[0012] [5] The side chain comprising a thioester group and / or the side chain comprising a dithioester group is a side chain consisting of a thioester group that is a methyl thioester group; and / or a side chain consisting of a dithioester group, which is at least one dithiocarbamate group selected from the group consisting of a dibutyldithiocarbamate group and a di(2-ethylhexyl)dithiocarbamate group; The elastomer composition according to any one of [1] to [4], wherein

[0013] [6] The thioester group- and / or dithioester group-containing elastomeric polymer is an elastomeric polymer containing a monomer unit having a cyclic acid anhydride group in a side chain and containing a double bond in a portion forming the main chain; a compound having two or more of at least one of a hydroxyl group, a thiol group, an amino group, and an imino group in one molecule; at least one thiuram vulcanization accelerator selected from the group consisting of tetrakis(2-ethylhexyl)thiuram disulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, tetrabenzylthiuram disulfide, and dipentamethylenethiuram tetrasulfide, and / or thiocarboxylic acid; The elastomer composition according to any one of [1] to [5], which is a reaction product of:

[0014] [7] An elastomer material for a tire, comprising the elastomer composition according to any one of [1] to [6]. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide an elastomer composition that can have a high level of tensile stress based on 100% modulus, elongation at break, and resistance to compression set in a well-balanced manner, and an elastomer material for a tire using the same. [Brief explanation of the drawings]

[0016] [Figure 1]1 is a graph showing the IR spectrum of the elastomer composition obtained in Example 1 in a specific wavelength range. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below with reference to preferred embodiments. In this specification, unless otherwise specified, the expression "X to Y" for numerical values ​​X and Y means "X or more and Y or less." In such an expression, when a unit is assigned only to the numerical value Y, the unit is also applied to the numerical value X.

[0018] [Elastomer composition] The elastomer composition of the present invention comprises: a thioester group- and / or dithioester group-containing elastomeric polymer having a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linkable moiety in its side chain, a side chain consisting of a thioester group and / or a side chain consisting of a dithioester group, and a glass transition point of 25°C or lower; at least one filler selected from the group consisting of carbon black and silica; at least one plasticizer selected from the group consisting of paraffinic oils, aromatic oils, naphthenic oils, and petroleum resins; First, each component will be described below.

[0019] (Thioester and / or dithioester group-containing elastomeric polymer) The thioester group- and / or dithioester group-containing elastomeric polymer according to the present invention is an elastomeric polymer which contains a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linkable moiety in its side chain, has a side chain comprising a thioester group and / or a side chain comprising a dithioester group, and has a glass transition point of 25°C or lower (hereinafter, for convenience, this may be simply referred to as "elastomeric polymer (I)" in some cases).

[0020] In the present specification, the term "side chain" refers to the side chain and terminal of an elastomeric polymer. Furthermore, in the present specification, the term "the side chain contains a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety" refers to a case in which both a side chain having a hydrogen-bond cross-linkable moiety (hereinafter, for convenience, sometimes referred to as "side chain (a')") and a side chain having a covalent-bond cross-linking moiety (hereinafter, for convenience, sometimes referred to as "side chain (b)") are contained in the side chain of the polymer, thereby containing both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety, as well as a case in which both a side chain having both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety are contained in the side chain of the polymer (a side chain containing both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety in one side chain; hereinafter, such a side chain is occasionally referred to as "side chain (c)" for convenience). Furthermore, in the present specification, the phrase "having a side chain comprising a thioester group and / or a side chain comprising a dithioester group" means that a side chain comprising a thioester group and / or a side chain comprising a dithioester group is introduced by being covalently bonded to any site on the main chain, and as a result, a thioester group and / or a dithioester group is present in the elastomeric polymer as a non-crosslinked side chain (so-called dangling chain: a chain that exists as a side chain rather than a crosslinked chain that crosslinks polymers together by a covalent bond).

[0021] The main chain (polymer forming the main chain portion) of such an elastomeric polymer (I) is not particularly limited as long as it is made of a polymer (so-called elastomer) whose glass transition temperature is room temperature (25°C) or lower and satisfies the above-mentioned side chain requirements. Natural or synthetic polymers appropriately selected to satisfy the above requirements can be used. Furthermore, the main chain (polymer forming the main chain portion) of such an elastomeric polymer (I) is preferably a polymer containing a monomer unit containing a double bond (double bond-containing monomer unit) at a site forming the main chain skeleton, from the viewpoint of facilitating the production of a polymer having a side chain consisting of a thioester group and / or a side chain consisting of a dithioester group. Among these, at least one selected from diene rubbers and hydrogenated diene rubbers is particularly preferred, from the viewpoint of enabling the production of products with higher performance when the final composition is used as a material for producing rubber products (preferably tires, belts, and hoses). The "monomer unit including a double bond (double bond-containing monomer unit)" referred to here refers to a monomer unit that includes a double bond not in the side chain portion but in the portion that forms the main chain skeleton (a portion other than the side chain), and examples thereof include a monomer unit derived from butadiene and represented by the formula: -CH2-CH=CH-CH2-, and a monomer unit derived from isoprene and represented by the formula: -CH2-C(CH3)=CH-CH2-.

[0022] Furthermore, the diene rubber and hydrogenated diene rubber suitable as the polymer constituting the main chain are, from the viewpoint that when the composition is used as a material for producing rubber products (preferably tires, belts, and hoses), products with higher performance can be obtained, more preferably at least one selected from the group consisting of styrene-butadiene copolymer, hydrogenated styrene-butadiene copolymer, butadiene-acrylonitrile copolymer, hydrogenated butadiene-acrylonitrile copolymer, butadiene polymer, hydrogenated butadiene polymer, isoprene-based polymer (including natural rubber, isoprene polymer, epoxidized isoprene polymer, epoxidized natural rubber, acrylic-modified natural rubber, and hydrogenated products thereof), and butyl-based polymer (including butyl rubber and hydrogenated products), even more preferably at least one selected from the group consisting of hydrogenated styrene-butadiene copolymer, isoprene-based polymer, butadiene-acrylonitrile copolymer, and hydrogenated butadiene-acrylonitrile copolymer, and particularly preferably hydrogenated styrene-butadiene copolymer.

[0023] The elastomeric polymer (I) may be used singly or in the form of a mixture of two or more. The glass transition point of the elastomeric polymer (I) is 25°C or lower, as described above. The elastomeric polymer (I) satisfies the condition that the glass transition point is 25°C or lower (hereinafter, for convenience, this condition may be simply referred to as "condition (I)"). By setting the glass transition point to 25°C or lower, it is possible to impart higher flexibility in the normal temperature range for use (room temperature (25°C) or higher). In the present invention, the "glass transition point" refers to a glass transition point measured by differential scanning calorimetry (DSC). When measuring the glass transition point, it is preferable to use a heating rate of 10°C / min. Such an elastomeric polymer exhibits rubber-like elasticity at room temperature (approximately 25°C).

[0024] Furthermore, as described above, the elastomeric polymer (I) satisfies the condition that the side chain contains a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety (hereinafter, for convenience, this condition may be simply referred to as "condition (II)"). Therefore, the elastomeric polymer (I) has, as a side chain, at least one of "side chain (a') containing a hydrogen-bond cross-linkable moiety and side chain (b) containing a covalent-bond cross-linking moiety" and "side chain (c) containing a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety." In the present invention, the side chain (c) can also be said to be a side chain that functions both as the side chain (a') and as the side chain (b). Each side chain will be described below.

[0025] <Side Chain (a'): Side Chain Containing a Hydrogen-Bond Cross-Linking Moiety> The side chain (a') containing a hydrogen-bond cross-linkable moiety has a group capable of forming a cross-link via hydrogen bonding (e.g., a hydroxyl group, a hydrogen-bond cross-linkable moiety contained in the side chain (a) described below, etc.), and the side chain may be one that forms a hydrogen bond based on the group, and its structure is not particularly limited. Here, the hydrogen-bond cross-linkable moiety is a moiety that cross-links molecules of the elastomeric polymer by hydrogen bonding. Note that a cross-link via hydrogen bonding can only be formed in the presence of a hydrogen acceptor (e.g., a group containing an atom with a lone electron pair) and a hydrogen donor (e.g., a group having a hydrogen atom covalently bonded to an atom with high electronegativity). Therefore, if both a hydrogen acceptor and a hydrogen donor are not present between the side chains of the elastomeric polymer molecules, a cross-link via hydrogen bonding will not be formed. Therefore, a hydrogen-bond cross-linkable moiety will only be present in the system if both a hydrogen acceptor and a hydrogen donor are present between the side chains of the elastomeric polymer molecules. In the present invention, when both a moiety capable of functioning as a hydrogen acceptor (for example, a carbonyl group) and a moiety capable of functioning as a hydrogen donor (for example, a hydroxyl group) are present between side chains of elastomeric polymer molecules, the moiety capable of functioning as a hydrogen acceptor and the moiety capable of functioning as a hydrogen donor in the side chain can be determined to be hydrogen-bond cross-linkable moieties.

[0026] As the hydrogen-bond cross-linkable moiety in such a side chain (a'), from the viewpoint of forming a stronger hydrogen bond, a "side chain (a) containing a hydrogen-bond cross-linkable moiety having a carbonyl-containing group and / or a nitrogen-containing heterocycle" described below is more preferable.

[0027] <Side Chain (a): Side Chain Containing a Carbonyl-Containing Group and / or a Hydrogen-Bond Cross-Linkable Moiety Having a Nitrogen-Containing Heterocycle> The side chain (a) containing a hydrogen-bond cross-linkable moiety having a carbonyl-containing group and / or a nitrogen-containing heterocycle is not particularly limited as long as it has a carbonyl-containing group and / or a nitrogen-containing heterocycle. Such a hydrogen-bond cross-linkable moiety is preferably one having a carbonyl-containing group and a nitrogen-containing heterocycle. The term "side chain (a) containing a hydrogen-bond cross-linkable moiety having a carbonyl-containing group and / or a nitrogen-containing heterocycle" as used herein means that the carbonyl-containing group and / or the nitrogen-containing heterocycle (more preferably the carbonyl-containing group and the nitrogen-containing heterocycle) serving as a hydrogen-bond cross-linkable moiety is bonded (covalently) to an atom (usually a carbon atom) forming the main chain of the elastomeric polymer.

[0028] Such carbonyl-containing groups may be any group containing a carbonyl group, and are not particularly limited. Specific examples include amide, ester, imide, carboxy, carbonyl, thioester, and acid anhydride groups. Such carbonyl-containing groups may be introduced into the main chain (the polymer main chain portion) using a compound capable of introducing a carbonyl-containing group into the main chain. The compound capable of introducing such a carbonyl-containing group into the main chain is not particularly limited. Specific examples include ketones, carboxylic acids, and derivatives thereof. Known compounds capable of introducing carbonyl-containing groups, such as carboxylic acids and their derivatives, into the main chain can be appropriately used (e.g., those described in paragraphs

[0051] to

[0053] of Japanese Patent Publication No. 5918878). Compounds capable of introducing such carbonyl groups (carbonyl-containing groups) are preferably cyclic acid anhydrides such as succinic anhydride, maleic anhydride, glutaric anhydride, and phthalic anhydride, with maleic anhydride being particularly preferred.

[0029] Furthermore, when the side chain (a) has a nitrogen-containing heterocycle, the nitrogen-containing heterocycle may be introduced into the side chain (a) directly or via an organic group, and its structure is not particularly limited. Such a nitrogen-containing heterocycle may contain a heteroatom other than the nitrogen atom, such as a sulfur atom, an oxygen atom, or a phosphorus atom, as long as it contains a nitrogen atom in the heterocycle. Such a nitrogen-containing heterocycle may have a substituent. When the side chain (a) contains a nitrogen-containing heterocycle, the heterocyclic structure strengthens the hydrogen bonds that form crosslinks, tending to further improve the durability and impact resistance of the composition. Furthermore, such a nitrogen-containing heterocycle is preferably a 5-membered ring and / or a 6-membered ring, from the viewpoint of strengthening the hydrogen bonds and further improving the resistance to compression set and mechanical strength. Furthermore, such a nitrogen-containing heterocycle may be a nitrogen-containing heterocycle fused with a benzene ring or a nitrogen-containing heterocycle fused with another nitrogen-containing heterocycle. As such a nitrogen-containing heterocycle, known compounds (for example, those described in paragraphs

[0054] to

[0067] of Japanese Patent No. 5918878, those described in paragraphs

[0035] to

[0048] of Japanese Patent Laid-Open No. 2017-206604, etc.) can be used as appropriate. Note that such a nitrogen-containing heterocycle may have a substituent.

[0030] Such a nitrogen-containing heterocycle is preferably at least one selected from a triazole ring, an isocyanurate ring, a thiadiazole ring, a pyridine ring, an imidazole ring, a triazine ring, and a hydantoin ring, each of which may have a substituent, because these rings are excellent in recyclability, compression set, hardness, and mechanical strength, particularly tensile strength, and is preferably at least one selected from a triazole ring, a thiadiazole ring, a pyridine ring, an imidazole ring, and a hydantoin ring, each of which may have a substituent.

[0031] Examples of substituents that such nitrogen-containing heterocycles may have include hydroxyl groups, amino groups, imino groups, carboxy groups, isocyanate groups, epoxy groups, alkoxysilyl groups, and thiol groups (mercapto groups). Examples of such substituents include alkyl groups such as methyl groups, ethyl groups, (iso)propyl groups, and hexyl groups; alkoxy groups such as methoxy groups, ethoxy groups, and (iso)propoxy groups; groups containing halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms; cyano groups; amino groups; imino groups; aromatic hydrocarbon groups; ester groups; ether groups; acyl groups; and thioether groups. The substitution positions of these substituents are not particularly limited, and the number of substituents is also not limited.

[0032] In addition, when the side chain (a) contains both the carbonyl-containing group and the nitrogen-containing heterocycle, the carbonyl-containing group and the nitrogen-containing heterocycle may be introduced into the main chain as independent side chains, but it is preferable that the carbonyl-containing group and the nitrogen-containing heterocycle are introduced into the main chain as a single side chain in which they are bonded via different groups. The structure of such side chain (a) may be, for example, a structure such as that described in paragraphs

[0068] to

[0081] of Japanese Patent No. 5918878.

[0033] The side chain (a) is preferably an elastomeric polymer having a cyclic acid anhydride group as a functional group, and the functional group (cyclic acid anhydride group) is reacted with a compound (a compound capable of introducing a nitrogen-containing heterocycle) that reacts with the cyclic acid anhydride group to form a hydrogen-bond cross-linkable moiety, thereby forming a hydrogen-bond cross-linkable moiety, and the side chain of the polymer is thus formed as the side chain (a). Such a compound that forms a hydrogen-bond cross-linkable moiety (a compound capable of introducing a nitrogen-containing heterocycle) may be the nitrogen-containing heterocycle itself, or may be a nitrogen-containing heterocycle having a substituent (e.g., a hydroxyl group, a thiol group, an amino group, etc.) that reacts with a cyclic acid anhydride group such as maleic anhydride.

[0034] <Side chain (b): Side chain containing a covalent cross-linking moiety> As used herein, "side chain (b) containing a covalent cross-linking moiety" refers to a side chain containing a moiety that cross-links polymer molecules forming the main chain together via a covalent bond (covalent cross-linking moiety: for example, when a polymer having a functional group (a polymer that forms the main chain after reaction) is used as a raw material, a moiety that cross-links polymer molecules together via a chemically stable bond (covalent bond) such as at least one bond selected from the group consisting of amide, ester, and thioester, which can be formed by reacting the functional group of the polymer with a compound that forms a covalent cross-linking moiety (a compound that generates a covalent bond). In this way, a "covalent cross-linking moiety" is a moiety that cross-links elastomeric polymer molecules together via a covalent bond. The side chain (b) is a side chain containing a covalent-bond cross-linking moiety, but when it has a covalent-bonding moiety and also has a group capable of hydrogen bonding, and cross-linking by hydrogen bonding is formed between side chains, it will be used as side chain (c) described later. (Note that when both a hydrogen donor and a hydrogen acceptor capable of forming a hydrogen bond between side chains of elastomeric polymer molecules are not contained, for example, when only side chains containing an ester group (-COO-) are present in the system, no particular hydrogen bond is formed between the ester groups (-COO-), and therefore such a group does not function as a hydrogen-bond cross-linking moiety. On the other hand, when, for example, a carboxyl group or a trimethylsilyl group is present in the system, hydrogen bonding is not formed between the ester groups (-COO-), and therefore such a group does not function as a hydrogen-bond cross-linking moiety. When the side chains of two polymer molecules each contain a structure, such as a zole ring, that has both a hydrogen donor moiety and a hydrogen acceptor moiety for a hydrogen bond, hydrogen bonds are formed between the side chains of the elastomeric polymer molecules, resulting in the inclusion of a hydrogen-bond cross-linkable moiety. Furthermore, for example, when an ester group and a hydroxyl group coexist between the side chains of two elastomeric polymer molecules, and hydrogen bonds are formed between the side chains by these groups, the moiety that forms the hydrogen bond becomes a hydrogen-bond cross-linkable moiety. Therefore, side chain (b) may be used as side chain (c) depending on the structure of side chain (b) itself, the type of substituents of the structure of side chain (b) and other side chains, etc.

[0035] The side chain (b) containing such a covalent cross-linking moiety is not particularly limited, but preferably contains a covalent cross-linking moiety formed by reacting, for example, an elastomeric polymer having a functional group in its side chain (the polymer for forming the main chain portion) with a compound that reacts with the functional group to form a covalent cross-linking moiety (a compound that generates a covalent bond). The cross-linking at the covalent cross-linking moiety of the side chain (b) is preferably formed by at least one bond selected from the group consisting of amide, ester, lactone, urethane, urea, ether, thiourethane, and thioether (hereinafter, such a bond may be simply referred to as "bond (A)"). Therefore, the functional group possessed by the polymer for forming the main chain portion (hereinafter, sometimes referred to as the "polymer constituting the main chain") is preferably a functional group capable of generating the bond (A). It is more preferable that the bond (A) be at least one bond selected from the group consisting of amide, ester, lactone, urethane, ether, thiourethane, and thioether.

[0036] Examples of such "compounds that form covalent cross-linking moieties (compounds that generate covalent bonds)" include polyamine compounds having two or more amino groups and / or imino groups in one molecule (when both amino groups and imino groups are present, the total number of these groups is two or more); polyol compounds having two or more hydroxyl groups in one molecule; polyisocyanate compounds having two or more isocyanate (NCO) groups in one molecule; polythiol compounds having two or more thiol groups (mercapto groups) in one molecule; and the like. Here, the "compound that forms a covalent-bond cross-linking moiety (compound that forms a covalent bond)" can be a compound that can introduce both the hydrogen-bond cross-linking moiety and the covalent-bond cross-linking moiety, depending on the type of substituent that the compound has, the degree of progress of the reaction when the compound is used for reaction, and other factors. (For example, when a cross-linking moiety by a covalent bond is formed using a compound having three or more hydroxyl groups, depending on the degree of progress of the reaction, there may be cases where two hydroxyl groups react with the functional group of an elastomeric polymer having the functional group in the side chain, leaving the remaining hydroxyl group as a hydroxyl group. In such cases, a moiety that forms a hydrogen-bond cross-linking moiety can also be introduced.) Therefore, the "compound that forms a covalent-bond cross-linking moiety (compound that forms a covalent bond)" exemplified here can also include a "compound that forms both a hydrogen-bond cross-linking moiety and a covalent-bond cross-linking moiety." From this perspective, when forming side chain (b), a compound can be appropriately selected from "compounds that form covalent cross-linking moieties (compounds that generate covalent bonds)" according to the intended design, or the degree of reaction progress can be appropriately controlled to form side chain (b). When the compound that forms the covalent cross-linking moiety has a heterocycle, it becomes possible to simultaneously produce a hydrogen-bond cross-linking moiety more efficiently, and it becomes possible to efficiently form a side chain having the covalent cross-linking moiety as side chain (c) described below. Therefore, specific examples of compounds having such a heterocycle will be described as suitable compounds for producing side chain (c), particularly together with side chain (c). It can also be said that side chain (c) is a suitable form of side chains such as side chain (a') and side chain (b) due to its structure.

[0037] As the polyamine compound, the polyol compound, the polyisocyanate compound, and the polythiol compound that can be used as such a "compound that forms a covalent-bond cross-linking moiety (compound that generates a covalent bond)", known compounds (for example, those described in paragraphs

[0094] to

[0106] of Japanese Patent No. 5918878) can be used appropriately.

[0038] The functional group contained in the polymer constituting the main chain, which reacts with such a "compound that forms a covalent-bond cross-linking moiety (compound that generates a covalent bond)", is preferably a functional group that can generate (generate: form) the bond (A), and suitable examples of such functional groups include a cyclic acid anhydride group, a hydroxyl group, an amino group, a carboxy group, an isocyanate group, and a thiol group.

[0039] <Side Chain (c): Side Chain Containing Both Hydrogen-Bond Cross-Linking Moieties and Covalent-Bond Cross-Linking Moieties> Such a side chain (c) is a side chain containing both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety in one side chain. The hydrogen-bond cross-linkable moiety contained in such a side chain (c) is the same as the hydrogen-bond cross-linkable moiety described in the side chain (a'), and is preferably the same as the hydrogen-bond cross-linking moiety in the side chain (a). In addition, as the covalent-bond cross-linking moiety contained in the side chain (c), the same as the covalent-bond cross-linking moiety in the side chain (b) can be used (the same preferred cross-links can also be used).

[0040] Such a side chain (c) is preferably a side chain formed by reacting an elastomeric polymer having a functional group at the side chain with a compound that reacts with the functional group to form both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety (a compound that introduces both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety).

[0041] As such a compound that forms both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linkable moiety (a compound that introduces both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linkable moiety), a compound that has a heterocycle (particularly preferably a nitrogen-containing heterocycle) and is capable of forming a covalent-bond cross-linkable moiety (a compound that forms a covalent bond) is preferred, and among these, heterocycle-containing polyols, heterocycle-containing polyamines, heterocycle-containing polythiols, etc. are more preferred. Note that, as such heterocycle-containing polyols, polyamines, and polythiols, the same polyol compounds, polyamine compounds, and polythiol compounds as described above in the "Compounds capable of forming a covalent-bond cross-linkable moiety (compounds that form a covalent bond)" section can be appropriately used, except that they have a heterocycle (particularly preferably a nitrogen-containing heterocycle). In addition, known heterocycle-containing polyols, polyamines, and polythiols can be appropriately used (for example, those described in paragraph

[0113] of Japanese Patent Publication No. 5918878). Note that the functional group that the polymer constituting the main chain has, and that reacts with "a compound that forms both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety (a compound that introduces both a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety)", is preferably a functional group that can generate (produce: form) the bond (A), and suitable examples of such a functional group include a cyclic acid anhydride group, a hydroxyl group, an amino group, a carboxy group, an isocyanate group, and a thiol group.

[0042] (Regarding structures suitable for covalent cross-linking moieties in side chains (b) to (c)) With regard to the side chains (b) and / or (c), from the viewpoint of further improving the compression set and mechanical strength (elongation at break, tensile stress) of the obtained composition, it is preferable that the crosslink at the covalent-bond crosslinking moiety contains a tertiary amino bond (-N<) and / or an ester bond (-COO-), and that these bond moieties also function as hydrogen-bond crosslinking moieties. In this way, when the tertiary amino bond (-N<) or ester bond (-COO-) in a side chain having a covalent-bond crosslinking moiety forms a hydrogen bond with another side chain, the covalent-bond crosslinking moiety containing such a tertiary amino bond (-N<) or ester bond (-COO-) also has a hydrogen-bond crosslinking moiety and can function as the side chain (c).

[0043] In the side chains (b) and (c), the crosslink at the covalent-bond crosslinking moiety is preferably formed by a reaction between a cyclic acid anhydride group and at least one functional group selected from a hydroxyl group, an amino group, and an imino group. For example, when a polymer forming the main chain after the reaction has a cyclic acid anhydride group (e.g., a maleic anhydride group) as a functional group, the cyclic acid anhydride group of the polymer may be reacted with a compound (a compound that forms a covalent bond) that forms the covalent-bond crosslinking moiety and has at least one functional group selected from a hydroxyl group, an amino group, and an imino group, to form a covalently crosslinked moiety, thereby crosslinking the polymers.

[0044] In such side chains (b) and (c), the crosslink at the covalent crosslinking moiety is more preferably formed by the bond (A). Furthermore, the crosslink at the covalent crosslinking moiety of the side chain (b) and / or the side chain (c) may be, for example, the same as the structure described in paragraphs

[0100] to

[0109] of JP 2017-206604 A or the structure described in paragraphs

[0055] to

[0061] of WO 2019 / 027022 A.

[0045] The side chain (a'), the side chain (a), the side chain (b), and the side chain (c) have been described above, but each group (structure) of the side chain in such a polymer can be confirmed by commonly used analytical means such as NMR or IR spectroscopy.

[0046] Furthermore, such an elastomeric polymer (I) may be a polymer having both a side chain (a') and a side chain (b), or a polymer having a side chain (c). However, the hydrogen-bond cross-linkable moiety contained in the side chain of such an elastomeric polymer (I) is preferably a hydrogen-bond cross-linkable moiety having a carbonyl-containing group and / or a nitrogen-containing heterocycle (more preferably a hydrogen-bond cross-linkable moiety having a carbonyl-containing group and a nitrogen-containing heterocycle) from the viewpoint of forming stronger hydrogen bonds. Furthermore, the crosslink at the covalent-bond cross-linking moiety contained in the side chain of the elastomeric polymer (I) is preferably formed by the bond (A) from the viewpoint of also being able to induce intermolecular interactions such as hydrogen bonds between side chains containing the cross-linking moiety.

[0047] Furthermore, such an elastomeric polymer (I) satisfies the above-mentioned conditions (I) and (II), and also satisfies the condition that it has a side chain consisting of a thioester group and / or a side chain consisting of a dithioester group (hereinafter, for convenience, such condition may be simply referred to as "condition (III)"). The side chain consisting of a thioester group and / or the side chain consisting of a dithioester group are side chains that have been introduced into the elastomeric polymer (I) as non-crosslinked side chains (so-called dangling chains).

[0048] Examples of the thioester group as the side chain (dangling chain) include those of the following formulae (100) to (103):

[0049] [ka]

[0050] [In each of the above formulas, R each independently represents a hydrocarbon group (preferably an alkyl group), and the bond marked with an * represents a bond that binds to the main chain of the elastomeric polymer.] As such a thioester group, from the viewpoint of availability of raw materials, a thioester group represented by the above formula (100) is more preferable, and from the viewpoint of having two hydrocarbon groups that contribute to energy dissipation, a thiocarbamate group represented by the above formula (103) is more preferable. Furthermore, R in the formulas (100) to (103) may be a hydrocarbon group (for example, an alkyl group, an aryl group, an aralkyl group, etc.), and other conditions are not particularly limited. However, from the viewpoint of easy availability of raw materials during production, it is preferably an alkyl group, and more preferably an alkyl group having 1 to 20 carbon atoms (more preferably 1 to 18, and even more preferably 1 to 16).

[0051] Furthermore, the thioester group as such a side chain (dangling chain) is particularly preferably at least one group selected from the group consisting of a methyl thioester group, a butyl thioester group, and a (2-ethylhexyl)hexyl thioester group, and is most preferably a methyl thioester group.

[0052] Thus, when the elastomeric polymer (I) has a side chain comprising a thioester group, the side chain comprising a thioester group is preferably a side chain comprising at least one group selected from the group consisting of a methyl thioester group, a butyl thioester group, and a (2-ethylhexyl)hexyl thioester group (more preferably a side chain comprising a methyl thioester group).

[0053] Furthermore, examples of the dithioester group as the side chain (dangling chain) include those represented by the following formula:

[0054] [ka]

[0055] [In each of the above formulas, R each independently represents a hydrocarbon group (preferably an alkyl group), and the bond marked with an * represents a bond that binds to the main chain of the elastomeric polymer.] Such a dithioester group is not particularly limited, but is particularly preferably a dithiocarbamate group represented by the formula (203) above, from the viewpoint of having two hydrocarbon groups that contribute to energy dissipation.

[0056] R in the formulas (200) to (203) may each independently be a hydrocarbon group (e.g., an alkyl group, an aryl group, an aralkyl group, etc.), and other conditions are not particularly limited, but an alkyl group is preferred (particularly in the dithiocarbamate group represented by the formula (203) above, an alkyl group is particularly suitable from the viewpoint that two R can interact to dissipate energy). Furthermore, when R is an alkyl group, the number of carbon atoms in the alkyl group is preferably 1 to 20 (more preferably 2 to 18, and even more preferably 3 to 16) (particularly in the dithiocarbamate group represented by the formula (203) above, from the viewpoint that two R can interact to dissipate energy).

[0057] Furthermore, from the viewpoint of industrial availability of raw materials during production, the dithiocarbamate group suitable for the dithioester group as the side chain is more preferably at least one group selected from the group consisting of a dimethyldithiocarbamate group, a diethyldithiocarbamate group, a dibutyldithiocarbamate group, and a di(2-ethylhexyl)dithiocarbamate group, and is particularly preferably at least one group selected from the group consisting of a dibutyldithiocarbamate group and a di(2-ethylhexyl)dithiocarbamate group.

[0058] Thus, when the elastomeric polymer (I) has a side chain consisting of the dithioester group, it is preferable that the dithioester group is a dithiocarbamate group, and that the dithiocarbamate group is at least one group selected from the group consisting of a dimethyldithiocarbamate group, a diethyldithiocarbamate group, a dibutyldithiocarbamate group, and a di(2-ethylhexyl)dithiocarbamate group (more preferably at least one group selected from the group consisting of a dibutyldithiocarbamate group and a di(2-ethylhexyl)dithiocarbamate group).

[0059] The side chain consisting of the thioester group and / or the side chain consisting of the dithioester group is preferably a side chain consisting of a thioester group represented by the above formula (100) and / or a side chain consisting of a dithiocarbamate group represented by the above formula (203), and is preferably a side chain consisting of at least one thioester group selected from the group consisting of a methyl thioester group, a butyl thioester group, and a (2-ethylhexyl)hexyl thioester group; and / or a dimethyldithiocarbamate group, a diethyldithiocarbamate group, a dibutyl ... a side chain comprising a dithioester group which is at least one dithiocarbamate group selected from the group consisting of a dithiocarbamate group, a di(2-ethylhexyl)dithiocarbamate group, and a di(2-ethylhexyl)dithiocarbamate group; and a side chain comprising a thioester group which is a methylthioester group (a side chain comprising a methylthioester group); and / or a side chain comprising a dithioester group which is at least one dithiocarbamate group selected from the group consisting of a dibutyldithiocarbamate group and a di(2-ethylhexyl)dithiocarbamate group.

[0060] Furthermore, when the elastomeric polymer (I) has a side chain consisting of a thioester group, it is more preferable that the thioester group constituting the side chain is at least one group selected from the group consisting of a methyl thioester group and a thiocarbamate group, and it is particularly preferable that the methyl thioester group is used. Furthermore, when the elastomeric polymer (I) has a side chain consisting of a dithioester group, it is particularly preferable that the dithioester group constituting the side chain is a dithiocarbamate group, and that the dithiocarbamate group is at least one group selected from the group consisting of a dibutyldithiocarbamate group and a di(2-ethylhexyl)dithiocarbamate group.

[0061] Such an elastomeric polymer (I) may be any elastomeric polymer that satisfies the above-mentioned conditions (I) to (III) (a thioester group- and / or dithioester group-containing elastomeric polymer that contains a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety in its side chain, has a side chain consisting of a thioester group and / or a side chain consisting of a dithioester group (more preferably a side chain consisting of a thioester group and / or a side chain consisting of a dithiocarbamate group), and has a glass transition point of 25°C or lower), and one of these may be used alone, or two or more of these may be used in combination.

[0062] The elastomeric polymer (I) is an elastomeric polymer (hereinafter, for convenience, sometimes simply referred to as a "raw polymer") containing a monomer unit having a cyclic acid anhydride group in a side chain and containing a double bond at a site forming the main chain skeleton; a crosslinking compound (more preferably a compound having two or more of at least one of hydroxyl groups, thiol groups, amino groups, and imino groups in one molecule, and even more preferably a compound having two or more of at least one of hydroxyl groups, thiol groups, amino groups, and imino groups in one molecule and having a nitrogen-containing heterocycle); at least one vulcanization accelerator selected from the group consisting of thiuram vulcanization accelerators and metal dithiocarbamate salts, which are metal salts of the thiuram vulcanization accelerators, and / or thiocarboxylic acid; Preferably, the reaction product is

[0063] Here, in the raw material polymer, examples of the cyclic acid anhydride group include a succinic anhydride group, a maleic anhydride group, a glutaric anhydride group, and a phthalic anhydride group. From the viewpoint of high reactivity, a maleic anhydride group is particularly preferred.

[0064] The raw polymer is preferably an elastomeric polymer modified with maleic anhydride (maleic anhydride-modified elastomeric polymer). Such maleic anhydride-modified elastomeric polymers more preferably have a maleic acid ratio of 0.1 to 20% by mass. The upper limit of the numerical range of the maleic acid ratio is more preferably 15% by mass, and even more preferably 10% by mass. The lower limit of the numerical range of the maleic acid ratio is more preferably 0.5% by mass, and even more preferably 1.0% by mass. In this specification, the "maleic acid ratio" (unit: mass%) is determined by the following "method for measuring maleic acid ratio."

[0065] [Method for measuring maleic acid ratio] First, 400 mg of the maleic anhydride-modified polymer to be measured is dissolved in 80 mL of tetrahydrofuran (hereinafter, for convenience, sometimes abbreviated as "THF") to obtain a THF solution for measurement. The THF solution for measurement is then titrated with a 0.1 mol / L ethanol solution of potassium hydroxide for which a factor is calculated to three or more decimal places (volumetric standard solution: a 0.1 mol / L ethanol solution of potassium hydroxide with correction; a commercially available solution with a factor (characteristic value: corrected value) calculated to three or more decimal places may be used). The endpoint (neutralization point) is determined by potentiometric titration using an instrument. The factor (characteristic value: corrected value) of the 0.1 mol / L ethanol solution of potassium hydroxide may be determined by titration with an oxalic acid standard solution. When using a commercially available product with a calculated factor, the factor listed on the commercially available reagent (e.g., the factor listed on the reagent's test report) may be used as is. Next, a similar measurement (blank test) is performed except that the maleic anhydride-modified polymer is not used, and titration is performed, and the amount of 0.1 mol / L potassium hydroxide ethanol solution added to 80 mL of THF (blank value) is also determined. Next, the acid value is calculated using the determined titration value (addition amount) based on the "Acid Value Calculation Formula" below, and the maleinization ratio is then calculated using the obtained acid value based on the "Maleinization Ratio Calculation Formula" below, thereby determining the maleinization ratio (unit: mass%). <Calculation formula for acid value> [Acid value]=(AB)×M1×C×f / S (In the formula, A represents the amount of 0.1 mol / L potassium hydroxide ethanol solution added (titer value: mL) required to neutralize the measurement solution, B represents the amount of 0.1 mol / L potassium hydroxide ethanol solution added in a blank (blank test) (the titer value (blank value: mL) obtained by performing the same measurement except that no maleic anhydride-modified polymer is used), M1 represents the molecular weight of potassium hydroxide (56.1 (constant)), C represents the potassium hydroxide concentration in the potassium hydroxide ethanol solution (0.1 mol / L (constant)), f represents the factor of the potassium hydroxide ethanol solution (correction value: the factor listed in a commercially available reagent (for example, the factor listed in the test report for the reagent) may be used as is), and S represents the mass of the maleic anhydride-modified polymer used in the measurement. The unit of the "acid value" determined by this calculation is "mgKOH / g.") <Maleate ratio calculation formula> [Maleication rate] = [Acid value] ÷ M1 × M2 ÷ 1000 × 100 ÷ 2 (In the formula, the acid value is the value (unit: mgKOH / g) calculated using the above-mentioned "acid value calculation formula," M1 is the molecular weight of potassium hydroxide (56.1 (constant)), and M2 is the molecular weight of maleic anhydride (98.1 (constant)). The unit of the "maleication ratio" calculated by this calculation is "mass %.")

[0066] Furthermore, as the raw material polymer, a diene rubber having the cyclic acid anhydride group on a side chain and a hydrogenated diene rubber having the cyclic acid anhydride group on a side chain are more preferred, and among these, a hydrogenated diene rubber having the cyclic acid anhydride group on a side chain is particularly preferred from the viewpoint that gelation during the reaction can be more highly suppressed (gelation is more likely when there are many double bonds).

[0067] As the crosslinking compound, the above-mentioned "compound that forms a hydrogen-bond crosslinkable moiety (more preferably, a compound that can introduce a nitrogen-containing heterocycle)" and "compound that forms a covalent-bond crosslinkable moiety" can be suitably used. Note that, as such "compound that forms a hydrogen-bond crosslinkable moiety (more preferably, a compound that can introduce a nitrogen-containing heterocycle)" and "compound that forms a covalent-bond crosslinkable moiety (compound that forms a covalent bond)", known compounds that can react with cyclic acid anhydride groups (preferably maleic anhydride groups) (compounds described in JP 2017-57322 A and JP 5918878 A) can be appropriately used.

[0068] From the viewpoints of high reactivity and industrial availability, the crosslinking compound may preferably be a nitrogen-containing compound having two or more substituents of at least one of hydroxyl groups, thiol groups, amino groups, and imino groups (hereinafter, such a substituent may be simply referred to as "substituent (A)") in one molecule, an oxygen-containing compound having two or more of the substituents (A) in one molecule (e.g., diethylene glycol, neopentyl glycol, pentaerythritol, trimethylolpropane, etc.), an aliphatic compound having two or more of the functional group (A) in one molecule (e.g., glycerin), a sulfur-containing compound having two or more of the substituents (A) in one molecule, or an aromatic compound (a compound having an aromatic ring) having two or more of the substituents (A) in one molecule.

[0069] In addition, from the viewpoint of allowing the reaction to proceed efficiently, such a crosslinking compound is preferably a compound having two or more of the above-mentioned substituents (A) in one molecule. Preferred examples of such a compound having two or more of the substituents (A) in one molecule include a compound having two or more of the substituents (A) in one molecule and a nitrogen-containing heterocycle (more preferably at least one selected from the group consisting of a triazole ring, an isocyanurate ring, a thiadiazole ring, a pyridine ring, an imidazole ring, a triazine ring, a hydantoin ring, and an oxopyrimidine ring), and a compound having two or more of the substituents (A) in one molecule and an aromatic ring (more preferably a benzene ring, a naphthalene ring, an indene ring, or an anthracene ring) (e.g., benzenetrimethanol, benzenedimethanol). Among these, from the viewpoint of being able to introduce a structural moiety capable of forming a hydrogen bond with a generated carboxy group or the like, a compound having two or more of the substituents (A) in one molecule and a nitrogen-containing heterocycle is more preferred (note that the "nitrogen-containing heterocycle" as used herein has the same meaning as the above, including preferred examples). As such a compound, for example, those described in paragraph

[0049] of International Publication No. 2020 / 027109 can be appropriately used. Such crosslinking compounds may be used alone or in combination of two or more.

[0070] Preferably, the crosslinking compound is at least one selected from the group consisting of triazoles having at least two substituents (A) per molecule, pyridines having at least two substituents (A), thiadiazoles having at least two substituents (A), imidazoles having at least two substituents (A), isocyanurates having at least two substituents (A), triazines having at least two substituents (A), hydantoins having at least two substituents (A), oxopyrimidines (e.g., barbituric acid) having at least two substituents (A), 1,3,5-benzenetrimethanol, and diethylene glycol. More preferably, the substituent (A) is at least one of a hydroxyl group, an amino group, and an imino group. Furthermore, triazole, pyridine, thiadiazole, imidazole, isocyanurate, triazine, hydantoin, and the like, each having at least two of the substituent (A) in one molecule, may have a substituent other than the substituent (A).

[0071] Moreover, as such a crosslinking compound, tris(2-hydroxyethyl)isocyanurate, 2,4-diamino-6-phenyl-1,3,5-triazine, 1,3,5-benzenetrimethanol, diethylene glycol, and xylylenediol are more preferable, tris(2-hydroxyethyl)isocyanurate, 1,3,5-benzenetrimethanol, diethylene glycol, and xylylenediol are even more preferable, and among them, tris(2-hydroxyethyl)isocyanurate and 2,4-diamino-6-phenyl-1,3,5-triazine are particularly preferable from the viewpoint of enabling more efficient introduction of hydrogen-bond crosslinking moieties together with covalent-bond crosslinking moieties. Such crosslinking compounds may be used alone or in combination of two or more.

[0072] The vulcanization accelerator is at least one selected from the group consisting of thiuram vulcanization accelerators and metal dithiocarbamates, which are metal salts of the thiuram vulcanization accelerators. Such vulcanization accelerators are not particularly limited as long as they are thiuram vulcanization accelerators and / or their metal salts, i.e., metal dithiocarbamates (metal salts of thiuram vulcanization accelerators), and known compounds used as vulcanization accelerators in the field of rubber, etc., can be used as appropriate.

[0073] Examples of such thiuram vulcanization accelerators and dithiocarbamic acid metal salts include tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N), tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabenzylthiuram disulfide, dipentamethylenethiuram tetrasulfide, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc N-pentamethylenedithiocarbamate, zinc dibenzyldithiocarbamate, sodium dibutyldithiocarbamate, copper dimethyldithiocarbamate, tellurium diethyldithiocarbamate, and zinc isopropylxanthogenate.

[0074] Furthermore, from the viewpoint of high break physical properties and high compatibility, thiuram vulcanization accelerators are more preferred as such vulcanization accelerators, and among these, at least one thiuram vulcanization accelerator selected from the group consisting of tetrakis(2-ethylhexyl)thiuram disulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, tetrabenzylthiuram disulfide, and dipentamethylenethiuram tetrasulfide is preferred, and at least one thiuram vulcanization accelerator selected from the group consisting of tetrakis(2-ethylhexyl)thiuram disulfide, tetrabutylthiuram disulfide, and tetrabenzylthiuram disulfide is more preferred. Furthermore, the vulcanization accelerator contains an alkyl group having a relatively large number of carbon atoms (an alkyl group having 3 or more carbon atoms (e.g., a long alkyl group such as a butyl group or a 2-ethylhexyl group)), which is more effective in improving compatibility and break properties due to increased energy loss caused by interactions between side chains when the alkyl group is introduced into the side chains (however, if the number of carbon atoms is too long (12 or more), the energy loss becomes too large and creep resistance tends to decrease), so at least one thiuram vulcanization accelerator selected from the group consisting of tetrabutylthiuram disulfide and tetrakis(2-ethylhexyl)thiuram disulfide is particularly preferred. Therefore, when the reactant is used as the elastomeric polymer (I), and the reactant is obtained using a thiuram vulcanization accelerator, the reactant may be: an elastomeric polymer (raw polymer) containing a monomer unit having a cyclic acid anhydride group in a side chain and containing a double bond in a portion forming a main chain skeleton; a compound having two or more of at least one of a hydroxyl group, a thiol group, an amino group, and an imino group in one molecule; at least one thiuram vulcanization accelerator selected from the group consisting of tetrakis(2-ethylhexyl)thiuram disulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, tetrabenzylthiuram disulfide, and dipentamethylenethiuram tetrasulfide (more preferably at least one thiuram vulcanization accelerator selected from the group consisting of tetrabutylthiuram disulfide and tetrakis(2-ethylhexyl)thiuram disulfide); It is more preferable that the reaction product is

[0075] Examples of the thiocarboxylic acid include thioacetic acid, thiopropionic acid, thiobutanoic acid, thio(2-ethylhexanoic) acid, thiostearic acid, etc. When the thiocarboxylic acid is used, it becomes possible to efficiently introduce a thioester group (preferably at least one of a methyl thioester group, a butyl thioester group, and a (2-ethylhexyl) thioester group) into the main chain portion of the polymer (I).

[0076] Among these, from the viewpoint of ease of application to the rubber production process, the reaction product is more preferably a reaction product of the raw material polymer; the crosslinking compound; and a vulcanization accelerator.

[0077] Furthermore, the method for obtaining the elastomeric polymer (I) is not particularly limited, and any method can be suitably used which is capable of reacting a cyclic acid anhydride group in the raw material polymer with a functional group in the crosslinking compound (for example, the substituent (A)) and which is capable of reacting a double bond in the main chain skeleton of the raw material polymer with the vulcanization accelerator (more preferably a thiuram vulcanization accelerator) and / or thiocarboxylic acid. In this case, the elastomeric polymer (I) can be produced by reaction under conditions appropriately selected depending on the type of main chain of the raw material polymer, the type of the crosslinking compound, the type of the vulcanization accelerator and / or thiocarboxylic acid, etc. For example, a method may be employed in which the raw material polymer is mixed (kneaded) at a temperature (for example, about 100 to 250°C) using a kneader or other mixer, at which the raw material polymer can be plasticized, the crosslinking compound to be added can be reacted with the cyclic acid anhydride group, and the double bond in the main chain skeleton of the raw material polymer can be reacted with the vulcanization accelerator and / or thiocarboxylic acid, and the crosslinking compound and the vulcanization accelerator (more preferably a thiuram vulcanization accelerator) and / or thiocarboxylic acid are added and reacted.

[0078] When a method for obtaining the elastomeric polymer (I) is adopted in which the raw polymer is mixed (kneaded) while the crosslinking compound and the vulcanization accelerator (more preferably, a thiuram vulcanization accelerator) and / or the thiocarboxylic acid are added and reacted, the raw polymer may be mixed (kneaded) while the vulcanization accelerator (more preferably, a thiuram vulcanization accelerator) and / or the thiocarboxylic acid are first added to the raw polymer to introduce dithiocarbamate groups and / or thioester groups into the double bonds, and then the crosslinking compound is added and reacted. The method for adding the vulcanization accelerator (more preferably, a thiuram vulcanization accelerator) and / or the thiocarboxylic acid and reacting them in this manner is not particularly limited, and a method can be adopted in which the raw polymer is mixed with the vulcanization accelerator (more preferably, a thiuram vulcanization accelerator) and / or the thiocarboxylic acid at a temperature of 100 to 230°C (more preferably, 120 to 200°C) to react them. In this way, by mixing the two under the above temperature conditions, the vulcanization accelerator (more preferably a thiuram vulcanization accelerator) and / or thiocarboxylic acid can be reacted with the double bonds in the main chain skeleton of the raw material polymer, thereby introducing dithiocarbamate groups and / or thioester groups.

[0079] The amount (addition amount) of the vulcanization accelerator and / or thiocarboxylic acid used in the method for obtaining the elastomeric polymer (I) is not particularly limited, but is more preferably 0.1 to 30 parts by mass, even more preferably 0.5 to 20 parts by mass, and particularly preferably 1 to 15 parts by mass, per 100 parts by mass of the raw polymer. By adding the vulcanization accelerator and / or thiocarboxylic acid in an amount equal to or greater than the lower limit, the amount of dithiocarbamate groups and / or thioester groups introduced from the vulcanization accelerator and / or thiocarboxylic acid increases compared to when the amount is less than the lower limit, which tends to result in better break properties. On the other hand, by adding the amount equal to or less than the upper limit, the amount of dithiocarbamate groups and / or thioester groups introduced from the vulcanization accelerator and / or thiocarboxylic acid can be efficiently adjusted to an appropriate range compared to when the amount exceeds the upper limit, which tends to result in better creep resistance when used as a rubber product.

[0080] In addition, in the case where the vulcanization accelerator (more preferably a thiuram vulcanization accelerator) and / or thiocarboxylic acid are first added and reacted while mixing (kneading) the raw material polymer, and then the crosslinking compound is added and reacted, for example, the raw material polymer and the vulcanization accelerator are reacted, and then the crosslinking compound is added thereto while maintaining the reaction temperature, and the reaction between the crosslinking compound and the cyclic acid anhydride group in the elastomeric polymer proceeds simultaneously with the addition of the crosslinking compound, thereby producing the elastomeric polymer (I). Alternatively, the vulcanization accelerator (more preferably a thiuram vulcanization accelerator) and / or thiocarboxylic acid may be first added and reacted, and then the crosslinking compound may be added thereto while maintaining the reaction temperature, thereby producing the elastomeric polymer (I). After adding and reacting a vulcanization accelerator (preferably a thiuram-based vulcanization accelerator) and / or thiocarboxylic acid, the reaction product with the vulcanization accelerator and / or thiocarboxylic acid is removed, and the reaction product is then placed in another kneader, plasticized and kneaded under temperature conditions where the crosslinking compound does not react, and the crosslinking compound is added thereto to obtain a mixture of the reaction product with the vulcanization accelerator and / or thiocarboxylic acid and unreacted crosslinking compound, and the mixture is then heated and molded to simultaneously perform molding and the reaction of the crosslinking compound with the cyclic acid anhydride groups in the elastomeric polymer, thereby producing the elastomeric polymer (I). The latter method has the advantage of making molding easier. In producing such an elastomeric polymer (I), the conditions for reacting the cyclic acid anhydride group with the crosslinking compound are not particularly limited, and conditions similar to those described in known documents describing methods for reacting the cyclic acid anhydride group with the crosslinking compound (e.g., the reaction conditions described in Japanese Patent No. 5918878) can be appropriately adopted, and optimal conditions can be appropriately set depending on the compounds used, etc. Here, the amount (addition amount) of the crosslinking compound used in the method for producing the elastomeric polymer (I) is not particularly limited, but from the viewpoint of achieving an appropriate crosslink density, it is more preferably 0.1 to 20 parts by mass, even more preferably 0.2 to 15 parts by mass, and particularly preferably 0.3 to 10 parts by mass, per 100 parts by mass of the raw material polymer.

[0081] Another method for producing the elastomeric polymer (I) involves, for example, preparing an elastomeric polymer containing a monomer unit containing a double bond in the main chain but without a cyclic acid anhydride group in its side chain, reacting the polymer with the vulcanization accelerator and / or the thiocarboxylic acid to introduce a dithiocarbamate group and / or a thioester group, then adding a cyclic acid anhydride (e.g., maleic anhydride) to the polymer to prepare an elastomeric polymer having both a dithiocarbamate group and a thioester group in its side chain and a cyclic acid anhydride group in its side chain, and then reacting the polymer with a crosslinking compound to produce the elastomeric polymer (I). In this way, the elastomeric polymer (I) may be synthesized by reacting the vulcanization accelerator and / or thiocarboxylic acid with the elastomeric polymer having a double bond in its main chain, adding maleic anhydride, and then adding a crosslinking compound.

[0082] (filler) The filler according to the present invention is at least one selected from the group consisting of carbon black and silica.

[0083] Such carbon black is not particularly limited, and known carbon blacks that can be used in rubber compositions and elastomer compositions can be used as appropriate. Among such carbon blacks, furnace blacks such as SAF, ISAF, HAF, XCF, FEF, GPF, SRF, MT, and FT are preferred from the viewpoints of reinforcing properties and dispersibility. Furthermore, carbon blacks with grades of ISAF, HAF, and FEF are preferred. Commercially available carbon blacks (commercial products) may be used as they are. Such carbon blacks are effective components in forming the tread and sidewall portions, particularly the cap tread portion, of tires. Such carbon blacks may be used alone or in combination with silica.

[0084] Furthermore, such silica is not particularly limited, and conventionally known silica can be used. Examples of such silica include dry-process silica (e.g., fumed silica) produced by thermal decomposition of silicon halide or organic silicon compound, and wet-process silica produced by decomposition of sodium silicate with acid. From the viewpoints of cost and performance, wet-process silica is more preferable. Furthermore, such silica should have a BET specific surface area (in accordance with ASTM D1993-03) of 70 to 300 m 2 / g (more preferably 80 to 250 m 2 / g) and a particle size of 10 to 40 nm (more preferably 15 to 30 nm). As such silica, commercially available silica for the rubber industry (commercially available product) may be used as is. Such silica may be used alone or in combination with carbon black.

[0085] When silica is contained in the rubber composition of the present invention (more preferably a diene-based rubber composition), it is preferable to further contain a silane coupling agent from the viewpoint of further improving the properties required of silica and further improving dispersibility in rubber (more preferably a diene-based rubber) that does not have the hydrogen-bond cross-linkable moiety. As such a silane coupling agent, a polysulfide-based silane coupling agent having an alkoxysilyl group that reacts with the silanol group on the silica surface and a sulfur chain that reacts with a polymer, such as bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, or bis(3-triethoxysilylpropyl)disulfide, can be suitably used.

[0086] (plasticizer) The plasticizer according to the present invention is at least one selected from the group consisting of paraffinic oil, aromatic oil, naphthenic oil, and petroleum resin. The paraffinic oil (paraffin oil), aromatic oil (aromatic oil), naphthenic oil (naphthenic oil), and petroleum resin are not particularly limited, and any known plasticizer used in rubber compositions can be used as appropriate.

[0087] Such paraffinic oils (paraffin oils) are not particularly limited, but for example, those described in paragraphs

[0153] to

[0157] of JP 2017-57323 A can be suitably used. When such paraffin oils are subjected to correlation ring analysis (ndM ring analysis) in accordance with ASTM D3238-85 to determine the percentage of paraffin carbon number relative to the total carbon number (paraffin fraction: %CP), the percentage of naphthenic carbon number relative to the total carbon number (naphthenic fraction: %CN), and the percentage of aromatic carbon number relative to the total carbon number (aromatic fraction: %CA), it is preferable that the percentage of paraffin carbon number relative to the total carbon number (%CP) is 60% or more. Commercially available paraffin oils can be used as appropriate.

[0088] The aromatic oil (aroma oil) is not particularly limited, and known ones (e.g., TDAE (Treated-Distillate Aromatic Extracts), A / O (Asphalt / Oil) mix, NC-RAE (Residual Aromatic Extracts), etc.) can be used as appropriate. As such aromatic oils, commercially available ones can be used as appropriate.

[0089] Furthermore, the naphthenic oil (naphthenic oil) is not particularly limited, and known oils can be used as appropriate. When correlation ring analysis (ndM ring analysis) according to ASTM D3238-85 is performed on the oil to determine the percentage of paraffin carbon number relative to the total carbon number (paraffinic portion: %CP), the percentage of naphthenic carbon number relative to the total carbon number (naphthenic portion: %CN), and the percentage of aromatic carbon number relative to the total carbon number (aromatic portion: %CA), naphthenic oils with a percentage of naphthenic carbon number relative to the total carbon number (%CN) of 30 to 45% can be suitably used. Commercially available naphthenic oils can be used as appropriate.

[0090] The petroleum resin is obtained by thermally cracking naphtha, removing useful compounds such as ethylene, propylene, and butadiene, and then polymerizing the remaining C4-C5 fraction (mainly the C5 fraction) or C5-C9 fraction (mainly the C9 fraction) in a mixed state. The properties of such petroleum resins vary depending on the composition ratio of the olefin fractions in the raw material. However, they are generally transparent, pale yellow to yellowish-brown, rosin-like resins with a molecular weight of 200-8000 and a softening point of 5-200°C. Known petroleum resins (e.g., those described in JP 2020-132822 A) can be used as appropriate. Suitable examples of such petroleum resins include C9-based petroleum resins, C5-based petroleum resins, C5 / C9-based petroleum resins, alicyclic compound (DCPD)-based petroleum resins, and hydrogenated petroleum resins thereof. Commercially available petroleum resins can also be used as appropriate.

[0091] As such a plasticizer, paraffin oil is more preferable from the viewpoint of improving resistance to compression set, and petroleum resin is more preferable from the viewpoint of improving tensile stress based on 100% modulus.

[0092] (About the composition) The elastomer composition of the present invention is a composition containing the elastomeric polymer (I), the filler, and the plasticizer.

[0093] In such an elastomer composition, the content of the elastomeric polymer (I) is preferably 5% by mass or more, more preferably 10 to 95% by mass, and particularly preferably 15 to 90% by mass, based on the total amount of the composition (the sum (total) of all components contained in the elastomer composition). By setting the content of such elastomeric polymer (I) at or above the lower limit, better effects in terms of creep resistance and tensile properties tend to be obtained compared to when the content is below the lower limit, while by setting the content at or below the upper limit, better effects in terms of processability tend to be obtained compared to when the content exceeds the upper limit.

[0094] The elastomer composition of the present invention preferably contains the elastomeric polymer (I) as an essential component. However, it is more preferable that the composition further contains, in addition to the elastomeric polymer (I), a thioester- and dithioester-free elastomeric polymer (hereinafter sometimes simply referred to as "elastomeric polymer (II)"), which contains hydrogen-bond cross-linkable moieties and covalent-bond cross-linkable moieties in its side chains, has a glass transition temperature of 25°C or lower, and does not contain either a thioester- or dithioester-containing side chain. Such an elastomeric polymer (II) can constitute, together with the elastomeric polymer (I), the elastomer component serving as the main material (base material) of the elastomer composition. Therefore, in other words, the elastomer composition of the present invention preferably contains an elastomer component that is a mixture of the elastomeric polymer (I) and the elastomeric polymer (II).

[0095] Such an elastomeric polymer (II) can be suitably used if it satisfies the same conditions as the elastomeric polymer (I), except that it does not satisfy the above-mentioned condition (III) (except that it does not have a side chain consisting of a thioester group or a side chain consisting of a dithioester group). In other words, the elastomeric polymer (II) can be said to be an elastomeric polymer that satisfies the above-mentioned conditions (I) and (II) but does not satisfy the above-mentioned condition (III). Therefore, the conditions for the side chains and the glass transition temperature of the elastomeric polymer (II) are the same as those for the elastomeric polymer (I), except for the presence or absence of a side chain consisting of a thioester group and a side chain consisting of a dithioester group. Such an elastomeric polymer (II) is not particularly limited, and an elastomeric polymer containing a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety in the side chain and having a glass transition point of 25°C or less can be appropriately selected and used from known elastomeric polymers (for example, those described in paragraphs

[0032] to

[0145] of Japanese Patent No. 5918878).

[0096] The main chain of such elastomeric polymer (II) is not particularly limited, and the polymers described as the main chain of elastomeric polymer (I) can be used as appropriate. Although not particularly limited, at least one selected from diene rubbers, hydrogenated diene rubbers, olefin rubbers, optionally hydrogenated polystyrene elastomeric polymers, polyolefin elastomeric polymers, polyvinyl chloride elastomeric polymers, polyurethane elastomeric polymers, polyester elastomeric polymers, and polyamide elastomeric polymers is preferred.

[0097] Furthermore, from the viewpoint that a product with higher performance can be obtained when the final composition is used as a material for producing a rubber product (preferably a tire, a belt, or a hose), an elastomeric polymer having an olefin-based rubber main chain is preferred as the elastomeric polymer (II). In this way, by making the main chain of the elastomeric polymer (II) an olefin-based rubber, it becomes possible to highly suppress deterioration of the composition caused by double bonds when used in combination with the elastomeric polymer (I).

[0098] The olefinic rubber constituting the main chain of such an elastomeric polymer (II) is not particularly limited, but from the viewpoint of high aging resistance, ethylene-propylene rubber (EPM: ethylene-propylene copolymer) and ethylene-butene rubber (EBM: ethylene-butene copolymer) are preferred. Note that, since such olefinic rubbers basically do not contain double bonds, they do not react with vulcanization accelerators or thiocarboxylic acids, and even if they are kneaded with vulcanization accelerators or thiocarboxylic acids, thioester groups and dithioester groups (e.g., dithiocarbamate groups) are not introduced into the olefinic rubber that is the main chain.

[0099] Furthermore, when the elastomer composition of the present invention contains the elastomeric polymer (II), the content of the elastomeric polymer (II) is preferably 5% by mass or more, more preferably 10 to 95% by mass, and particularly preferably 15 to 90% by mass, based on the total amount of the composition (the sum (total) of all components contained in the elastomer composition). By setting the content of such elastomeric polymer (I) at or above the lower limit, better effects in terms of creep resistance and tensile properties tend to be obtained compared to when it is below the lower limit, while by setting it at or below the upper limit, better effects in terms of processability tend to be obtained compared to when it exceeds the upper limit.

[0100] In the elastomer composition of the present invention, the elastomer component serving as the main material (substrate) of the elastomer composition may consist solely of the elastomeric polymer (I), or may be a mixture of the elastomeric polymer (I) and the elastomeric polymer (II). The content of the elastomeric component serving as the main material (substrate) (the total amount of the elastomeric polymer (I) and the elastomeric polymer (II)) is preferably 10% by mass or more, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass, based on the total amount of the composition (the total amount (total) of all components contained in the elastomer composition).

[0101] The content (content ratio) of the filler in the elastomer composition is not particularly limited, but is more preferably 10 to 100 parts by mass, even more preferably 15 to 90 parts by mass, and particularly preferably 20 to 80 parts by mass, per 100 parts by mass of the elastomer component containing the elastomeric polymer (I) (100 parts by mass of the elastomeric polymer (I) if the elastomer component consists solely of the elastomeric polymer (I); or 100 parts by mass of the mixture if the elastomer component is a mixture of the elastomeric polymer (I) and the elastomeric polymer (II)). By setting the filler content at or above the lower limit, better effects in terms of tensile properties tend to be obtained compared to when the filler content is below the lower limit. On the other hand, by setting the filler content below the upper limit, better effects in terms of flowability (moldability) tend to be obtained compared to when the filler content exceeds the upper limit, due to the reduced filling amount.

[0102] The content (content ratio) of the plasticizer in the elastomer composition is not particularly limited, but is more preferably 3 to 60 parts by mass, even more preferably 5 to 50 parts by mass, and particularly preferably 8 to 40 parts by mass, per 100 parts by mass of the elastomer component containing the elastomeric polymer (I) (100 parts by mass of the elastomeric polymer (I) if the elastomer component consists solely of the elastomeric polymer (I); or 100 parts by mass of the mixture if the elastomer component is a mixture of the elastomeric polymer (I) and the elastomeric polymer (II)). By setting the content of the plasticizer at or above the lower limit, the amount of plasticizer increases compared to when the content is below the lower limit, and therefore, better effects in terms of flowability and break properties tend to be obtained. On the other hand, by setting the content at or below the upper limit, the amount of plasticizer decreases compared to when the content exceeds the upper limit, and therefore, better effects in terms of heat resistance (hot break properties) tend to be obtained.

[0103] Furthermore, the elastomer composition of the present invention may contain known additives (additive components) used in the field of elastomer compositions, as needed, within the scope of the present invention. However, from the viewpoint of being able to more effectively suppress the deterioration of the break properties, it is preferable that the elastomer composition of the present invention does not contain clay (including organized clay). This is because, in the thermoplastic elastomer composition of the present invention, the clay tends to become the starting point of break, resulting in a decrease in elongation at break. Thus, it is preferable that the elastomer composition of the present invention does not contain clay as an additive.

[0104] Furthermore, examples of additives (additive components) that can be suitably used in the elastomer composition of the present invention include known additives other than the clay, such as polymers other than the elastomer component (e.g., polymers not having chemically bonded cross-linking moieties (such as α-olefin resins not having chemically bonded cross-linking moieties)), reinforcing agents (other fillers), hydrogen-bonding reinforcing agents (fillers), fillers having an amino group introduced therein (hereinafter simply referred to as "amino group-introduced fillers"), amino group-containing compounds other than the amino group-introduced fillers, compounds containing metal elements (hereinafter simply referred to as "metal salts"), maleic anhydride-modified polymers, antioxidants, antioxidants, pigments (dyes), plasticizers, thixotropy-imparting agents, ultraviolet absorbers, flame retardants, solvents, surfactants (including leveling agents), fillers, dispersants, dehydrating agents, rust inhibitors, adhesion promoters, and antistatic agents. Such additives are not particularly limited, and known additives can be used as appropriate, and for example, those described in JP 2017-57322 A and WO 2019 / 027022 A may be used as appropriate. Note that the elastomer composition of the present invention can more efficiently exhibit properties suitable for the application by appropriately changing the type of elastomeric polymer (I) or appropriately using additives depending on the application.

[0105] The uses of the elastomer composition of the present invention are not particularly limited, but it can be suitably used as a material for forming various automotive products, such as tires, various powertrain products for automobiles, various products for hybrid and electric vehicles, various products for diesel engines, starters, alternators, engine cooling products, and drivetrain products. Thus, the uses of the elastomer composition of the present invention are not particularly limited, but it can be suitably used as a material for forming industrial rubber parts (rubber parts used in various industrial products, such as the various automotive products mentioned above and rubber parts used in industrial machinery). Furthermore, because the elastomer composition of the present invention has excellent creep resistance (compression set resistance) and elongation at break, it can be suitably used, in particular, as a material for use in tire production (elastomer material for tires).

[0106] Furthermore, the method for producing such an elastomer composition is not particularly limited, and any method can be used as long as it allows the elastomeric polymer (I), the filler, and the plasticizer to be contained in the composition (and, if necessary, the above-mentioned additives to be contained in the composition as well). Except for changing the components used so that the above-mentioned components are contained (except for adding a vulcanization accelerator as an essential component), methods similar to those used in known methods for producing thermoplastic elastomer compositions (for example, the method described in Japanese Patent No. 5918878) can be appropriately used.The method for producing such an elastomer composition is not particularly limited, and may be, for example, a method of kneading (mixing) the raw material polymer (when the elastomeric polymer (II) is to be contained in the final composition, it is preferable to use an elastomeric polymer modified with maleic anhydride that does not contain a monomer unit containing a double bond at a site that forms the main chain skeleton in combination with the raw material polymer), the crosslinking compound, the filler, the plasticizer, the vulcanization accelerator, and / or the thiocarboxylic acid to obtain a composition. In this case, from the viewpoint of enabling each component to be dispersed more uniformly, the method may be as follows: first, the raw material polymer (optionally the raw material polymer and the elastomeric polymer modified with maleic anhydride that does not contain a monomer unit containing a double bond at a site that forms the main chain skeleton), the filler, the plasticizer, the vulcanization accelerator, and / or the thiocarboxylic acid are kneaded (mixed) under heating, to obtain a composition containing the elastomeric polymer (II) in the raw material polymer.

[0033] It is more preferable that the method comprises reacting the vulcanization accelerator and / or the thiocarboxylic acid at the double bond site to obtain a mixture containing a reaction product of the raw polymer and the vulcanization accelerator and / or the thiocarboxylic acid, then adding the crosslinking compound to the mixture and kneading (mixing) it under heating, thereby reacting the cyclic acid anhydride group of the raw polymer (optionally the raw polymer and the elastomeric polymer modified with maleic anhydride which does not contain a monomer unit containing a double bond at a site forming the main chain skeleton) with the crosslinking compound in the mixture in which the filler, the plasticizer, and the reactant (optionally the reactant and the elastomeric polymer modified with maleic anhydride which does not contain a monomer unit containing a double bond at a site forming the main chain skeleton) are dispersed, thereby obtaining a composition containing the elastomeric polymer (I) (optionally a mixture consisting of the elastomeric polymer (I) and the elastomeric polymer (II)), the filler, and the plasticizer.The temperature conditions for kneading the raw polymer, the filler, the plasticizer, and the vulcanization accelerator and / or the thiocarboxylic acid are not particularly limited, but are preferably set appropriately depending on the type of raw polymer to a temperature (e.g., about 100 to 250°C) at which the reaction between the double bonds in the raw polymer and the vulcanization accelerator and / or the thiocarboxylic acid proceeds while plasticizing the polymer and uniformly mixing the components. The temperature conditions for reacting the cyclic acid anhydride group with the crosslinking compound are also not particularly limited, and may be set appropriately to a temperature (e.g., about 100 to 250°C) at which the crosslinking compound to be added can react with the cyclic acid anhydride group. The crosslinking compound may be added at a temperature lower than the reaction temperature (e.g., room temperature to about 120°C) to produce a kneaded mixture in which the crosslinking compound remains unreacted. The crosslinking compound and the cyclic acid anhydride group in the kneaded mixture are then reacted during molding to form a composition containing the elastomeric polymer (I), the filler, and the plasticizer. The method for kneading the components is not particularly limited, and examples of suitable methods include kneading with a roll, kneader, extruder, or universal mixer. The raw material polymer is not particularly limited, and commercially available polymers or polymers appropriately prepared by known methods may be used.

[0107] A suitable example of a method for producing the elastomer composition is as follows. First, a mixture of the raw polymer and a maleic anhydride-modified elastomeric polymer that does not contain a monomer unit containing a double bond in the main chain structure is kneaded (mixed) with the filler, the plasticizer, and the vulcanization accelerator and / or the thiocarboxylic acid at approximately 180°C to obtain a mixture in which the double bonds in the raw polymer have reacted with the vulcanization accelerator and / or the thiocarboxylic acid. Next, the mixture is cooled to a relatively low temperature of 120°C or less (a temperature at which the crosslinking compound does not react; for example, approximately 60°C, depending on the type of crosslinking compound), and the crosslinking compound is added to the mixture and kneaded (mixed) at a low temperature of 120°C or less to obtain a kneaded product containing the crosslinking compound in an unreacted state. The resulting kneaded mixture is then heated to promote the reaction (crosslinking reaction) between the crosslinking compound and the acid anhydride group, thereby producing an elastomer composition containing elastomeric polymers (I) and (II). When such a method is adopted, crosslinking by the crosslinking compound has not progressed at the stage when the kneaded mixture is produced, so that molding processing of the kneaded mixture can be carried out more easily, and after molding the kneaded mixture, it can be placed in a mold and heated to crosslink the mixture, thereby efficiently producing a rubber product of the desired shape.

[0108] [Elastomer materials for tires] The elastomer material for a tire of the present invention comprises the elastomer composition of the present invention. Such an elastomer material for a tire can be used, for example, as a material for forming the cap tread portion, sidewall portion, undertread portion, inner liner portion, carcass portion, belt portion, or bead portion of a tire, and the actual portion in which it is used in the tire is not particularly limited. From the viewpoint of excellent creep resistance and mechanical properties, it is preferable to use it in the cap tread portion or sidewall portion of a tire. The method for manufacturing a tire using such an elastomer material for a tire is not particularly limited, and any known method can be used as appropriate. For example, when manufacturing a tire whose cap tread portion is formed from an elastomer material for a tire comprising the elastomer composition of the present invention, the manufacturing method may be a method in which the elastomer composition of the present invention is used to mold the tire by injection molding or extrusion processing according to the shape of the tread, thereby obtaining a tire having a tread portion formed using the elastomer material for a tire. In this way, a tire can be manufactured using an elastomer material for a tire comprising the elastomer composition of the present invention by appropriately using a known method. In such tire molding, the tire elastomer material may consist solely of the elastomer composition of the present invention, and a tire may be directly manufactured from the elastomer composition of the present invention, or the tire elastomer material may be in the form of a mixture of the elastomer composition of the present invention and other components (e.g., uncrosslinked rubber, vulcanizing agent, etc.), which is cured by heating and vulcanization to manufacture a tire. In this way, since the elastomer composition of the present invention can be molded into a tire as is, the tire elastomer material of the present invention may be used as it is, consisting solely of the elastomer composition of the present invention, without adding other components, depending on the application, etc.In other words, a tire obtained using the elastomer material for a tire of the present invention may be obtained by forming a tire component directly from the elastomer composition of the present invention, or by adding other components and molding the composition to form a tire component, depending on the intended use, the portion to be formed (tread portion, etc.), etc. In this way, the elastomer composition of the present invention may be molded into a tire as is and used, or other components may be added to form a thermoset product which is then molded into a tire.

[0109] Furthermore, when the elastomeric polymer (I) is a polymer in which the crosslinks are formed by the reaction of a cyclic acid anhydride group in the raw polymer with an alcohol, the elastomer composition of the present invention can be recycled by decomposing the crosslinked portion with an alcohol. [Example]

[0110] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples.

[0111] <Ingredients used in each example> First, the components and abbreviations used in each example will be explained below. In each example and table, the components will be represented by the abbreviations shown below. The "maleic acid ratio" of the maleic anhydride-modified elastomeric polymer described below is a value measured by the above-mentioned [Method for measuring maleic acid ratio].

[0112] (1) Maleic anhydride modified elastomeric polymer Maleic anhydride-modified hydrogenated styrene-butadiene copolymer (abbreviation: maleated hydrogenated SBR: prepared using the method described in Synthesis Example 1 below, maleic ratio: 1.8% by mass, polymer containing double bonds in the main chain) Maleic anhydride-modified ethylene-butene copolymer (abbreviation: maleated EBM, trade name "Tafmer MH5040" manufactured by Mitsui Chemicals, Inc., maleic acid content: 2.2% by mass, crystallinity: 4%, polymer containing no double bonds in the main chain) (2) Compounds for introducing dangling chains (side chains) (vulcanization accelerators and thiocarboxylic acids) Tetrabutylthiuram disulfide (thiuram-based vulcanization accelerator, product name "Noccela TBT-N" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Thioacetic acid (abbreviated as thiocarboxylic acid, manufactured by Tokyo Chemical Industry Co., Ltd.) (3) Crosslinking compound Tris(2-hydroxyethyl)isocyanurate (abbreviation: THI: product name "Tanac P" manufactured by Nissei Sangyo Co., Ltd., a compound that can introduce covalent bond crosslinking moieties and hydrogen bond crosslinking moieties by reacting with maleic anhydride groups) (4) Plasticizer Paraffin oil (product name "300HV-S(J)" manufactured by ENEOS Corporation) Aroma oil (product name "T-DAE" manufactured by ENEOS Corporation) Petroleum resin (product name "T-REZ PR-803" manufactured by ENEOS Corporation) (5) Carbon black Carbon Black N339 (abbreviated as CB, manufactured by Tokai Carbon Co., Ltd.) (6) Other ingredients Anti-aging agent (manufactured by Ouchi Shinko Chemical, product name "Nolac 6C") Acid catalyst (p-toluenesulfonic acid monohydrate, manufactured by Tokyo Chemical Industry Co., Ltd.).

[0113] (Synthesis Example 1: Preparation of Maleated Hydrogenated SBR) First, 70 g of hydrogenated SBR (trade name: NT120, manufactured by ENEOS Materials Co., Ltd.) was placed in a pressure kneader (trade name: Labo Plastomill (using an R100 mixer), manufactured by Toyo Seiki Seisakusho Co., Ltd.) and kneaded for 60 seconds at 90°C and 50 rpm. Next, 7 g of maleic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.), 3.5 g of tris(2-ethylhexyl)phosphate (trade name: "TOP" manufactured by Daihachi Chemical Industry Co., Ltd.), and 0.7 g of an antioxidant (trade name: "Norac 6C" manufactured by Ouchi Shinko Chemical Co., Ltd.) were placed in the pressure kneader and kneaded for an additional 10 minutes at 90°C and 50 rpm, after which the mixture was discharged. The mixture thus released was again charged into a pressure kneader (manufactured by Toyo Seiki Seisakusho, trade name: Labo Plastomill (using an R100 mixer)) and kneaded for 30 minutes at a temperature of 250°C and a rotation speed of 50 rpm, and then released. The mixture thus released was dried under reduced pressure at 160°C for 3 hours, and unreacted maleic anhydride was then distilled off to obtain hydrogenated SBR modified with maleic anhydride (hereinafter simply referred to as "maleated, hydrogenated SBR").

[0114] Example 1 An elastomer was prepared as follows using the raw material components in the proportions shown in Table 1. Specifically, first, 22 g of maleated hydrogenated SBR (a maleic anhydride-modified elastomeric polymer) and 22 g of maleated EBM (a maleic anhydride-modified elastomeric polymer) were placed in a 100 cc pressure kneader and masticated for 2 minutes at 180°C and 100 rpm to plasticize the maleic anhydride-modified elastomeric polymer. Next, 17.6 g of carbon black N339 (CB), 6.6 g of paraffin oil as a plasticizer, 1.32 g of tetrabutyl thiuram disulfide as a vulcanization accelerator (thiuram vulcanization accelerator), and 0.44 g of an antioxidant were added to the plasticized maleic anhydride-modified elastomeric polymer, and the mixture was kneaded for 8 minutes and then discharged to obtain a mixture.

[0115] The resulting mixture was then reloaded into a kneader heated to 60°C, and the crosslinking compound trishydroxyisocyanurate (THI: 0.783 g) and the acid catalyst p-toluenesulfonic acid monohydrate (0.171 g) were added and kneaded for 5 minutes at 60°C to obtain a kneaded mixture containing the reaction product of maleated EBM, maleated hydrogenated SBR, and vulcanization accelerator (maleated hydrogenated SBR with dibutyldithiocarbamate groups), the crosslinking compound, carbon black, plasticizer, antioxidant, and acid catalyst. Considering the temperature conditions (60°C) used during kneading, it is believed that the reaction between the maleic anhydride groups in the maleated EBM and maleated hydrogenated SBR and THI did not proceed within the resulting kneaded mixture.

[0116] Next, using a pressure press equipped with a water-cooling function, 49 g of the kneaded product obtained as described above was placed in a mold measuring 15 cm in length, 15 cm in width, and 2 mm in thickness, and pressurized (hot-pressed) under conditions of a temperature of 200°C, a working pressure of 20 MPa, and a pressing time of 30 minutes. The heating during the hot press promoted the reaction between the maleated EBM in the kneaded product and THI, and the reaction between the reaction product (the reaction product of maleated hydrogenated SBR and a vulcanization accelerator) and THI. Thereafter, further water-cooled pressing was performed under conditions of a working pressure of 20 MPa and a pressing time of 2 minutes, and the product was removed from the mold to prepare a 2 mm-thick sheet (15 cm in length, 15 cm in width). From the manufacturing conditions, it is clear that such a sheet is made of an elastomer composition containing: a reaction product of maleated EBM and THI; a reaction product of maleated hydrogenated SBR, THI, and a vulcanization accelerator; a plasticizer; carbon black; an antioxidant; and an acid catalyst. The IR spectrum of the obtained elastomer composition was measured using a Fourier transform infrared spectrophotometer (FT-IR, manufactured by Thermo Scientific under the trade name "Nicolet IS10"). Part of the measurement results included: wavelength: 820-1350 cm -1A graph of the IR spectrum of the elastomer composition for the range is shown in Figure 1. For reference, Figure 1 also shows the IR spectrum of hydrogenated SBR (manufactured by ENEOS Materials Corporation, trade name: NT120), the IR spectrum of the maleated hydrogenated SBR obtained in Synthesis Example 1, and the IR spectrum of tetrabutylthiuram disulfide (thiuram vulcanization accelerator). From the results of measuring the IR spectrum of the elastomer composition, the obtained elastomer composition showed a peak at 1718 cm -1 and the absorption of carboxylic acids at 1726cm -1 The absorption of the ester was confirmed. Therefore, it was found that the crosslinked elastomer in the composition had crosslinks formed by the reaction between the hydroxyl group of THI and the maleic anhydride group. In addition, the IR spectrum measurement results (IR spectrum shown in Figure 1) showed that the absorption of the ester at 1060 cm -1 A peak was confirmed at this position, revealing that dibutyl carbamate groups had been introduced into the crosslinked elastomer in the composition. Furthermore, the IR spectrum measurement results and the raw materials used indicate that the dibutyl carbamate groups are bonded to the main chain of the maleated, hydrogenated SBR, forming side chains of the maleated, hydrogenated SBR. Furthermore, based on the types of polymers (hydrogenated SBR and EBM) that make up the main chains, it is clear that the glass transition temperatures of both the reaction product of maleated EBM and THI, and the reaction product of maleated, hydrogenated SBR, THI, and a vulcanization accelerator are 25°C or lower.

[0117] (Examples 2 and 3) Except for changing the type of plasticizer to one shown in Table 1, elastomer compositions were prepared in the same manner as in Example 1, and sheets with a thickness of 2 mm (15 cm length, 15 cm width) were obtained.

[0118] Example 4 An elastomer composition was prepared in the same manner as in Example 1, except that no acid catalyst was used and the amount of plasticizer used was changed from 6.6 g to 13.2 g to obtain the composition shown in Table 1, and a sheet (15 cm long, 15 cm wide) with a thickness of 2 mm was obtained.

[0119] Example 5 An elastomer was prepared as follows using the raw material components in the proportions shown in Table 1. First, maleated hydrogenated SBR (20 g), which is a maleic anhydride-modified elastomeric polymer, and maleated EBM (20 g), which is a maleic anhydride-modified elastomeric polymer, were placed in a 100 cc pressure kneader and masticated for 2 minutes at a temperature of 180°C and a rotation speed of 20 rpm, thereby plasticizing the maleic anhydride-modified elastomeric polymer. Then, while maintaining the temperature at 180°C, carbon black N339 (CB: 16 g), paraffin oil (12 g) as a plasticizer, and tetrabutylthiuram disulfide (thiuram vulcanization accelerator: 1.2 g) as a vulcanization accelerator were added to the plasticized maleic anhydride-modified elastomeric polymer and kneaded for 4 minutes to obtain a mixture, followed by the addition of trishydroxyisocyanurate (THI: 0.851 g) as a crosslinking compound and kneading for 8 minutes to prepare an elastomer composition. The resulting elastomer composition was subjected to IR analysis in the same manner as in Example 1, and the results revealed that the elastomer composition contained elastomer components consisting of the reaction product of maleated EBM and THI, and the reaction product of maleated hydrogenated SBR, THI, and the vulcanization accelerator.

[0120] Next, using a water-cooled press, the mixture was heated to 200°C. Then, 42 g of the elastomer composition obtained above was placed in a mold measuring 15 cm long, 15 cm wide, and 2 mm thick. The mixture was preheated at 200°C for 3 minutes, then hot-pressed at 200°C under a pressure of 20 MPa for 5 minutes. This was followed by a water-cooled press under a pressure of 20 MPa for 2 minutes. The pressed elastomer composition was removed from the mold to prepare a 2 mm-thick sheet (15 cm long, 15 cm wide). Based on the manufacturing conditions, it was clear that this sheet was composed of an elastomer composition containing a reaction product of maleated EBM and THI, a reaction product of maleated hydrogenated SBR, THI, and a vulcanization accelerator, a plasticizer, carbon black, and an antioxidant.

[0121] (Example 6) An elastomer composition was prepared in the same manner as in Example 5, except that thioacetic acid (thiocarboxylic acid) was used instead of tetrabutylthiuram disulfide and the composition was changed to the composition shown in Table 1, and a sheet with a thickness of 2 mm (15 cm long and 15 cm wide) was obtained. When IR measurement was performed on the obtained elastomer composition in the same manner as in Example 1, it was confirmed from the results that it had a crosslink formed by the reaction of the hydroxyl group of THI and the maleic anhydride group, and a peak was confirmed at the position of 1132 cm -1 . From this, it was also revealed that a methylthioester group was introduced into the crosslinked elastomer in the composition.

[0122] (Comparative Example 1) An elastomer composition was prepared in the same manner as in Example 1, except that a vulcanization accelerator was not used, and a sheet with a thickness of 2 mm (15 cm long and 15 cm wide) was obtained.

[0123] (Comparative Example 2) An elastomer composition was prepared in the same manner as in Example 5, except that a crosslinking compound was not used and the amount of the plasticizer was changed from 12 g to 6 g to obtain the composition shown in Table 1, and a sheet with a thickness of 2 mm (15 cm long and 15 cm wide) was obtained.

[0124] (Comparative Example 3) An elastomer composition was prepared in the same manner as in Example 5, except that a vulcanization accelerator and a crosslinking compound were not used and the amount of the plasticizer was changed from 12 g to 6 g to obtain the composition shown in Table ', and a sheet with a thickness of 2 mm (15 cm long and 15 cm wide) was obtained.

[0125] [Evaluation of the properties of the elastomer compositions obtained in each example, etc.] [Measurement of JIS-A hardness] From the 2 mm thick sheets obtained in each example, 29 mm diameter disk-shaped sheets were punched out, and seven sheets were stacked together to prepare a measurement sample with a height (thickness) of 12.5 ± 0.5 mm. The measurement samples thus obtained were used to measure the JIS-A hardness in accordance with JIS K6253 (published in 2012). The results are shown in Table 1.

[0126] <Measurement of compression set (C-Set)> Seven 29 mm diameter disc-shaped sheets were punched out from the 2 mm thick sheets obtained in each example, and the seven disc-shaped sheets were then stacked to prepare a measurement sample with a height (thickness) of 12.5 ± 0.5 mm. The measurement sample was then compressed by 25% using a dedicated tool and allowed to stand at 70°C for 22 hours. The pressure was then released, and the compression set (unit: %) was measured in accordance with JIS K6262 (published in 2013). The compression device used was a "Vulcanized Rubber Compression Set Tester SCM-1000LAKC" manufactured by Dumbbell. The results are shown in Table 1. A compression set of 55% (preferably 52%) or less measured in this manner can be evaluated as having high creep resistance.

[0127] <Measurement of 100% modulus (M100) and elongation at break (EB) when heated> No. 3 dumbbell-shaped test pieces were punched out from the 2 mm thick sheets obtained in each example, and tensile tests were conducted in accordance with JIS K6251 using a tensile testing machine equipped with a high-temperature chamber at a temperature of 100°C and a tensile speed of 500 mm / min, and the 100% modulus (M100: units in MPa) and elongation at break (EB: units in %) were measured. The results are shown in Table 1. A 100% modulus (M100) of 0.8 MPa or more can be evaluated as having a high level of tensile stress, and a 150% or more elongation at break (EB) can be evaluated as having a high level of elongation properties.

[0128] [Table 1]

[0129] As is clear from the results shown in Table 1, the elastomer compositions obtained in Examples 1 to 6 exhibited excellent creep resistance (compression set resistance), tensile stress based on 100% modulus when heated, and elongation at break when heated, demonstrating a high level of well-balanced properties. Because of these properties, the elastomer compositions obtained in Examples 1 to 6 were found to be suitable for use as materials for tire manufacturing. While Examples 1 to 3 had the same composition except for the type of plasticizer, the results shown in Table 1 confirmed that, among paraffin oil, aromatic oil, and petroleum resin, the use of paraffin oil (Example 1) provided improved resistance to compression set, and the use of petroleum resin (Example 3) provided improved 100% modulus. Furthermore, the results shown in Table 1 reveal that among paraffin oil, aromatic oil, and petroleum resin, when paraffin oil was used (Example 1), creep resistance (compression set resistance), tensile stress based on 100% modulus at heating, and elongation at break at heating were better balanced. Furthermore, while the amounts of components used were adjusted to achieve the same composition in Examples 4 and 5, the manufacturing methods differ in that the crosslinking compound was reacted during molding in Example 4, whereas the crosslinking compound was reacted before molding in Example 5. Comparing the compositions obtained in Examples 4 and 5, as described in Example 5, when the crosslinking compound was reacted during kneading and then molded, creep resistance (compression set resistance) and elongation at break at heating were improved, while the 100% modulus at heating was comparable. The inventors speculate that this is due to a greater degree of reaction when the crosslinking compound was reacted during kneading (Example 5) than when the crosslinking compound was reacted during molding (Example 4). Furthermore, when the compositions obtained in Examples 5 and 6 are compared, the only difference in the raw material composition is whether a thiuram vulcanization accelerator or thioacetic acid is used to introduce dangling chains (side chains). However, it was confirmed that basically the same effects as those of Example 5 were obtained, except that the breaking elongation during heating was at a higher level in Example 5.

[0130] In contrast, the elastomer composition obtained in Comparative Example 1, which differed from Example 1 in that no vulcanization accelerator was used, did not have sufficient elongation at break when heated, and the 100% modulus could not even be measured. The inventors speculate that this is because the elastomer component does not contain a side chain (dangling chain) consisting of a dibutyl carbamate group, so there is no energy loss and no improvement in the physical properties at break can be obtained.

[0131] Furthermore, the elastomer composition obtained in Comparative Example 2, which differed from Example 1 in that a crosslinking compound and an acid catalyst were not used, did not have sufficient creep resistance (resistance to compression set). The present inventors speculate that this is because the absence of crosslinking sites in the elastomer component reduced the resistance of the composition to compression set.

[0132] Furthermore, the elastomer composition obtained in Comparative Example 3, which differed from Example 1 in that it did not use a crosslinking compound or a vulcanization accelerator, did not have sufficient 100% modulus and resistance to compression set. The inventors speculate that this result is due to the absence of side chains (dangling chains) consisting of dibutyl carbamate groups and crosslinking sites in the elastomer component.

[0133] From the results shown above (Table 1), it is clear that the elastomer compositions of the present invention (e.g., Examples 1 to 6) have excellent creep resistance (compression set resistance), tensile stress based on 100% modulus when heated, and elongation at break when heated, and have a high level of these properties in a well-balanced manner. [Industrial Applicability]

[0134] As described above, the present invention makes it possible to provide an elastomer composition that can have a high level of tensile stress based on 100% modulus, elongation at break, and resistance to compression set in a well-balanced manner, as well as an elastomer material for tires using the same. As described above, the elastomer composition of the present invention is excellent in creep resistance (compression set resistance), tensile stress, and elongation at break, and is therefore particularly useful as a material used in manufacturing tires (elastomer material for tires), etc.

Claims

1. a thioester group- and / or dithioester group-containing elastomeric polymer having a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linkable moiety in its side chain, having a side chain consisting of a thioester group and / or a side chain consisting of a dithioester group, and having a glass transition temperature of 25°C or lower; at least one filler selected from the group consisting of carbon black and silica; at least one plasticizer selected from the group consisting of paraffinic oils, aromatic oils, naphthenic oils, and petroleum resins; An elastomer composition comprising:

2. 2. The elastomer composition according to claim 1, further comprising a thioester group- and dithioester group-free elastomeric polymer that contains a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety in its side chain, has a glass transition point of 25°C or lower, and has neither a side chain consisting of a thioester group nor a side chain consisting of a dithioester group.

3. The elastomer composition according to claim 1, characterized in that the side chain comprising a thioester group and / or the side chain comprising a dithioester group is a side chain comprising a thioester group and / or a side chain comprising a dithiocarbamate group.

4. the side chain comprising a thioester group and / or the side chain comprising a dithioester group is a side chain consisting of at least one thioester group selected from the group consisting of a methyl thioester group, a butyl thioester group, and a (2-ethylhexyl)hexyl thioester group; and / or a side chain consisting of a dithioester group which is at least one dithiocarbamate group selected from the group consisting of a dimethyldithiocarbamate group, a diethyldithiocarbamate group, a dibutyldithiocarbamate group, and a di(2-ethylhexyl)dithiocarbamate group; 2. The elastomer composition according to claim 1, wherein

5. the side chain comprising a thioester group and / or the side chain comprising a dithioester group is a side chain consisting of a thioester group which is a methyl thioester group; and / or a side chain consisting of a dithioester group which is at least one dithiocarbamate group selected from the group consisting of a dibutyldithiocarbamate group and a di(2-ethylhexyl)dithiocarbamate group; 2. The elastomer composition according to claim 1, wherein

6. The thioester group- and / or dithioester group-containing elastomeric polymer is an elastomeric polymer containing a monomer unit having a cyclic acid anhydride group in a side chain and containing a double bond in a portion forming the main chain; a compound having two or more of at least one of a hydroxyl group, a thiol group, an amino group, and an imino group in one molecule; at least one thiuram vulcanization accelerator selected from the group consisting of tetrakis(2-ethylhexyl)thiuram disulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, tetrabenzylthiuram disulfide, and dipentamethylenethiuram tetrasulfide, and / or a thiocarboxylic acid; 2. The elastomer composition of claim 1, which is a reaction product of:

7. An elastomer material for a tire, comprising the elastomer composition according to any one of claims 1 to 6.

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