Rubber composition and modified diene rubber

Abstract

To provide a rubber composition improved in low heat build-up properties.SOLUTION: The rubber composition contains a compound represented by the following formula (1), a diene rubber, and a filler. (In the formula (1), X represents an anion which forms a salt with pyridinium; L represents CR2 or a nitrogen atom; R1 and R2 each independently represent a hydrogen atom or an alkyl group, an aryl group, an aralkyl group, an alkenyl group or a monovalent heterocyclic group which may have a substituent; and R3 represents an alkyl group, an aryl group, an aralkyl group or an alkenyl group which may have a substituent optionally having one or more selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom.)SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a rubber composition and a modified diene-based rubber. [Background technology]

[0002] Fillers are compounding agents that are mixed into rubber to reinforce the rubber, increase its volume, or impart special functions. A method of using inorganic fillers such as silica is known as a method for obtaining a rubber composition that has a reinforcing effect and low heat generation, i.e., low loss. The method of using inorganic fillers is applied to rubber compositions for environmentally friendly, low fuel consumption tires, etc.

[0003] When an inorganic filler is compounded in a rubber composition, the inorganic filler, particularly hydrophilic silica having a silanol group on its surface, has low affinity with hydrophobic rubber and is prone to agglomeration in the rubber composition. Therefore, in order to increase the reinforcing property of the rubber by the inorganic filler and obtain low heat generation (low loss), it is necessary to increase the affinity between the inorganic filler and the rubber. As such a method, a method of imparting low heat generation to the rubber component using a specific tetrazine compound (see Patent Document 1) is known. As another method, a method of using a modified polymer obtained by reacting a modifier having a nitrone group and a carboxy group with a conjugated diene polymer not containing a 4-substituted olefin and / or a 3-substituted olefin together with a diene rubber (see Patent Document 2) is known. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 057758 [Patent Document 2] International Publication No. 2015 / 114845 Summary of the Invention [Problem to be solved by the invention]

[0005] However, it is expected that the world will become increasingly concerned about environmental issues such as atmospheric carbon dioxide concentration and air pollution in the future, and there is a demand for technology that reduces the rolling resistance of tires and leads to improved fuel efficiency of automobiles. More specifically, there is a demand for technology that imparts further low loss properties to rubber compositions containing diene rubber and inorganic fillers such as silica, but such demands have not yet been fully met.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a rubber composition and a modified diene-based rubber having improved low heat build-up properties. [Means for solving the problem]

[0007] Means of the Invention The present inventors have conducted extensive research to achieve the above object and have discovered that a specific rubber composition and modified diene rubber can improve low heat build-up, thereby completing the present invention.

[0008] That is, the present invention is as follows. [1] A rubber composition comprising a compound represented by the following formula (1), a diene rubber, and a filler: [ka] (In formula (1), X represents an anion that forms a salt with pyridinium, L represents CR2 or a nitrogen atom, R1 and R2 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a monovalent heterocyclic group which may have a substituent, and R3 represents an alkyl group, an aryl group, an aralkyl group, or an alkenyl group which may have one or more substituents selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom.) [2] The above rubber composition, wherein the compound is a compound represented by the following formula (2): [ka] (In formula (2), X represents an anion that forms a salt with pyridinium, L represents CR2 or a nitrogen atom, R1 and R2 each independently represent a hydrogen atom, or an alkyl group, aryl group, aralkyl group, alkenyl group, or monovalent heterocyclic group which may have a substituent, and R7 represents a hydrogen atom, or an alkyl group, aryl group, aralkyl group, or alkenyl group which may have one or more selected from the group consisting of a hydroxy group, an alkoxy group, an acyl group, an amino group, an amido group, an epoxy group, a sulfanyl group, and an alkylsulfanyl group.) [3] The above rubber composition, wherein the compound is a compound represented by the following formula (3): [ka] (In formula (3), X represents an anion that forms a salt with pyridinium; L represents CR2 or a nitrogen atom; R1 and R2 each independently represent a hydrogen atom, or an alkyl group, aryl group, aralkyl group, alkenyl group, or monovalent heterocyclic group which may have a substituent; Z represents an oxygen atom, a sulfur atom, an alkylene group, or a group represented by -NR6-; and R5 and R6 each independently represent a hydrogen atom, or an alkyl group, aryl group, aralkyl group, or alkenyl group which may have one or more selected from the group consisting of a hydroxy group, an alkoxy group, an acyl group, an amino group, an amido group, an epoxy group, a sulfanyl group, and an alkylsulfanyl group.) [4] The above rubber composition, wherein Z is a group represented by -NR6-. [5] The above rubber composition, wherein R1 and R2 are hydrogen atoms. [6] The above rubber composition, wherein the diene rubber comprises at least one rubber selected from the group consisting of styrene-butadiene rubber, butadiene rubber, isoprene rubber, and natural rubber. [7] The above rubber composition, wherein the filler comprises at least one selected from the group consisting of carbon black and silica. [8] The above rubber composition, further comprising a silane coupling agent. [9] The above rubber composition further containing sulfur and a vulcanization accelerator.

[10] A modified diene rubber having a modifying group represented by the following formula (4a), (4b), (4c), (4d), (4e), (4f), (4g), (4h), (4i), (4j) or (4k): [ka] (In each formula, X represents an anion that forms a salt with pyridinium, L represents CR2 or a nitrogen atom, R1 and R2 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group or a monovalent heterocyclic group which may have a substituent, R3 represents an alkyl group, an aryl group, an aralkyl group or an alkenyl group which may have one or more substituents selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom, R represents a halogen atom or an alkyl group, and the wavy line represents a bonding site of the diene rubber with the modifying group.)

[11] The modified diene rubber as described above, wherein R1 and R2 each independently represent a hydrogen atom or a methyl group.

[12] A rubber composition comprising the modified diene rubber and a filler. Effect of the Invention

[0009] According to the present invention, it is possible to provide a rubber composition and a modified diene-based rubber having improved low heat generation properties. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention (hereinafter, simply referred to as the present embodiment) will be described in detail, but the present invention is not limited to the present embodiment. The present invention can be modified in various ways without departing from the gist of the present invention.

[0011] (Rubber composition containing compound represented by formula (1)) An example of the rubber composition of this embodiment (hereinafter referred to as the "first rubber composition") contains a compound represented by the following formula (1) (hereinafter also referred to as "compound (1)"), a diene rubber, and a filler. [ka] Here, in formula (1), X represents an anion that forms a salt with pyridinium, L represents CR2 or a nitrogen atom, R1 and R2 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a monovalent heterocyclic group that may have a substituent, and R3 represents an alkyl group, an aryl group, an aralkyl group, or an alkenyl group that may have one or more substituents selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom. From the viewpoint of more effectively and reliably achieving the effects of the present invention, R1 and R2 each independently represent a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. From the same viewpoint, R3 is preferably an alkyl group, and more preferably a methyl group.

[0012] From the viewpoint of more effectively and reliably achieving the effects of the present invention, the alkyl group in R1 and R2 is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Examples of such an alkyl group include a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and a cyclic alkyl group having 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, and even more preferably 3 to 6 carbon atoms. More specifically, examples of such an alkyl group include linear or branched alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, 1-ethylpropyl group, n-pentyl group, neopentyl group, n-hexyl group, isohexyl group, 3-methylpentyl group, and n-octyl group; and cyclic alkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group. Among these, even more preferred alkyl groups are linear or branched alkyl groups having 1 to 6 carbon atoms, particularly preferred are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and n-pentyl groups, extremely preferred are methyl and ethyl groups, and most preferred is methyl group.

[0013] From the viewpoint of more effectively and reliably achieving the effects of the present invention, the aryl group in R1 and R2 is preferably an aryl group having 6 to 14 carbon atoms. Examples of such aryl groups include a phenyl group, a biphenyl group, a naphthyl group, a dihydroindenyl group, and a 9H-fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferred, and a phenyl group is even more preferred. It is also preferred that the phenyl group has a substituent.

[0014] From the viewpoint of more effectively and reliably achieving the effects of the present invention, the aralkyl group in R1 and R2 is preferably an aralkyl group having 7 to 20 carbon atoms. Examples of such aralkyl groups include a benzyl group, a phenethyl group, a trityl group, a 1-naphthylmethyl group, a 2-(1-naphthyl)ethyl group, and a 2-(2-naphthyl)ethyl group. Among these, a benzyl group and a phenethyl group are more preferable, and a benzyl group is further preferable.

[0015] From the viewpoint of more effectively and reliably achieving the effects of the present invention, the alkenyl group in R1 and R2 is preferably an alkenyl group having 2 to 18 carbon atoms. Examples of such alkenyl groups include alkenyl groups having 2 to 6 carbon atoms, and specific examples thereof include a vinyl group, a 1-propenyl group, an allyl group, an isopropenyl group, a 1-butenyl group, and a 2-butenyl group.

[0016] From the viewpoint of more effectively and reliably achieving the effects of the present invention, the monovalent heterocyclic group in R1 and R2 preferably has a number of atoms constituting the heterocycle (number of ring members) of 4 to 14, more preferably 5 to 10. Examples of such monovalent heterocyclic groups include a 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 2-pyrazinyl group, a 2-pyrimidyl group, a 4-pyrimidyl group, a 5-pyrimidyl group, a 3-pyridazyl group, a 4-pyridazyl group, a 4-(1,2,3-triazyl) group, a 5-(1,2,3-triazyl) group, a 2-(1,3,5-triazyl) group, a 3-(1,2,4-triazyl) group, a 5-(1,2,4-triazyl) group, a 6-(1,2,4-triazyl) group, 2-quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalyl group, 3-quinoxalyl group, 5-quinoxalyl group, 6-quinoxalyl group, 7-quinoxalyl group, 8-quinoxalyl group, 3-cinnolyl group, 4-cinnolyl group, 5-cinnolyl group, 6-cinnolyl group, 7-cinnolyl group, 8-cinnolyl group, 2-quinazolyl, 4-quinazolyl, 5-quinazolyl, 6-quinazolyl, 7-quinazolyl, 8-quinazolyl, 1-phthalazyl, 4-phthalazyl, 5-phthalazyl, 6-phthalazyl, 7-phthalazyl, 8-phthalazyl, 1-tetrahydroquinolyl, 2-tetrahydroquinolyl, 3-tetrahydroquinolyl, 4-tetrahydroquinolyl, 5-tetrahydroquinolyl, 6-tetrahydroquinolyl, 7-tetrahydroquinolyl, 8-tetrahydroquinolyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-furyl , 3-furyl group, 2-thienyl group, 3-thienyl group, 1-imidazolyl group, 2-imidazolyl group, 4-imidazolyl group, 5-imidazolyl group, 1-pyrazolyl group, 3-pyrazolyl group, 4-pyrazolyl group, 5-pyrazolyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-thiazolyl group, 4-thiazolyl group, 5-thiazolyl group, 3-isoxazolyl group, 4-isoxazolyl group, 5-isoxazolyl group, 3-isothiazolyl group, 4-isothiazolyl group, 5-isothiazolyl group, 4-(1,2,3-thiadiazolyl) group, 5-(1, 2,3-thiadiazolyl group, 3-(1,2,5-thiadiazole) group, 2-(1,3,4-thiadiazole) group, 4-(1,2,3-oxadiazolyl) group, 5-(1,2,3-oxadiazolyl) group, 3-(1,2,4-oxadiazolyl) group, 5-(1,2,4-oxadiazolyl) group, 3-(1,2,5-oxadiazolyl) group, 2-(1,3,4-oxadiazolyl) group, 1-(1,2,3-triazolyl) group, 4-(1,2,3-triazolyl) group, 5-(1,2,3-triazolyl) group, 1-(1,2,4-triazolyl) group, 3-(1,2,4-triazolyl) group, 5-(1,2,4-triazolyl) group, 1-tetrazolyl group, 5-tetrazolyl group, 1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 1-benzimidazolyl group, 2-benzimidazolyl group, 4-benzimidazolyl group, 5- Benzimidazolyl group, 6-benzimidazolyl group, 7-benzimidazolyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, 2-benzothienyl group, 3-benzothienyl group, 4-benzothienyl group, 5-benzothienyl group, 6-benzothienyl group 1-indazolyl, 3-indazolyl, 4-indazolyl, 5-indazolyl, 6-indazolyl, 7-indazolyl, 2-morpholyl, 3-morpholyl, 4-morpholyl, 1-piperyl, 2-benzothiazolyl, 4-benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl, 1-indazolyl, 3-indazolyl, 4-indazolyl, 5-indazolyl, 6-indazolyl, 7-indazolyl, 2-morpholyl, 3-morpholyl, 4-morpholyl, 1-piperyl, 2-benzothiazolyl, 4-benzothia ... Examples of the aryl group include a pyrazyl group, a 2-piperazyl group, a 1-piperidyl group, a 2-piperidyl group, a 3-piperidyl group, a 4-piperidyl group, a 2-tetrahydropyranyl group, a 3-tetrahydropyranyl group, a 4-tetrahydropyranyl group, a 2-tetrahydrothiopyranyl group, a 3-tetrahydrothiopyranyl group, a 4-tetrahydrothiopyranyl group, a 1-pyrrolidyl group, a 2-pyrrolidyl group, a 3-pyrrolidyl group, a 2-tetrahydrofuranyl group, a 3-tetrahydrofuranyl group, a 2-tetrahydrothienyl group, and a 3-tetrahydrothienyl group. Among these, a pyridyl group, a furanyl group, a thienyl group, a pyrimidyl group, and a pyrazyl group are more preferred, and a pyridyl group is particularly preferred.

[0017] Examples of the substituents in R1 and R2 include halogen atoms, amino groups, aminoalkyl groups, alkoxycarbonyl groups, acyl groups, acyloxy groups, amide groups, carboxyl groups, carboxyalkyl groups, formyl groups, nitrile groups, nitro groups, alkyl groups, hydroxyalkyl groups, hydroxy groups, alkoxy groups, aryl groups, aryloxy groups, monovalent heterocyclic groups, sulfanyl groups, alkylsulfanyl groups, and arylsulfanyl groups. The number of the substituents in each of R1 and R2 may be preferably 1 to 5, more preferably 1 to 3.

[0018] Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0019] The amino group as a substituent includes not only an amino group represented by -NH2, but also substituted amino groups such as linear or branched monoalkylamino groups having 1 to 6 carbon atoms (particularly, 1 to 4 carbon atoms), such as a methylamino group, an ethylamino group, an n-propylamino group, an isopropylamino group, an n-butylamino group, an isobutylamino group, an s-butylamino group, a t-butylamino group, a 1-ethylpropylamino group, an n-pentylamino group, a neopentylamino group, an n-hexylamino group, an isohexylamino group, and a 3-methylpentylamino group; and dialkylamino groups having two linear or branched alkyl groups having 1 to 6 carbon atoms (particularly, 1 to 4 carbon atoms), such as a dimethylamino group, an ethylmethylamino group, and a diethylamino group.

[0020] Examples of the aminoalkyl group as a substituent include aminoalkyl groups having 1 to 4 carbon atoms, such as an aminomethyl group, a 2-aminoethyl group, and a 3-aminopropyl group.

[0021] Examples of the alkoxycarbonyl group as a substituent include alkoxycarbonyl groups having 1 to 4 carbon atoms in the alkoxy group, such as a methoxycarbonyl group and an ethoxycarbonyl group.

[0022] Examples of the acyl group as a substituent include linear or branched alkylcarbonyl groups having 1 to 4 alkyl carbon atoms, such as an acetyl group, a propionyl group, and a pivaloyl group.

[0023] Examples of the acyloxy group as a substituent include alkylcarbonyloxy groups having an alkyl group of 1 to 4 carbon atoms, such as an acetyloxy group, a propionyloxy group, and an n-butyryloxy group.

[0024] Examples of the amide group as a substituent include carboxylic acid amide groups having 2 to 8 carbon atoms, such as an acetamide group and a benzamide group; a thioamide group having 2 to 8 carbon atoms, such as a thioacetamide group and a thiobenzamide group; and an N-substituted amide group having 2 to 8 carbon atoms, such as an N-methylacetamide group and an N-benzylacetamide group.

[0025] Examples of the carboxyalkyl group as a substituent include carboxy-alkyl groups having an alkyl carbon number of 1 to 6, such as a carboxymethyl group, a carboxyethyl group, a carboxy-n-propyl group, a carboxy-n-butyl group, a carboxy-n-butyl group, and a carboxy-n-hexyl group.

[0026] Examples of the hydroxyalkyl group as a substituent include hydroxyalkyl groups having 1 to 6 carbon atoms, such as a hydroxymethyl group, a hydroxyethyl group, a hydroxy-n-propyl group, and a hydroxy-n-butyl group.

[0027] Examples of the alkoxy group as a substituent include linear, branched, or cyclic alkoxy groups. More specifically, linear or branched alkoxy groups having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms) such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, t-butoxy, n-pentyloxy, neopentyloxy, and n-hexyloxy groups; and cyclic alkoxy groups having 3 to 8 carbon atoms (preferably 3 to 6 carbon atoms) such as cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, cycloheptyloxy, and cyclooctyloxy groups.

[0028] Examples of the aryloxy group as a substituent include aryloxy groups having 6 to 14 carbon atoms, such as a phenoxy group, a biphenyloxy group, and a naphthoxy group.

[0029] The alkylsulfanyl group as the substituent can be exemplified by the above-mentioned alkoxy group with the oxygen atom replaced by a sulfur atom.The arylsulfanyl group as the substituent can be exemplified by the above-mentioned aryloxy group with the oxygen atom replaced by a sulfur atom.The alkyl group, aryl group and monovalent heterocyclic group as the substituent can be exemplified by the same as those in R1 and R2, and the description here is omitted.

[0030] Preferred embodiments and examples of the alkyl group, aryl group, aralkyl group, and alkenyl group in R3 are the same as those in R1 and R2, and the explanation here is omitted. In addition, the substituent in R3 that may have one or more selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom may be any of the substituents in R1 and R2 that have one or more selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom.

[0031] X is not particularly limited as long as it is an anion capable of forming a salt with pyridinium. Examples of X include halide ions such as chloride ion, bromide ion, and iodide ion; alkyl sulfate ions having 1 to 4 carbon atoms such as methyl sulfate ion, ethyl sulfate ion, propyl sulfate ion, and butyl sulfate ion; hydrocarbon sulfonate ions such as methanesulfonate ion, ethanesulfonate ion, propanesulfonate ion, butanesulfonate ion, and tosyl ion; phosphate ion; nitrate ion; and organic acid ions such as acetate ion and lactate ion. Among these, from the viewpoint of more effectively and reliably exerting the effects of the present invention, halide ions and organic acid ions are preferred, and chloride ions, bromide ions, iodide ions, and acetate ions are more preferred.

[0032] From the viewpoint of more effectively and reliably exerting the effects of the present invention, the compound (1) according to this embodiment is preferably a compound represented by the following formula (2). [ka] Here, in formula (2), X represents an anion that forms a salt with pyridinium, L represents CR2 or a nitrogen atom, R1 and R2 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a monovalent heterocyclic group that may have a substituent, and R7 represents a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, or an alkenyl group that may have one or more selected from the group consisting of a hydroxy group, an alkoxy group, an acyl group, an amino group, an amide group, an epoxy group, a sulfanyl group, and an alkylsulfanyl group. From the viewpoint of more effectively and reliably achieving the effects of the present invention, L is preferably CR2, and R7 is preferably -CH(OH)R4. Here, R4 represents a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, or an alkenyl group that may have one or more selected from the group consisting of a hydroxy group, an alkoxy group, an acyl group, an amino group, an amide group, an epoxy group, a sulfanyl group, and an alkylsulfanyl group.

[0033] X, L, R1, and R2 have the same meanings as those in the above formula (1), and are the same examples and preferred embodiments as those in the above formula (1), so the explanation here is omitted.

[0034] The preferred embodiments and examples of the alkyl group, aryl group, aralkyl group, and alkenyl group in R7, as well as the alkoxy group, acyl group, amino group, amido group, and alkylsulfanyl group, which are the substituents thereof, are the same as those in R1 and R2, and the description here is omitted. However, when R3 in the above formula (1) has -CH2-CH(OH)- (wherein a methylene group is bonded to the nitrogen atom) bonded to the nitrogen atom of the pyridine ring shown in formula (1), R7 differs from R3 in that it does not have the group. In addition, the preferred embodiments and examples of the alkyl group, aryl group, aralkyl group, and alkenyl group in R4, as well as the alkoxy group, acyl group, amino group, amido group, and alkylsulfanyl group, which are the substituents thereof, are the same as those in R3, and the description here is omitted. However, when R7 has -C(H)OH- bonded to the above methylene group, R4 differs from R7 in that it does not have the group.

[0035] From the viewpoint of more effectively and reliably achieving the effects of the present invention, compound (1) according to this embodiment is more preferably a compound represented by the following formula (3). [ka] Here, in formula (3), X represents an anion that forms a salt with pyridinium, L represents CR2 or a nitrogen atom, and R1 and R2 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a monovalent heterocyclic group that may have a substituent. Z represents an oxygen atom, a sulfur atom, an alkylene group, or a group represented by -NR6-, and the number of carbon atoms in the alkylene group is, for example, 1 to 10. R5 and R6 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, or an alkenyl group that may have one or more selected from the group consisting of a hydroxy group, an alkoxy group, an acyl group, an amino group, an amide group, an epoxy group, a sulfanyl group, and an alkylsulfanyl group, and are preferably hydrogen atoms from the viewpoint of more effectively and reliably achieving the effects of the present invention. From the viewpoint of more effectively and reliably achieving the effects of the present invention, L is preferably CR2.

[0036] X, L, R1, and R2 have the same meanings as those in the above formula (1), and are the same examples and preferred embodiments as those in the above formula (1), so the explanation here is omitted.

[0037] Preferred embodiments and examples of the alkyl group, aryl group, aralkyl group, and alkenyl group in R5 and R6, and the alkoxy group, acyl group, amino group, amido group, and alkylsulfanyl group that are the substituents thereof, are the same as those in R1 and R2, and the explanation here is omitted. However, when R3 in the above formula (1) has -CH2C(=O)Z- (wherein a methylene group is bonded to the nitrogen atom) bonded to the nitrogen atom of the pyridine ring, R5 differs from R3 in that it does not have said -CH2C(=O)Z-.

[0038] Regarding the combination of Z and R5, when Z is an oxygen atom or a sulfur atom, R5 may be, for example, an alkyl group, an aryl group, or an alkoxy group. When Z is an alkylene group, R5 may be, for example, an alkyl group. When Z is a group represented by -NR6-, R5 and R6 may be, for example, each independently, a hydrogen atom, an alkyl group, an aryl group, or an alkoxy group.

[0039] The compound (1) according to this embodiment may be synthesized by a conventional method, or may be synthesized by a method described in the Examples or a method based thereon.

[0040] In order to more effectively and reliably exert the effects of the present invention, the amount of compound (1) in the first rubber composition is preferably 0.1% by mass or more and 5.0% by mass or less, and more preferably 0.3% by mass or more and 3.0% by mass or less, relative to 100% by mass of the diene rubber.

[0041] From the viewpoint of achieving a higher rubber reinforcing effect and further improving low heat generation, the filler contained in the first rubber composition preferably contains at least one type selected from the group consisting of inorganic fillers and carbon black, but the filler is not limited thereto. The inorganic filler may be used alone or in combination of two or more types.

[0042] The inorganic filler contains at least one solid particle selected from the group consisting of oxides or hydroxides of silicon, typical metals or transition metals, and hydrates thereof, as well as carbonates of these metals. Examples of the inorganic filler include silica; alumina (Al2O3) such as γ-alumina and α-alumina; alumina monohydrate (Al2O3·H2O) such as boehmite and diaspore; aluminum hydroxide [Al(OH)3] such as gibbsite and bayerite; aluminum carbonate [Al2(CO3)2], magnesium hydroxide [Mg(OH)2], magnesium oxide (MgO), magnesium carbonate (MgCO3), talc (3MgO·4SiO2·H2O), attapulgite (5MgO·8SiO2·9H2O), titanium white (TiO2), titanium black (TiO 2n-1), calcium oxide (CaO), calcium hydroxide [Ca(OH)2], magnesium aluminum oxide (MgO·Al2O3), clay (Al2O3·2SiO2), kaolin (Al2O3·2SiO2·2H2O), pyrophyllite (Al2O3·4SiO2·H2O), bentonite (Al2O3·4SiO2·2H2O), aluminum silicates (clay; e.g. Al2SiO5, Al4·3SiO4·5H2O), magnesium silicates (talc; e.g. Mg2SiO4, MgSiO3), calcium silicate Examples of such inorganic fillers include crystalline aluminosilicates containing hydrogen, alkali metals or alkaline earth metals to correct the charge, such as calcium (e.g., Ca2·SiO4), calcium aluminum silicate (e.g., Al2O3·CaO·2SiO2), calcium magnesium silicate (CaMgSiO4), calcium carbonate (CaCO3), zirconium oxide (ZrO2), zirconium hydroxide [ZrO(OH)2·nH2O], zirconium carbonate [Zr(CO3)2], zinc acrylate, zinc methacrylate, and various zeolites. The surfaces of these inorganic fillers may be organically treated to improve their affinity with diene rubber.

[0043] Among the above fillers, the inorganic filler preferably contains silica, from the viewpoint of obtaining a higher rubber reinforcing effect and further improving low heat generation. Examples of silica include wet silica, dry silica, and colloidal silica, and wet silica is more preferable from the same viewpoint as above. The silica may be subjected to an organic treatment on its surface in order to improve its affinity with diene rubber.

[0044] The BET specific surface area of ​​silica is not particularly limited. For example, 2 / g or more 350m 2 / g or less. By having the BET specific surface area within the above range, both the rubber reinforcing effect and the dispersibility of silica in the diene rubber can be achieved at a higher level. From the same viewpoint, the BET specific surface area of ​​silica is preferably 80 to 300 m 2 / g is more preferable, and 100m 2 / g or more 270m 2 / g or less is more preferable. 2 / g or more 270m 2 It is more preferable that the BET specific surface area is not more than 1 / g. The BET specific surface area is measured in accordance with ISO5794 / 1.

[0045] An example of a commercially available product of this type of silica is the product name "HD165MP" (BET specific surface area = 165 m) manufactured by Quechen Silicon Chemical Co., Ltd. 2 / g), product name "HD115MP" (BET specific surface area = 115m 2 / g), product name "HD200MP" (BET specific surface area = 200m 2 / g), product name "HD250MP" (BET specific surface area = 250m 2 / g), and the product name "Nipsil AQ" manufactured by Tosoh Silica Corporation (BET specific surface area = 205 m 2 / g), product name "Nipsil KQ" (BET specific surface area = 240 m 2 / g), and Ultrasil VN3 (BET specific surface area = 175 m 2 / g) etc.

[0046] By including an inorganic filler, preferably silica, in the first rubber composition together with the compound (1), the dispersibility of the inorganic filler is significantly improved, and the low heat build-up property of the rubber composition can be further improved.

[0047] The filler contained in the first rubber composition may contain carbon black. By using carbon black, the electrical resistance of the rubber composition can be reduced, the effect of suppressing static electricity can be enhanced, and the rubber strength can be further increased. There is no particular limitation on the carbon black, and for example, commercially available carbon black may be used.

[0048] More specifically, the carbon black may be high, medium or low structure SAF, ISAF, IISAF, N110, N134, N220, N234, N330, N339, N375, N550, HAF, FEF, GPF or SRF grade carbon black. Of these, the carbon black preferably includes SAF, ISAF, IISAF, N134, N234, N330, N339, N375, HAF or FEF grade carbon black.

[0049] From the viewpoint of more effectively and reliably achieving the effects of the present invention and the effects of using the filler, the amount of the filler in the rubber composition is preferably 20 parts by mass or more and 120 parts by mass or less, and more preferably 50 parts by mass or more and 100 parts by mass or less, per 100 parts by mass of the diene rubber. In this embodiment, particularly by using compound (1), the coagulant of the filler can be suppressed even if the amount of the filler is increased more than before, so that the low heat generation property and the reinforcement property of the rubber can be further improved.

[0050] The first rubber composition of the present embodiment preferably contains a silane coupling agent from the viewpoint of further enhancing the bonding strength between the filler and the diene rubber.

[0051] Examples of the silane coupling agent include, but are not limited to, bis-(3-triethoxysilylpropyl)tetrasulfide, bis-(3-trimethoxysilylpropyl)tetrasulfide, bis-(3-methyldimethoxysilylpropyl)tetrasulfide, bis-(2-triethoxysilylethyl)tetrasulfide, bis-(3-triethoxysilylpropyl)disulfide, bis-(3-trimethoxysilylpropyl)disulfide, bis-(3-triethoxysilylpropyl)disulfide, pyl) trisulfide, 3-hexanoylthiopropyl triethoxysilane, 3-octanoylthiopropyl triethoxysilane, 3-decanoylthiopropyl triethoxysilane, 3-lauroylthiopropyl triethoxysilane, 2-hexanoylthioethyl triethoxysilane, 2-octanoylthioethyl triethoxysilane, 2-decanoylthioethyl triethoxysilane, 2-lauroylthioethyl triethoxysilane, 3-hexanoylthiopropyl trimeth xysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octanoylthioethyltrimethoxysilane, 2-decanoylthioethyltrimethoxysilane, 2-lauroylthioethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, and 3-trimethoxysilylpropylmethacryloyl monosulfide.

[0052] When the rubber composition contains a silane coupling agent, the amount of the silane coupling agent is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the filler, from the viewpoint of further enhancing the effect of using the silane coupling agent while further suppressing the decrease in the effect of using other materials.

[0053] The first rubber composition of the present embodiment may contain compounding agents that are commonly used in the rubber industry, such as anti-aging agents, softening agents, vulcanization accelerators, vulcanization accelerator assistants, vulcanizing agents, etc., appropriately selected within a range that does not impair the object of the present embodiment. Among these, it is preferable that the first rubber composition contains a vulcanization accelerator and a vulcanizing agent, and it is more preferable that the first rubber composition contains a vulcanization accelerator and sulfur, which is a type of vulcanizing agent. Commercially available products can be suitably used as these compounding agents.

[0054] The type of antiaging agent is not particularly limited, but examples thereof include naphthylamine-based, p-phenylenediamine-based, hydroquinone derivatives, bis, tris, polyphenol-based, diphenylamine-based, quinoline-based, monophenol-based, thiobisphenol-based, and hindered phenol-based. Among these, p-phenylenediamine-based and diphenylamine-based amine-based antiaging agents are preferred from the viewpoint of further antiaging effect. Examples of diphenylamine-based antiaging agents include 4,4'-(α-methylbenzyl)diphenylamine, 4,4'-(α,α-dimethylbenzyl)diphenylamine, p-(p-toluene-sulfonylamide)diphenylamine, and 4,4'-dioctyldiphenylamine. Among these, 4,4'-(α-methylbenzyl)diphenylamine is particularly preferred from the viewpoint of further high antiaging effect. Furthermore, examples of the p-phenylenediamine-based antiaging agents include N,N'-diphenyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N,N'-di-2-naphthyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenylenediamine, N-phenyl-N'-(3-methacryloyloxy-2-hydroxypropyl)-p-phenylenediamine, N,N'-bis(1-methylheptyl)-p-phenylenediamine, N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, and N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine. Among these, from the viewpoints of even higher antiaging effect and cost, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine is particularly preferred. The amount of the antiaging agent in the rubber composition may be 0.1 parts by mass or more and 5 parts by mass or less based on 100 parts by mass of the diene rubber contained in the rubber composition.

[0055] The type of softener is not particularly limited, but examples include mineral oil-based softeners derived from petroleum or coal tar, vegetable oil-based softeners derived from fatty oil or pine trees, and synthetic resin-based softeners.

[0056] The type of vulcanization accelerator is not particularly limited, but examples thereof include thiazoles such as mercaptobenzothiazole and di-2-benzothiazolyl disulfide, sulfenamides such as N-cyclohexyl-2-benzothiazolylsulfenamide, N,N'-dicyclohexyl-2-benzothiazolylsulfenamide, and N'-tert-butyl-2-benzothiazolylsulfenamide, and guanidines such as aminoguanidine and diphenylguanidine. These vulcanization accelerators are used alone or in combination of two or more. The amount of the vulcanization accelerator in the rubber composition is preferably 0.1 parts by mass or more and 5 parts by mass or less per 100 parts by mass of diene rubber. The vulcanization accelerator assistant is not particularly limited, but examples thereof include stearic acid and zinc oxide.

[0057] The type of vulcanizing agent is not particularly limited, but examples thereof include sulfur and peroxide, and is preferably sulfur. The amount of the vulcanizing agent in the rubber composition is preferably 0.1 parts by mass or more and 5 parts by mass or less, and more preferably 0.5 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the diene rubber. When the amount of the vulcanizing agent is 0.1 parts by mass or more, more sufficient vulcanization is obtained, and when the amount is 5 parts by mass or less, the so-called scorch time does not shorten, and problems such as the rubber burning during kneading can be more effectively suppressed.

[0058] The first rubber composition of the present embodiment may contain a rubber other than the diene rubber described above, as long as it does not impede the solution of the problems of the present invention. As such a rubber, a known rubber may be used.

[0059] The first rubber composition of the present embodiment is produced, for example, by the following production method. However, the production method is not limited thereto. That is, the production method includes a kneading and mixing step (A) of kneading or mixing a diene rubber, a compound (1), and a filler to obtain a rubber composition.

[0060] As the kneading and mixing means in the kneading and mixing step (A), it is preferable to use a kneader from the viewpoint of improving the interaction rate, and examples of such kneaders include a Labo Plastomill, a Banbury mixer, an intensive mixer, an internal mixer, a roller, a kneader-ruder, a twin-screw extruder, and a mixing roll. In addition, there is no particular restriction on the order in which each component is added to the kneading and mixing means, but it is preferable to first add the diene rubber and then add the other components. In addition, there is no particular restriction on the method of adding the other components, but for example, when the component is a powder, the powder can be added as it is, the component can be dissolved in a solvent and added as a solution, and the component can be added as an emulsion solution. In addition, in the kneading and mixing step (A), it is preferable to knead in one stage from the viewpoint of efficiency, but it may be divided into multiple stages as necessary.

[0061] The temperature in the kneading and mixing step (A) is preferably from 80° C. to 180° C., and more preferably from 100° C. to 160° C. The kneading or mixing time in the kneading and mixing step (A) is preferably from 30 to 600 seconds, and more preferably from 60 to 300 seconds.

[0062] In the first rubber composition manufacturing method of the present embodiment, other conditions than those described above may be known, and for example, the manufacturing method may have a mastication step of kneading the diene rubber alone prior to the kneading and mixing step (A). Furthermore, the compound (1) may be added in the mastication step.

[0063] (Modified diene rubber) The modified diene rubber of the present embodiment is a modified diene rubber having a modifying group represented by the following formula (4a), (4b), (4c), (4d), (4e), (4f), (4g), (4h), (4i), (4j) or (4k) (hereinafter, these modifying groups are collectively referred to as "modifying groups (4a) to (4k)"). [ka] In each formula, X represents an anion that forms a salt with pyridinium, L represents CR2 or a nitrogen atom, R1 and R2 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group or a monovalent heterocyclic group which may have a substituent, R3 represents an alkyl group, an aryl group, an aralkyl group or an alkenyl group which may have a substituent which may have one or more selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom, R represents a halogen atom or an alkyl group, and the wavy line represents a bonding site with the above-mentioned modifying group of the diene rubber.

[0064] X, L, R1, R2 and R3 have the same meanings as those in the above formula (1), and are the same examples and preferred embodiments as those in the above formula (1), so the explanation here is omitted.

[0065] The preferred embodiments and examples of the alkyl group in R are the same as those in R1 and R2, and therefore the explanation will be omitted here.

[0066] The modified diene rubber having modifying groups (4a) to (4k) can be obtained by allowing an inverse electron demand Aza-Diels-Alder reaction to proceed between compound (1) and a double bond in the diene rubber.

[0067] Specifically, the reaction shown in the following scheme (7), (8), (9) or (10) proceeds, whereby compound (1) is bonded to the double bond site of the diene rubber to form a six-membered ring structure, thereby producing a modified diene rubber. <Scheme (7)> [ka] Here, X, L, R1, R2 and R3 in each formula have the same meaning as in the above formula (1), and are the same examples and preferred embodiments as in the above formula (1), so the explanation here is omitted.

[0068] In the above scheme (7), the double bond site of the diene rubber represented by formula (1A) and the compound (1) undergo an inverse electron demand Aza-Diels-Alder reaction to form a bicyclo ring structure represented by formula (1B). The -N=N- portion in this bicyclo ring structure is easily denitrified to form a structure represented by formula (1C1), (1C2) or (1C3), which is further oxidized by oxygen in the air to produce a modified polymer having a structure represented by formula (4a). <Scheme (8)> [ka] Here, X, L, R1, R2 and R3 in each formula have the same meaning as in the above formula (1), and are the same examples and preferred embodiments as in the above formula (1), so the explanation here is omitted.

[0069] In the above scheme (8), similarly to the scheme (7), a bicyclo ring structure represented by formula (1E1) or (1E2) and then a structure represented by formula (1F1), (1F2), (1F3), (1F4), (1F5) or (1F6) are formed from the double bond site of the diene rubber represented by formula (1D) and compound (1), and then a modified diene rubber having a structure represented by formula (4b) or (4c) is produced. <Scheme 9> [ka] Here, X, L, R1, R2 and R3 in each formula are the same as those in the above formula (1), and are the same examples and preferred embodiments as those in the above formula (1), so the explanation here is omitted. In addition, the preferred embodiments and exemplified alkyl groups in R in each formula are the same as those in R3, so the explanation here is omitted.

[0070] In scheme (9), a bicyclo ring structure represented by formula (1H1) or (1H2) is formed by an inverse electron demand type Aza-Diels-Alder reaction between the double bond portion of the diene rubber represented by formula (1G) and compound (1), and then a modified diene rubber having a structure represented by formula (4d), (4e), (4f) or (4g) is produced by denitrification. When R at the double bond portion of the diene rubber represented by formula (1G) is a halogen atom, the halogen atom may be eliminated, and in that case, a modified diene rubber having a structure represented by formula (4a) is produced by an oxidation reaction. <Scheme 10> [ka] Here, X, L, R1, R2 and R3 in each formula are the same as those in the above formula (1), and are the same examples and preferred embodiments as those in the above formula (1), so the explanation here is omitted. In addition, the preferred embodiments and exemplified alkyl groups in R in each formula are the same as those in R3, so the explanation here is omitted.

[0071] In scheme (9), similarly to scheme 8, a bicyclo ring structure represented by formula (1J1) or (1J2) is formed by reacting the double bond portion of the diene rubber represented by formula (1I) with compound (1), and then a modified diene rubber having a structure represented by formula (4h), (4i), (4j) or (4k) is produced. When R at the double bond portion of the diene rubber represented by formula (1I) is a halogen atom, the halogen atom may be eliminated, and in that case, a modified diene rubber having a structure represented by formula (4a) is produced by an oxidation reaction.

[0072] From the viewpoint of more effectively and reliably exerting the effects of the present invention, the modified diene rubber of the present embodiment is preferably a modified diene rubber having a modifying group represented by the following formula (5a), (5b), (5c), (5d), (5e), ​​(5f), (5g), (5h), (5i), (5j) or (5k). [ka] In each formula, X represents an anion that forms a salt with pyridinium, L represents CR2 or a nitrogen atom, R1 and R2 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a monovalent heterocyclic group which may have a substituent, R7 represents a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, or an alkenyl group which may have one or more selected from the group consisting of a hydroxyl group, an alkoxy group, an acyl group, an amino group, an amide group, an epoxy group, a sulfanyl group, and an alkylsulfanyl group, R represents a halogen atom or an alkyl group, and the wavy line represents a bonding site with the above-mentioned modifying group of the diene rubber.

[0073] X, L, R1, R2 and R7 have the same meanings as those in the above formula (2), and are the same examples and preferred embodiments as those in the above formula (2), so the explanation here is omitted.

[0074] The preferred embodiments and examples of the alkyl group in R are the same as those in R1 and R2, and therefore the explanation will be omitted here.

[0075] From the viewpoint of more effectively and reliably exerting the effects of the present invention, the modified diene rubber of the present embodiment is preferably a modified diene rubber having a modifying group represented by the following formula (6a), (6b), (6c), (6d), (6e), (6f), (6g), (6h), (6i), (6j) or (6k). [ka] In each formula, X represents an anion that forms a salt with pyridinium, L represents CR2 or a nitrogen atom, R1 and R2 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a monovalent heterocyclic group that may have a substituent, Z represents an oxygen atom, a sulfur atom, an alkylene group, or a group represented by -NR6-, R5 and R6 each independently represent a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, or an alkenyl group that may have one or more selected from the group consisting of a hydroxyl group, an alkoxy group, an acyl group, an amino group, an amide group, an epoxy group, a sulfanyl group, and an alkylsulfanyl group, R represents a halogen atom or an alkyl group, and the wavy line represents a bonding site with the above-mentioned modified group of the diene rubber.

[0076] X, L, R1, R2, R5 and R6 have the same meanings as those in the above formula (3), and are the same examples and preferred embodiments as those in the above formula (3), so the explanation here is omitted.

[0077] The preferred embodiments and examples of the alkyl group in R are the same as those in R1 and R2, and therefore the explanation will be omitted here.

[0078] The diene rubber constituting the portion other than the modified group of the modified diene rubber of the present embodiment includes synthetic rubber and natural rubber. Examples of the synthetic rubber include styrene-butadiene copolymer rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene-propylene-diene terpolymer rubber (EPDM), styrene-isoprene-styrene terblock copolymer (SIS), and styrene-butadiene-styrene terblock copolymer (SBS).

[0079] The natural rubber may be any rubber having a carbon-carbon double bond, and examples of such natural rubber include natural rubber latex, technically graded rubber (TSR), smoked sheet (RSS), gutta percha, eucommia-derived natural rubber, guayule-derived natural rubber, and Russian dandelion-derived natural rubber. Furthermore, modified natural rubbers obtained by modifying these natural rubbers, such as methacrylic acid-modified natural rubber and styrene-modified natural rubber, are also included in the natural rubber of this embodiment.

[0080] Among these, SBR, BR, IR and natural rubber are preferred from the viewpoint of more effectively and reliably exerting the effects of the present invention. These diene rubbers may be modified with a modifying group other than the above-mentioned modifying groups (hereinafter referred to as "other modifying groups"). The portion modified with the other modifying group may be the main chain, one end, or both ends. Examples of the other modifying group include an epoxy group, an amino group, an alkoxysilyl group, and a hydroxyl group. These other modifying groups may be used alone or in combination of two or more.

[0081] The weight average molecular weight of the diene rubber is not particularly limited, and may be, for example, 2.0×10 5 ~2.0×10 6 The weight average molecular weight (Mw) is measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent and converted into standard polystyrene.

[0082] The method for producing the diene rubber is not particularly limited, and examples thereof include emulsion polymerization, solution polymerization, radical polymerization, anionic polymerization, and cationic polymerization.

[0083] The synthesis conditions for synthesizing the modified diene rubber of the present embodiment are not particularly limited. For example, when synthesizing the modified diene rubber, if the diene rubber is solid, the modified diene rubber is obtained by kneading the compound (1) and the diene rubber. Also, when synthesizing the modified diene rubber, if the diene rubber is liquid, the modified diene rubber is obtained by mixing the solution or suspension of the diene rubber with the compound (1).

[0084] The heating temperature when synthesizing the modified diene rubber is not particularly limited. For example, in the case of the above-mentioned kneading method, the upper limit of the temperature is preferably 80°C or more and 180°C or less, and more preferably 100°C or more and 160°C or less.

[0085] The kneading or mixing time when synthesizing the modified diene rubber is not particularly limited. For example, in the case of a kneading method, the kneading time is preferably 30 seconds or more and 600 seconds or less, and more preferably 60 seconds or more and 300 seconds or less.

[0086] The amount of compound (1) used when synthesizing the modified diene rubber of this embodiment is preferably 0.1 mass% or more and 5.0 mass% or less, and more preferably 0.3 mass% or more and 3.0 mass% or less, relative to 100 mass% of the diene rubber.

[0087] (Rubber composition containing modified diene rubber) Another example of the rubber composition of this embodiment (hereinafter referred to as the "second rubber composition") contains the above-mentioned modified diene rubber and a filler. The modified diene rubber is as described above, so its description will be omitted here. The filler, as well as optional components such as the silane coupling agent, various compounding agents, and diene rubber, are the same as those in the first rubber composition, so their description will be omitted here. Among the above, the diene rubber may contain the diene rubber before the modified diene rubber is modified. The second rubber composition may contain the above-mentioned compound (1). The compounding amounts of these components in the second rubber composition are the same as those in the first rubber composition, except that the compounding amounts are based on the total of 100 parts by mass of the modified diene rubber and the diene rubber instead of 100 parts by mass of the diene rubber. Therefore, the description of the preferred compounding amounts will be omitted.

[0088] The second rubber composition of the present embodiment may contain a rubber other than the modified diene rubber described above, as long as it does not impede the solution of the problems of the present invention. As such a rubber, a known rubber may be used.

[0089] The second rubber composition of the present embodiment is produced, for example, by the following production method. However, the production method is not limited to this. That is, the production method has a kneading and mixing step (B) of kneading or mixing a diene rubber, a compound (1), and a filler while heating to obtain a rubber composition. Alternatively, the production method has a kneading step (C) of kneading the modified diene rubber obtained as described above with a filler to obtain a rubber composition.

[0090] The manufacturing method may further include a kneading step (D) of kneading or mixing the rubber composition, a vulcanizing agent, and a vulcanization accelerator to obtain an unvulcanized rubber composition. The manufacturing method may further include a vulcanization step of vulcanizing the unvulcanized rubber composition to obtain a vulcanized rubber composition.

[0091] The vulcanizing agent and the vulcanization accelerator are preferably added to the kneading and mixing means in the kneading step (D). This makes it possible to more reliably prevent scorching from occurring early. Also, the antioxidant and the softening agent that may be contained in the rubber composition are preferably added to the kneading and mixing means in the kneading and mixing step (B) or the kneading step (C).

[0092] The kneading and mixing means in the kneading and mixing step (B) and the kneading and mixing step (C) may be the same as that in the kneading and mixing step (A), and therefore the description will be omitted. In addition, there is no particular restriction on the order in which each component is fed into the kneading and mixing means, but it is preferable to feed the diene rubber or modified diene rubber first, and then feed the other components. In addition, the method of feeding the other components is not particularly limited, but for example, when the component is a powder, the powder may be fed as it is, the component may be dissolved in a solvent and fed as a solution, and the component may be fed as an emulsion solution. In addition, the kneading and mixing in the kneading and mixing step (B) and the kneading and mixing step (C) are preferably kneaded in one stage for efficiency, but may be divided into multiple stages as necessary.

[0093] The kneading temperature in the kneading mixing step (B) and the kneading step (C) is preferably 80°C or more and 180°C or less, more preferably 100°C or more and 160°C or less. By adjusting the temperature within the above range, the diene rubber and the compound (1) can be reacted more reliably, and when the rubber composition contains a silane coupling agent, the filler and the silane coupling agent can interact more effectively and reliably. From the same viewpoint, the kneading time in the kneading mixing step (B) and the kneading step (C) is preferably 30 seconds or more and 600 seconds or less, more preferably 60 seconds or more and 300 seconds or less.

[0094] As the kneading means in the kneading step (D), the kneading machine exemplified in the kneading and mixing step (B) can be used. The kneading temperature in the kneading step (D) is preferably 100° C. or lower from the viewpoint of suppressing the progress of vulcanization.

[0095] In the second rubber composition manufacturing method of the present embodiment, other conditions than those described above may be known, and for example, the manufacturing method may have a mastication step of kneading the diene rubber alone prior to the kneading and mixing step (B). Furthermore, the compound (1) may be added in the mastication step.

[0096] The factors that enable this embodiment to solve the problem are considered to be as follows. However, the factors are not limited to these. In this embodiment, by using compound (1), compound (1) can easily react with the carbon-carbon double bond site in the main chain of the diene rubber to produce a modified diene rubber. This easy reactivity is considered to be due to compound (1) being a salt. By reacting compound (1) with the main chain of the diene rubber, the resulting modified diene rubber has many modifying groups derived from compound (1). The modifying group has multiple nitrogen atoms that have high affinity with the filler in different rings, so it is considered that the dispersibility of the filler in the rubber composition is increased. As a result, it is presumed that friction between the fillers is suppressed, resulting in an excellent low heat generation property.

[0097] Compound (1) can be used as a dispersant for fillers, a heat reducing agent, a heat preventing material, and a heat suppressant, and more specifically, can be used as a dispersant for rubber, a heat reducing agent for rubber, a heat preventing material for rubber, or a heat suppressant for rubber. The rubber composition of the present embodiment can be used, for example, in tires, anti-vibration rubber, conveyor belts, and rubber parts thereof. Among these, when the rubber composition of the present embodiment is used in tires, the grip of the tire is improved and the tire can also contribute to low fuel consumption, so it is preferable. EXAMPLES

[0098] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0099] Details of each component used in the following Examples and Comparative Examples are given below. Rubber component: 100 parts by weight, natural rubber, RSS#3 Vulcanization aid: 3 parts by weight, zinc oxide (zinc white), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. : 2 parts by weight, stearic acid, Fujifilm Wako Pure Chemical Industries, Ltd. Anti-aging agent: 2 parts by mass, N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Carbon black: 10 parts by weight, manufactured by Asahi Carbon Co., Ltd., product name "Asahi #70" Silica: 50 parts by weight, BET surface area = 207 m 2 / g, manufactured by Tosoh Silica Corporation, product name "Nipsil AQ" Silane coupling agent: 4 parts by mass, bis(triethoxysilylpropyl) disulfide, manufactured by Evonik Japan Co., Ltd. Vulcanizing agent: 1.5 parts by mass, sulfur, average particle size 250 μm, manufactured by Hosoi Chemical Industry Co., Ltd. : 1 part by mass, 1,3-diphenylguanidine, Fujifilm Wako Pure Chemical Industries, Ltd.

[0100] Example 1 (Synthesis of compound (1a)) Compound (1a) in which R1 is a hydrogen atom, R2 is a hydrogen atom, R3 is an ethyl group, the bonding site of the triazine ring in the pyridine ring is the 4-position relative to the nitrogen atom in the pyridine ring, and X is a bromide ion in the formula (1) was synthesized as follows. In a 100mL one-neck flask, 1.58g (0.01mol) of 4-cyanopyridine, 1.5 equivalents of bromoethane, and 10mL of methyl ethyl ketone were added, and a reflux condenser was attached and the mixture was heated and stirred at an external temperature of 80°C for 6 hours. The reaction solution was cooled to room temperature, and 30mL of isopropanol and 30mL of diethyl ether were added thereto to obtain a suspension. The suspension was filtered and washed with a small amount of chloroform, and then dried under reduced pressure to obtain 0.98g of compound (1a) as a brown powder. The structure of the obtained powder was analyzed by 1H-NMR, and the results were as follows. 1H-NMR(500MHz, CDCl3, δppm):9.80(d,J=6.5Hz,2H),9.47(d,J=2.0Hz,1H),9.19( d,J=6.5Hz,2H),8.97(d,J=2.5Hz,1H),5.26(q,J=7.5Hz,2H),1.83(t,J=7.5Hz,3H)

[0101] (Production of Rubber Composition) An unvulcanized rubber composition and a vulcanized rubber composition were prepared according to the following procedure. Mastication: Natural rubber was placed in a Banbury mixer (250 mL Labo Plastomill manufactured by Toyo Seiki Co., Ltd.; the same applies below) whose inside had been heated to 60°C, and kneaded at 60 rpm for 5 minutes. First kneading and mixing: The masticated rubber components were put into a Banbury mixer heated to 70°C, and kneading was started at a rotation speed of 100 rpm. After 30 seconds, the vulcanization aid, antiaging agent, carbon black, and 0.5 parts by mass of compound (1a) were added. After 30 seconds, half of the silica was added, and 60 seconds later, the remaining half of the silica sprinkled with a silane coupling agent was added. After that, the cylinder was opened for 1 minute when the rubber temperature reached 140°C. After sealing the cylinder again, kneading was performed until the rubber temperature reached 150°C to obtain a kneaded product. Second kneading and mixing: Using a 6-inch two-roll kneader (manufactured by Ikeda Kikai Kogyo Co., Ltd.), a vulcanizing agent and a vulcanization accelerator were added to the entire amount of the kneaded material obtained in the first kneading and mixing was carried out under conditions of a roll temperature of 30°C and a rotation speed of 25 rpm, and an unvulcanized rubber composition was obtained. Press vulcanization: The unvulcanized rubber composition was vulcanized for 4.5 minutes at 160° C. and 10 MPa using a hydraulic press (manufactured by Ohtake Machinery Co., Ltd.) to obtain a vulcanized rubber composition. The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 90. The rubber reinforcing property of the vulcanized rubber composition (affinity between rubber and filler) was evaluated as described below and found to be 102.

[0102] The progress of the reaction between compound (1a) and diene rubber was confirmed as follows. That is, 60 parts by mass of isoprene rubber (manufactured by JSR, product name "IR2000"), 40 parts by mass of styrene-butadiene rubber (manufactured by Nippon Zeon, product name "NS166"), 1 part by mass of compound (1a) and 10 parts by mass of silica were kneaded for 10 minutes in a Banbury mixer at 140°C. Acetone-insoluble matter was extracted from the kneaded mixture by Soxhlet extraction using acetone. The extract was 1 The compound (1a) was analyzed by H-HMR. As a result, it was confirmed that the peak of compound (1a) disappeared and a new peak appeared at 8 to 10 ppm. This indicated that an inverse electron demand Aza-Diels-Alder reaction had taken place between compound (1a) and the double bond of the rubber.

[0103] Example 2 (Synthesis of compound (1b)) Compound (1b) represented by formula (1), in which R1 is a hydrogen atom, R2 is a hydrogen atom, R3 is an n-propyl group, the bonding site of the triazine ring in the pyridine ring is the 4-position relative to the nitrogen atom in the pyridine ring, and X is a bromide ion, was synthesized as follows. In a 100mL one-neck flask, 1.58g (0.01mol) of 4-cyanopyridine, 3.0 equivalents of bromopropane, 3mL of water and 7mL of methyl ethyl ketone were added, and a reflux condenser was attached and stirred at an external temperature of 80°C for 12 hours. The reaction solution was cooled to room temperature, and 30mL of isopropanol and 30mL of diethyl ether were added thereto to obtain a suspension. The suspension was filtered and washed with a small amount of chloroform, and then dried under reduced pressure to obtain compound (1b) as 2.0g of brown powder. The structure of the obtained powder was analyzed by 1H-NMR, and the results were as follows. 1H-NMR(500MHz,DMSO-d6,δppm):9.68(d,J=2.5Hz,1H),9.35(d,J=6.5Hz,2H),9.21(d,J=2.5Hz ,1H),9.01(d,J=6.5Hz,1H),4.72(q,J=7.5Hz,2H),2.02(tq,J=7.5Hz,2H),0.94(t,J=7.5Hz,3H)

[0104] (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 1, except that compound (1a) was replaced with compound (1b). The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 87. In addition, the rubber reinforcing property (affinity between rubber and filler) of the vulcanized rubber composition was evaluated as described below and found to be 98.

[0105] Example 3 (Synthesis of compound (1c)) Compound (1c) represented by formula (1), in which R1 is a hydrogen atom, R2 is a hydrogen atom, R3 is an n-octyl group, the bonding site of the triazine ring in the pyridine ring is the 4-position relative to the nitrogen atom in the pyridine ring, and X is an iodide ion, was synthesized as follows. In a 100mL one-neck flask, 1.58g (0.01mol) of 4-cyanopyridine, 1.2 equivalents of octane iodide, and 10mL of methyl ethyl ketone were added, and the mixture was stirred for 6 hours at an external temperature of 100°C with a reflux condenser attached. The reaction solution was cooled to room temperature, and 10mL of isopropanol and 30mL of diethyl ether were added thereto to obtain a suspension. The suspension was filtered and washed with a small amount of chloroform, and then dried under reduced pressure to obtain compound (1c) as a brown powder of 1.39g. The structure of the obtained powder was analyzed by 1H-NMR. The results were as follows. 1H-NMR(500MHz, CDCl3, δppm):9.56(d,J=6.5Hz,2H),9.46(d,J=2.0Hz,1H),9.12(d,J=6.5Hz,2H),8.94( d,J=2.0Hz,1H),5.10(t,J=7.5Hz,2H),2.13(tq,J=7.5Hz,2H),1.58~1.24(m,10H),0.89(t,J=7.5Hz,3H)

[0106] (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 1, except that compound (1a) was replaced with compound (1c). The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 88. In addition, the rubber reinforcing property (affinity between rubber and filler) of the vulcanized rubber composition was evaluated as described below and found to be 101.

[0107] Example 4 (Synthesis of compound (1d)) Compound (1d) represented by formula (1), in which R1 is a hydrogen atom, R2 is a hydrogen atom, R3 is a methyl group, the bonding site of the triazine ring in the pyridine ring is the 3-position relative to the nitrogen atom in the pyridine ring, and X is an iodide ion, was synthesized as follows. In a 100mL one-neck flask, 1.58g (0.01mol) of 3-cyanopyridine, 1.2 equivalents of methyl iodide, and 10mL of methyl ethyl ketone were added, and a reflux condenser was attached and stirred at an external temperature of 80°C for 4 hours to obtain a suspension. This suspension was filtered and washed with a small amount of chloroform, and then dried under reduced pressure to obtain compound (1d) as 2.79g of a brown powder. The structure of the obtained powder was analyzed by 1H-NMR, and the results were as follows. 1H-NMR(500MHz,DMSO-d6,δppm):9.96(bs,1H),9.64(d,J=2.5Hz,1H),9.42(d,J=8.0Hz,1 H),9.21(d,J=6.0Hz,1H),9.16(d,J=2.5Hz,1H),8.36(dd,J=8.0,6.5Hz,1H),4.53(s,3H)

[0108] (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 1, except that compound (1a) was changed to compound (1d). The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 91. In addition, the reinforcing property of the rubber of the vulcanized rubber composition (affinity between rubber and filler) was evaluated as described below and found to be 104.

[0109] Example 5 (Synthesis of compound (1e)) Compound (1e) represented by formula (1), in which R1 is a hydrogen atom, R2 is a hydrogen atom, R3 is an ethoxycarbonylmethyl group (-CH2COOC2H5), the bonding site of the triazine ring in the pyridine ring is the 4-position relative to the nitrogen atom in the pyridine ring, and X is a chloride ion, was synthesized as follows. In a 100mL one-neck flask, 1.58g (0.01mol) of 4-cyanopyridine, 1.5 equivalents of ethyl chloroacetate, 9mL of toluene and 1mL of butanol were added, and a reflux condenser was attached and the mixture was stirred at an external temperature of 110°C for 6 hours to obtain a suspension. This suspension was filtered and washed with a small amount of chloroform, and then dried under reduced pressure to obtain the title compound (1e) as 1.34g of a brown powder. The structure of the obtained powder was analyzed by 1H-NMR, and the results were as follows. 1H-NMR(500MHz,DMSO-d6,δppm):9.69(d,J=2.5Hz,1H),9.41(d,J=6.5Hz,2H),9.23(d,J=2 .5Hz,1H),9.10(d,J=6.5Hz,2H),5.95(s,2H),4.28(q,J=7.0Hz,2H),1.29(t,J=7.0Hz,3H)

[0110] (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 1, except that compound (1a) was replaced with compound (1e). The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 89. In addition, the reinforcing property of the rubber of the vulcanized rubber composition (affinity between rubber and filler) was evaluated as described below and found to be 107.

[0111] Example 6 (Synthesis of compound (1f)) Compound (1f) in which R1 is a hydrogen atom, R2 is a hydrogen atom, R3 is an acetamide group (-CH2CONH2), the binding site of the triazine ring in the pyridine ring is the 4-position relative to the nitrogen atom in the pyridine ring, and X is a chloride ion in the formula (1) was synthesized as follows. In a 100mL one-neck flask, 1.58g (0.01mol) of 4-cyanopyridine, 1.5 equivalents of chloroacetic acid amide, 3mL of water and 7mL of methyl ethyl ketone were added, and the mixture was stirred for 6 hours at an external temperature of 100°C with a reflux condenser attached. The reaction solution was cooled to room temperature, and 100mL of isopropanol and 20mL of diethyl ether were added to obtain a suspension. The suspension was filtered and washed with a small amount of chloroform, and then dried under reduced pressure to obtain compound (1f) as 2.47g of brown powder. The structure of the obtained powder was analyzed by 1H-NMR, and the results were as follows. 1H-NMR(500MHz,DMSO-d6,δppm):9.67(d,J=2.5Hz,1H),9.24(d,J=6.0Hz,2H),9.2 1(d,J=2.5Hz,1H),9.02(d,J=7.0Hz,2H),8.28(bs,1H),7.77(bs,1H),5.61(s,2H)

[0112] (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 1, except that compound (1a) was replaced with compound (1f). The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 87. In addition, the rubber reinforcing property (affinity between rubber and filler) of the vulcanized rubber composition was evaluated as described below and found to be 110.

[0113] Example 7 (Synthesis of compound (1g)) Compound (1g) represented by formula (1), in which R1 is a hydrogen atom, R2 is a hydrogen atom, R3 is an ethoxycarbonylmethyl group (-CH2COOC2H5), the bonding site of the triazine ring in the pyridine ring is the 3rd position relative to the nitrogen atom in the pyridine ring, and X is a chloride ion, was synthesized as follows. In a 100mL one-neck flask, 1.58g (0.01mol) of 3-cyanopyridine, 1.5 equivalents of ethyl chloroacetate, 9mL of toluene and 1mL of acetonitrile were added, and the mixture was stirred for 6 hours at an external temperature of 100°C with a reflux condenser attached. The reaction solution was cooled to room temperature, and 100mL of isopropanol and 20mL of diethyl ether were added to obtain a suspension. The suspension was filtered and washed with a small amount of chloroform, and then dried under reduced pressure to obtain compound (1g) as 1.49g of brown powder. The structure of the obtained powder was analyzed by 1H-NMR, and the results were as follows. 1H-NMR(500MHz,D2O,δppm):9.82(bs,1H),9.51(d,8.0Hz,1H),9.39(d,2.5Hz,1H),9.00(m,2H),8.31(dd,8.0 Hz,6.0Hz,1H),5.67(s,2H),4.28(q,7.0Hz,2H),1.10(t,7.0Hz,3H)

[0114] (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 1, except that compound (1a) was replaced with compound (1g). The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 89. In addition, the rubber reinforcing property (affinity between rubber and filler) of the vulcanized rubber composition was evaluated as described below and found to be 100.

[0115] Example 8 (Synthesis of compound (1h)) Compound (1h) represented by formula (1), in which R1 is a hydrogen atom, R2 is a hydrogen atom, R3 is a 2-butanol group (-CHCH(OH)CH), the binding site of the triazine ring in the pyridine ring is the 3-position relative to the nitrogen atom in the pyridine ring, and X is an acetate ion, was synthesized as follows. In a 100mL one-neck flask, 1.58g (0.01mol) of 3-cyanopyridine, 1.5 equivalents of butylene oxide, and 20mL of acetic acid were added and stirred at room temperature overnight. The solvent of this reaction solution was distilled off, washed with a small amount of diethyl ether, and then dried under reduced pressure to obtain compound (1h) as 2.46g of brown oil. The structure of the obtained compound was analyzed by 1H-NMR, and the results were as follows. 1H-NMR(500MHz,D2O,δppm):(s,1H),9.51(d,8.5Hz,1H),9.47(d,2.0Hz,1H),9.09(d,2.0Hz,1H),9.06(d,6.0Hz,1H),8.33(d d,8.0,6.0Hz,1H),4.98(dd,13.5,3.0Hz,1H),4.59(dd,13.5,3.0Hz,1H),4.08(m,1H),1.88(s,3H),1.60(m,2H),0.90(m,3H)

[0116] (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 1, except that compound (1a) was replaced with compound (1h). The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 82. In addition, the rubber reinforcing property (affinity between rubber and filler) of the vulcanized rubber composition was evaluated as described below and found to be 108.

[0117] Example 9 (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 6, except that compound (1f) was added in the mastication step before the first kneading and mixing. The heat generation property of the obtained vulcanized rubber composition was evaluated as described below and found to be 87. In addition, the reinforcing property of the rubber of the vulcanized rubber composition (affinity between rubber and filler) was evaluated as described below and found to be 108.

[0118] Comparative Example 1 (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 1, except that the compound (1a) was not used. The heat generation property of the obtained vulcanized rubber composition was evaluated as described below, and was found to be 100. In addition, the reinforcing property of the rubber of the vulcanized rubber composition (affinity between the rubber and the filler) was evaluated as described below, and was found to be 100.

[0119] Comparative Example 2 (Production of Rubber Composition) A vulcanized rubber composition was obtained in the same manner as in Example 1, except that compound (1a) was changed to 3-(4-pyridyl)-1,2,4-triazine (hereinafter referred to as "compound (1i)"). The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 100. In addition, the rubber reinforcing property of the vulcanized rubber composition (affinity between rubber and filler) was evaluated as described below and found to be 91.

[0120] In addition, whether or not the reaction between compound (1i) and diene rubber proceeded was confirmed in the same manner as in Example 1. As a result, it was confirmed that the peak of compound (1i) remained without disappearing, which revealed that the reaction between compound (1i) and rubber did not proceed.

[0121] Comparative Example 3 A vulcanized rubber composition was obtained in the same manner as in Example 1, except that compound (1a) was changed to 3,6-di(2-pyridyl)-1,2,4,5-tetrazine (hereinafter referred to as "compound (1j)"). The heat buildup of the obtained vulcanized rubber composition was evaluated as described below and found to be 98. In addition, the rubber reinforcing property of the vulcanized rubber composition (affinity between rubber and filler) was evaluated as described below and found to be 103.

[0122] In addition, whether or not the reaction between compound (1j) and diene rubber proceeded was confirmed in the same manner as in Example 1. As a result, it was confirmed that the peak of compound (1j) disappeared, which revealed that the inverse electron demand type Aza-Diels-Alder reaction between compound (1j) and the double bond of the rubber proceeded.

[0123] (Evaluation of heat generation) For each vulcanized rubber composition, a dynamic viscoelasticity measuring device (manufactured by Seiko Instruments Inc., product name "DMS6100") was used to measure the loss tangent (tan δ) at a temperature of 60°C, a dynamic strain of 0.5%, and a frequency of 10 Hz. The loss tangent value in Comparative Example 1 was set to 100, and the results were evaluated as a relative value. The smaller the value, the lower the tan δ, indicating that the rubber composition has low heat buildup.

[0124] (Evaluation of rubber reinforcement) For each vulcanized rubber composition, a dynamic viscoelasticity measuring device (manufactured by Seiko Instruments Inc., product name "DMS6100") was used to measure the loss tangent (tan δ) at the glass transition temperature of the vulcanized rubber composition, with a dynamic strain of 0.5% and a frequency of 10 Hz. The loss tangent value in Comparative Example 1 was set at 100, and the results were evaluated as a relative value. The larger the value, the higher the tan δ, indicating a higher affinity between the filler and the rubber in the rubber composition and a higher reinforcing property of the rubber. [Industrial Applicability]

[0125] According to the present invention, it is possible to provide a compound that can be used as a dispersant for fillers, a heat reducing agent, a heat preventing material, and a heat suppressant, more specifically, a dispersant for rubber, a heat reducing agent for rubber, a heat preventing material for rubber, or a heat suppressant for rubber. Furthermore, according to the present invention, it is possible to provide a rubber composition that can be used for tires, anti-vibration rubber, conveyor belts, and rubber parts thereof. Therefore, there is industrial applicability in these fields.

Claims

1. The present invention includes a compound represented by the following formula (1), a diene rubber, and a filler, The filler includes at least one selected from the group consisting of inorganic fillers and carbon black. Rubber composition. 【Chemistry 1】 (In formula (1), X represents an anion that forms a salt with pyridinium, and L represents CR 2 or a nitrogen atom, R 1 and R 2 each independently represents a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a monovalent heterocyclic group, each of which may have a substituent; R 3 represents an alkyl group, an aryl group, an aralkyl group, or an alkenyl group, which may have one or more substituents selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom.

2. The rubber composition according to claim 1 , wherein the compound is a compound represented by the following formula (2): 【Chemistry 2】 (In formula (2), X represents an anion that forms a salt with pyridinium, and L represents CR 2 or a nitrogen atom, R 1 and R 2 each independently represents a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a monovalent heterocyclic group, each of which may have a substituent; R 7 represents a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, or an alkenyl group, which may have one or more groups selected from the group consisting of a hydroxy group, an alkoxy group, an acyl group, an amino group, an amido group, an epoxy group, a sulfanyl group, and an alkylsulfanyl group.

3. The rubber composition according to claim 1 , wherein the compound is a compound represented by the following formula (3): 【Chemistry 3】 (In formula (3), X represents an anion that forms a salt with pyridinium, and L represents CR 2 or a nitrogen atom, R 1 and R 2 each independently represents a hydrogen atom, or an optionally substituted alkyl group, aryl group, aralkyl group, alkenyl group, or monovalent heterocyclic group; Z represents an oxygen atom, a sulfur atom, an alkylene group, or -NR 6 R represents a group represented by -; 5 and R 6 each independently represents a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, or an alkenyl group which may have one or more groups selected from the group consisting of a hydroxy group, an alkoxy group, an acyl group, an amino group, an amido group, an epoxy group, a sulfanyl group, and an alkylsulfanyl group.

4. The Z is -NR 6 The rubber composition according to claim 3, wherein the R 1 -R 2 group is a group represented by the formula:

5. The R 1 and R 2 The rubber composition according to any one of claims 1 to 4, wherein is a hydrogen atom.

6. The rubber composition according to any one of claims 1 to 5, wherein the diene rubber comprises at least one selected from the group consisting of styrene-butadiene rubber, butadiene rubber, isoprene rubber and natural rubber.

7. The rubber composition according to any one of claims 1 to 6, wherein the filler comprises at least one selected from the group consisting of carbon black and silica.

8. The rubber composition according to any one of claims 1 to 7, further comprising a silane coupling agent.

9. The rubber composition according to any one of claims 1 to 8, further comprising sulfur and a vulcanization accelerator.

10. A modified diene rubber having a modifying group represented by the following formula (4a), (4b), (4c), (4d), (4e), (4f), (4g), (4h), (4i), (4j) or (4k). 【Chemistry 4】 (In each formula, X represents an anion that forms a salt with pyridinium, and L represents CR 2 or a nitrogen atom, R 1 and R 2 each independently represents a hydrogen atom, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a monovalent heterocyclic group, each of which may have a substituent; R 3 represents an alkyl group, an aryl group, an aralkyl group, or an alkenyl group, which may have one or more substituents selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom; R represents a halogen atom or an alkyl group; and the wavy line represents a bonding site of the diene rubber with the modifying group.

11. The R 1 and R 2 The modified diene rubber according to claim 10, wherein each of the is independently a hydrogen atom or a methyl group.

12. The modified diene rubber according to claim 10 or 11 and a filler, The filler includes at least one selected from the group consisting of inorganic fillers and carbon black. Rubber composition.

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