Additives used to impart low heat generation properties to rubber components

Abstract

This application relates to additives for imparting low heat generation properties to rubber components. The additive, which is used to impart low heat generation properties to rubber components, contains a tetrazine compound or a salt thereof represented by the following general formula (1). Wherein, X... 1 and X 2 "Same" or "different" refers to a hydrogen atom, alkyl, alkylthio, aralkyl, aryl, arylthio, heterocyclic, or amino group. Each of the above groups may have more than one substituent.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 201680054491.5 (international application No. PCT / JP2016 / 079170), filed on September 30, 2016, entitled "Additive for imparting low heat generation properties to rubber components". Technical Field

[0002] This invention relates to additives for imparting low heat generation properties to rubber components. Background Technology

[0003] In recent years, due to environmental concerns, global restrictions on carbon dioxide emissions have become increasingly stringent, leading to a high demand for fuel-efficient automobiles. The efficiency of the engine and other drive and transmission systems contributes significantly to fuel efficiency, and is also closely related to tire rolling resistance. Therefore, reducing rolling resistance is crucial for achieving fuel-efficient automobiles.

[0004] As a method to reduce the rolling resistance of tires, it is known to use a rubber composition with low heat generation in tires. Examples of such low heat generation rubber compositions include: (1) a rubber composition containing a functionalized polymer that improves the affinity with carbon black and silica as filler materials (Patent Document 1); (2) a rubber composition containing a diene elastomer, an inorganic filler as a reinforcing filler, a polysulfide alkoxysilane as a coupling agent, 1,2-dihydropyridine and a guanidine derivative (Patent Document 2); (3) a rubber composition containing a rubber component, an aminopyridine derivative and an inorganic filler material (Patent Document 3); (4) a rubber composition containing a terminal modified polymer and an inorganic filler (Patent Documents 4 and 5), etc.

[0005] According to the inventions described in these patent documents 1 to 5, by increasing the affinity between the filler material and the rubber component, the heat generation of the rubber composition can be reduced, resulting in a tire with low hysteresis loss (rolling resistance).

[0006] However, even with the use of the rubber compositions described in these patent documents 1-5, the improvement in low heat generation is still insufficient.

[0007] Expectations for fuel-efficient automobiles are rising, with a strong desire to develop tires with excellent low heat generation.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2003-514079

[0011] Patent Document 2: Japanese Patent Publication No. 2003-523472

[0012] Patent Document 3: Japanese Patent Application Publication No. 2013-108004

[0013] Patent Document 4: Japanese Patent Application Publication No. 2000-169631

[0014] Patent Document 5: Japanese Patent Application Publication No. 2005-220323 Summary of the Invention

[0015] The problem that the invention aims to solve

[0016] The object of this invention is to provide an additive for imparting low heat generation properties to rubber components.

[0017] Another object of the present invention is to provide a rubber composition that exhibits low heat generation.

[0018] Another object of the present invention is to provide a modified polymer capable of imparting low heat generation.

[0019] Another object of the present invention is to provide a tire with excellent low heat generation properties.

[0020] Methods for solving problems

[0021] To address the aforementioned issues, the inventors of this application conducted repeated and in-depth research, discovering that tetrazine compounds can impart low-heat properties to rubber components. Based on this insight, the inventors of this application further explored the subject matter, resulting in the completion of this invention.

[0022] That is, the present invention provides additives, modified polymers, rubber compositions, methods for manufacturing the rubber compositions, and tires for imparting low heat generation properties to rubber components, as described below.

[0023] Invention 1.

[0024] An additive, which is used to impart low heat generation to rubber components, wherein it contains a tetrazine compound or a salt thereof as shown in the following general formula (1).

[0025] [Chemical Formula 1]

[0026]

[0027] [In the formula, X] 1 and X 2 "Same" or "different" refers to a hydrogen atom, alkyl, alkylthio, aralkyl, aryl, arylthio, heterocyclic, or amino group. Each of these groups may have one or more substituents.

[0028] Invention 2.

[0029] The additive as described in Invention 1, wherein X1 and X 2 It is a heterocyclic group.

[0030] Invention 3.

[0031] The additive as described in Invention 2, wherein the heterocyclic group is pyridyl or furanyl.

[0032] Invention 4.

[0033] The additive as described in Invention 2, wherein the heterocyclic group is 2-pyridinyl or 3-pyridinyl.

[0034] Invention 5.

[0035] The additive as described in any one of inventions 1 to 4, wherein the rubber component is a diene rubber.

[0036] Invention 6.

[0037] A modified polymer, which is prepared using a rubber mixture containing a rubber component and an additive as described in any one of inventions 1 to 5.

[0038] Invention 7.

[0039] The modified polymer as described in Invention 6, wherein the rubber component is a diene rubber.

[0040] Invention 8.

[0041] A modified polymer is a modified polymer obtained by treating diene rubber with any one of the additives described in any one of inventions 1 to 5.

[0042] Invention 9.

[0043] A modified polymer obtained by treating diene rubber with any one of the additives described in any one of inventions 1 to 5.

[0044] Invention 10.

[0045] The modified polymer as described in any one of inventions 7 to 9, wherein the diene rubber is natural rubber and / or synthetic diene rubber.

[0046] Invention 11.

[0047] The modified polymer as described in Invention 10, wherein the synthetic diene rubber is selected from at least one of styrene-butadiene copolymer rubber, butadiene rubber, isoprene rubber, nitrile rubber, chloroprene rubber, ethylene-propylene-diene terpolymer rubber, styrene-isoprene-styrene terblock copolymer rubber, and styrene-butadiene-styrene terblock copolymer rubber.

[0048] Invention 12.

[0049] The modified polymer as described in Invention 10, wherein the diene rubber is selected from at least one of natural rubber, isoprene rubber, styrene-butadiene copolymer rubber and butadiene rubber.

[0050] Invention 13.

[0051] The modified polymer as described in invention 11 or 12, wherein 100 parts by weight of the rubber component contains 50 to 100 parts by weight of at least one rubber selected from styrene-butadiene copolymer rubber and butadiene rubber.

[0052] Invention 14.

[0053] The modified polymer as described in any one of inventions 11 to 13, wherein 100 parts by weight of the rubber component contains 75 to 100 parts by weight of at least one rubber selected from styrene-butadiene copolymer rubber and butadiene rubber.

[0054] Invention 15.

[0055] A modified polymer having at least one of the compound structures selected from those shown in formulas (2) to (12) below.

[0056] [Chemical Formula 2]

[0057]

[0058] [In the formula, X] 1 and X 2 X in Invention 1 1 and X 2 Same here, R represents a halogen atom or an alkyl group.

[0059] Invention 16.

[0060] A rubber composition comprising: a rubber component; an additive as described in any one of inventions 1 to 5; and an inorganic filler and / or carbon black.

[0061] Invention 17.

[0062] A rubber composition comprising: the modified polymer described in any one of inventions 6 to 15; and an inorganic filler and / or carbon black.

[0063] Invention 18.

[0064] The rubber composition as described in invention 16 or 17, wherein, relative to 100 parts by weight of the rubber component, contains 0.1 to 10 parts by weight of the additive described in any one of inventions 1 to 5.

[0065] Invention 19.

[0066] The rubber composition as described in any one of inventions 16 to 18, wherein the inorganic filler contains silicon dioxide.

[0067] Invention 20.

[0068] The rubber composition as described in Invention 19, wherein 20 to 120 parts by mass of silicon dioxide are contained relative to 100 parts by mass of the rubber component.

[0069] Invention 21.

[0070] The rubber composition as described in Invention 19, wherein 40 to 120 parts by mass of silica are contained relative to 100 parts by mass of rubber components.

[0071] Invention 22.

[0072] The rubber composition as described in any one of inventions 16 to 21, wherein the rubber component is a diene rubber.

[0073] Invention 23.

[0074] The rubber composition as described in Invention 22, wherein the diene rubber is natural rubber and / or synthetic diene rubber.

[0075] Invention 24.

[0076] The rubber composition of the present invention 23, wherein the synthetic diene rubber is selected from at least one of styrene-butadiene copolymer rubber, butadiene rubber, isoprene rubber, nitrile rubber, chloroprene rubber, ethylene-propylene-diene terpolymer rubber, styrene-isoprene-styrene terblock copolymer rubber and styrene-butadiene-styrene terblock copolymer rubber.

[0077] Invention 25.

[0078] The rubber composition of the present invention 23, wherein the diene rubber is selected from at least one of natural rubber, isoprene rubber, styrene-butadiene copolymer rubber and butadiene rubber.

[0079] Invention 26.

[0080] The rubber composition as described in invention 24 or 25, wherein 100 parts by weight of the rubber component contains 50 to 100 parts by weight of at least one rubber selected from styrene-butadiene copolymer rubber and butadiene rubber.

[0081] Invention 27.

[0082] The rubber composition of invention 24 or 25, wherein 100 parts by weight of the rubber component contains 75 to 100 parts by weight of at least one rubber selected from styrene-butadiene copolymer rubber and butadiene rubber.

[0083] Invention 28.

[0084] A rubber composition, wherein 100 parts by weight of the rubber component contains: 50 to 100 parts by weight of styrene-butadiene copolymer rubber and / or butadiene rubber, 20 to 120 parts by weight of silica, and 0.1 to 10 parts by weight of the additives described in any one of inventions 1 to 5.

[0085] Invention 29.

[0086] A rubber composition, wherein 100 parts by weight of the rubber component contains: 75 to 100 parts by weight of styrene-butadiene copolymer rubber and / or butadiene rubber, 20 to 120 parts by weight of silica, and 0.1 to 10 parts by weight of the additives described in any one of inventions 1 to 5.

[0087] Invention 30.

[0088] The rubber composition as described in any one of inventions 16 to 29 is used in at least one component selected from the tread, sidewall, bead area, belt, carcass, and shoulder.

[0089] Invention 31.

[0090] The rubber composition as described in any one of inventions 16 to 29 is used for at least one component selected from the outer tire face and the tire sidewall.

[0091] Invention 32.

[0092] The rubber composition as described in any one of inventions 16 to 29 is used for components of the outer tire face.

[0093] Invention 33.

[0094] Tires made using any one of the rubber compositions described in inventions 16 to 29.

[0095] Invention 34.

[0096] A method for manufacturing a rubber composition, comprising the following steps: step (A), mixing raw material components containing rubber components, additives as described in any one of inventions 1 to 5, and inorganic fillers and / or carbon black; and step (B), mixing the mixture obtained in step (A) with a vulcanizing agent.

[0097] Invention 35.

[0098] The manufacturing method as described in invention 34, wherein step (A) includes: step (A-1), mixing the rubber component and the additives described in any one of inventions 1 to 5; and step (A-2), mixing the mixture obtained in step (A-1), the inorganic filler material and / or carbon black.

[0099] Invention 36.

[0100] Dispersant containing a tetrazine compound or a salt thereof as shown in general formula (1).

[0101] [Chemical Formula 3]

[0102]

[0103] [In the formula, X] 1 and X 2 "Same" or "different" refers to a hydrogen atom, alkyl, alkylthio, aralkyl, aryl, arylthio, heterocyclic, or amino group. Each of these groups may have one or more substituents.

[0104] Invention 37.

[0105] Low-temperature oxidizing agent, which contains a tetrazine compound or a salt thereof as shown in general formula (1).

[0106] [Chemical Formula 4]

[0107]

[0108] [In the formula, X] 1 and X 2 "Same" or "different" refers to a hydrogen atom, alkyl, alkylthio, aralkyl, aryl, arylthio, heterocyclic, or amino group. Each of these groups may have one or more substituents.

[0109] Invention 38.

[0110] Fever preventive agents containing a tetrazine compound or a salt thereof as shown in general formula (1).

[0111] [Chemical Formula 5]

[0112]

[0113] [In the formula, X] 1 and X 2 "Same" or "different" refers to a hydrogen atom, alkyl, alkylthio, aralkyl, aryl, arylthio, heterocyclic, or amino group. Each of these groups may have one or more substituents.

[0114] Invention 39.

[0115] Fever suppressant containing a tetrazine compound or a salt thereof as shown in general formula (1).

[0116] [Chemical Formula 6]

[0117]

[0118] [In the formula, X] 1 and X 2 "Same" or "different" refers to a hydrogen atom, alkyl, alkylthio, aralkyl, aryl, arylthio, heterocyclic, or amino group. Each of these groups may have one or more substituents.

[0119] The effects of the invention

[0120] This invention provides an additive for imparting low heat generation properties to rubber components. The additive contains a tetrazine compound, and with this additive, inorganic fillers and / or carbon black are dispersed in the rubber component.

[0121] The present invention can provide rubber compositions that exhibit low heat generation properties, and modified polymers that impart low heat generation properties.

[0122] This invention reduces tire rolling resistance and heat generation by using a rubber composition exhibiting low heat generation, thus providing a low-fuel-consumption tire. Furthermore, even rubber compositions heavily filled with silica exhibit high low heat generation, thus providing a low-fuel-consumption tire with high performance characteristics. Attached Figure Description

[0123] [ Figure 1 Tetraazine compound (1b) 13 C-NMR spectrum.

[0124] [ Figure 2 S-SBR 13 C-NMR spectrum.

[0125] [ Figure 3 ] Figure 2 Enlarged image.

[0126] [ Figure 4 Modified S-SBR obtained by modification with tetrazine compound (1b) 13 C-NMR spectrum.

[0127] [ Figure 5 ] Figure 4 Enlarged image.

[0128] [ Figure 6 [Regarding tetrazine compounds (1b), S-SBR and modified S-SBR] 13 A graph comparing C-NMR images. Detailed Implementation

[0129] The present invention will now be described in detail.

[0130] 1. An additive used to impart low heat generation properties to rubber components.

[0131] The additive of the present invention for imparting low heat generation to rubber components (hereinafter, sometimes referred to as "the additive of the present invention") contains a compound or a salt thereof represented by the following general formula (1).

[0132] [Chemical Formula 7]

[0133]

[0134] [In the formula, X] 1 and X 2 "Same" or "different" refers to a hydrogen atom, alkyl, alkylthio, aralkyl, aryl, arylthio, heterocyclic, or amino group. Each of these groups may have one or more substituents.

[0135] In this specification, the term "alkyl" is not particularly limited and can include, for example, straight-chain, branched, or cyclic alkyl groups. Specifically, examples include straight-chain or branched alkyl groups with 1 to 6 carbons (especially 1 to 4 carbons), such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 1-ethylpropyl, n-pentyl, neopentyl, n-hexyl, isohexyl, and 3-methylpentyl; and cyclic alkyl groups with 3 to 8 carbons (especially 3 to 6 carbons), such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Preferred alkyl groups are straight-chain or branched alkyl groups with 1 to 6 carbons, more preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or n-pentyl, and particularly preferably methyl or ethyl.

[0136] In this specification, the term "alkathioyl" is not particularly limited and can include, for example, linear, branched, or cyclic alkathioyl groups. Specifically, examples include linear or branched alkathioyl groups with 1 to 6 carbons (especially 1 to 4 carbons), such as methylthioyl, ethylthioyl, n-propylthioyl, isopropylthioyl, n-butylthioyl, isobutylthioyl, sec-butylthioyl, tert-butylthioyl, 1-ethylpropylthioyl, n-pentylthioyl, neopentylthioyl, n-hexylthio, isohexylthioyl, and 3-methylpentylthioyl; and cyclic alkathioyl groups with 3 to 8 carbons (especially 3 to 6 carbons), such as cyclopropylthioyl, cyclobutylthioyl, cyclopentylthioyl, cyclohexylthioyl, cycloheptylthioyl, and cyclooctylthioyl. Preferred alkathioyl groups are methylthioyl, ethylthioyl, isopropylthio, or isobutylthioyl, with methylthio or ethylthio being more preferred.

[0137] In this specification, the term "aralkyl group" is not specifically limited, and examples include benzyl, phenethyl, triphenylmethyl, 1-naphthylmethyl, 2-(1-naphthyl)ethyl, 2-(2-naphthyl)ethyl, etc. More preferably, benzyl or phenethyl, and even more preferably, benzyl.

[0138] In this specification, the term "aryl" is not specifically limited and can include, for example, phenyl, biphenyl, naphthyl, dihydroindene, 9H-fluorenyl, etc. More preferably, phenyl or naphthyl, and even more preferably phenyl.

[0139] In this specification, the term "aryl thio" is not specifically limited, and examples include phenyl thio, biphenyl thio, naphthyl thio, etc.

[0140] In this specification, the term "heterocyclic group" is not specifically limited, and examples include 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrazinyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 3-pyridazinyl, 4-pyridazinyl, 4-(1,2,3-triazinyl), 5-(1,2,3-triazinyl), 2-(1,3,5-triazinyl), 3-(1,2,4-triazinyl), 5-(1,2,4-triazinyl), 6-(1,2,4-triazinyl), 2-quinolinyl, 3-quinolinyl, 4-quinolinyl, 5-quinolinyl, 6-quinolinyl, 7-quinolinyl, 8-quinolinyl, 1-isoquinolinyl, 3- Isoquinolinyl, 4-isoquinolinyl, 5-isoquinolinyl, 6-isoquinolinyl, 7-isoquinolinyl, 8-isoquinolinyl, 2-quinoxalinyl, 3-quinoxalinyl, 5-quinoxalinyl, 6-quinoxalinyl, 7-quinoxalinyl, 8-quinoxalinyl, 3-benzolinyl, 4-benzolinyl, 5-benzolinyl, 6-benzolinyl, 7-benzolinyl, 8-benzolinyl, 2-quinazolinyl, 4-quinazolinyl, 5-quinazolinyl, 6-quinazolinyl, 7-quinazolinyl, 8-quinazolinyl, 1-phthalazyl, 4-phthalazyl, 5-phthalazyl, 6-phthalazyl, 7-phthalazyl, 8-phthalazyl, 1-tetrahydroquinolinyl, 2-tetrahydroquinolinyl, 3 -Tetrahydroquinolinyl, 4-Tetrahydroquinolinyl, 5-Tetrahydroquinolinyl, 6-Tetrahydroquinolinyl, 7-Tetrahydroquinolinyl, 8-Tetrahydroquinolinyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-furanyl, 3-furanyl, 2-thienyl, 3-thienyl, 1-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl, 1-pyrazolyl, 3-pyrazolyl, 4-pyrazolyl, 5-pyrazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl 4-(1,2,3-thiadiazolyl), 5-(1,2,3-thiadiazolyl), 3-(1,2,5-thiadiazolyl), 2-(1,3,4-thiadiazolyl), 4-(1,2,3-oxadiazolyl), 5-(1,2,3-oxadiazolyl), 3-(1,2,4-oxadiazolyl), 5-(1,2,4-oxadiazolyl), 3-(1,2,5-oxadiazolyl), 2-(1,3,4-oxadiazolyl), 1-(1,2,3-triazolyl), 4-(1,2,3-triazolyl), 5-(1,2,3-triazolyl), 1-(1,2,4-triazolyl), 3-(1,2,4-triazolyl), 5-(1,2,3-triazolyl), 1-(1,2,4-triazolyl), 3-(1,2,4-triazolyl), 5-(1,2,3-thiadiazolyl), 1-(1,2,4-triazolyl), 3-(1,2,4-triazolyl), 5-(1,2,3-thiadiazolyl), 1-(1,2,4-triazolyl), 1-(1,2,4-triazolyl), 1-(1,2,4-triazolyl), 1-(1,2,4-triazolyl), 1-(1,2,3-thiadi ...4-Triazolyl), 1-Tetraazolyl, 5-Tetraazolyl, 1-Indoleyl, 2-Indoleyl, 3-Indoleyl, 4-Indoleyl, 5-Indoleyl, 6-Indoleyl, 7-Indoleyl, 1-Isoindoleyl, 2-Isoindoleyl, 3-Isoindoleyl, 4-Isoindoleyl, 5-Isoindoleyl, 6-Isoindoleyl, 7-Isoindoleyl, 1-Benzimidazolyl, 2-Benzimidazolyl, 4-Benzimidazolyl, 5-Benzimidazolyl, 6-Benzimidazolyl, 7- Benzimidazolyl, 2-benzofuranyl, 3-benzofuranyl, 4-benzofuranyl, 5-benzofuranyl, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-isobenzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-isobenzofuranyl, 7-isobenzofuranyl, 2-benzothiamyl, 3-benzothiamyl, 4-benzothiamyl, 5-benzothiamyl, 6-benzothiamyl, 7-benzothiamyl Thionyl, 2-benzoxazolyl, 4-benzoxazolyl, 5-benzoxazolyl, 6-benzoxazolyl, 7-benzoxazolyl, 2-benzothiazolyl, 4-benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl, 1-indazolel, 3-indazolel, 4-indazolel, 5-indazolel, 6-indazolel, 7-indazolel, 2-morpholyl, 3-morpholyl, 4-morpholyl, 1-piperazolyl The heterocyclic groups include piperazyl, 2-piperazyl, 1-piperidinyl, 2-piperidinyl, 3-piperidinyl, 4-piperidinyl, 2-tetrahydropyranyl, 3-tetrahydropyranyl, 4-tetrahydropyranyl, 2-tetrahydrothiopyranyl, 3-tetrahydrothiopyranyl, 4-tetrahydrothiopyranyl, 1-pyrrolidinyl, 2-pyrrolidinyl, 3-pyrrolidinyl, 2-tetrahydrofuranyl, 3-tetrahydrofuranyl, 2-tetrahydrothiopyranyl, 3-tetrahydrothiopyranyl, etc. Among these, preferred heterocyclic groups are pyridinyl, furanyl, thiopyrimidyl, pyrazyl, or pyrazyl, with pyridinyl being more preferred.

[0141] In this specification, "amino" includes not only the amino group represented by -NH2, but also monoalkylamino groups such as methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino, isobutylamino, sec-butylamino, tert-butylamino, 1-ethylpropylamino, n-pentylamino, neopentylamino, n-hexylamino, isohexylamino, 3-methylpentylamino, etc., which are straight-chain or branched monoalkylamino groups having 1 to 6 carbons (especially 1 to 4 carbons); and dialkylamino groups having 2 alkyl groups such as dimethylamino, ethylmethylamino, diethylamino, etc., which are straight-chain or branched dialkylamino groups having 1 to 6 carbons (especially 1 to 4 carbons).

[0142] Each of these alkyl, alkylthio, aralkyl, aryl, arylthio, heterocyclic, and amino groups may have one or more substituents. The term "substituent" is not particularly limited, and examples include halogen atoms, amino groups, aminoalkyl groups, alkoxycarbonyl groups, acyl groups, acyloxy groups, amide groups, carboxyl groups, carboxyalkyl groups, formyl groups, nitrile groups, alkyl groups, hydroxyalkyl groups, hydroxyl groups, alkoxy groups, aryl groups, aryloxy groups, heterocyclic groups, thiols, alkylthio groups, and arylthio groups. Preferably, 1 to 5 of these substituents may be present, and more preferably, 1 to 3 of these substituents may be present.

[0143] In this specification, fluorine, chlorine, bromine and iodine atoms can be cited as "halogen atoms", with chlorine, bromine and iodine atoms being preferred.

[0144] In this specification, the term "aminoalkyl" is not specifically limited, and examples include aminomethyl, 2-aminoethyl, 3-aminopropyl, and other aminoalkyl compounds.

[0145] In this specification, "alkoxycarbonyl" is not specifically limited, and examples such as methoxycarbonyl and ethoxycarbonyl can be given.

[0146] In this specification, the term "acyl group" is not specifically limited and can include, for example, straight-chain or branched alkyl carbonyl groups with 1 to 4 carbon atoms, such as acetyl, propionyl, and neopentyl.

[0147] In this specification, the term "acyloxy group" is not specifically limited, and examples include acetyloxy, propionyloxy, and n-butyryloxy.

[0148] In this specification, the term "amide group" is not specifically limited and can include, for example, carboxylic acid amide groups such as acetamide group and benzamide group; thioacetamide groups such as thiobenzamide group; N-substituted amide groups such as N-methylacetamide group and N-benzylacetamide group; and so on.

[0149] In this specification, the term "carboxyalkyl" is not specifically limited, and examples include carboxymethyl, carboxyethyl, carboxy-n-propyl, carboxy-n-butyl, carboxy-n-butyl, carboxy-n-hexyl, etc. (preferably alkyl groups having a carboxyl group and 1 to 6 carbon atoms).

[0150] In this specification, the term "hydroxyalkyl" is not particularly limited, and examples of hydroxyalkyl (preferably alkyl with 1 to 6 carbon atoms) include hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, etc.

[0151] In this specification, the term "alkoxy" is not specifically limited and can include, for example, linear, branched, or cyclic alkoxy groups. Specifically, examples include linear or branched alkoxy groups with 1 to 6 carbons (especially 1 to 4 carbons), such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, n-pentoxy, neopentoxy, and n-hexyloxy; and cyclic alkoxy groups with 3 to 8 carbons (especially 3 to 6 carbons), such as cyclopropoxy, cyclobutoxy, cyclopentoxy, cyclohexyloxy, cycloheptoxy, and cyclooctoxy.

[0152] In this specification, the term "aryloxy" is not specifically limited, and examples include phenoxy, biphenyloxy, naphthoxy, etc.

[0153] The term "salt" as used for tetrazine compounds represented by general formula (1) is not particularly limited and includes all kinds of salts. Examples of such salts include inorganic acid salts such as hydrochloride, sulfate, and nitrate; organic acid salts such as acetate and methanesulfonate; alkali metal salts such as sodium and potassium salts; alkaline earth metal salts such as magnesium and calcium salts; and quaternary ammonium salts such as dimethylammonium and triethylammonium.

[0154] Among these tetrazine compounds (1), the preferred compounds are the following: X 1 and X 2 Compounds that are the same or different from alkyl groups that may have substituents, aralkyl groups that may have substituents, aryl groups that may have substituents, or heterocyclic groups that may have substituents.

[0155] More preferred tetrazine compound (1) is the following compound: X 1 and X 2 Compounds that are the same or different from aralkyl groups that may have substituents, aryl groups that may have substituents, or heterocyclic groups that may have substituents.

[0156] Further preferred tetrazine compounds (1) are the following compounds: X 1 and X 2 Compounds that are the same as or different from those having substituents, such as benzyl, phenyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-furanyl, thienyl, 1-pyrazolyl, 2-pyrimidinyl, or 2-pyrazinyl groups; of these compounds, X is particularly preferred. 1 and X 2 Compounds that are the same or different from compounds that may have substituents such as 2-pyridyl, 3-pyridyl, or 2-furanyl.

[0157] Specifically, examples of tetrazine compounds (1) include:

[0158] 1,2,4,5-Tetraazine,

[0159] 3,6-Bis(2-pyridyl)-1,2,4,5-tetraazine,

[0160] 3,6-Bis(3-pyridyl)-1,2,4,5-tetraazine,

[0161] 3,6-Bis(4-pyridyl)-1,2,4,5-tetraazine,

[0162] 3,6-Diphenyl-1,2,4,5-Tetraazine

[0163] 3,6-Dibenzyl-1,2,4,5-Tetraazine

[0164] 3,6-Bis(2-furanyl)-1,2,4,5-tetraazine,

[0165] 3-Methyl-6-(3-pyridyl)-1,2,4,5-tetraazine,

[0166] 3,6-Bis(3,5-dimethyl-1-pyrazolyl)-1,2,4,5-tetraazine,

[0167] 3,6-Bis(2-thiamyl)-1,2,4,5-tetraazine,

[0168] 3-Methyl-6-(2-pyridyl)-1,2,4,5-tetraazine,

[0169] 3,6-Bis(4-hydroxyphenyl)-1,2,4,5-tetraazine,

[0170] 3,6-Bis(3-hydroxyphenyl)-1,2,4,5-tetraazine,

[0171] 3,6-Bis(2-pyrimidinyl)-1,2,4,5-tetraazine,

[0172] 3,6-bis(2-pyrazinyl)-1,2,4,5-tetraazine, etc.

[0173] The preferred tetrazine compound (1) is 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine, 3,6-bis(3-pyridyl)-1,2,4,5-tetrazine, 3,6-bis(2-furanyl)-1,2,4,5-tetrazine, 3-methyl-6-(3-pyridyl)-1,2,4,5-tetrazine and 3-methyl-6-(2-pyridyl)-1,2,4,5-tetrazine, and more preferably 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine and 3,6-bis(3-pyridyl)-1,2,4,5-tetrazine.

[0174] By adding a tetrazine compound (1) to a rubber composition, the rubber composition can be endowed with low heat generation properties. Tires made from rubber compositions containing such a tetrazine compound (1) can be endowed with low heat generation properties, thus reducing rolling resistance and resulting in low fuel consumption performance.

[0175] rubber components

[0176] In this specification, the rubber component is not specifically limited, and examples include natural rubber (NR), synthetic diene rubber, mixtures of natural rubber and synthetic diene rubber, and other non-diene rubbers.

[0177] Examples of natural rubber include natural rubber latex, technically specified rubber (TSR), ribbed smoked sheet (RSS), eucommia gum, natural rubber derived from eucommia, natural rubber derived from chrysanthemum, and natural rubber derived from Russian dandelion. Furthermore, modified natural rubbers such as epoxidized natural rubber, methacrylic acid modified natural rubber, and styrene modified natural rubber obtained by modifying these natural rubbers are also included in the natural rubbers of this invention.

[0178] Examples of synthetic diene rubbers 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), as well as their modified synthetic diene rubbers. Modified synthetic diene rubbers include those obtained through main-chain modification, single-end modification, and two-end modification. The modifying functional groups in modified synthetic diene rubbers include epoxy, amino, alkoxysilyl, and hydroxyl groups, and the modified synthetic diene rubber may contain one or more of these functional groups.

[0179] There are no particular limitations on the manufacturing methods for synthetic diene rubbers; examples include emulsion polymerization, solution polymerization, free radical polymerization, anionic polymerization, and cationic polymerization. Furthermore, there are no particular limitations on the glass transition temperature of synthetic diene rubbers.

[0180] Furthermore, there are no particular limitations on the cis / trans / vinyl ratio of the double bonds in natural rubber and synthetic diene rubber; any ratio is suitable. Additionally, there are no particular limitations on the number-average molecular weight and molecular weight distribution of the diene rubber; however, a number-average molecular weight of 500–3,000,000 and a molecular weight distribution of 1.5–15 are preferred.

[0181] As a non-diene rubber, known non-diene rubbers can be widely used.

[0182] Regarding the rubber components, one type can be used alone, or two or more types can be mixed (blended). Preferred rubber components include natural rubber, IR, SBR, BR, or a mixture of two or more of these, with natural rubber, SBR, BR, or a mixture of two or more of these being more preferred. Furthermore, there is no particular limitation on the blending ratio; it is preferable to blend SBR, BR, or a mixture thereof at a ratio of 50 to 100 parts by weight of the rubber component, and particularly preferably at 75 to 100 parts by weight. When blending a mixture of SBR and BR, the total amount of SBR and BR is preferably within the above-mentioned range. In this case, it is preferable that SBR is 50 to 100 parts by weight and BR is in the range of 0 to 50 parts by weight.

[0183] 2. Modified polymers

[0184] The modified polymer of the present invention is prepared using a rubber mixture containing diene rubber and the additives of the present invention described above.

[0185] In other words, the modified polymer of the present invention is a modified polymer obtained by treating diene rubber with a tetrazine compound (1).

[0186] In addition, further modification can be achieved by applying tetrazine compound (1) to diene rubber modified with epoxy, amino, alkoxysilyl, hydroxyl, etc.

[0187] The raw materials used to manufacture the modified polymer of the present invention contain the above-mentioned tetrazine compound (1) and diene rubber. The amount of the tetrazine compound (1) is not particularly limited, and can be appropriately adjusted, for example, to a typically 0.1 to 10 parts by mass, preferably 0.2 to 5 parts by mass, and more preferably 0.5 to 2 parts by mass relative to 100 parts by mass of the rubber component in the rubber composition described later.

[0188] The modified polymer of the present invention has heteroatoms such as nitrogen atoms, which interact strongly with silica and carbon black. Therefore, the dispersibility of silica or carbon black in diene rubber components can be improved, and the modified polymer is endowed with excellent low heat generation properties.

[0189] The modified polymer of the present invention preferably has at least one structure selected from the compound structures shown in formulas (2) to (12) below.

[0190] [Chemical Formula 8]

[0191]

[0192] [In the formula, X] 1 and X 2 X in Invention 1 1 and X 2 They represent the same thing. R represents a halogen atom or an alkyl group.

[0193] Here, the modified polymer of the present invention is considered to be obtained through the following reaction mechanism.

[0194] [Reaction mechanism of rubber components and additives of the present invention]

[0195] An anti-electron-demanding Aza-Diels-Alder reaction occurs between the tetrazine compound (1) and the double bond in the rubber component.

[0196] Specifically, the tetrazine compound (1) is bonded to the double bond site of the diene rubber by performing the reactions shown in reaction formulas -1 to 4, thereby forming a six-membered ring structure and obtaining a modified polymer.

[0197] Reaction Formula-1

[0198] [Chemical Formula 9]

[0199]

[0200] [In the formula, X] 1 and X 2 The meaning is the same as above.

[0201] In reaction formula-1, the double bond site of the diene rubber shown in formula (A-1) undergoes a reverse electron-demanding Aza-Diels-Alder reaction with the tetrazine compound (1) to form a bicyclic structure shown in formula (B-1). The -N=N- part in this bicyclic structure is readily denitrified to form a six-membered ring structure shown in formulas (C-1), (C-2), or (C-3), which is then oxidized by oxygen in the air to obtain a modified polymer with a six-membered ring structure shown in formula (2).

[0202] Reaction-2

[0203] [Chemical Formula 10]

[0204]

[0205] [In the formula, X]1 and X 2 The meaning is the same as above.

[0206] In reaction-2, similar to reaction-1, the double bond site of the diene rubber shown in formula (A-2) and the tetrazine compound (1) form a bicyclic structure shown in formula (B-2) or (B-2'), and then form a six-membered ring structure shown in formula (C-4) to (C-9) to obtain a modified polymer having a six-membered ring structure shown in formula (3) or (4).

[0207] Reaction Formula 3

[0208] [Chemical Formula 11]

[0209]

[0210] [In the formula, X] 1 and X 2 The meaning is the same as above. R represents an alkyl or halogen atom.

[0211] In reaction formula-3, a bicyclic structure as shown in formula (B-3) or (B-3') is formed by the reverse electron-demanding Aza-Diels-Alder reaction between the double bond site of the diene rubber shown in formula (A-3) and the tetrazine compound (1). Then, a modified polymer with a six-membered ring structure as shown in formulas (5) to (8) is obtained by denitrification. It should be noted that when R on the double bond site of the diene rubber shown in formula (A-3) is a halogen atom, the halogen atom may sometimes be removed. In this case, a modified polymer with a six-membered ring structure as shown in formula (2) is obtained through an oxidation reaction.

[0212] Reaction-4

[0213] [Chemical Formula 12]

[0214]

[0215] [In the formula, X] 1 X 2 The meaning of R is the same as described above.

[0216] In reaction-4, similar to the reaction in reaction-3, a modified polymer having a six-membered ring structure as shown in formula (9) to (12) is obtained by reacting the double bond site of the diene rubber shown in formula (A-4) with the tetrazine compound (1).

[0217] Furthermore, the additives of this invention can be used to disperse silica into the rubber component. The proposed silica dispersion mechanism is as follows.

[0218] [Silica Dispersion Mechanism]

[0219] The nitrogen atom of the tetrazine compound (1) constituting the additive of the present invention exhibits a high affinity for silica. Furthermore, it is speculated that the modified polymer formed by the reaction of the rubber component with the tetrazine compound (1) has its affinity for silica further improved due to the presence of the nitrogen atom from this tetrazine compound. It is speculated that this affinity is particularly enhanced by the presence of the nitrogen atom at the 3-position (X) of the tetrazine compound (1). 1 (base) and 6-bit (X) 2 By introducing substituents or polar groups with heteroatoms onto the base, the affinity for silica is enhanced. Therefore, it is believed that the additive of the present invention enables silica to be dispersed into the rubber component.

[0220] Methods for manufacturing modified polymers

[0221] There are no particular limitations on the method for manufacturing the modified polymer of the present invention. The modified polymer of the present invention can be prepared, for example, using a rubber mixture containing at least one rubber component selected from natural rubber and synthetic diene rubber and a tetrazine compound (1).

[0222] As a specific method for manufacturing the modified polymer of the present invention, the following methods can be cited: when the rubber component is solid, a method of mixing the rubber component with a tetrazine compound (1) under heating conditions (mixing method); when the rubber component is liquid, a method of mixing a solution or emulsion (suspension) of the rubber component with a tetrazine compound (1) under heating conditions (liquid mixing method), etc.

[0223] There are no particular limitations on the heating temperature. For example, when using the above-described mixing method, the upper limit of the temperature of the rubber composition is preferably 80–190°C, more preferably 90–160°C, and even more preferably 100–150°C. When using a liquid mixing method, the upper limit of the temperature of the liquid rubber composition is preferably 80–190°C, more preferably 90–160°C, and even more preferably 100–150°C.

[0224] There are no particular limitations on the mixing or kneading time. For example, in a kneading method, 10 seconds to 20 minutes is preferred, more preferably 30 seconds to 10 minutes, and even more preferably 60 seconds to 7 minutes. In a liquid mixing method, 10 seconds to 60 minutes is preferred, more preferably 30 seconds to 40 minutes, and even more preferably 60 seconds to 30 minutes. After the mixing reaction using a liquid mixing method, the solvent in the mixture can be evaporated (removed), for example, under reduced pressure, to recover the solid rubber composition.

[0225] In the method for manufacturing the modified polymer of the present invention, there is no particular limitation on the amount of tetrazine compound (1) used. For example, it can be appropriately adjusted to be 0.1 to 10 parts by mass, preferably 0.25 to 5 parts by mass, and more preferably 0.5 to 2 parts by mass relative to 100 parts by mass of the rubber component in the rubber composition.

[0226] 3. Rubber composition

[0227] The rubber composition of the present invention comprises: a rubber component; the additives of the present invention described above; and inorganic fillers and / or carbon black.

[0228] In addition, the rubber composition of the present invention contains: the above-mentioned modified polymer; and inorganic filler and / or carbon black.

[0229] The rubber component, the additives of this invention, and the modified polymer are as described above.

[0230] The amount of the additive of the present invention is typically 0.1 to 10 parts by mass relative to 100 parts by mass of the rubber component in the rubber composition, preferably 0.25 to 5 parts by mass, and more preferably 0.5 to 2 parts by mass.

[0231] The amount of inorganic filler and / or carbon black is not particularly limited. For example, it is usually 2 to 200 parts by weight relative to 100 parts by weight of rubber component, preferably 30 to 130 parts by weight, and more preferably 35 to 110 parts by weight. When both inorganic filler and carbon black are combined, the total amount of the two components can be appropriately adjusted so that it is within the above range.

[0232] Regarding the amount of inorganic filler and / or carbon black, it is preferable to have 2 parts by mass or more from the viewpoint of improving the reinforcing properties of the rubber composition, and preferably 200 parts by mass or less from the viewpoint of reducing rolling resistance. It should be noted that when incorporating inorganic filler and / or carbon black, a masterbatch obtained by pre-mixing the polymer wet or dry may also be used.

[0233] The aforementioned inorganic fillers or carbon black are typically used to improve the reinforcing properties of rubber. It should be noted that carbon black is not included in the list of inorganic fillers in this specification.

[0234] Inorganic filler materials

[0235] As inorganic filler materials, there are no particular restrictions on commonly used inorganic compounds in the rubber industry. Examples of usable inorganic compounds include, for instance, silicon dioxide; alumina (Al₂O₃) such as γ-alumina and α-alumina; alumina monohydrates (Al₂O₃·H₂O) such as boehmite and diaspore; aluminum hydroxide [Al(OH)₃] such as gibbsite and gibbsite; aluminum carbonate [Al₂(CO₃)₂]; magnesium hydroxide [Mg(OH)₂]; magnesium oxide (MgO); magnesium carbonate (MgCO₃); talc (3MgO·4SiO₂·H₂O); palygorskite (5MgO·8SiO₂·9H₂O); titanium dioxide (TiO₂); and titanium black (TiO₂). 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 silicate (Al2SiO5, Al4·3SiO4·5H2O, etc.), magnesium silicate (Mg2SiO4, Examples of inorganic fillers include calcium silicate (Ca2·SiO4, etc.), calcium aluminum silicate (Al2O3·CaO·2SiO2, etc.), 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 crystalline aluminosilicates containing hydrogen, alkali metals, or alkaline earth metals, such as various zeolites, to compensate for charge. For these inorganic fillers, organic treatment can be applied to their surface to improve their affinity with rubber components.

[0236] The amount of inorganic filler used is typically 10 to 200 parts by mass relative to 100 parts by mass of the rubber component.

[0237] From the viewpoint of imparting strength to rubber, silica is preferred as an inorganic filler material. More preferably, silica can be used alone or in combination with one or more inorganic compounds commonly used in the rubber industry. When silica is used in combination with the aforementioned inorganic compounds other than silica as an inorganic filler material, the total amount of all components of the inorganic filler material should be appropriately adjusted to fall within the aforementioned range.

[0238] Silica is preferred because it imparts strength to rubber. All commercially available silica products can be used. Among these, wet silica, dry silica, or colloidal silica are preferred, with wet silica being more preferred. For these silicas, the surface may be organically treated to improve their affinity with the rubber components.

[0239] There is no particular limitation on the BET specific surface area of ​​silica; examples include 40–350 m². 2 The range of / g. Silica with a BET specific surface area within this range has the advantage of balancing rubber reinforcement and dispersibility in rubber components. This BET specific surface area is measured according to ISO 5794 / 1.

[0240] From this perspective, the preferred silica is one with a BET specific surface area of ​​80–300 m². 2 Silica in the range of / g, preferably with a BET specific surface area of ​​100-270m². 2 / g of silica, preferably with a BET specific surface area of ​​110-270m². 2 Silica in the range of / g.

[0241] As a commercially available product of this type of silica, one example is "HD165MP" (BET specific surface area = 165m²) manufactured by Quechen Silicon Chemical Co., Ltd. 2 / g), "HD115MP" (BET specific surface area = 115m²) 2 / g), "HD200MP" (BET specific surface area = 200m²) 2 / g), "HD250MP" (BET specific surface area = 250m²) 2 / g), trade name "Nipsil AQ" manufactured by Tosoh Silica Corporation (BET specific surface area = 205m²) 2 / g), "Nipsil KQ" (BET specific surface area = 240m²) 2 / g), the trade name "Ultrasil VN3" manufactured by Degussa (BET specific surface area = 175m²). 2 / g), etc.

[0242] The amount of silica added is typically 20 to 120 parts by mass relative to 100 parts by mass of the rubber component, preferably 30 to 100 parts by mass, and more preferably 40 to 90 parts by mass.

[0243] Typically, adding silica improves motion performance; however, excessive addition of silica tends to degrade low-heat properties. But, by using the additive of this invention, excellent low-heat properties are observed even with a large amount of silica.

[0244] In particular, the amount of silica used when both athletic performance and low fuel consumption are required is typically 40 to 120 parts by mass relative to 100 parts by mass of the rubber component, preferably 60 to 115 parts by mass, and more preferably 70 to 110 parts by mass.

[0245] For rubber compositions containing inorganic fillers, particularly silica, the low-heat properties of the rubber composition can be significantly improved by incorporating a tetrazine compound (1), thereby greatly enhancing the dispersibility of silica. In other words, the additive of the present invention can be used as a dispersant, low-heat agent, heat-preventing agent, or heat-inhibiting agent for inorganic fillers and / or carbon black, preferably as a dispersant, low-heat agent, heat-preventing agent, or heat-inhibiting agent for rubber.

[0246] carbon black

[0247] There are no particular limitations on the type of carbon black used; examples include commercially available carbon black and carbon-silica dual-phase fillers. By including carbon black in rubber components, it is possible to reduce the rubber's electrical resistance, suppress static electricity, and further improve the rubber's strength.

[0248] Specifically, examples of carbon black include high-, medium-, or low-structure carbon black such as SAF, ISAF, IIAF, N110, N134, N220, N234, N330, N339, N375, N550, HAF, FEF, GPF, and SRF grades. Among these, SAF, ISAF, IIAF, N134, N234, N330, N339, N375, HAF, or FEF grades are preferred.

[0249] There are no particular limitations on the DBP absorption of carbon black, but it is preferably 60 to 200 cm⁻¹. 3 / 100g, further preferably 70-180cm 3 / 100g or more, especially preferred is 80-160cm 3 / 100g.

[0250] In addition, the nitrogen adsorption specific surface area (N2SA, determined according to JIS K 6217-2:2001) of carbon black is preferably 30 to 200 m². 2 / g, further preferably 40-180m 2 / g, particularly preferably 50-160mg 2 / g.

[0251] It is believed that in rubber compositions containing carbon black, the tetrazine compound (1), or the reaction product of the rubber component and the tetrazine compound (1), interacts strongly with the carbon black. Therefore, with the rubber compositions of the present invention, the dispersibility of carbon black is significantly improved, and the low heat generation of the rubber composition can be significantly improved.

[0252] The amount of carbon black incorporated is typically 2 to 150 parts by mass relative to 100 parts by mass of the rubber component, preferably 4 to 120 parts by mass, and more preferably 6 to 100 parts by mass.

[0253] From the viewpoint of ensuring antistatic properties and rubber strength, it is preferable that the amount of carbon black added is 2 parts by mass or more, and from the viewpoint of reducing rolling resistance, it is preferable to be 150 parts by mass or less.

[0254] Other compounding agents

[0255] In the rubber composition of the present invention, in addition to the aforementioned tetrazine compound (1) and inorganic fillers and / or carbon black, compounding agents commonly used in the rubber industry may be selected within a scope that does not impair the purpose of the present invention, such as anti-aging agents, anti-ozone agents, softeners, processing aids, waxes, resins, foaming agents, oils, stearic acid, zinc oxide (ZnO), vulcanization accelerators, vulcanization retarders, vulcanizing agents (sulfur), etc. Commercially available products may be used as these compounding agents.

[0256] In addition, in rubber compositions containing inorganic fillers such as silica, silane coupling agents may be added to improve the reinforcing properties of silica-based rubber compositions, or to improve the low heat generation and wear resistance of rubber compositions.

[0257] As a silane coupling agent that can be used in conjunction with inorganic fillers, there are no particular limitations, and commercially available products can be used appropriately. Examples of such silane coupling agents include sulfide-based, polysulfide-based, thioester-based, thiol-based, olefin-based, epoxy-based, amino-based, and alkyl-based silane coupling agents.

[0258] Examples of silane coupling agents based on sulfide systems include 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-methyldimethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-trimethoxysilylpropyl)trisulfide, and bis(3-methyldimethoxysilylpropyl)tetrasulfide. Bis(2-triethoxysilylethyl) trisulfide, bis(3-monoethoxydimethylsilylpropyl) tetrasulfide, bis(3-monoethoxydimethylsilylpropyl) trisulfide, bis(3-monoethoxydimethylsilylpropyl) disulfide, bis(3-monoethoxydimethylsilylpropyl) tetrasulfide, bis(3-monoethoxydimethylsilylpropyl) trisulfide, bis(3-monoethoxydimethylsilylpropyl) disulfide, bis(2-monoethoxydimethylsilylethyl) tetrasulfide, bis(2-monoethoxydimethylsilylethyl) trisulfide, bis(2-monoethoxydimethylsilylethyl) disulfide, etc. Among these, bis(3-triethoxysilylpropyl) tetrasulfide is particularly preferred.

[0259] Examples of thioester-based silane coupling agents include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, 3-lauroylthiopropyltriethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, and 2-lauroylthioethyltriethoxysilane. Triethoxysilane, 3-hexanoylthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octanoylthioethyltrimethoxysilane, 2-decanoylthioethyltrimethoxysilane, 2-lauroylthioethyltrimethoxysilane, etc.

[0260] Examples of thiol-based silane coupling agents include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropylmethyldimethoxysilane.

[0261] Examples of olefin-based silane coupling agents include dimethoxymethylvinylsilane, vinyltrimethoxysilane, dimethylethoxyvinylsilane, diethoxymethylvinylsilane, triethoxyvinylsilane, vinyltri(2-methoxyethoxy)silane, allyltrimethoxysilane, allyltriethoxysilane, p-styryltrimethoxysilane, 3-(methoxydimethoxydimethylsilyl)propyl acrylate, 3-(trimethoxysilyl)propyl acrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-[triethoxysilyl]propyl methacrylate, and 3-[tris(trimethylsiloxy)silyl]propyl methacrylate.

[0262] Examples of epoxy-based silane coupling agents include 3-glycidyloxypropyl(dimethoxy)methylsilane, 3-glycidyloxypropyltrimethoxysilane, diethoxy(3-glycidyloxypropyl)methylsilane, triethoxy(3-glycidyloxypropyl)silane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Among these, 3-glycidyloxypropyltrimethoxysilane is preferred.

[0263] Examples of amino-based silane coupling agents include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-ethoxysilyl-N-(1,3-dimethylbutylene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane. Among these, 3-aminopropyltriethoxysilane is preferred.

[0264] Examples of alkyl-based silane coupling agents include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, and n-decyltrimethoxysilane. Methyltriethoxysilane is preferred.

[0265] Among these silane coupling agents, bis(3-triethoxysilylpropyl)tetrasulfide is particularly preferred.

[0266] In this invention, a single silane coupling agent can be used, or two or more can be used in combination.

[0267] The amount of silane coupling agent in the rubber composition of the present invention is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of inorganic filler, and particularly preferably 3 to 15 parts by mass. This is because if it is 0.1 parts by mass or more, the effect of improving the low heat generation of the rubber composition can be more ideally exhibited, while if it is 20 parts by mass or less, the cost of the rubber composition can be reduced and the economy can be improved.

[0268] Uses of rubber compositions

[0269] There are no particular limitations on the applications of the rubber composition of the present invention, and examples include tires, vibration damping rubber, conveyor belts, and their rubber parts. Among these, tires are a preferred application.

[0270] Method for manufacturing rubber composition

[0271] There are no particular limitations on the method for manufacturing the rubber composition of the present invention. The method for manufacturing the rubber composition of the present invention includes, for example, the following steps: step (A), mixing raw material components containing rubber components, additives of the present invention, and inorganic fillers and / or carbon black; and step (B), mixing the mixture obtained in step (A) with a vulcanizing agent.

[0272] Process (A)

[0273] Step (A) is the process of mixing raw material components containing rubber components, the additives of the present invention, and inorganic fillers and / or carbon black, and refers to the process before the vulcanizing agent is added.

[0274] In process (A), other compounding agents mentioned above may be added as needed.

[0275] As a mixing method in step (A), examples include mixing a composition containing raw material components, including a rubber component, the additive of the present invention, and inorganic fillers and / or carbon black. In this mixing method, the entire amount of each component can be mixed at once, or the components can be added and mixed in stages for purposes such as viscosity adjustment. Alternatively, the rubber component can be mixed with the inorganic fillers and / or carbon black before adding the additive of the present invention for mixing, or the rubber component can be mixed with the additive of the present invention before adding the inorganic fillers and / or carbon black for mixing. To ensure uniform dispersion of the components, the mixing operation can be repeated.

[0276] In addition, as another mixing method in step (A), a two-stage mixing method including step (A-1) and step (A-2) can be cited, in which the rubber component and the additive of the present invention are mixed, and in step (A-2) the raw material components containing the mixture (modified polymer) obtained in step (A-1) and inorganic filler and / or carbon black are mixed.

[0277] There are no particular limitations on the temperature at which the rubber composition is mixed in step (A). For example, the upper limit of the temperature of the rubber composition is preferably 120 to 190°C, more preferably 130 to 175°C, and even more preferably 140 to 170°C.

[0278] There are no particular limitations on the mixing time in step (A), for example, it is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 2 minutes to 7 minutes.

[0279] The temperature at which the rubber component and the additive of the present invention are mixed in step (A-1) is preferably 80 to 190°C, more preferably 90 to 160°C, and even more preferably 100 to 150°C. This is because if the mixing temperature is below 80°C, the reaction will not occur, and if it is above 190°C, the rubber will deteriorate.

[0280] The mixing time in step (A-1) is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 60 seconds to 7 minutes. This is because if the mixing time is less than 10 seconds, the reaction cannot proceed sufficiently, and if it is more than 20 minutes, the productivity will decrease.

[0281] There are no particular limitations on the temperature at which the mixture (modified polymer) obtained in step (A-1) is mixed with inorganic filler and / or carbon black in step (A-2). For example, the upper limit of the temperature of the mixture is preferably 120 to 190°C, more preferably 130 to 175°C, and even more preferably 140 to 170°C.

[0282] There are no particular limitations on the mixing time in step (A-2), for example, it is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 2 minutes to 7 minutes.

[0283] In step (A), the amount of tetrazine compound (1) used as an additive of the present invention is not particularly limited, for example, it is 0.1 to 10 parts by mass relative to 100 parts by mass of rubber component, preferably 0.25 to 5 parts by mass, and more preferably 0.5 to 2 parts by mass.

[0284] In step (A), the double bond portion of the rubber component (diene rubber) reacts with the additive of the present invention and the tetrazine compound (1) to form a modified polymer having a six-membered ring structure as shown in formulas (2) to (12) above, and a mixture in which inorganic filler and / or carbon black are appropriately dispersed can be obtained.

[0285] Process (B)

[0286] Process (B) is the process of mixing the mixture obtained in process (A) with the vulcanizing agent, and refers to the final stage of mixing.

[0287] In process (B), vulcanization accelerators may also be added as needed.

[0288] Step (B) can be performed under heating conditions. There are no particular limitations on the heating temperature for this step, but it is preferably 60 to 140°C, more preferably 80 to 120°C, and even more preferably 90 to 120°C.

[0289] There are no particular limitations on the mixing (or kneading) time, for example, it is 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 60 seconds to 5 minutes.

[0290] When moving from process (A) to process (B), it is preferable to lower the temperature by more than 30°C compared to the temperature at the end of the previous process before proceeding to the next process (B).

[0291] In the manufacturing method of the rubber composition of the present invention, various compounding agents such as stearic acid, zinc oxide and other vulcanization accelerators, anti-aging agents and other compounding agents that are usually compounded in the rubber composition may be added in step (A) or step (B) as needed.

[0292] The rubber composition of this invention can be mixed or compounded using a Banbury mixer, rollers, high-intensity mixer, kneader, twin-screw extruder, etc. It is then processed by extrusion, for example, forming it into a tread component or sidewall component. Next, it is bonded and molded on a tire forming machine using conventional methods to obtain a green tire. This green tire is then heated and pressurized in a vulcanizing machine to obtain a tire.

[0293] 4. Tires

[0294] The tires of the present invention are tires manufactured using the additives, rubber compositions or modified polymers of the present invention described above.

[0295] Examples of tires that can be used as tires in this invention include pneumatic tires (radial tires, bias tires, etc.) and solid tires.

[0296] There are no particular restrictions on the uses of tires. Examples include passenger car tires, high-load tires, motorcycle (electric bicycle) tires, studless tires, etc. Among these, passenger car tires are a suitable application.

[0297] There are no particular limitations on the shape, structure, size, and material of the tire used in this invention, and they can be appropriately selected according to the purpose.

[0298] In the tires of the present invention, the above-mentioned additives, rubber compositions or modified polymers may be used in at least one component selected from the tire face, tire sidewall, tire bead area, belt portion, tire body portion and tire shoulder portion.

[0299] One preferred method is to use the rubber composition to form the tire tread or sidewall of a pneumatic tire.

[0300] The term "tire tread" refers to the part of the tire that has the tread pattern and is in direct contact with the road surface. It is the outer skin of the tire that protects the tire body and prevents wear and damage. It refers to the cap tread that forms the contact patch of the tire and / or the base tread located inside the cap tread.

[0301] The sidewall, also known as the tire sidewall, refers to the portion of a radial tire that extends from the underside of the shoulder to the bead. It is the part that protects the tire body and bends most violently during driving.

[0302] The tire bead area refers to the part that secures the two ends of the tire carcass cords and also serves to fix the tire to the rim. The tire bead is a structure made of bundled high-carbon steel.

[0303] The term "belt section" refers to the reinforcing belt that extends circumferentially between the tread and the carcass in a radial tire structure. It acts like a hoop on a bucket, tightening the carcass and increasing the rigidity of the tread.

[0304] The tire carcass refers to the cord layer that forms the tire's skeleton, and it plays a role in absorbing the load, impact, and air pressure that the tire is subjected to.

[0305] The tire shoulder is the shoulder area of ​​the tire, which serves to protect the tire body.

[0306] The tire of the present invention can be manufactured according to methods known to date in the tire industry. Furthermore, as the gas filled into the tire, ordinary air or air with adjusted oxygen partial pressure; inert gases such as nitrogen, argon, and helium can be used.

[0307] The tire of the present invention exhibits low heat generation and reduced rolling resistance, thus enabling fuel-efficient automobiles. Furthermore, the rubber composition, richly filled with silica, also demonstrates excellent low heat generation, thereby providing a fuel-efficient tire with high performance.

[0308] Example

[0309] The following examples and embodiments illustrate the invention in detail. However, these embodiments are merely examples, and the invention is not limited to them.

[0310] Manufacturing Example 1: Manufacturing of 3,6-bis(3-pyridyl)-1,2,4,5-tetraazine (1a)

[0311] To a 200 mL four-necked flask, add 24 g (0.23 mol) of 3-cyanopyridine, 15 g (1.3 equivalents) of hydrazine hydrate, and 48 mL of methanol, and stir at room temperature. Next, add 3.6 g (15 wt%) of sulfur to the mixture, attach a condenser, and heat and stir overnight at an external temperature of 70 °C. Cool the reaction solution to ice, filter the crystals, and wash with a small amount of cold methanol. Dry the crude crystals under reduced pressure to obtain 19 g of orange dihydrotetraazine crude crystals.

[0312] 17.8 g of the obtained crude crystals were dissolved in 178 g (40 equivalents) of acetic acid, and the sulfur was removed by filtration. A 1 L four-necked flask was added to a solution of dihydrotetraazine acetic acid and 178 mL of distilled water, and stirred under ice-cooling conditions. 15.5 g (3 equivalents) of sodium nitrite was dissolved in 35 mL of distilled water and added dropwise to the reaction solution over approximately one hour, stirring overnight at room temperature. The precipitated crystals were filtered, and the crystals were neutralized with a 10% sodium bicarbonate aqueous solution to form crude crystals. The crude crystals were purified using a silica gel column (ethyl acetate) to obtain 8.4 g of the title tetraazine compound (1a) (purple-red, needle-like crystals).

[0313] Melting point: 200℃

[0314] 1 H-NMR (300MHz, CDCl3, δppm):

[0315] 7.59 (ddd, J=0.9, 5.1, 7.8Hz, 2H), 8.89-8.96 (m, 4H), 9.88 (dd, J=0.9, 2.4Hz, 2H)

[0316] Manufacturing Example 2: Manufacturing of 3,6-diphenyl-1,2,4,5-tetraazine (1d)

[0317] To a 500 mL four-necked flask, add 120 g (1.16 mol) of benzonitrile, 76 g (1.3 equivalents) of hydrazine hydrate, and 348 mL of methanol, and stir at room temperature. Next, add 10 g (8.6 wt%) of sulfur to the mixture, attach a condenser, and heat and stir overnight at an external temperature of 70 °C. Cool the resulting reaction solution to ice, filter the crystals, and wash with a small amount of cold methanol. Dissolve the crude crystals in 2.5 L of warm methanol, filter the insoluble matter, and evaporate the solvent from the filtrate. Dry the crude crystals under reduced pressure to obtain 48 g of yellow dihydrotetraazine crude crystals.

[0318] Add 4.8 g of crude crystals, 48 ​​mL of acetic acid, and 48 mL of distilled water to a 300 mL four-necked flask and stir under ice-cooling conditions. Dissolve 4.2 g (3 equivalents) of sodium nitrite in 48 mL of distilled water. Add this solution dropwise to the reaction mixture over approximately one hour, then stir overnight at room temperature. Add 100 mL of distilled water to the reaction mixture and filter the crystals. Wash the resulting crude crystals with 10 mL of acetic acid and filter to obtain 3.9 g of the diphenyltetraazine compound (1d) (purple-red, needle-like crystals).

[0319] Melting point: 166℃

[0320] 1 H-NMR (300MHz, CDCl3, δppm):

[0321] 7.58-7.68(m, 6H), 8.64-8.69(m, 4H)

[0322] Manufacturing Example 3: Manufacturing of 3,6-dibenzyl-1,2,4,5-tetraazine (1e)

[0323] To a 300 mL four-necked flask, add 58.5 g (0.5 mol) of phenylacetonitrile and 100 g (4.0 equivalent) of hydrazine hydrate, and stir at room temperature. Next, add 9.0 g (15 wt%) of sulfur to the mixture, attach a condenser, and heat and stir overnight at an external temperature of 90 °C. Cool the reaction mixture to ice, add 100 mL of distilled water, crush the contents with a spatula, filter the crystals, and wash with distilled water. Dry the crude crystals under reduced pressure to obtain 61 g of white crude crystals containing dihydrotetraazine.

[0324] To a 1L four-necked flask, add 61g of the obtained crude crystals, 210g of acetic acid, and 200mL of distilled water, and stir under ice-cooling conditions. Dissolve 23.9g (1.5 equivalents) of sodium nitrite in 100mL of distilled water and add it dropwise to the reaction solution over approximately one hour, stirring overnight at room temperature. Add 500mL of distilled water to the reaction solution and extract three times with 100mL of ethyl acetate. Wash the resulting organic layer once with 100mL of distilled water, once with 200mL of saturated sodium bicarbonate solution, and once with 200mL of saturated brine. Evaporate the solvent to obtain 48g of red crude crystals. Purify the crude crystals using a silica gel column (n-hexane:ethyl acetate = 5:1) to obtain 5.1g of the title tetrazine compound (1e) (red, scaly crystals).

[0325] Melting point: 68℃

[0326] 1 H-NMR (300MHz, CDCl3, δppm):

[0327] 4.60(s, 4H), 7.22-7.35(m, 6H), 7.39-7.43(m, 4H)

[0328] Manufacturing Example 4: Manufacturing of 3,6-bis(2-furanyl)-1,2,4,5-tetraazine (1f)

[0329] To a 50 mL three-necked flask, add 3 g (0.032 mol) of 2-furanonitrile, 3.3 g (2.0 equivalent) of hydrazine hydrate, and 15 mL of ethanol, and stir under ice-cooling conditions. Next, add 0.3 g (10 wt%) of sulfur to the mixture, attach a condenser, and heat and stir at an external temperature of 80 °C for 2 hours. Cool the resulting reaction solution under ice, filter the crystals, and dry under reduced pressure to obtain 2.48 g of yellow crude dihydrotetraazine crystals.

[0330] To a 500 mL four-necked flask, add 2.48 g of crude crystals, 150 mL of chloroform, and 35 mL of isoamyl nitrite, and stir overnight at room temperature. Remove the solvent by vacuum drying, and purify the obtained crude crystals (2.39 g) using a silica gel column (chloroform: n-hexane = 3:1) to obtain 1.31 g of the title tetrazine compound (1f) (red solid).

[0331] Melting point: 198-199℃

[0332] 1 H-NMR (500MHz, CDCl3, δppm):

[0333] 7.81 (dd, J=0.4, 1.7Hz, 2H), 7.67 (dd, J=0.4, 3.6Hz, 2H), 6.72 (dd, J=1.7, 3.6Hz, 2H)

[0334] Manufacturing Example 5: Manufacturing of 3-methyl-6-(3-pyridyl)-1,2,4,5-tetraazine (1 g)

[0335] Under ice-cooled conditions, 124.8 g (1.2 mol) of 3-cyanopyridine, 567.6 g (5.0 equivalents) of acetamiprid hydrochloride, and 564 g (10.0 equivalents) of hydrazine hydrate were added to a 2 L four-necked flask and stirred overnight at room temperature. The reaction solution was then ice-cooled, filtered to crystallize, and dried under reduced pressure to obtain 431.2 g of crude crystals.

[0336] In a 5L beaker, 431.2g of crude crystals, 720g of acetic acid (10 equivalents), and 200mL of distilled water were added and stirred under ice-cooling conditions. 300g of sodium nitrite (3.7 equivalents) was dissolved in 720mL of distilled water and added dropwise to the reaction mixture over approximately one hour, while stirring under ice-cooling conditions for one hour. The reaction mixture was neutralized with an aqueous sodium bicarbonate solution, extracted with ethyl acetate, and the organic layer was concentrated under reduced pressure to obtain 156.54g of crude crystals. Purification was performed using a silica gel column (n-hexane:ethyl acetate = 3:1) to obtain 71.81g of the title tetrazine compound (purple-red, crystalline).

[0337] Melting point: 102℃

[0338] 1 H-NMR (500MHz, CDCl3, δppm):

[0339] 9.80 (m, J=1.6Hz, 1H), 8.84-8.87 (m, 2H), 7.55 (ddd, J=0.7, 4.9, 8.0Hz, 1H), 3.14 (s, 3H)

[0340] Manufacturing Example 6: Manufacturing of 3,6-bis(3,5-dimethyl-1-pyrazolyl)-1,2,4,5-tetraazine (1h)

[0341] To a 2000 mL four-necked flask, add 250 g (2.26 mol) of aminoguanidine hydrochloride, 249 g (2.2 equivalents) of hydrazine hydrate, and 400 mL of methanol, and heat under reflux for 24 hours. After cooling to room temperature, filter the solid and wash with methanol. Dry the resulting solid under reduced pressure to obtain 286 g of white triaminoguanidine hydrochloride (90% yield).

[0342] To a 2000 mL four-necked flask, 150 g (1.07 mol) of the synthesized triaminoguanidine hydrochloride and 1250 mL of distilled water were added. While maintaining the internal temperature below 30 °C, 214 g (2.0 equivalents) of acetylacetone was added over 20 minutes. The internal temperature was then raised to 70 °C and stirring continued for 5 hours. After cooling to room temperature, the solid was filtered and washed with distilled water and n-hexane. The resulting solid was dried under reduced pressure to give 125 g (86% yield) of pale yellow dihydrotetraazine.

[0343] To a 5000 mL beaker, 65 g (0.24 mol) of the synthesized dihydrotetraazine, 350 mL of distilled water, and 137 mL (10.0 equivalents) of acetic acid were added, and the mixture was cooled in an ice bath. 33 g (2.0 equivalents) of sodium nitrite dissolved in 50 mL of distilled water was added dropwise. The mixture was stirred in the ice bath for 2 hours, then heated to room temperature and stirred for another 4 hours. The solid was then filtered and washed with distilled water and n-hexane. The resulting solid was dried under reduced pressure to give 64 g (98% yield) of the red tetraazine (1 h) mentioned in the title.

[0344] Melting point: 220℃

[0345] 1 H-NMR (300MHz, CDCl3, δppm):

[0346] 2.40(s, 6H), 2.72(s, 6H), 6.20(s, 2H)

[0347] Manufacturing Example 7: Manufacturing of 3,6-bis(2-thiamyl)-1,2,4,5-tetraazine (1i)

[0348] Under ice-cooled conditions, 21.48 g (0.197 mol) of 2-thiophenecarboxynitrile, 4.3 g (20 wt%) of sulfur, 92 mL of ethanol, and 20.1 g (2.1 equivalents) of hydrazine hydrate were added to a 300 mL four-necked flask, and the mixture was stirred at 65 °C for 4 hours. The reaction solution was then ice-cooled, filtered to crystallize, washed with distilled water, and dried under reduced pressure to obtain 20.56 g of crude crystals.

[0349] In a 1L beaker, 20.56g of crude crystals, 59.1g of acetic acid (5 equivalents), and 60mL of distilled water were added and stirred under ice-cooling conditions. 40.7g of sodium nitrite (3 equivalents) was dissolved in 80mL of distilled water and added dropwise to the reaction mixture over approximately 1 hour, with stirring under ice-cooling conditions for 5 hours. The reaction mixture was neutralized with an aqueous sodium bicarbonate solution, extracted with ethyl acetate, and the organic layer was then concentrated under reduced pressure to obtain 18.7g of crude crystals. Purification was performed using a silica gel column (dichloromethane:n-hexane = 2:1) to give 16.8g of the title tetrazine compound (1i) (red, crystalline).

[0350] Melting point: 198℃

[0351] 1 H-NMR (500MHz, CDCl3, δppm):

[0352] 8.28(dd, J=0.9, 3.8Hz, 2H), 7.69(dd, 0.9, 5.0Hz, 2H), 7.28(m, 2H)

[0353] Manufacturing Example 8: Manufacturing of 3-methyl,6-(2-pyridyl)-1,2,4,5-tetraazine (1j)

[0354] Under ice-cooled conditions, 5 g (0.048 mol) of 2-cyanopyridine, 22.7 g (5.0 equivalents) of acetamiprid hydrochloride, and 24 g (10.0 equivalents) of hydrazine hydrate were added to a 100 mL four-necked flask, and the mixture was stirred overnight at room temperature. The reaction solution was then ice-cooled, and the crystals were filtered. The crude crystals were dried under reduced pressure to obtain 14.15 g of crude crystals.

[0355] In a 1L beaker, 14.15g of crude crystals, 42.5g (15 equivalents) of acetic acid, and 41mL of distilled water were added and stirred under ice-cooling conditions. 32.2g (10 equivalents) of sodium nitrite was dissolved in 60mL of distilled water and added dropwise to the reaction mixture over approximately one hour, while stirring under ice-cooling conditions for 5 hours. The reaction mixture was neutralized with an aqueous sodium bicarbonate solution, extracted with ethyl acetate, and the organic layer was concentrated under reduced pressure to obtain 4.74g of crude crystals. This was purified using a silica gel column (n-hexane:ethyl acetate = 3:1) to obtain 1.02g (red, crystalline) of the tetrazine compound (1j) as titled.

[0356] Melting point: 63℃

[0357] 1 H-NMR (500MHz, CDCl3, δppm):

[0358] 8.96 (m, 1H), 8.65 (m, 1H), 7.99 (ddd, J=1.5, 7.8, 8.3Hz, 1H), 7.57 (ddd, J=0.7, 4.7, 7.8Hz, 1H), 3.17 (s, 3H)

[0359] Manufacturing Example 9: Manufacturing of 3,6-bis(4-hydroxyphenyl)-1,2,4,5-tetraazine (1k)

[0360] 50.0 g (0.42 mol) of 4-hydroxybenzonitrile and 63.0 g (3.0 equivalent) of hydrazine hydrate were added to a 300 mL three-necked flask. After stirring under ice-cooling conditions, the mixture was heated and stirred at 70 °C for 20 hours. The resulting reaction solution was ice-cooled, and the crystals were filtered and dried under reduced pressure to obtain 49.8 g of yellow crude dihydrotetraazine crystals.

[0361] Add 49.8 g of crude crystals and 500 mL of chloroform to a 1 L four-necked flask, and bubble with oxygen while stirring at room temperature for 20 hours. After filtration, recrystallize the crude crystals with DMF to obtain 52.0 g of the title tetrazine compound (1k) (red solid).

[0362] Melting point: 320℃ (decomposes)

[0363] 1 H-NMR (300MHz, CDCl3, δppm):

[0364] 8.36 (m, 4H), 7.03 (m, 4H)

[0365] Manufacturing Example 10: Manufacturing of 3,6-bis(3-hydroxyphenyl)-1,2,4,5-tetraazine (1l)

[0366] To a 300 mL four-necked flask, add 50 g (0.42 mol) of 3-cyanophenol, 42 g (2 equivalents) of hydrazine hydrate, and 5 g (10 wt%) of sulfur. After stirring at room temperature, attach a condenser and heat and stir overnight at an external temperature of 50 °C. Cool the resulting reaction solution to ice, filter to crystallize, and wash with a small amount of cold ethanol. Dry under reduced pressure to obtain 21.5 g of crude dihydrotetraazine crystals.

[0367] In a 1L flask, 21.5g of crude crystals and 430mL of ethanol were added and stirred at room temperature. Oxygen was bubbled into the reaction mixture while stirring for 10 hours, followed by concentration under reduced pressure to obtain 21.5g of crude crystals. These crystals were washed with ethanol and distilled water to obtain 7.3g of the title tetrazine compound (1L) (orange, solid).

[0368] Melting point: 304-305.5℃

[0369] 1 H-NMR (500MHz, d6-DMSO, δppm):

[0370] 10.01 (s, 2H), 7.98 (dd, J=1.6, 7.8Hz, 2H), 7.94 (dd, J=1.6, 1.8Hz, 2H), 7.49 (dd, J=7.8, 8.0Hz, 2H), 7.09 (dd, J=1.8, 8.0Hz, 2H)

[0371] Manufacturing Example 11: Manufacturing of 3,6-bis(2-pyrimidinyl)-1,2,4,5-tetraazine (1m)

[0372] To a 200 mL four-necked flask, add 25 g (0.238 mol) of 2-cyanopyrimidine, 23.8 g (2 equivalents) of hydrazine hydrate, 28.6 g (2 equivalents) of acetic acid, and 8.3 mL of dimethyl sulfoxide, and stir at room temperature. Heat and stir the mixture overnight at an external temperature of 50 °C. Cool the reaction mixture to ice, filter to crystallize, and dry under reduced pressure to obtain 30.1 g of crude dihydrotetraazine crystals.

[0373] To a 5L beaker, add 30.1g of crude crystals, 500mL of tetrahydrofuran, and 3.8L (8 equivalents) of 0.5N hydrochloric acid, and stir under ice-cooling conditions. Dissolve 32.8g (2 equivalents) of sodium nitrite in 60mL of distilled water and add it dropwise to the reaction mixture over approximately 0.5 hours, stirring for 1 hour under ice-cooling conditions. Extract with dichloromethane, and wash the 3.4g of crude crystals obtained by vacuum concentration with 250mL of acetone to obtain 3.2g (purple, solid) of the tetrazine compound (1m) in the title.

[0374] Melting point: 264-267℃

[0375] 1 H-NMR (500MHz, CDCl3, δppm):

[0376] 9.18(d, J=4.9Hz, 4H), 7.63(t, J=4.9Hz, 2H)

[0377] Manufacturing Example 12: Manufacturing of 3,6-bis(2-pyrazinyl)-1,2,4,5-tetraazine (1n)

[0378] To a 2L four-necked flask, add 25g (0.238 mol) of cyanopyrazine, 23.8g (2 equivalents) of hydrazine hydrate, 28.6g (2 equivalents) of acetic acid, and 720mL of methanol, and stir at room temperature. Heat and stir the mixture overnight at an external temperature of 50°C. Cool the reaction solution to ice, filter to crystallize, wash with methanol, and dry under reduced pressure to obtain 26.6g of crude dihydrotetraazine crystals.

[0379] To a 5 L beaker, add 13.3 g of half the amount of the crude dihydrotetraazine crystals, 400 mL of tetrahydrofuran, and 2.4 L (10 equivalents) of 0.5 N hydrochloric acid, and stir under ice-cooling conditions. Dissolve 24.6 g (3 equivalents) of sodium nitrite in 50 mL of distilled water and add it dropwise to the reaction mixture over 0.5 hours, stirring for 1 hour under ice-cooling conditions. Extract with dichloromethane and concentrate under reduced pressure to obtain crude crystals. Repeat the same procedure on the remaining half of the crude dihydrotetraazine crystals to obtain 19.1 g of crude tetraazine crystals. Dissolve in 960 mL of chloroform, add 320 mL of n-hexane, filter, and concentrate the filtrate under reduced pressure to obtain 11.9 g (red, solid) of the tetraazine compound (1n) in the title.

[0380] Melting point: 208-210℃

[0381] 1 H-NMR (500MHz, CDCl3, δppm):

[0382] 9.97(s, 2H), 8.98(s, 2H), 8.92(d, J=2.1Hz, 2H)

[0383] Manufacturing Examples 13-44: Compounding of Modified Polymers

[0384] Using a Banbury internal mixer, the rubber components and tetrazine compounds listed in Tables 1-3 were mixed in their respective proportions (parts by mass). Starting from the moment the temperature of the mixture reached 130-150°C, the mixing was carried out for about 2 minutes while adjusting and maintaining this temperature. Afterward, the mixture was cooled using a roll mill to produce the modified polymer.

[0385] [Table 1]

[0386]

[0387] [Table 2]

[0388]

[0389] [Table 3]

[0390]

[0391] [Explanation of symbols in the table]

[0392] The raw materials used in the examples (in the table) are shown below.

[0393] *1: Solution polymerized SBR (S-SBR), manufactured by PetroChina Dushanzi Petrochemical Company, trade name "RC2557S"

[0394] *2: Solution polymerized SBR (S-SBR), manufactured by Asahi Kasei Chemicals Corporation, trade name "Tafdene 3835"

[0395] *3: Solution polymerized SBR (S-SBR), manufactured by LANXESS, trade name "Buna VSL 5025-2"

[0396] *4: Solution polymerized SBR (S-SBR), manufactured by LANXESS, trade name "Buna VSL 4526-2"

[0397] *5: Solution polymerized SBR (S-SBR), manufactured by LANXESS, trade name "Buna VSL 2538-2"

[0398] *6: End-modified solution polymerized SBR (end-modified S-SBR), manufactured by Zeon Corporation, Japan, trade name "Nipol NS116R"

[0399] *7: End-modified solution polymerized SBR (end-modified S-SBR), manufactured by Zeon Corporation, Japan, trade name "Nipol NS616"

[0400] *8: End-modified solution polymerized SBR (end-modified S-SBR), manufactured by Asahi Kasei Chemicals Corporation, trade name "F3420"

[0401] *9: End-modified solution polymerized SBR (end-modified S-SBR), manufactured by Asahi Kasei Chemicals Corporation, trade name "Asaprene Y031"

[0402] *10: Emulsion polymerized SBR (E-SBR), manufactured by Shenhua Chemical Industrial Co., Ltd., trade name "SBR1739"

[0403] *11: Emulsion polymerized SBR (E-SBR), manufactured by Zeon Corporation, Japan, trade name "Nipol 1502"

[0404] *12: Butadiene rubber (BR), manufactured by Sinopec Qilu Petrochemical Co., Ltd., trade name "BR9000"

[0405] *13: Natural rubber (NR), manufactured by GUANGKEN RUBBER, trade name "TSR20"

[0406] *14: Natural Rubber (NR), manufactured by Sinochem International, trade name "RSS3"

[0407] *15: Isoprene rubber (IR), manufactured by Stellitamak, trade name "IR-1"

[0408] *16: Isoprene rubber (IR), manufactured by Sterlitamak, trade name "IR-2"

[0409] *17: Isoprene rubber (IR), manufactured by Sterlitamak, trade name "SKI-3"

[0410] *18: Nitrile butadiene rubber (NBR), manufactured by Zeon Corporation, Japan, trade name "NBR3350"

[0411] *19: Chloroprene rubber (CR), manufactured by Mitsui Plastics Trading Co., Ltd., trade name "DCR40A"

[0412] *20: Carbon black, manufactured by Cabot Corporation, trade name "N234"

[0413] *21: Carbon black, manufactured by Cabot Corporation, trade name "N330"

[0414] *22: Carbon black, manufactured by Cabot Corporation, trade name "N375"

[0415] *23: Carbon black, manufactured by Cabot Corporation, trade name "N550"

[0416] *24: Manufactured by Quechen Silicon Chemical Co., Ltd., trade name "HD60MP"

[0417] *25: Manufactured by Quechen Silicon Chemical Co., Ltd., trade name "HD90MP"

[0418] *26: Manufactured by Quechen Silicon Chemical Co., Ltd., trade name "HD115MP"

[0419] *27: Manufactured by Quechen Silicon Chemical Co., Ltd., trade name "HD165MP"

[0420] *28: Manufactured by Quechen Silicon Chemical Co., Ltd., trade name "HD200MP"

[0421] *29: Manufactured by Quechen Silicon Chemical Co., Ltd., trade name "HD250MP"

[0422] *30: Manufactured by Evonik Industries AG, trade name "Si69"

[0423] *31: Manufactured by Zhangjiagang Guotai Huarong Chemical New Materials Co., Ltd., product name "SCA-1113"

[0424] *32: Manufactured by Zhangjiagang Guotai Huarong Chemical New Materials Co., Ltd., trade name "SCA-113"

[0425] *33: Manufactured by Zhangjiagang Guotai Huarong Chemical New Materials Co., Ltd., trade name "SCA-403"

[0426] *34: Manufactured by Kemai Chemical Co., Ltd., trade name "6-PPD"

[0427] *35: Manufactured by Kemai Chemical Co., Ltd., trade name "DPG"

[0428] *36: Manufactured by Kemai Chemical Co., Ltd., trade name "CBS"

[0429] *37: Manufactured by Kemai Chemical Co., Ltd., trade name "TMQ"

[0430] *38: Manufactured by Kemai Chemical Co., Ltd., trade name "DM"

[0431] *39: Manufactured by AkzoNobel, product name "DCP"

[0432] *40: Manufactured by Kemai Chemical Co., Ltd., trade name "TMTD"

[0433] *41: Manufactured by Rhein Chemie Rheinau GmbH, trade name "Antilux 111"

[0434] *42: Stearic acid, manufactured by Sichuan Tianyu Grease Chemical Co., Ltd.

[0435] *43: Zinc oxide, manufactured by Dalian Zinc Oxide Co., Ltd.

[0436] *44: Magnesium oxide, manufactured by Xingtai Magnesium Chemical Co., Ltd.

[0437] *45: Sulfur, manufactured by Shanghai Jinghai Chemical Co., Ltd.

[0438] *46: Manufactured by Hansen & Rosenthal, product name "Vivatec 500"

[0439] *47: Manufactured by Hansen & Rosenthal, product name "Vivatec 700"

[0440] *48: Manufactured by Jiangsu Hongxin Chemical Co., Ltd., trade name "DOP"

[0441] *49: Manufactured by Zhejiang Huangyan Zhedong Rubber Additives Co., Ltd., trade name "MB"

[0442] *50: Manufactured by Dizhan International Trading Co., Ltd., product name "OCTAMINE"

[0443] *51: Tetraazine compound (1a): 3,6-bis(3-pyridyl)-1,2,4,5-tetraazine (the compound obtained in Manufacturing Example 1)

[0444] *52: Tetraazine compound (1b): 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, manufactured by Tokyo Chemical Industry Co., Ltd.

[0445] *53: Tetraazine compound (1c): 3,6-bis(4-pyridyl)-1,2,4,5-tetraazine, manufactured by Tokyo Chemical Industry Co., Ltd.

[0446] *54: Tetraazine compound (1d): 3,6-Diphenyl-1,2,4,5-Tetraazine (the compound obtained in Manufacturing Example 2)

[0447] *55: Tetraazine compound (1e): 3,6-Dibenzyl-1,2,4,5-Tetraazine (the compound obtained in Manufacturing Example 3)

[0448] *56: Tetraazine compound (1f): 3,6-bis(2-furanyl)-1,2,4,5-tetraazine (the compound obtained in Manufacturing Example 4)

[0449] *57: Tetraazine compound (1g): 3-Methyl-6-(3-pyridyl)-1,2,4,5-tetraazine (the compound obtained in Manufacturing Example 5)

[0450] *58: Tetraazine compound (1h): 3,6-bis(3,5-dimethyl-1-pyrazolyl)-1,2,4,5-tetraazine (the compound obtained in Manufacturing Example 6)

[0451] *59: Tetraazine compound (1i): 3,6-bis(2-thienyl)-1,2,4,5-tetraazine (the compound obtained in manufacturing example 7)

[0452] *60: Tetraazine compound (1j): 3-Methyl-6-(2-pyridyl)-1,2,4,5-tetraazine (the compound obtained in Manufacturing Example 8)

[0453] *61: Tetraazine compound (1k): 3,6-bis(4-hydroxyphenyl)-1,2,4,5-tetraazine (the compound obtained in Manufacturing Example 9)

[0454] *62: Tetraazine compound (1l): 3,6-bis(3-hydroxyphenyl)-1,2,4,5-tetraazine (the compound obtained in Manufacturing Example 10)

[0455] *63: Tetraazine compound (1m): 3,6-bis(2-pyrimidinyl)-1,2,4,5-tetraazine (the compound obtained in Manufacturing Example 11)

[0456] *64: Tetraazine compound (1n): 3,6-bis(2-pyrazinyl)-1,2,4,5-tetraazine (the compound obtained in manufacturing example 12)

[0457] *65: Modified S-SBR prepared in Manufacturing Example 13

[0458] *66: Modified S-SBR prepared in Manufacturing Example 14

[0459] *67: Modified S-SBR prepared in Manufacturing Example 15

[0460] *68: Modified S-SBR prepared in Manufacturing Example 16

[0461] *69: Modified S-SBR prepared in Manufacturing Example 17

[0462] *70: Modified S-SBR obtained in Manufacturing Example 18

[0463] *71: Modified BR obtained in Manufacturing Example 19

[0464] *72: Modified S-SBR·BR obtained in Manufacturing Example 20

[0465] *73: Modified S-SBR·BR obtained in Manufacturing Example 21

[0466] *74: Modified S-SBR·BR obtained in Manufacturing Example 22

[0467] *75: Modified S-SBR·BR obtained in Manufacturing Example 23

[0468] *76: Modified S-SBR·BR obtained in Manufacturing Example 24

[0469] *77: Modified E-SBR prepared in Manufacturing Example 25

[0470] *78: Modified E-SBR prepared in Manufacturing Example 26

[0471] *79: Modified S-SBR / E-SBR obtained in Manufacturing Example 27 *80: Modified NR obtained in Manufacturing Example 28

[0472] *81: Modified NR obtained in manufacturing example 29

[0473] *82: Modified NR·BR obtained in Manufacturing Example 30

[0474] *83: Modified NR·BR obtained in Manufacturing Example 31

[0475] *84: Modified IR obtained in manufacturing example 32

[0476] *85: Modified NBR prepared in Manufacturing Example 33

[0477] *86: Modified S-SBR·BR obtained in Manufacturing Example 34

[0478] *87: Modified S-SBR·BR obtained in Manufacturing Example 35

[0479] *88: Modified S-SBR·BR obtained in Manufacturing Example 36

[0480] *89: Modified S-SBR·BR obtained in Manufacturing Example 37

[0481] *90: Modified S-SBR·BR obtained in Manufacturing Example 38

[0482] *91: Modified CR obtained in manufacturing example 39

[0483] *92: Modified S-SBR·BR obtained in Manufacturing Example 40

[0484] *93: Modified S-SBR·BR obtained in Manufacturing Example 41

[0485] *94: Modified S-SBR·BR obtained in Manufacturing Example 42

[0486] *95: Modified S-SBR·BR obtained in Manufacturing Example 43

[0487] *96: Modified S-SBR·BR obtained in Manufacturing Example 44

[0488] Manufacturing Example 45: Manufacturing and Structure Confirmation of Tetraazine Modified Polymers

[0489] (1) Using a Banbury internal mixer, S-SBR*2 (100 parts by mass) and tetrazine compound (1b) (5 parts by mass) were mixed. Starting from the moment the temperature of the mixture reached 130 to 150°C, the mixture was mixed for about 2 minutes while adjusting to maintain the temperature, and then cooled using an open mill to produce the modified polymer (modified S-SBR).

[0490] (2) Dissolve tetrazine compound (1b), S-SBR, and modified S-SBR extracted by THF in CDCl3, and determine... 13 C-NMR. The results of the determination of tetrazine compound (1b) are shown in... Figure 1The results of the S-SBR determination are shown in Figure 2 and 3 The determination results of modified S-SBR extracted by THF are shown in... Figure 4 and 5 Furthermore, in Figure 6 The diagram shows the effects of tetrazine compound (1b), S-SBR, and modified S-SBR. 13 A graph comparing C-NMR images.

[0491] according to Figure 6 It can be seen that the peak of tetrazine compound (1b) disappeared, and a new peak representing the following structure was identified.

[0492] [Chemical Formula 13]

[0493]

[0494] The results above clearly show that an electron-demanding Aza-Diels-Alder reaction was carried out through the double bond between the tetrazine compound (1b) and SBR.

[0495] Tetraazine compounds are red to purple in color. Upon mixing with SBR, the characteristic color of tetraazine disappears. For polymers other than SBR shown in the examples of tetraazine-modified polymer manufacturing, the characteristic color of the tetraazine compounds also disappears, indicating that an electron-demanding Aza-Diels-Alder reaction occurred with the polymer's double bonds.

[0496] Examples 1-129

[0497] Mix the components listed in step (A) of Tables 4-13 according to their proportions (parts by mass), and mix for 5 minutes using a Banbury internal mixer while adjusting the speed to keep the maximum temperature of the mixture at 160°C. Allow the mixture to cure until the temperature of the mixture is below 80°C. Then, add the components listed in step (B) of Tables 4-11 according to their proportions (parts by mass), and mix while adjusting the speed to keep the maximum temperature of the mixture below 110°C to produce a rubber composition.

[0498] Examples 130-133

[0499] Mix the components listed in step (A-1) of Table 14 according to their proportions (parts by mass). Using a Banbury internal mixer, adjust the speed to maintain the temperature of the mixture as listed in Table 14 (mixture temperature) while mixing for the time (mixing time) listed in Table 14. Then, add the components listed in step (A-2) according to their proportions, and adjust the speed to maintain the temperature of the mixture at 160°C while mixing for 4 minutes. Allow the mixture to cure until the temperature of the mixture is below 80°C. Then, add the components listed in step (B) of Table 14 according to their proportions, and use a Banbury internal mixer to mix for 1 minute while adjusting the speed to maintain a maximum temperature of 110°C or lower, to produce a rubber composition.

[0500] [Table 4]

[0501]

[0502] [Table 5]

[0503]

[0504] [Table 6]

[0505]

[0506] [Table 7]

[0507]

[0508] [Table 8]

[0509]

[0510] [Table 9]

[0511]

[0512] [Table 10]

[0513]

[0514] [Table 11]

[0515]

[0516] [Table 12]

[0517]

[0518] [Table 13]

[0519]

[0520] [Table 14]

[0521]

[0522] Low pyrogenicity (tanδ index) test

[0523] For the rubber compositions of Examples 1 to 133 below, tanδ was measured using a viscoelasticity measuring apparatus (Metravib) at a temperature of 40°C, dynamic strain of 5%, and frequency of 15Hz. For comparison, rubber compositions (reference compositions) were prepared according to the same formulation and preparation method as in each example, except without the addition of a tetrazine compound, and the reciprocal of their tanδ was taken as 100. The low-heat index was calculated based on the following formula. It should be noted that a larger low-heat index indicates lower heat generation and smaller hysteresis loss. Furthermore, the low-heat index of each reference vulcanized rubber composition was taken as 100.

[0524] Formula: Low heat generation index = {(tanδ of the rubber composition without tetrazine compound (1)) / (tanδ of the rubber composition of the present invention)} × 100

[0525] Compared to the comparative rubber composition without the addition of a tetrazine compound, the rubber compositions of any of the embodiments exhibited excellent heat resistance. Specifically, the rubber compositions of Examples 2, 4, 7, 11, 21, 22, 24, 26, 27, 36, 37, 41, 42, 52–54, 73, 75, 76, 81, 84, 88, 122, 123, and 131–133 exhibited a low heat resistance index of 130 or higher but lower than 140, while the rubber compositions of Examples 13, 29, 63, 68, 72, 74, 83, 85, 87, 111, 113, 119, 124, and 128 exhibited a low heat resistance index of 140 or higher but lower than 150. Furthermore, the rubber compositions of Examples 3, 5, 19, 30, 35, 62, 66, 67, 79, 82, 99, 110, 114, 116, 117, 126, 127 and 129 exhibited a low heat generation index of over 150.

[0526] Industrial availability

[0527] For the rubber composition of the present invention, by incorporating a tetrazine compound (1), the dispersibility of inorganic filler materials (e.g., silica) and / or carbon black is improved, resulting in excellent low-heat properties. Even without the addition of a silane coupling agent, the rubber composition exhibits excellent low-heat properties. Therefore, it can be used as various components of various pneumatic tires for various automobiles, particularly as tread components, sidewall components, bead area components, belt components, carcass components, and shoulder components for pneumatic radial tires.

Claims

1,3,6-bis(3-pyridyl)-1,2,4,5-tetraazine, 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, 3-methyl-6-(3-pyridyl)-1,2,4,5-tetraazine, or salts thereof, as additives for imparting low heat generation properties to rubber components. The amount of the 3,6-bis(3-pyridyl)-1,2,4,5-tetraazine, 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, 3-methyl-6-(3-pyridyl)-1,2,4,5-tetraazine, or their salts is 0.1 to 10 parts by weight relative to 100 parts by weight of the rubber component.

2. The use as described in claim 1, wherein, The rubber component is diene-based rubber.

3. A tire, wherein the tire tread, sidewall, bead area, belt portion, carcass portion or shoulder portion contains 3,6-bis(3-pyridyl)-1,2,4,5-tetraazine, 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, 3-methyl-6-(3-pyridyl)-1,2,4,5-tetraazine or salts thereof.

4. A method of adding an additive to a rubber component to impart low heat generation properties to the rubber component, wherein, The additive contains 3,6-bis(3-pyridyl)-1,2,4,5-tetraazine, 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, 3-methyl-6-(3-pyridyl)-1,2,4,5-tetraazine, or salts thereof. The amount of the 3,6-bis(3-pyridyl)-1,2,4,5-tetraazine, 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, 3-methyl-6-(3-pyridyl)-1,2,4,5-tetraazine, or their salts is 0.1 to 10 parts by weight relative to 100 parts by weight of the rubber component.

5. The method of claim 4, wherein, The rubber component is diene-based rubber.

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