Rubber composition and tire

Abstract

The purpose of the present invention is to provide a rubber composition having superior tear strength and low heat generation properties (low fuel consumption properties) in vulcanized rubber. A rubber composition containing a rubber component, and a compound represented by formula (1) and / or a salt thereof.

Description

TECHNICAL FIELD

[0001] The present application relates to a rubber composition and a tire. BACKGROUND

[0002] In recent years, automobiles have been remarkably high in performance and high in output power, and tires that come into contact with a road surface are also required to be high in durability. Among such durability, high mechanical strength, and more specifically, high tear strength is required, and thus a rubber additive is needed.

[0003] Patent Documents 1 and 2 are technologies disclosed by the present applicant, and according to the technologies, a rubber component can be imparted with low heat generation and tear strength.

[0004] PRIOR ART DOCUMENTS PATENT DOCUMENTS Patent Document 1: International Publication No. WO2020 / 045575A1 Patent Document 2: Japanese Patent Application Publication No. 2021-134317 SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION An object of the present application is to provide a rubber composition that is more excellent in tear strength and low heat generation (low fuel consumption) in vulcanized rubber.

[0006] MEANS FOR SOLVING THE PROBLEMS The present inventors have repeatedly conducted intensive research in order to solve the aforementioned problems.

[0007] The present inventors have found that a specific pyrazolone-based compound can impart more excellent tear strength and low heat generation in vulcanized rubber. These rubber compositions are improved in tear strength after vulcanization, and in addition, tires manufactured using the rubber compositions are improved in low fuel consumption.

[0008] The present inventors have further conducted research based on this insight, and as a result, completed the present application. The present application includes a rubber composition and a tire shown below.

[0009] Item 1. A rubber composition including a rubber component, and a compound represented by the following formula (1) and / or a salt thereof.

[0010] [Chemical Formula 1] [In the formula, R 1 and R 2 are the same or different, and each represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, an acyl group, or R 1 and R 2 are linked together to represent an alkylidene group or an alkylene group.

[0011] wherein R 3 represents a hydrogen atom, an alkyl group or an aryl group.

[0012] wherein R 4 and R 5 are the same or different and each represents a hydrogen atom, an alkyl group, or R 4 and R 5 together represent an alkylidene group or an alkylene group.

[0013] wherein each of the above groups can have one or more substituents. Item 2. The rubber composition described in the above Item 1, wherein the compound represented by the above formula (1) is the following compound: wherein R 1 and R 2 are the same or different and each represents a hydrogen atom, an alkyl group, an aryl group, an acyl group, or R 1 and R 2 together represent an alkylene group, R 3 represents a hydrogen atom, an alkyl group, an aryl group, R 4 and R 5 are the same or different and each represents a hydrogen atom, an alkyl group, or R 4 and R 5 together represent an alkylene group.

[0014] Item 3. The rubber composition described in the above Item 1, wherein the compound represented by the above formula (1) is the following compound: wherein R 1 and R 2 are the same or different and each represents a hydrogen atom, an alkyl group, an aryl group, or R 1 and R 2 together represent an alkylene group, R 3 represents a hydrogen atom, an alkyl group, an aryl group, R 4 and R 5 are the same or different and each represents a hydrogen atom, an alkyl group, or R 4 and R 5 together represent an alkylene group.

[0015] Item 4. The rubber composition as described in the aforementioned item 1, wherein the compound represented by the aforementioned formula (1) and / or a salt thereof is at least one compound selected from the group consisting of 3-amino-5-pyrazolone, 3-isopropylamino-5-pyrazolone, 3-phenylamino-5-pyrazolone, 3-dodecylamino-5-pyrazolone, 3-amino-1-methyl-5-pyrazolone, 3-amino-1-phenyl-5-pyrazolone, 3-amino-4-methyl-5-pyrazolone, and 3-amino-4-phenylalkylamino-5-pyrazolone, and / or a salt thereof.

[0016] Item 5. The rubber composition as described in the aforementioned item 1, wherein the compound represented by the aforementioned formula (1) and / or a salt thereof is at least one compound selected from the group consisting of 3-amino-5-pyrazolone, 3-isopropylamino-5-pyrazolone, 3-phenylamino-5-pyrazolone, 3-dodecylamino-5-pyrazolone, 3-amino-1-methyl-5-pyrazolone, 3-amino-1-phenyl-5-pyrazolone, 3-amino-4-methyl-5-pyrazolone, and 3-amino-4-phenylalkylamino-5-pyrazolone, and / or a salt thereof.

[0017] Item 6. The rubber composition as described in the aforementioned item 1, wherein the compound represented by the aforementioned formula (1) and / or a salt thereof is at least one compound selected from the group consisting of 3-amino-5-pyrazolone and 3-dodecylamino-5-pyrazolone, and / or a salt thereof.

[0018] Item 7. The rubber composition as described in the aforementioned item 1, wherein the aforementioned rubber component is at least one rubber component selected from the group consisting of natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, and butadiene rubber.

[0019] Item 8. The rubber composition as described in the aforementioned item 1, wherein the aforementioned rubber component is natural rubber.

[0020] Item 9. The rubber composition as described in the aforementioned item 1, further comprising carbon black and / or an inorganic filler.

[0021] Item 10. The rubber composition as described in the aforementioned item 1 for use in a tire.

[0022] Item 11. A tire made using the rubber composition described in any one of the aforementioned items 1 to 10.

[0023] The rubber composition of the present application is obtained by combining a rubber component and a specific pyrazolone compound, and has more excellent tear strength and low heat generation in vulcanized rubber. The rubber composition has improved tear strength after vulcanization, and a tire manufactured using the rubber composition has improved low fuel consumption.

[0024] Effects of Invention The present application can provide a rubber composition having more excellent tear strength and low heat generation (low fuel consumption) in vulcanized rubber. DETAILED DESCRIPTION

[0025] The present application is described in detail below.

[0026] The embodiments representing the present application are illustrative of the principles of the application, and are not intended to limit the scope of the application unless otherwise specifically indicated.

[0027] In the present specification, "comprise," "comprising," "consist essentially of," "consist essentially of," and "consist of" are to be construed as open-ended terms (i.e., meaning "including but not limited to," "including," and the like).

[0028] In the present specification, in the case where a numerical range is represented by "A to B," it means "A or more and B or less."

[0029] In the present specification, generally, parts, %, and the like are used.

[0030] In the present specification, unless otherwise specified, mass parts or mass % (wt%) are indicated.

[0031] [1] Rubber composition The rubber composition of the present application contains a rubber component, and a compound represented by the following formula (1) and / or a salt thereof.

[0032] [Chemical Formula 2] In the formula, R 1 and R 2 are the same or different, and each represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, an acyl group, or R 1 and R 2 are linked together to represent an alkylene group or an alkylidene group.

[0033] In the formula, R 3 represents a hydrogen atom, an alkyl group, or an aryl group.

[0034] In the formula, R 4 and R5 identical or different, represent a hydrogen atom, an alkyl group, or R 4 identical or different, represent a hydrogen atom, an alkyl group, or R 5 identical or different, represent a hydrogen atom, an alkyl group, or R

[0035] In the formula, each of the above groups can have one or more substituents.

[0036] The aforementioned rubber component is preferably at least one rubber component selected from the group consisting of natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, and butadiene rubber.

[0037] The rubber composition of the present application preferably further contains carbon black and / or an inorganic filler.

[0038] The rubber composition of the present application requires compounding of a rubber component and a specific pyrazolone-based compound, and exhibits more excellent tear strength and low heat generation in vulcanized rubber. These rubber compositions have improved tear strength after vulcanization, and a tire manufactured using the rubber composition has improved low fuel consumption.

[0039] [1-1] Rubber component The rubber composition of the present application contains a rubber component.

[0040] The rubber component is not particularly limited, and is preferably natural rubber (NR), a synthetic diene-based rubber, and a mixture of natural rubber and a synthetic diene-based rubber, and a non-diene-based rubber other than these.

[0041] The natural rubber (NR) is preferably natural rubber latex, technical specification rubber (TSR), smoked sheet rubber (RSS), gutta-percha, natural rubber from Eucommia ulmoides, natural rubber from Parthenium argentatum, natural rubber from Taraxacum kok-saghyz, and the like.

[0042] The natural rubber (NR) includes a modified natural rubber obtained by modifying the aforementioned natural rubber. The modified natural rubber is preferably an epoxidized natural rubber, a methacrylic acid-modified natural rubber, a styrene-modified natural rubber, and the like.

[0043] The synthetic diene-based rubber is preferably 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 triblock copolymer (SIS), styrene-butadiene-styrene triblock copolymer (SBS), and the like.

[0044] The synthetic diene rubber includes a modified synthetic diene rubber obtained by modifying the aforementioned synthetic diene rubber. The modified synthetic diene rubber preferably includes a diene rubber obtained by a modification method such as main chain modification, mono-terminal modification, double-terminal modification, or the like. The modified functional group of the modified synthetic diene rubber is preferably various functional groups such as an epoxy group, an amino group, an alkoxysilyl group, a hydroxyl group, or the like, and one or two or more of these functional groups can be included in the modified synthetic diene rubber.

[0045] The method for producing the synthetic diene rubber is not particularly limited, and is emulsion polymerization, solution polymerization, radical polymerization, anionic polymerization, cationic polymerization, or the like. The glass transition temperature of the synthetic diene rubber is not particularly limited.

[0046] The ratio of cis / trans / vinyl group of the double bond portion of the natural rubber and the synthetic diene rubber is not particularly limited, and any ratio can be suitably used.

[0047] The number average molecular weight and the molecular weight distribution of the diene rubber are not particularly limited, and the number average molecular weight is preferably about 500 to 3,000,000, and the molecular weight distribution is preferably about 1.5 to 15.

[0048] As the rubber component, one of these rubber components can be used alone, or two or more can be mixed (blended) and used.

[0049] As the rubber component, the rubber composition preferably includes at least one rubber component selected from the group consisting of the aforementioned rubber components, more preferably at least one rubber component selected from the group consisting of NR, IR, SBR, and BR, and further preferably at least one rubber component selected from the group consisting of NR, SBR, and BR.

[0050] The rubber composition particularly preferably includes NR as the rubber component. The rubber composition preferably includes 30 parts by mass or more of NR, further preferably 50 parts by mass or more of NR, and particularly preferably 90 parts by mass or more of NR, in 100 parts by mass of the rubber component.

[0051] The blending ratio of the rubber component in the rubber composition is not particularly limited. As the blending ratio of the rubber component, NR, SBR, BR, or a mixture of two or more selected from them is preferably blended at a ratio of 50 parts by mass to 100 parts by mass, and further preferably at a ratio of 75 parts by mass to 100 parts by mass, in 100 parts by mass of the rubber component.

[0052] [1-2] Compound represented by formula (1) and / or salt thereof The rubber composition of the present application includes a compound represented by the following formula (1) and / or a salt thereof.

[0053] [Chemical Formula 3] in the formula, R 1 and R 2 are the same or different, and each represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, an acyl group, or R 1 and R 2 , taken together, represent an alkylidene group or an alkanediyl group.

[0054] in the formula, R 3 represents a hydrogen atom, an alkyl group, or an aryl group.

[0055] in the formula, R 4 and R 5 are the same or different, and each represents a hydrogen atom, an alkyl group, or R 4 and R 5 , taken together, represent an alkylidene group or an alkanediyl group.

[0056] in the formula, each of the above groups can have one or more substituents.

[0057] The alkyl group is not particularly limited. The alkyl group can be exemplified by a linear, branched, or cyclic alkyl group. The alkyl group is specifically a linear or branched alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a 1-ethylpropyl group, and the like, a linear or branched alkyl group having 5 to 18 carbon atoms such as an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an isohexyl group, a 3-methylpentyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, a 5-propylnonyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, and the like, and a cyclic alkyl group having 3 to 8 carbon atoms such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and the like.

[0058] The aralkyl group is not particularly limited. The aralkyl group is specifically a benzyl group, a phenethyl group, a trityl group, a 1-naphthylmethyl group, a 2-(1-naphthyl)ethyl group, a 2-(2-naphthyl)ethyl group, and the like.

[0059] The aryl group is not particularly limited. The aryl group is specifically a phenyl group, a biphenyl group, a naphthyl group, an indenyl group, a 9H-fluorenyl group, and the like.

[0060] The acyl group is not particularly limited. The acyl group is specifically a linear or branched alkylcarbonyl group having 1 to 4 carbon atoms such as an acetyl group, a propionyl group, a neopentanoyl group, and the like, an arylcarbonyl group such as a benzoyl group, a naphthoyl group, and the like.

[0061] The alkylidene group is not particularly limited. The alkylidene group is R 1 and R 2 , or R 4 and R 5Alkyl groups are groups that link together to form a ring structure. Specifically, alkylidenes include ethylene, propionyl, butyryl, pentyl, hexyl, and heptyl groups. Alkyl groups can contain nitrogen, oxygen, and sulfur atoms, and may also include benzoyl groups. Specific examples of such alkylidenes include -CH2NHCH2-, -CH2NHCH2CH2-, -CH2NHNHCH2-, -CH2CH2NHCH2CH2-, -CH2NHNHCH2CH2-, -CH2NHCH2NHCH2-, -CH2CH2CH2NHCH2CH2CH2-, -CH2OCH2CH2-, -CH2CH2OCH2CH2-, -CH2SCH2CH2-, -CH2CH2SCH2CH2-, and alkylidenes with the following structures.

[0062] [Chemical Formula 4] The alkyl subunit is not specifically defined. The alkyl subunit is R. 1 With R 2 、or R 4 With R 5 Groups that link together to form a double bond. Specifically, alkyl subunits include methyl subunits, ethyl subunits, propyl subunits, isopropyl subunits, butyl subunits, 1,3-dimethylpropyl subunits, etc.

[0063] In the formula, these alkyl, aralkyl, aryl, acyl, alkylidene or alkylidene groups may each have one or more substituents at any substituted position.

[0064] The substituents are not particularly limited. Preferred substituents 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, alkylthiols, arylthiols, etc. Preferably, there are 1 to 5 substituents, more preferably 1 to 3.

[0065] Specifically, halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., with chlorine atoms, bromine atoms, iodine atoms, etc. being preferred.

[0066] Specifically, besides the amino group represented by -NH2, the amino group can also be a straight-chain or branched monoalkyl amino group such as methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino, isobutylamino, sec-butylamino, tert-butylamino, 1-ethylpropylamino, n-pentylamino, neopentylamino, n-hexylamino, isohexylamino, and 3-methylpentylamino. The amino group is preferably a dialkylamino group having two straight-chain or branched alkyl groups, such as dimethylamino, ethylmethylamino, or diethylamino.

[0067] The term "aminoalkyl" is not specifically limited. Specifically, aminoalkyl includes aminomethyl, methylaminomethyl, ethylaminomethyl, dimethylaminomethyl, ethylmethylaminomethyl, diethylaminomethyl, 2-aminoethyl, 2-(methylamino)ethyl, 2-(ethylamino)ethyl, 2-(dimethylamino)ethyl, 2-(ethylmethylamino)ethyl, 2-(diethylamino)ethyl, 3-aminopropyl, 3-(methylamino)propyl, 3-(ethylamino)propyl, 3-(dimethylamino)propyl, 3-(ethylmethylamino)propyl, 3-(diethylamino)propyl, etc., as well as monoalkyl-substituted aminoalkyl or dialkyl-substituted aminoalkyl.

[0068] The alkoxycarbonyl group is not specifically defined. More specifically, alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, etc.

[0069] Acyl groups are not particularly limited, but examples include straight-chain or branched alkyl carbonyl groups with 1 to 4 carbon atoms, such as acetyl, propionyl, and neopentyl.

[0070] There is no specific definition for acyloxy groups. Acyloxy groups specifically include acetoxy, propionyloxy, and n-butyryloxy groups.

[0071] The amide group is not specifically limited. Specifically, the amide group includes carboxylic acid amide groups such as acetamide and benzamide, thioacetamide and thiobenzamide, N-methylacetamide, N-benzylacetamide, and other N-substituted amide groups.

[0072] There is no particular limitation on carboxyl alkyl groups. Specifically, carboxyl alkyl groups include carboxymethyl, carboxyethyl, carboxy-n-propyl, carboxy-n-butyl, carboxy-n-pentyl, carboxy-n-hexyl, and other carboxyl alkyl groups.

[0073] There is no particular limitation on hydroxyalkyl. Specifically, hydroxyalkyl includes hydroxymethyl, hydroxyethyl, hydroxy-n-propyl, hydroxy-n-butyl, and other hydroxy-alkyl compounds.

[0074] Alkoxy groups are not specifically defined. Alkoxy groups can be straight-chain, branched, or cyclic. Specifically, alkoxy groups include straight-chain or branched alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, n-pentoxy, neopentoxy, and n-hexyloxy, as well as cyclic alkoxy groups such as cyclopropoxy, cyclobutoxy, cyclopentoxy, cyclohexyloxy, cycloheptoxy, and cyclooctoxy.

[0075] There is no particular limitation on aryloxy groups. Specifically, aryloxy groups include phenoxy, biphenyloxy, naphthoxy, etc.

[0076] The heterocyclic group is not particularly limited. Specifically, the heterocyclic group includes 2-pyridinyl, 3-pyridinyl, 4-pyridinyl, 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 ...7-quinolinyl, 8-quinolinyl, 1-isoquinolinyl, 3-isoquinolinyl, 4-isoquinolinyl, 5-isoquinolinyl, -Isoquinolinyl, 7-isoquinolinyl, 8-isoquinolinyl, 2-quinoxalyl, 3-quinoxalyl, 5-quinoxalyl, 6-quinoxalyl, 7-quinoxalyl, 8-quinoxalyl, 3-cinnolyl, 4-cinnolyl, 5-cinnolyl, 6-cinnolyl, 7-cinnolyl, 8-cinnolyl, 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 Linol, 4-tetrahydroquinolinyl, 5-tetrahydroquinolinyl, 6-tetrahydroquinolinyl, 7-tetrahydroquinolinyl, 8-tetrahydroquinolinyl, 1-pyrrole, 2-pyrrole, 3-pyrrole, 2-furanyl, 3-furanyl, 2-thienyl, 3-thienyl, 1-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl, 1-pyrazolyl, 3-pyrazolyl, 4-pyrazolyl, 5-pyrazolyl, 1-pyrazolyl, 3-pyrazolyl, 4-pyrazolyl, 5-pyrazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isooxazolyl, 4-isooxazolyl, 5-isooxazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl, 4-(1,2,3) -thiadiazole), 5-(1,2,3-thiadiazole), 3-(1,2,5-thiadiazole), 2-(1,3,4-thiadiazole), 4-(1,2,3-oxadiazole), 5-(1,2,3-oxadiazole), 3-(1,2,4-oxadiazole), 5-(1,2,4-oxadiazole), 3-(1,2,5-oxadiazole), 2-(1,3,4-oxadiazole), 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-thiadiazole),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-benzothiophenyl, 3-benzothiophenyl, 4-benzothiophenyl, 5-benzothiophenyl, 6-benzothiophenyl, 7-benzothiophenyl Fenyl, 2-benzoxazolyl, 4-benzoxazolyl, 5-benzoxazolyl, 6-benzoxazolyl, 7-benzoxazolyl, 2-benzothiazolyl, 4-benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl, 1-indazolyl, 3-indazolyl, 4-indazolyl, 5-indazolyl, 6-indazolyl, 7-indazolyl, 2-morpholinyl, 3-morpholinyl, 4-morpholinyl, 1-piperazinyl, 2-piperazinyl, 1-piperidine The list includes 2-piperidinyl, 3-piperidinyl, 4-piperidinyl, 2-tetrahydropyranyl, 3-tetrahydropyranyl, 4-tetrahydropyranyl, 2-tetrahydrothiaranyl, 3-tetrahydrothiaranyl, 4-tetrahydrothiaranyl, 1-pyrrolidinyl, 2-pyrrolidinyl, 3-pyrrolidinyl, furanyl, 2-tetrahydrofuranyl, 3-tetrahydrofuranyl, 2-tetrahydrothiophenyl, 3-tetrahydrothiophenyl, 5-methyl-3-oxo-2,3-dihydro-1H-pyrazol-4-yl, etc.

[0077] With regard to the compound represented by formula (1) and / or its salt, wherein the following compound is preferred: R 1 and R 2 The same or different, respectively representing hydrogen atom, alkyl, aryl, acyl, or R 1 With R 2 When linked together, they represent alkyl subunits.

[0078] With regard to the compound represented by formula (1) and / or its salt, wherein, more preferably, the following compound: R 1 and R 2 All are hydrogen atoms.

[0079] With regard to the compound represented by formula (1) and / or its salt, wherein, more preferably, the following compound: R 1 and R 2 One of them is a hydrogen atom, and R 1 and R 2 One of them is alkyl or aryl.

[0080] With regard to the compound represented by formula (1) and / or its salt, wherein, more preferably, the following compound: R 1 With R 2 When linked together, they represent alkyl subunits.

[0081] With regard to the compound represented by formula (1) and / or its salt, the following compound is particularly preferred: R 1 and R 2 All are hydrogen atoms.

[0082] With regard to the compound represented by formula (1) and / or its salt, the following compound is particularly preferred: R 1 and R 2 One of them is a hydrogen atom, and R 1 and R 2 One of them is a straight-chain or branched alkyl, phenyl, or acetyl group with 1 to 4 carbon atoms.

[0083] With regard to the compound represented by formula (1) and / or its salt, the following compound is particularly preferred: R 1 With R 2 When linked together, they represent alkyl subunits.

[0084] With regard to the compound represented by formula (1) and / or its salt, wherein the following compound is preferred: R 3 It represents a hydrogen atom, a straight-chain or branched alkyl or aryl group (phenyl or naphthyl).

[0085] With regard to the compound represented by formula (1) and / or its salt, the following compound is particularly preferred: R 3 It refers to a straight-chain or branched alkyl or phenyl group with 1 to 4 hydrogen atoms and carbon atoms.

[0086] With regard to the compound represented by formula (1) and / or its salt, wherein the following compound is preferred: R 4 and R 5 The same or different, respectively, represent hydrogen atoms, alkyl groups, or R. 4 With R 5 When linked together, they represent alkyl subunits.

[0087] With regard to the compound represented by formula (1) and / or its salt, wherein, more preferably, the following compound: R 4 and R 5 All are hydrogen atoms.

[0088] With regard to the compound represented by formula (1) and / or its salt, wherein, more preferably, the following compound: R 4 and R 5 One of them is a hydrogen atom, and R 4 and R 5 One of them is an alkyl group.

[0089] With regard to the compound represented by formula (1) and / or its salt, wherein, more preferably, the following compound: R 4 With R 5 When linked together, they represent alkyl subunits.

[0090] With regard to the compound represented by formula (1) and / or its salt, the following compound is particularly preferred: R 4 and R 5 All are hydrogen atoms.

[0091] With regard to the compound represented by formula (1) and / or its salt, the following compound is particularly preferred: R 4 and R 5 One of them is a hydrogen atom, and R 4 and R 5 One of them is a straight-chain or branched alkyl group having 1 to 4 carbon atoms.

[0092] With regard to the compound represented by formula (1) and / or its salt, the following compound is particularly preferred: R 4 With R 5 When linked together, they represent alkyl subunits.

[0093] With regard to the compound represented by formula (1) and / or its salt, wherein the following compound is preferred: R 1 and R 2 The same or different, respectively representing hydrogen atom, alkyl, aryl, acyl, or R 1 With R 2 Together they represent alkyl subunits; R 3 R represents hydrogen atoms, alkyl groups, and aryl groups. 4 and R 5 The same or different, respectively representing hydrogen atoms or alkyl groups, or R 4 With R 5 When linked together, they represent alkyl subunits.

[0094] With regard to the compound represented by formula (1) and / or its salt, wherein, more preferably, the following compound: R 1 and R 2 The same or different, respectively representing hydrogen atom, alkyl, aryl, or R 1 With R 2 Together they represent alkyl subunits; R 3 Represents hydrogen atom, alkyl group, aryl group; R 4 and R 5 The same or different, respectively, represent hydrogen atoms, alkyl groups, or R. 4 With R 5 When linked together, they represent alkyl subunits.

[0095] With regard to the compound represented by formula (1) and / or its salt, the following compound is particularly preferred: R 1 and R 2 All are hydrogen atoms, R 1 and R 2 One of them is a hydrogen atom and R 1 and R 2 One of them is a straight-chain or branched alkyl or phenyl group having 1 to 4 carbon atoms, or R 1 With R 2 Together they represent alkyl subunits; R 3 It is a straight-chain or branched alkyl or phenyl group with 1 to 4 hydrogen atoms and carbon atoms; R 4 and R 5 All are hydrogen atoms, R 4 and R 5 One of them is a hydrogen atom and R 4 and R 5 One of them is a straight-chain or branched alkyl group having 1 to 4 carbon atoms, or R 4 With R 5 When linked together, they represent alkyl subunits.

[0096] Specifically, with regard to the compound represented by formula (1) and / or its salt, 3-amino-5-pyrazolone, 3-isopropylamino-5-pyrazolone, 3-phenylamino-5-pyrazolone, 3-acetylamino-5-pyrazolone, 3-dodecylamino-5-pyrazolone, 3-amino-1-methyl-5-pyrazolone, 3-amino-1-phenyl-5-pyrazolone, 3-amino-4-methyl-5-pyrazolone, and 3-amino-4-phenylalkyl-5-pyrazolone are preferred.

[0097] With regard to the compound represented by formula (1) and / or its salt, more preferably 3-amino-5-pyrazolone, 3-isopropylamino-5-pyrazolone, 3-phenylamino-5-pyrazolone, 3-dodecylamino-5-pyrazolone, 3-amino-1-methyl-5-pyrazolone, 3-amino-1-phenyl-5-pyrazolone, 3-amino-4-methyl-5-pyrazolone, and 3-amino-4-phenylalkyl-5-pyrazolone.

[0098] With regard to the compound represented by formula (1) and / or its salt, 3-amino-5-pyrazolone and 3-dodecylamino-5-pyrazolone are further preferred.

[0099] The compound represented by formula (1) produces tautomers. When tautomerization is possible (e.g., in solution), a chemical equilibrium of tautomers can be reached.

[0100] The compounds and / or their salts represented by formula (1) have reached an equilibrium state in which any of the tautomers coexist. Unless otherwise stated, the compounds and / or their salts represented by formula (1) included in this invention comprise all of the aforementioned tautomer forms.

[0101] The compound represented by formula (1) can be in the form of a salt. There are no particular limitations on the salt of the compound represented by formula (1), and it can include all kinds of salts.

[0102] 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 ammonium salts such as dimethylammonium and triethylammonium.

[0103] In the rubber composition of the present invention, relative to 100 parts by mass of rubber component, it is preferable to include 0.1 to 50 parts by mass of the compound represented by formula (1) and / or its salt, more preferably 0.1 to 20 parts by mass of the compound represented by formula (1) and / or its salt, even more preferably 0.2 to 10 parts by mass of the compound represented by formula (1) and / or its salt, and particularly preferably 0.5 to 5 parts by mass of the compound represented by formula (1) and / or its salt.

[0104] The rubber compositions of the present invention combine rubber components with specific pyrazolone compounds to achieve superior tear strength and low heat generation in vulcanized rubber. These rubber compositions exhibit increased tear strength after vulcanization, and tires manufactured using these compositions also exhibit improved fuel efficiency.

[0105] [1-3] Carbon black and / or inorganic filler The rubber composition of the present invention preferably further comprises carbon black and / or inorganic fillers.

[0106] Carbon black Carbon black is not included in the inorganic filler materials described in this specification.

[0107] Carbon black is used to improve the reinforcing properties of rubber.

[0108] There are no particular restrictions on carbon black. Examples of carbon black include commercially available carbon black and carbon-silica dual-phase fillers.

[0109] By including carbon black in the rubber components, the following effects can be achieved: reducing the rubber's resistance and suppressing its charge; and increasing the rubber's strength.

[0110] The carbon black is preferably high-, medium-, or low-structure carbon black of grades SAF, ISAF, IIAF, N110, N134, N220, N234, N330, N339, N375, N550, HAF, FEF, GPF, and SRF. The carbon black is preferably of grades SAF, ISAF, IIAF, N134, N234, N330, N339, N375, HAF, and FEF.

[0111] The preferred range for DBP absorption of carbon black is 60 cm⁻¹. 3 / 100g~200cm 3 / 100g, more preferably 70cm 3 / 100g~180cm 3 / 100g, preferably 80cm 3 / 100g~160cm 3 / 100g.

[0112] The nitrogen adsorption specific surface area (N2SA) of carbon black was determined according to JIS K6217-2:2001. The preferred range for the nitrogen adsorption specific surface area of ​​carbon black is 30 m². 2 / g~200m 2 / g, more preferably 40m 2 / g~180m 2 / g, preferably 50m 2 / g~160m 2 / g.

[0113] Inorganic filler As an inorganic filler, there are no particular restrictions; inorganic compounds commonly used in the rubber industry can be used.

[0114] The preferred inorganic compound is silicon dioxide.

[0115] The inorganic compound is preferably aluminum oxide (Al2O3) such as γ-alumina and α-alumina.

[0116] The inorganic compounds are preferably alumina monohydrates (Al2O3·H2O) such as boehmite and diaspore.

[0117] The inorganic compound is preferably aluminum hydroxide [Al(OH)3] such as gibbsite or diaspore.

[0118] The preferred inorganic compounds are aluminum carbonate [Al2(CO3)3], 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-1Calcium 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, MgSiO3, etc.), 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] 2· [nH2O], zirconium carbonate [Zr(CO3)2], zinc acrylate, zinc methacrylate, etc.

[0119] The inorganic compound is preferably a crystalline aluminosilicate containing hydrogen, alkali metal or alkaline earth metal for correcting charge, such as various zeolites.

[0120] In the case of inorganic filler materials, preferably, the surface of the inorganic compound can be organically treated in order to improve its affinity with the rubber component.

[0121] From the perspective of imparting strength to rubber, inorganic filler materials are preferably silica.

[0122] Silica is preferably wet silica, dry silica, or colloidal silica, and more preferably wet silica.

[0123] In the case of silica, preferably, the surface of silica can be organically treated to improve its affinity with rubber components.

[0124] The BET specific surface area of ​​silica was determined according to ISO 5794 / 1. The preferred range for the BET specific surface area of ​​silica is 40 μm². 2 / g~350m 2 The range is / g. Silica with a BET specific surface area in this range has the advantage of combining rubber-reinforcing properties with good dispersibility in rubber components. A more preferred BET specific surface area for silica is 80m². 2 / g~300m 2 / g, more preferably 100m 2 / g~270m 2 / g, preferably 110m 2 / g~270m 2 / g.

[0125] Commercially available silica products include, for example, the product "HD165MP" manufactured by Quechen Silicon Chemical Co., Ltd. (BET specific surface area = 165m²). 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), Degussa AG's trade name "Ultrasil VN3" (BET specific surface area = 175m²) 2 (g), etc.

[0126] Regarding carbon black and / or inorganic fillers, these carbon black and / or inorganic fillers can be used alone, or two or more can be mixed (blended) for use.

[0127] Blending amount of carbon black and / or inorganic filler In the rubber composition of the present invention, relative to 100 parts by weight of rubber component, it preferably contains 20 to 200 parts by weight of carbon black and / or inorganic filler, more preferably 30 to 130 parts by weight of carbon black and / or inorganic filler, and even more preferably 35 to 110 parts by weight of carbon black and / or inorganic filler.

[0128] From the viewpoint of improving the reinforcing properties of the rubber composition, the amount of carbon black and / or inorganic filler is preferably 20 parts by mass or more, and from the viewpoint of improving tear strength, it is preferably 200 parts by mass or less.

[0129] When combining carbon black and inorganic filler materials, the total amount of the two components can be adjusted appropriately within the aforementioned range.

[0130] The amount of carbon black in a compound relative to 100 parts by weight of rubber is preferably 2 to 200 parts by weight, more preferably 30 to 130 parts by weight, and even more preferably 35 to 100 parts by weight.

[0131] From the perspective of ensuring antistatic properties and rubber strength, the amount of carbon black added is preferably 2 parts by mass or more, and from the perspective of improving tear strength, it is preferably 200 parts by mass or less.

[0132] The proportion of inorganic filler material relative to 100 parts by weight of rubber component is preferably 2 to 200 parts by weight, more preferably 30 to 130 parts by weight, and even more preferably 35 to 100 parts by weight.

[0133] When silica is used as an inorganic filler, the amount of silica used is preferably 2 to 200 parts by mass relative to 100 parts by mass of rubber component, more preferably 30 to 130 parts by mass, and even more preferably 35 to 100 parts by mass.

[0134] [1-4] Other additives In the rubber composition of the present invention, in addition to the rubber component, the compound represented by formula (1) and / or its salt, and the carbon black and / or inorganic filler as required, appropriate compounding agents commonly used in the rubber industry can be selected and combined.

[0135] Compounding agents include, for example, anti-aging agents, anti-ozone agents, softeners, processing aids, waxes, resins, foaming agents, oils, zinc oxide (ZnO), stearic acid, vulcanization accelerators, vulcanization retarders, and vulcanizing agents (such as sulfur).

[0136] Silane coupling agent, etc. When the rubber composition of the present invention contains inorganic fillers such as carbon black and silica, for the purpose of improving the reinforcing properties of the rubber composition by utilizing carbon black and silica, improving the tear strength and abrasion resistance of the rubber composition, silane coupling agents, titanate coupling agents, aluminate coupling agents, zirconate coupling agents, etc., can be added to the rubber composition.

[0137] The preferred silane coupling agents are sulfide-based, polysulfide-based, thioester-based, thiol-based, olefin-based, epoxy-based, amino-based, and alkyl-based silane coupling agents.

[0138] The preferred titanate coupling agents are alkoxide-based, chelate-based, and acylate-based titanate coupling agents.

[0139] The preferred zirconate coupling agents are alkoxide-based, chelate-based, and acylate-based zirconate coupling agents.

[0140] Regarding silane coupling agents, titanate coupling agents, aluminate coupling agents, or zirconate coupling agents, these silane coupling agents, titanate coupling agents, aluminate coupling agents, or zirconate coupling agents can be used individually, or two or more can be mixed (blended) for use.

[0141] In the rubber composition of the present invention, the amount of silane coupling agent, titanate coupling agent, aluminate coupling agent, or zirconate coupling agent is preferably 0.1 to 20 parts by weight, more preferably 3 to 15 parts by weight, relative to 100 parts by weight of carbon black and / or inorganic filler. By setting the amount of silane coupling agent, titanate coupling agent, aluminate coupling agent, or zirconate coupling agent to 0.1 parts by weight or more relative to 100 parts by weight of carbon black and / or inorganic filler, the effect of improving the tear strength of the rubber composition can be better achieved; by setting it to 20 parts by weight or less, the cost of the rubber composition can be reduced, and the economy can be improved.

[0142] The rubber compositions of the present invention combine rubber components with specific pyrazolone compounds to achieve superior tear strength and low heat generation in vulcanized rubber. These rubber compositions exhibit increased tear strength after vulcanization, and tires manufactured using these compositions also exhibit improved fuel efficiency.

[0143] [2] Method for producing rubber composition The method for manufacturing the rubber composition of the present invention includes: (1) A process of mixing raw material components comprising a rubber component, a compound represented by formula (1) and / or its salt, and, as needed, carbon black and / or inorganic filler; and (2) A process of mixing the mixture obtained in the aforementioned process (1) with a vulcanizing agent (sulfur, etc.).

[0144] Step (1) Step (1) is a process of mixing raw material components including rubber components, compounds represented by formula (1) and / or their salts, and carbon black and / or inorganic fillers as needed, and is a process before the vulcanizing agent is applied.

[0145] The mixing method in step (1) is, for example, a method of mixing a composition containing raw material components such as rubber components, compounds represented by formula (1) and / or their salts, and carbon black and / or inorganic fillers as needed. In step (1), other compounding agents mentioned above can be added as needed.

[0146] In terms of mixing methods, the total amount of each component can be mixed at once, or the components can be added in batches for mixing purposes such as viscosity adjustment.

[0147] In terms of the mixing method, the rubber component can be mixed with carbon black and / or inorganic filler, and then the compound represented by formula (1) and / or its salt can be added for mixing, or the rubber component can be mixed with the compound represented by formula (1) and / or its salt, and then carbon black and / or inorganic filler can be added for mixing.

[0148] In terms of mixing methods, the mixing operation can be repeated in order to disperse the components evenly.

[0149] Regarding the mixing temperature of step (1), preferably, the upper limit of the temperature of the rubber composition is 100°C to 190°C, more preferably 110°C to 175°C, and even more preferably 120°C to 170°C.

[0150] The mixing time in process (1) is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 1 minute to 8 minutes.

[0151] Two-stage mixing of step (1) Other mixing methods for process (1) may include a two-stage mixing method comprising the following steps: Step (1-1) is the process of mixing the rubber component with a compound represented by formula (1) and / or its salt; and, Step (1-2) is a process of mixing the mixture obtained in the aforementioned step (1-1) with raw material components containing carbon black and / or inorganic filler materials.

[0152] The mixing temperature in step (1-1) is preferably 60℃~190℃, more preferably 70℃~160℃, and even more preferably 80℃~150℃. By adjusting the mixing temperature to 60℃~190℃, the reaction can proceed well and the deterioration of the rubber can be suppressed.

[0153] The mixing time for step (1-1) is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 60 seconds to 7 minutes. By adjusting the mixing time to 10 seconds to 20 minutes, the reaction can proceed well, thereby improving productivity.

[0154] Regarding the mixing temperature of process (1-2), preferably, the upper limit of the temperature of the mixture is 100℃~190℃, more preferably 130℃~175℃, and even more preferably 110℃~170℃.

[0155] The mixing time for process (1-2) is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 1 minute to 8 minutes.

[0156] In steps (1) and (1-1), the amount of compound and / or its salt represented by formula (1) is preferably 0.1 to 50 parts by mass relative to 100 parts by mass of rubber component, more preferably 0.1 to 20 parts by mass, and even more preferably 0.2 to 10 parts by mass.

[0157] When moving from process (1) to process (2), it is preferable to move to the next process (2) after the temperature has dropped by more than 30°C compared to the temperature at the end of process (1).

[0158] Step (2) Process (2) is the process of mixing the mixture obtained in process (1) with the vulcanizing agent (sulfur, etc.), and is the final stage of mixing.

[0159] In process (2), vulcanization accelerators and other additives can be added as needed.

[0160] Step (2) is preferably carried out under heating conditions, with the heating temperature preferably being 60℃~140℃, more preferably 80℃~120℃, and even more preferably 90℃~120℃.

[0161] The mixing (or kneading) time of step (2) is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 60 seconds to 5 minutes.

[0162] Addition of other additives In the method for manufacturing the rubber composition of the present invention, various compounding agents such as stearic acid, zinc oxide, vulcanization accelerator, and anti-aging agent can be added to the rubber composition in step (1) (step (1-1) and step (1-2)) and step (2) as needed.

[0163] Other compounding agents may be added in either step (1) and / or step (2), or may be added separately in steps (1) and (2).

[0164] The rubber compositions of the present invention combine rubber components with specific pyrazolone compounds to achieve superior tear strength and low heat generation in vulcanized rubber. These rubber compositions exhibit increased tear strength after vulcanization, and tires manufactured using these compositions also exhibit improved fuel efficiency.

[0165] [3] Tire The rubber composition of the present invention is preferably used in tires. The present invention includes tires made using the rubber composition of the present invention.

[0166] The rubber composition of the present invention is mixed or compounded using a Banbury mixer, roller, high-intensity mixer, kneader, single-screw extruder, twin-screw extruder, etc.

[0167] The rubber composition is then processed by extrusion in an extrusion process, for example, by molding it into tread or sidewall components.

[0168] Then, the rubber composition is bonded and molded on a tire forming machine using conventional methods to form a raw tire.

[0169] The raw tire is heated and pressurized in a vulcanizing machine to obtain a tire.

[0170] Tire and other uses The tires of the present invention are made using the rubber composition of the present invention.

[0171] The tires are preferably pneumatic tires (radial tires, bias-ply tires, etc.) or solid tires. The preferred applications are passenger car tires, high-load tires, motorcycle (motorized two-wheeled vehicle) tires, studless anti-skid tires, and large tires for trucks, buses, etc. More preferably, the tires are suitable for use as passenger car tires.

[0172] The shape, structure, size, and material of the tire of the present invention are not particularly limited, and can be appropriately selected according to the purpose.

[0173] In the tire of the present invention, preferred components include the tread portion, sidewall portion, bead area portion, belt layer portion, carcass portion, and shoulder portion.

[0174] The preferred components of a tire are the tire tread or the sidewall.

[0175] The tread portion is the part with the tread pattern that comes into direct contact with the road surface. It is the outer skin of the tire that protects the tire body and prevents wear and damage. Within the tread portion, the crown that forms the contact patch of the tire and / or the base tread located inside the crown are included. By applying the rubber composition of the present invention to the tread portion, which combines rubber components and specific pyrazolone compounds, the tread portion exhibits superior tear strength and low heat generation.

[0176] The sidewall portion, extending from the lower side of the shoulder to the bead portion of a pneumatic radial tire, protects the tire body and is the part that bends most violently during driving. By applying the rubber composition of the present invention to the sidewall portion, which combines rubber components and specific pyrazolone compounds, the sidewall portion exhibits superior tear strength and low heat generation.

[0177] The bead region serves to secure the two ends of the tire carcass cords and simultaneously fix the tire to the rim. The bead is a structure made of high-carbon steel bundled together. By applying the rubber composition of the present invention to the bead region, which combines rubber components and specific pyrazolone compounds, the bead region exhibits superior tear strength and low heat generation.

[0178] The belt layer is a reinforcing belt stretched circumferentially between the tread and carcass in a radial structure. Like a barrel hoop, it securely fastens the carcass, improving tread rigidity. By applying the rubber composition of the present invention to the belt layer, which combines rubber components and specific pyrazolone compounds, the belt layer exhibits superior tear strength and low heat generation.

[0179] The carcass portion, consisting of the cord layers that form the tire's skeleton, serves to withstand the loads, impacts, and air pressure borne by the tire. By applying the rubber composition of the present invention to the carcass portion, which combines rubber components and specific pyrazolone compounds, the carcass portion exhibits superior tear strength and low heat generation.

[0180] The tire shoulder is the shoulder portion of the tire, serving to protect the tire body. By applying the rubber composition of the present invention to the tire shoulder, which combines rubber components and specific pyrazolone compounds, the tire shoulder exhibits superior tear strength and low heat generation.

[0181] The tire of this invention can be manufactured using methods conventional in the tire industry. The gas filled in the tire is ordinary air or air with adjusted oxygen partial pressure; inert gases such as nitrogen, argon, and helium.

[0182] In addition to tire applications, the rubber composition of the present invention can also be preferably used in various rubber components such as anti-vibration rubber, shock-absorbing rubber, and conveyor belts.

[0183] The rubber compositions of the present invention combine rubber components with specific pyrazolone compounds to achieve superior tear strength and low heat generation in vulcanized rubber. These rubber compositions exhibit increased tear strength after vulcanization, and tires manufactured using these compositions also exhibit improved fuel efficiency.

[0184] Example The present invention will be specifically described below with examples of manufacturing and embodiments.

[0185] The embodiments are merely examples, and the present invention is not limited to the embodiments.

[0186] [1] Production of rubber composition of examples and comparative examples Step (1) The components listed in step (1) of Table 1 below are mixed in proportion (parts by mass) and then mixed using a Banbury mixer.

[0187] Step (2) Next, the mixture is cured until the temperature of the mixture is below 60°C, thereby producing an uncured rubber composition.

[0188] Next, the components listed in step (2) of Table 1 are added to the unvulcanized rubber composition in their respective proportions (parts by mass), and the mixture is kneaded while adjusting the mixture so that the highest temperature of the mixture is below 70°C.

[0189] Vulcanization step The uncured rubber composition was heated at 150°C for 25 minutes using a vulcanizing press to vulcanize it, thus obtaining a vulcanized rubber composition.

[0190] [2] Evaluation test [2-1] Tearing test: measurement of tearing strength of vulcanized rubber Based on JIS K6252, using crescent-shaped test pieces, the tear strength of the obtained vulcanized rubber composition was determined at room temperature and a tensile speed of 500 mm / min.

[0191] Regarding the tear strength index of the vulcanized rubber composition, when the tear strength value of Comparative Example 1 (an example of a compound not represented by formula (1)) is set to 100, it is expressed as an index and the tear strength is calculated based on the following formula.

[0192] Examples 1 and 2 are examples of compounds represented by formula (1).

[0193] The higher the tear strength index, the better the tear strength of the vulcanized rubber composition.

[0194] Formula: Tear Strength Index = (Tear strength of the vulcanized rubber compositions of Examples 1 and 2) / (Tear strength of the vulcanized rubber composition of Comparative Example 1) × 100 [2-2] Low heat generation test: measurement of Tan δ value The "Tanδ value" of the obtained vulcanized rubber composition was measured using a viscoelasticity measuring device (made by Metravib) at a temperature of 40°C, a dynamic strain of 5%, and a frequency of 15Hz.

[0195] Regarding the low heat generation index of the vulcanized rubber composition, the tear strength is calculated based on the following formula when the Tanδ value of Comparative Example 1 (an example of a compound not represented by formula (1)) is set to 100, expressed as an index.

[0196] Examples 1 and 2 are examples of compounds represented by formula (1).

[0197] The smaller the low heat generation index, the better the low heat generation of the vulcanized rubber composition and the smaller the hysteresis loss.

[0198] Formula: Low fever index = (Tanδ value of the vulcanized rubber compositions of Examples 1 and 2) / (Tanδ value of the vulcanized rubber composition of Comparative Example 1) × 100 The results of the tear strength index and handling stability index are shown in Table 1.

[0199] [Table 1] ※1: Natural rubber TSR-20 ※2: Carbon black, N234 grade ※3: Anti-aging agent, N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine ※4: Wax, manufactured by Rhein Chemie Rheinau, Antilux 111 ※5: Vulcanization accelerator, N-cyclohexyl-2-benzothiazole sulfenamide (CBS) ※6: Compound A, 3-amino-5-pyrazolone ※7: Compound B, 3-dodecylamino-5-pyrazolone [3] Explanation of evaluation test results [3-1] Tearing strength The rubber compositions of Examples 1 and 2 containing the compound represented by formula (1) have superior tear strength compared to the rubber composition of Comparative Example 1 (prior art).

[0200] Regarding the rubber composition of the present invention, the tear strength index of the vulcanized rubber composition is high, and it can be evaluated that the tear strength of the vulcanized rubber composition is improved.

[0201] [4-2] Low heat generation The rubber compositions of the compounds represented by formula (1) in Examples 1 and 2 exhibit superior low heat generation compared to the rubber composition of Comparative Example 1 (prior art).

[0202] Regarding the rubber composition of the present invention, the low heat generation index of the vulcanized rubber composition is low, which can be evaluated as an improvement in the low heat generation of the vulcanized rubber composition.

[0203] Industrial availability The rubber compositions of the present invention combine rubber components with specific pyrazolone compounds to achieve superior tear strength and low heat generation in vulcanized rubber. These rubber compositions exhibit increased tear strength after vulcanization, and tires manufactured using these compositions also exhibit improved fuel efficiency.

Claims

1. A rubber composition comprising a rubber component, and a compound represented by formula (1) below and / or a salt thereof, [Chemical Formula 1] In the formula, R 1 and R 2 The same or different, respectively representing hydrogen atom, alkyl, aralkyl, aryl, acyl, or R 1 With R 2 When linked together, they represent alkylidene groups or alkyl subgroups. In the formula, R 3 Indicates hydrogen atom, alkyl or aryl, In the formula, R 4 and R 5 The same or different, respectively, represent hydrogen atoms, alkyl groups, or R. 4 With R 5 When linked together, they represent alkylidene groups or alkyl subgroups. In the formula, each of the above groups may have one or more substituents.

2. The rubber composition according to claim 1, wherein, The compound represented by formula (1) is the following compound: R in the formula 1 and R 2 The same or different, respectively representing hydrogen atom, alkyl, aryl, acyl, or R 1 With R 2 Together they represent alkyl subunits. R 3 Indicates hydrogen atom, alkyl group, aryl group, R 4 and R 5 The same or different, respectively, represent hydrogen atoms, alkyl groups, or R. 4 With R 5 When linked together, they represent alkyl subunits.

3. The rubber composition according to claim 1, wherein, The compound represented by formula (1) is the following compound: R in the formula 1 and R 2 The same or different, respectively representing hydrogen atom, alkyl, aryl, or R 1 With R 2 Together they represent alkyl subunits. R 3 Indicates hydrogen atom, alkyl group, aryl group, R 4 and R 5 The same or different, respectively, represent hydrogen atoms, alkyl groups, or R. 4 With R 5 When linked together, they represent alkyl subunits.

4. The rubber composition of claim 1, wherein, The compound represented by formula (1) and / or its salt is at least one compound selected from the group consisting of 3-amino-5-pyrazolone, 3-isopropylamino-5-pyrazolone, 3-phenylamino-5-pyrazolone, 3-acetylamino-5-pyrazolone, 3-dodecylamino-5-pyrazolone, 3-amino-1-methyl-5-pyrazolone, 3-amino-1-phenyl-5-pyrazolone, 3-amino-4-methyl-5-pyrazolone and 3-amino-4-phenylalkyl-5-pyrazolone, and 3-amino-4-phenylalkyl-5-pyrazolone, and / or its salt.

5. The rubber composition according to claim 1, wherein, The compound represented by formula (1) and / or its salt is at least one compound selected from the group consisting of 3-amino-5-pyrazolone, 3-isopropylamino-5-pyrazolone, 3-phenylamino-5-pyrazolone, 3-dodecylamino-5-pyrazolone, 3-amino-1-methyl-5-pyrazolone, 3-amino-1-phenyl-5-pyrazolone, 3-amino-4-methyl-5-pyrazolone and 3-amino-4-phenylalkyl-5-pyrazolone, and 3-amino-4-phenylalkyl-5-pyrazolone.

6. The rubber composition of claim 1, wherein, The compound represented by formula (1) and / or its salt is at least one compound selected from the group consisting of 3-amino-5-pyrazolone and 3-dodecylamino-5-pyrazolone, and / or its salt.

7. The rubber composition of claim 1, wherein, The rubber component is at least one rubber component selected from the group consisting of natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, and butadiene rubber.

8. The rubber composition of claim 1, wherein, The rubber component is natural rubber.

9. The rubber composition of claim 1, further comprising carbon black and / or inorganic filler.

10. The rubber composition of claim 1, used in a tire.

11. A tire made using the rubber composition according to any one of claims 1 to 10.

Images