Constant viscosity agent for natural rubber raw materials, rubber composition, method for manufacturing the rubber composition, modified natural rubber, and method for manufacturing modified natural rubber.

Abstract

The object of the present invention is to provide a constant viscosity agent for natural rubber raw materials that exhibits excellent constant viscosity. [Solution] A constant viscosity agent for natural rubber raw materials, a rubber composition, a method for producing a rubber composition, modified natural rubber, and a method for producing modified natural rubber.

Description

[Technical Field]

[0001] The present invention relates to a constant viscosity agent for natural rubber raw materials, a rubber composition, a method for producing a rubber composition, modified natural rubber, and a method for producing modified natural rubber. [Background technology]

[0002] It is known that natural rubber increases in viscosity during transportation from production areas such as Southeast Asia to consumption areas. This is due to crosslinking and gelation, caused by the reaction of carbonyl groups in the isoprene chains of natural rubber with proteins in the rubber. Methods to suppress the increase in viscosity of natural rubber during transportation are being investigated.

[0003] One method for suppressing the increase in viscosity of natural rubber is to add an additive with constant viscosity properties (hereinafter referred to as a constant viscosity agent) to the rubber.

[0004] As an example of a viscosity constant agent, Patent Document 1 discloses a compound having an amino group or the like in a triazole skeleton. Patent Document 1 also discloses a method for suppressing the increase in viscosity of natural rubber by adding a triazole compound to natural rubber. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2006-213754 [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a constant viscosity agent for natural rubber raw materials that exhibits excellent constant viscosity. [Means for solving the problem]

[0007] The inventors have found that compounds having specific functional groups in the triazole and pyrrole skeletons have better constant viscosity properties compared to conventional triazole compounds (Patent Document 1).

[0008] Based on such findings, the inventor further investigated and as a result, completed the present invention. The present invention includes a constant viscosity agent for natural rubber raw materials as shown below.

[0009] Item 1. A constant viscosity agent for natural rubber raw materials, comprising a compound represented by at least one formula selected from the following general formulas (1), (2), and (3), or a salt of the compound.

[0010]

Chemical formula

[0011] In general formula (1), X 1 , X 2 , X 3 , and X 4 are the same or different and each represents a hydrogen atom or a hydrocarbon group. Any two of X 1 , X 2 , X 3 , and X 4 may combine together to form a cyclic structure. The hydrocarbon group may each have one or more substituents.

[0012]

Chemical formula

[0013] In general formula (2), X 5 , X 6 , X 7 , and X 8 are the same or different and each represents a hydrogen atom or a hydrocarbon group. The hydrocarbon group may each have one or more substituents. However, among the general formula (2), X 5 , X 6 , X 7 , and X 8However, this excludes compounds that consist entirely of hydrogen atoms.

[0014] [ka]

[0015] In general formula (3), X 9 , X 10 , X 11 , and X 12 These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each of the hydrocarbon groups may have one or more substituents.

[0016] Section 2. The above general formula (1) is X 1 , and X 2 A constant viscosity agent for natural rubber raw materials as described in item 1, wherein the hydrocarbon group is a compound in which these groups together form a cyclic structure.

[0017] Section 3. The above general formula (2) is X 5 , and X 6 A constant viscosity agent for natural rubber raw materials according to item 1, wherein at least one of the compounds is a hydrocarbon group.

[0018] Section 4. The above general formula (3) is X 9 , and X 10 A constant viscosity agent for natural rubber raw materials according to item 1, wherein at least one of the compounds is a hydrocarbon group.

[0019] Section 5. The constant viscosity agent for natural rubber raw materials according to claim 1, wherein the compound represented by the general formula (1), or a salt of said compound, is at least one compound selected from the group consisting of 1-amino-1H-indole, 1-aminopyrrole, and 9-aminocarbazole, or a salt of said compound.

[0020] The constant viscosity agent for natural rubber raw materials according to claim 1, wherein the compound represented by the general formula (2) above, or a salt of said compound, is at least one compound selected from the group consisting of N-(1-methylethyl)-4H-1,2,4-triazole-4-amine, N-(1-ethylpropyl)-1,2,4-triazole-4-amine, and N-(1,3-dimethylbutyl)-4H-1,2,4-triazole-4-amine, or a salt of said compound.

[0021] The constant viscosity agent for natural rubber raw materials according to claim 1, wherein the compound represented by the general formula (3) above, or a salt of said compound, is at least one compound selected from the group consisting of N-(1-methylethylidene)-4H-1,2,4-triazole-4-amine and N-(1,3-dimethylbutylidene)-4H-1,2,4-triazole-4-amine, or a salt of said compound.

[0022] Section 6. The constant viscosity agent for natural rubber raw materials according to claim 1, wherein the natural rubber raw material is at least one natural rubber material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex.

[0023] Section 7. A rubber composition, A constant viscosity agent for natural rubber raw materials as described in any one of items 1 to 6, and A rubber composition comprising a rubber component containing at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulations, and latex.

[0024] Section 8. Furthermore, the rubber composition according to item 7, comprising carbon black and / or an inorganic filler.

[0025] Section 9. A rubber mixture comprising rubber components including natural rubber, and optionally, further additives (except for the natural rubber raw material constant viscosity agents described in any one of items 1 to 6), A constant viscosity agent for natural rubber raw materials described in any one of items 1 to 6 and A method for producing a rubber composition, comprising the step of mixing the following.

[0026] Section 10. A method for producing the rubber composition according to claim 9, comprising the step of mixing carbon black and / or an inorganic filler (wherein the additive is excluding the carbon black and / or inorganic filler).

[0027] Section 11. A method for producing a rubber composition, A rubber mixture comprising a rubber component containing natural rubber latex solids, and optionally further additives (except for the constant viscosity agents for natural rubber raw materials described in any one of items 1 to 6), (A) A step of mixing with a constant viscosity agent for natural rubber raw materials as described in any one of items 1 to 6, This includes, and if necessary, at least one of the following steps (B) and (C): (B) A step of mixing carbon black and / or inorganic fillers, (C) Drying process, A method for producing a rubber composition.

[0028] Section 12. A method for producing a rubber composition, A rubber mixture comprising a rubber component containing natural rubber latex, and optionally further additives (except for the constant viscosity agents for natural rubber raw materials described in any one of items 1 to 6), (A) A step of mixing with a constant viscosity agent for natural rubber raw materials as described in any one of items 1 to 6, This includes, and, if necessary, at least one of the following steps (B), (C), and (D): (B) A step of mixing carbon black and / or inorganic fillers, (C) Solidification process, (D) Drying process, A method for producing a rubber composition.

[0029] Section 13. Modified natural rubber obtained by modifying at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex with a compound represented by at least one formula selected from the following general formulas (1), (2), and (3), or a salt of said compound.

[0030] [ka]

[0031] In general formula (1), X 1 , X 2 , X 3 , and X 4 These represent the same or different hydrogen atoms or hydrocarbon groups. 1 , X 2 , X 3 , and X 4 Any two of these may combine to form a cyclic structure. Each hydrocarbon group may have one or more substituents.

[0032] [ka]

[0033] In general formula (2), X 5 , X 6 , X 7 , and X 8 X represents the same or different hydrogen atom or hydrocarbon group. Each hydrocarbon group may have one or more substituents. However, among general formula (2), X 5 , X 6 , X 7 , and X 8 However, this excludes compounds that consist entirely of hydrogen atoms.

[0034] [ka]

[0035] In general formula (3), X 9 , X 10 , X 11, and X 12 These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each hydrocarbon group may have one or more substituents.

[0036] Section 14. A method for producing modified natural rubber, A method for producing modified natural rubber, comprising the step of modifying at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex with a compound represented by at least one formula selected from the following general formulas (1), (2), and (3), or a salt of said compound.

[0037] [ka]

[0038] In general formula (1), X 1 , X 2 , X 3 , and X 4 These represent the same or different hydrogen atoms or hydrocarbon groups. 1 , X 2 , X 3 , and X 4 Any two of these may combine to form a cyclic structure. Each hydrocarbon group may have one or more substituents.

[0039] [ka]

[0040] In general formula (2), X 5 , X 6 , X 7 , and X 8 X represents the same or different hydrogen atom or hydrocarbon group. Each hydrocarbon group may have one or more substituents. However, among general formula (2), X 5 , X 6 , X 7 , and X 8 However, this excludes compounds that consist entirely of hydrogen atoms.

[0041] [ka]

[0042] In general formula (3), X 9 , X 10 , X 11 , and X 12 These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each hydrocarbon group may have one or more substituents. [Effects of the Invention]

[0043] The constant viscosity agent of the present invention has superior constant viscosity properties. [Modes for carrying out the invention]

[0044] The present invention will be described in detail below. The embodiments illustrating the present invention are intended to provide a better understanding of the spirit of the invention and do not limit the scope of the invention unless otherwise specified.

[0045] In this specification, "contains" and "include" are concepts that include "comprise," "consist essentially of," and "consist of."

[0046] In this specification, when a numerical range is indicated as "A to B", it means "greater than or equal to A and less than or equal to B".

[0047] In this specification, when expressions such as parts and percentages are used, they generally represent parts by mass, parts by weight, mass%, or weight.

[0048] [1] Constant viscosity agent for natural rubber raw materials The constant viscosity agent for natural rubber raw materials of the present invention comprises a compound represented by at least one formula selected from the following general formulas (1), (2), and (3), or a salt of said compound.

[0049] [ka]

[0050] In general formula (1), X 1 , X 2 , X 3 , and X 4 X represents a hydrogen atom or a hydrocarbon group, either identical or distinct. 1 , X 2 , X 3 , and X 4 Any two of these may combine to form a cyclic structure. Each hydrocarbon group may have one or more substituents.

[0051] [ka]

[0052] In general formula (2), X 5 , X 6 , X 7 , and X 8 X represents the same or different hydrogen atom or hydrocarbon group. Each hydrocarbon group may have one or more substituents. However, among general formula (2), X 5 , X 6 , X 7 , and X 8 However, this excludes compounds that consist entirely of hydrogen atoms.

[0053] [ka]

[0054] In general formula (3), X 9 , X 10 , X 11 , and X 12 These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each hydrocarbon group may have one or more substituents.

[0055] There are no particular limitations on the hydrocarbon group. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Furthermore, the aliphatic hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, and may be linear, branched, or cyclic.

[0056] Examples of saturated hydrocarbon groups in aliphatic hydrocarbon groups include alkyl groups and alkylene groups.

[0057] Alkyl groups include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, 1-ethylpropyl, 2-ethylpropyl, n-pentyl, 1-methylbutyl, s-pentyl, isopentyl, neopentyl, n-hexyl, 1-methylpentyl, 1,3-dimethylbutyl, isohexyl, 1-isopropyl-2-methylpropyl, 1,4-dimethylpentyl, 3-methylpentyl, n-heptyl, 1-methylhexyl, 1-methylheptyl, n-octyl, 1-methylheptyl, 1-isobutyl-3-methylbutyl, 1-ethyl-3- These are linear or branched alkyl groups having 1 to 20 carbon atoms, such as methylpentyl, n-nonyl, 1-methyloctyl, n-decyl, 1-methylnosyl, n-undecyl, 1-methyldecyl, n-dodecyl, 1-methyldecyl, 5-propylnonyl, n-tridecyl, 1-methyldodecyl, n-tetradecyl, 1-methyltridecyl, n-pentadecyl, 1-methyltetradecyl, hexadecyl, 1-methylpentadecyl, heptadecyl, 1-methylhexadecyl, octadecyl, 1-methylheptadecyl, nonadecyl, 1-methyloctadecyl, eicosyl, and 1-methylnonadecyl.

[0058] Alkyl groups are cyclic alkyl groups having 3 to 10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclonosyl, and cyclodecyl.

[0059] The alkylene group is, for example, a linear or branched alkylene group such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, 1-methylethylene group, etc.

[0060] The alkylene group is, for example, a cyclic alkylene group such as cyclobutane-1,2-diyl, cyclopentane-1,2-diyl, cyclohexane-1,2-diyl, norbornylene, adamantylene group, etc.

[0061] The unsaturated hydrocarbon group of the aliphatic hydrocarbon group is, for example, an alkenyl group, an alkenylene group, etc.

[0062] The alkenyl group is, for example, vinyl, propenyl, isopropenyl, butenyl, pentenyl, hexenyl group, etc.

[0063] The alkenylene group is, for example, vinylene, propenylene, isopropenylene, butenylene, pentenylene, hexenylene group, etc.

[0064] Examples of the aromatic hydrocarbon group include an aryl group, an arylene group, etc.

[0065] Examples of the aryl group include phenyl, biphenyl, naphthyl, dihydroindenyl, 9H-fluorenyl group, etc.

[0066] Examples of the arylene group include 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, naphthylene group, etc.

[0067] X in General Formula (1) 1 , X 2 , X 3 , and X 4 When they are hydrocarbon groups (the hydrocarbon groups may each have one or more substituents), in the compound represented by General Formula (1), two hydrocarbon groups may combine to form a cyclic structure, for example, an alkylene group or an alkenylene group.

[0068] Furthermore, these hydrocarbon groups may each have one or more substituents at any substituted position. These substituents are not particularly limited.

[0069] The substituents are preferably halogen atoms, amino groups, aminoalkyl groups, alkoxycarbonyl groups, acyl groups, acyloxy groups, amide groups, carboxyl groups, carboxyalkyl groups, formyl groups, nitrile groups, nitro groups, alkyl groups, hydroxyalkyl groups, hydroxyl groups, alkoxy groups, aryl groups, aryloxy groups, heterocyclic groups, etc.

[0070] The hydrocarbon group may have, preferably, 1 to 3 substituents, more preferably 1 to 2 substituents.

[0071] The halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and more preferably a chlorine atom, a bromine atom, an iodine atom, etc.

[0072] The amino group is not limited to amino groups represented by -NH2, but preferably includes linear or branched monoalkylamino groups such as methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino, isobutylamino, s-butylamino, t-butylamino, 1-ethylpropylamino, n-pentylamino, neopentylamino, n-hexylamino, isohexylamino, and 3-methylpentylamino groups.

[0073] The amino group is preferably a substituted amino group such as a dialkylamino group having two linear or branched alkyl groups, such as dimethylamino, ethylmethylamino, or diethylamino.

[0074] The aminoalkyl group is preferably an aminoalkyl group such as 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, monoalkyl-substituted aminoalkyl group, or dialkyl-substituted aminoalkyl group.

[0075] The alkoxycarbonyl group is preferably a methoxycarbonyl group, an ethoxycarbonyl group, etc.

[0076] The acyl group is preferably a linear or branched alkylcarbonyl group having 1 to 4 carbon atoms, such as acetyl, propionyl, or pivaloyl.

[0077] The acyloxy group is preferably an acetyloxy, propionyloxy, or n-butyryloxy group.

[0078] The amide group is preferably a carboxylic acid amide group such as acetamide or benzamide. The amide group is preferably a thioamide group such as thioacetamide or thiobenzamide. The amide group is preferably an N-substituted amide group such as N-methylacetamide or N-benzylacetamide.

[0079] The carboxyalkyl group is preferably a carboxyalkyl group such as carboxymethyl, carboxyethyl, carboxy-n-propyl, carboxy-n-butyl, carboxy-n-pentyl, or carboxy-n-hexyl.

[0080] The hydroxyalkyl group is preferably a hydroxyalkyl group such as hydroxymethyl, hydroxyethyl, hydroxy-n-propyl, or hydroxy-n-butyl.

[0081] The alkoxy group is preferably a linear, branched, or cyclic alkoxy group. The alkoxy group is preferably a linear or branched alkoxy group such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, t-butoxy, n-pentyloxy, neopentyloxy, or n-hexyloxy. The alkoxy group is preferably a cyclic alkoxy group such as cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, cycloheptyloxy, or cyclooctyloxy.

[0082] The aryloxy group is preferably a phenoxy, biphenyloxy, naphthoxy, or the like.

[0083] The heterocyclic groups are preferably 4-(1,2,3-triazil), 5-(1,2,3-triazil), 2-(1,3,5-triazil), 3-(1,2,4-triazil), 5-(1,2,4-triazil), 6-(1,2,4-triazil), etc.

[0084] The heterocyclic groups are preferably 2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl, 2-quinoxalyl, 3-quinoxalyl, 5-quinoxalyl, 6-quinoxalyl, 7-quinoxalyl, 8-quinoxalyl, 3-sinnoryl, 4-sinnoryl, 5-sinnoryl, 6-sinnoryl, 7-sinnoryl, 8-sinnoryl, 2-quinazolyl, 4-quinazolyl, 5-quinazolyl, 6-quinazolyl, 7-quinazolyl, 8-quinazolyl, etc.

[0085] The heterocyclic group is preferably 1-phthalazyl, 4-phthalazyl, 5-phthalazyl, 6-phthalazyl, 7-phthalazyl, 8-phthalazyl, 1-tetrahydroquinolyl, 2-tetrahydroquinolyl, 3-tetrahydroquinolyl, 4-tetrahydroquinolyl, 5-tetrahydroquinolyl, 6-tetrahydroquinolyl, 7-tetrahydroquinolyl, 8-tetrahydroquinolyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 1-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl, 1-pyrazolyl, 3-pyrazolyl, 4-pyrazolyl, 5-pyrazolyl, etc.

[0086] The heterocyclic group is preferably 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), etc.

[0087] The heterocyclic group is preferably 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-(1,2,4-triazolyl), etc.

[0088] The heterocyclic group is preferably 1-tetrazolyl, 5-tetrazolyl, 1-indolyl, 2-indolyl, 3-indolyl, 4-indolyl, 5-indolyl, 6-indolyl, 7-indolyl, 1-isoindolyl, 2-isoindolyl, 3-isoindolyl, 4-isoindolyl, 5-isoindolyl, 6-isoindolyl, 7-isoindolyl, etc.

[0089] The heterocyclic group is preferably 1-benzimidazolyl, 2-benzimidazolyl, 4-benzimidazolyl, 5-benzimidazolyl, 6-benzimidazolyl, 7-benzimidazolyl, etc.

[0090] The heterocyclic group is preferably 2-benzofuranyl, 3-benzofuranyl, 4-benzofuranyl, 5-benzofuranyl, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-isobenzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-isobenzofuranyl, 7-isobenzofuranyl, etc.

[0091] The heterocyclic group is preferably 2-benzothienyl, 3-benzothienyl, 4-benzothienyl, 5-benzothienyl, 6-benzothienyl, 7-benzothienyl, 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, etc.

[0092] The heterocyclic group is preferably 2-morpholyl, 3-morpholyl, 4-morpholyl, 1-piperazyl, 2-piperazyl, 1-piperidyl, 2-piperidyl, 3-piperidyl, 4-piperidyl, 2-tetrahydropyranyl, 3-tetrahydropyranyl, 4-tetrahydropyranyl, 2-tetrahydrothiopyranyl, 3-tetrahydrothiopyranyl, 4-tetrahydrothiopyranyl, 1-pyrrolidyl, 2-pyrrolidyl, 3-pyrrolidyl, etc.

[0093] The heterocyclic group is preferably furanyl, 2-tetrahydrofuranyl, 3-tetrahydrofuranyl, 2-tetrahydrothienyl, 3-tetrahydrothienyl, or 5-methyl-3-oxo-2,3-dihydro-1H-pyrazole-4-yl group.

[0094] The constant viscosity agent for natural rubber raw materials of the present invention contains a compound represented by the following general formula (1) or a salt of the compound.

[0095]

Chemical formula

[0096] In general formula (1), X 1 , X 2 , X 3 , and X 4 are the same or different and represent a hydrogen atom or a hydrocarbon group. Any two of X 1 , X 2 , X 3 , and X 4 may combine together to form a cyclic structure. The hydrocarbon group may each have one or more substituents.

[0097] Among the compounds represented by general formula (1), preferably, X 1 , and X 2 are hydrocarbon groups and these combine together to form a cyclic structure.

[0098] Examples of the compound represented by general formula (1) include 1-amino-1H-indole, 1-aminopyrrole, 9-aminocarbazole, tetrahydroindole-1-amine, 1,2,4,5,6,7,8-octahydrocarbazole-9-amine, etc. Among them, 1-amino-1H-indole, 1-aminopyrrole, and 9-aminocarbazole are preferred.

[0099] The constant viscosity agent for natural rubber raw materials of the present invention contains a compound represented by the following general formula (2) or a salt of the compound.

[0100]

Chemical formula

[0101] In general formula (2), X 5 , X6 , X 7 , and X 8 X represents the same or different hydrogen atom or hydrocarbon group. Each hydrocarbon group may have one or more substituents. However, among general formula (2), X 5 , X 6 , X 7 , and X 8 However, this excludes compounds that consist entirely of hydrogen atoms.

[0102] Among the compounds represented by general formula (2), X 5 , and X 6 It is a compound in which at least one of the groups is a hydrocarbon group.

[0103] Examples of compounds represented by general formula (2) include N-(1-methylethyl)-4H-1,2,4-triazole-4-amine, N-sec-butyl-1,2,4-triazole-4-amine, N-(1-methylpentyl)-1,2,4-triazole-4-amine, N-(1-ethylpropyl)-1,2,4-triazole-4-amine, N-(1,3-dimethylbutyl)-4H-1,2,4-triazole-4-amine, N-(1-ethylbutyl)-1,2,4-triazole-4-amine, N-(1-propylbutyl)-1,2,4-triazole-4-amine, and N-cyclohexyl-1,2,4-triazole-4-amine, among which N-(1-methylethyl)-4H-1,2,4-triazole-4-amine is preferred.

[0104] The constant viscosity agent for natural rubber raw materials of the present invention comprises a compound represented by the following general formula (3), or a salt of said compound.

[0105] [ka]

[0106] In general formula (3), X 9 , X 10 , X 11 , and X 12These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each hydrocarbon group may have one or more substituents.

[0107] Among the compounds represented by general formula (3), X 9 , and X 10 It is a compound in which at least one of the groups is a hydrocarbon group.

[0108] Compounds represented by general formula (3) include, for example, N-(1-methylethylidene)-4H-1,2,4-triazole-4-amine, N-(1,3-dimethylbutylidene)-4H-1,2,4-triazole-4-amine, N-(1,2,4-triazole-4H-yl)butane-2-imine, N-(1,2,4-triazole-4H-yl)pentan-3-imine, N-(1,2,4-triazole-4H-yl)hexane-2-imine, and N-(1,2,4-triazole-4H-yl)butane-2-imine. Examples include N-(1,2,4-triazole-4H-yl)pentan-3-imine, N-(1,2,4-triazole-4H-yl)hexane-3-imine, N-(1,2,4-triazole-4H-yl)heptan-4-imine, and N-(1,2,4-triazole-4H-yl)hexaneimine, among which N-(1-methylethylidene)-4H-1,2,4-triazole-4-amine and N-(1,3-dimethylbutylidene)-4H-1,2,4-triazole-4-amine are preferred.

[0109] When the constant viscosity agent of the present invention is added to natural rubber raw materials, it is believed that at least one compound represented by general formulas (1), (2), and (3) contained in the constant viscosity agent of the present invention, or a salt of said compound, destroys the crosslinking points in the natural rubber or reacts with the crosslinking points of the natural rubber, thereby preventing the gelation of the natural rubber and, as a result, suppressing the increase in the viscosity of the natural rubber.

[0110] Among the compounds represented by at least one formula selected from the above general formulas (1), (2), and (3), compounds having hydrophobic hydrocarbon groups can prevent the formation of hydrogen bonds between hydrophilic groups at the ends of molecules of natural rubber raw materials, thereby exhibiting higher viscosity.

[0111] [2] Rubber composition The rubber composition of the present invention comprises a rubber component containing at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex, and a constant viscosity agent for natural rubber raw materials of the present invention.

[0112] [2-1] Rubber component The rubber composition of the present invention comprises a rubber component containing at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex.

[0113] Natural rubber raw materials include various forms of natural rubber raw materials, such as latex extracted from rubber trees, natural rubber latex solids obtained by adding coagulants to the latex and solidifying it, and natural rubber obtained by drying the natural rubber latex solids.

[0114] Latex is not particularly limited as long as it is a liquid. Examples of latex include field latex extracted from rubber trees and concentrated latex obtained by processing field latex.

[0115] Natural rubber latex solids are not particularly limited as long as they are made by solidifying latex. Examples of natural rubber latex solids include those made by adding a coagulant to latex and allowing it to solidify.

[0116] Natural rubber is not particularly limited as long as it is a dried natural rubber latex solid. Examples of natural rubber include natural rubber latex solid dried with hot air. Natural rubber also includes modified natural rubber and modified natural rubber.

[0117] If natural rubber without a viscosity constant agent is left standing, it will gel and its viscosity will increase. By kneading the natural rubber, it returns to its pre-gelling state. The agent can also be applied to natural rubber in this state. Alternatively, natural rubber that has already gelled and been kneaded can also be used.

[0118] Other types of rubber besides natural rubber raw materials may also be added as rubber components, such as synthetic diene rubber and non-diene rubber.

[0119] The synthetic diene rubbers are 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 terblock copolymer (SIS), styrene-butadiene-styrene terblock copolymer (SBS), etc.

[0120] The synthetic diene rubber includes modified synthetic diene rubber obtained by modifying the aforementioned synthetic diene rubber. The modified synthetic diene rubber preferably includes diene rubber obtained by modification methods such as main chain modification, one-end modification, or both-end modification. The modified functional groups of the modified synthetic diene rubber are preferably various functional groups such as epoxy groups, amino groups, alkoxysilyl groups, and hydroxyl groups, and one or more of these functional groups may be included in the modified synthetic diene rubber.

[0121] There are no particular limitations on the method for producing synthetic diene rubber. Preferably, the method for producing synthetic diene rubber is emulsion polymerization, solution polymerization, radical polymerization, anionic polymerization, cationic polymerization, etc. There are no particular limitations on the glass transition temperature of synthetic diene rubber.

[0122] There are no particular limitations on the cis / trans / vinyl ratio of the double bond in natural rubber and synthetic diene rubber; any ratio can be suitably used.

[0123] There are no particular limitations on the number-average molecular weight and molecular weight distribution of diene rubber. Preferably, the number-average molecular weight of diene rubber is around 500 to 3,000,000, and the molecular weight distribution is preferably around 1.5 to 15.

[0124] As non-diene rubbers, a wide range of known types can be used.

[0125] The rubber components may be used individually or in a mixture (blend) of two or more types.

[0126] The rubber composition of the present invention contains 5 parts by mass or more, and preferably 10 parts by mass or more, of the above-mentioned natural rubber raw material per 100 parts by mass of the rubber component.

[0127] [2-2] Constant viscosity agent for natural rubber raw materials The rubber composition of the present invention contains the above-described constant viscosity agent for natural rubber raw materials of the present invention.

[0128] The content of the constant viscosity agent for natural rubber raw materials of the present invention in the rubber composition is 0.01 parts by mass or more, preferably 0.02 parts by mass or more, more preferably 0.03 parts by mass or more, particularly preferably 0.05 parts by mass or more, and 5 parts by mass or less, preferably 2 parts by mass or less, more preferably 1 part by mass or less, particularly preferably 0.5 parts by mass or less, per 100 parts by mass of rubber components.

[0129] When the constant viscosity agent of the present invention is added to natural rubber, it is believed that the compounds represented by at least one formula selected from general formulas (1), (2), and (3) contained in the constant viscosity agent of the present invention, or salts of said compounds, destroy the crosslinking points in the natural rubber or react with the crosslinking points of the natural rubber, thereby preventing the gelation of the natural rubber and suppressing the increase in viscosity of the natural rubber. Therefore, the rubber composition of the present invention has excellent constant viscosity.

[0130] [2-3] Carbon black and / or inorganic fillers The rubber composition of the present invention preferably further comprises carbon black and / or an inorganic filler. In this specification, the inorganic filler does not contain carbon black.

[0131] Carbon Black Carbon black is used to improve the reinforcing properties of rubber. By including carbon black in the rubber component, it is possible to reduce the electrical resistance of the rubber, suppress static electricity, and further improve the strength of the rubber.

[0132] There are no particular restrictions on the type of carbon black used. Examples of carbon black include commercially available carbon black, Carbon-Silica Dual Phase Filler, etc.

[0133] The carbon black is preferably SAF, ISAF, IISAF, N110, N134, N220, N234, N330, N339, N375, N550, HAF, FEF, GPF, SRF grade carbon black, etc.

[0134] The range of DBP absorption by carbon black is preferably 60 cm 3 / 100g~200cm 3 / 100g, more preferably 70cm 3 / 100g~180cm 3 / 100g, particularly preferably 80cm 3 / 100g~160cm 3 It is / 100g.

[0135] The nitrogen adsorption specific surface area (N2SA) of carbon black is measured in accordance with JIS K6217-2:2001. The range of the nitrogen adsorption specific surface area of ​​carbon black is preferably 30 m². 2 / g~200m 2 / g, more preferably 40m2 / g~180m 2 / g, and particularly preferably 50m 2 / g~160m 2 It is / g.

[0136] inorganic filler There are no particular limitations on the inorganic filler. The inorganic filler used is typically an inorganic compound commonly used in the rubber industry.

[0137] The inorganic compound is preferably silica. The inorganic compound is preferably alumina (Al2O3), such as γ-alumina or α-alumina. The inorganic compound is preferably alumina monohydrate (Al2O3·H2O), such as boehmite or diaspore. The inorganic compound is preferably aluminum hydroxide [Al(OH)3], such as gibbsite or bayerite. The inorganic compound is preferably a crystalline aluminosilicate containing hydrogen, alkali metals, or alkaline earth metals to correct the charge, as in various zeolites.

[0138] The inorganic compounds are preferably aluminum carbonate [Al2(CO3)3], magnesium hydroxide [Mg(OH)2], magnesium oxide (MgO), magnesium carbonate (MgCO3), talc (3MgO·4SiO2·H2O), attapulgite (5MgO·8SiO2·9H2O), titanium white (TiO2), 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 These include um (Mg2SiO4, MgSiO3, etc.), calcium silicate (Ca2·SiO4, etc.), aluminum calcium silicate (Al2O3·CaO·2SiO2, etc.), magnesium calcium silicate (CaMgSiO4), calcium carbonate (CaCO3), zirconium oxide (ZrO2), zirconium hydroxide [ZrO(OH)2·nH2O], zirconium carbonate [Zr(CO3)2], zinc acrylate, zinc methacrylate, etc.

[0139] Preferably, the inorganic filler may have its surface organically treated to improve its affinity with the rubber component.

[0140] The inorganic filler is preferably silica, from the viewpoint of being able to impart rubber strength. The silica is preferably wet silica, dry silica, or colloidal silica, and more preferably wet silica. The silica surface may be organically treated to improve its affinity with the rubber component.

[0141] The BET specific surface area of ​​silica is measured in accordance with ISO 5794 / 1. The BET specific surface area range of silica is preferably 40 m². 2 / g~350m 2 The BET specific surface area is in the range of / g. Silica with a BET specific surface area in this range has the advantage of being able to achieve both rubber reinforcing properties and dispersibility in rubber components. The BET specific surface area of ​​silica is more preferably 80m². 2 / g~300m 2 It is / g, more preferably 100m 2 / g~270m 2 / g, and particularly preferably 110m 2 / g~270m2 It is / g.

[0142] Commercially available silica products include, for example, the product name "HD165MP" manufactured by Quechen Silicon Chemical Co., Ltd. (BET specific surface area = 165 m²). 2 / g), "HD115MP" (BET specific surface area = 115m 2 / g), "HD200MP" (BET specific surface area = 200m 2 / g), "HD250MP" (BET specific surface area = 250m 2 / g), product name "NipSeal AQ" manufactured by Tosoh Silica Co., Ltd. (BET specific surface area = 205m²) 2 / g), "NipSeal KQ" (BET specific surface area = 240m²) 2 / g), Degussa's product name "UltraZil VN3" (BET specific surface area = 175m²) 2 (e.g., / g) etc.

[0143] Carbon black and / or inorganic fillers may be used individually or in combination (blended) of two or more types.

[0144] Amount of carbon black and / or inorganic filler The rubber composition of the present invention contains, with respect to 100 parts by mass of rubber component, preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 120 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, carbon black and / or inorganic filler. When both carbon black and inorganic filler are included, the total amount of both components may be adjusted as appropriate so that it falls within the above range.

[0145] The amount of carbon black added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component. From the viewpoint of ensuring rubber strength performance, the amount of carbon black added is preferably 30 parts by mass or more, and from the viewpoint of low fuel consumption or improved workability, it is preferably 60 parts by mass or less.

[0146] The amount of inorganic filler (such as silica) added is preferably 5 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 35 parts by mass or more, preferably 85 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 75 parts by mass or less, per 100 parts by mass of rubber component.

[0147] Silane coupling agents, etc. If the rubber composition of the present invention contains inorganic fillers such as carbon black and silica, silane coupling agents, titanate coupling agents, aluminate coupling agents, zirconate coupling agents, etc., may be added to the rubber composition for the purpose of further enhancing the reinforcing properties of the rubber composition by carbon black, silica, etc., and for the purpose of further enhancing the abrasion resistance along with the tear strength of the rubber composition.

[0148] The silane coupling agent is preferably a sulfide-based, polysulfide-based, thioester-based, thiol-based, olefin-based, epoxy-based, amino-based, or alkyl-based silane coupling agent.

[0149] The titanate coupling agent is preferably a titanate coupling agent such as an alkoxide, chelating agent, or acylate agent.

[0150] The zirconate coupling agent is preferably an alkoxide, chelating, or acylate type zirconate coupling agent.

[0151] Silane coupling agents, titanate coupling agents, aluminate coupling agents, or zirconate coupling agents may be used individually or in combination (blended) of two or more types.

[0152] In the rubber composition of the present invention, the amount of silane coupling agent, titanate coupling agent, aluminate coupling agent, or zirconate coupling agent blended is preferably 0.1 parts by mass or more, more preferably 3 parts by mass or more, preferably 20 parts by mass or less, and more preferably 15 parts by mass or less, per 100 parts by mass of carbon black and / or inorganic filler. By blending the silane coupling agent, titanate coupling agent, aluminate coupling agent, or zirconate coupling agent at 0.1 parts by mass or more per 100 parts by mass of carbon black and / or inorganic filler, the effect of improving the tear strength of the rubber composition can be more favorably expressed, and by setting it to 20 parts by mass or less, the cost of the rubber composition can be reduced and economic efficiency can be improved.

[0153] [2-4] Additives (except for the natural rubber raw material constant viscosity agent of the present invention) The rubber composition of the present invention may contain, as appropriate, rubber components, the viscosity constant agent for natural rubber raw materials of the present invention, and, if necessary, carbon black and / or inorganic fillers, in addition to additives commonly used in the rubber industry (except for the viscosity constant agent for natural rubber raw materials of the present invention).

[0154] Additives include, for example, antioxidants, ozone inhibitors, softeners, processing aids, waxes, resins, foaming agents, oils, zinc oxide (ZnO), stearic acid, vulcanization accelerators, vulcanization retarders, and vulcanizing agents (such as sulfur). Note that the additives exclude the carbon black and / or inorganic fillers.

[0155] [3] Method for producing rubber composition The present invention includes a method for producing the rubber composition of the present invention.

[0156] (1) Extract latex from rubber trees. (2) A coagulant is added to the latex and allowed to solidify, thereby preparing a natural rubber latex solid. (3) Dry the natural rubber latex solids to prepare natural rubber (product).

[0157] The method for producing the rubber composition of the present invention is not particularly limited, as long as it can produce the rubber composition of the present invention, but the following method is preferred.

[0158] Manufacturing method (a) The method for producing the rubber composition of the present invention (a) includes the following steps. A rubber mixture comprising rubber components including natural rubber, and optionally, further additives (however, the additives are excluding the natural rubber raw material constant viscosity agent of the present invention), A step of mixing the present invention with a constant viscosity agent for natural rubber raw materials.

[0159] Specifically, the manufacturing method includes the following steps:

[0160] (a1) (a1-1) A step of mixing a rubber component containing natural rubber with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture.

[0161] (a1') (a1'-1) A step of mixing a rubber mixture containing a rubber component including natural rubber and an additive (except the constant viscosity agent for natural rubber raw materials of the present invention) with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture.

[0162] If the natural rubber used has gelled, a kneading operation should be performed before carrying out steps (a1-1) and (a1'-1).

[0163] In steps (a1-1) and (a1'-1), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0164] The mixing temperature in steps (a1-1) and (a1'-1) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0165] The mixing time for steps (a1-1) and (a'-1) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0166] The additives used in step (a1'-1) include those mentioned above.

[0167] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0168] Furthermore, the method for producing the rubber composition of the present invention (a) may also include the following steps in addition to the step (a1) described above. A step of mixing carbon black and / or inorganic fillers (except that the additives exclude the carbon black and / or inorganic fillers).

[0169] Specifically, the manufacturing method includes the following steps:

[0170] (a2) (a2-1) A step of mixing a rubber component containing natural rubber with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture, and (a2-2) A step of mixing the mixture obtained in (a2-1) with carbon black and / or an inorganic filler.

[0171] (a2') (a2'-1) A step of mixing a rubber mixture containing a rubber component including natural rubber and an additive (however, the additive is excluding the natural rubber raw material constant viscosity agent of the present invention) with the natural rubber raw material constant viscosity agent of the present invention to obtain a mixture, and (a2'-2) A step of mixing the mixture obtained in (a2'-1) with carbon black and / or an inorganic filler.

[0172] If the natural rubber used has gelled, a kneading operation should be performed before carrying out steps (a2-1) and (a2'-1).

[0173] In steps (a2-1) and (a2'-1), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0174] The mixing temperature in steps (a2-1) and (a2'-1) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0175] The mixing time for steps (a2-1) and (a2'-1) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0176] The additives used in step (a2'-1) include those mentioned above.

[0177] In steps (a2-2) and (a2'-2), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0178] The mixing temperature in steps (a2-2) and (a2'-2) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0179] The mixing time for steps (a2-2) and (a2'-2) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0180] The above-mentioned additives may be added in steps (a2-2) and (a2'-2).

[0181] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0182] Other specific manufacturing methods include the following steps:

[0183] (a3) (a3-1) Rubber components including natural rubber, carbon black, and / or inorganic fillers The process of mixing and to obtain a mixture, (a3-2) A step of mixing the mixture obtained in (a3-1) with the constant viscosity agent for natural rubber raw materials of the present invention.

[0184] (a3') (a3'-1) A step of mixing carbon black and / or an inorganic filler with a rubber mixture containing a rubber component including natural rubber and an additive (however, the additive is excluding the natural rubber raw material constant viscosity agent of the present invention) to obtain a mixture, and (a3'-2) A step of mixing the mixture obtained in (a3'-1) with the constant viscosity agent for natural rubber raw materials of the present invention.

[0185] If the natural rubber used has gelled, a kneading operation should be performed before carrying out steps (a3-1) and (a3'-1).

[0186] In steps (a3-1) and (a3'-1), the compounding amount of carbon black and / or inorganic filler is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, still more preferably 30 parts by mass or more, and preferably 100 parts by mass or less, more preferably 80 parts by mass or less, still more preferably 60 parts by mass or less, based on 100 parts by mass of the rubber component.

[0187] The mixing temperature in steps (a3-1) and (a3'-1) is preferably 50°C or higher, more preferably 80°C or higher, and preferably 170°C or lower, more preferably 150°C or lower.

[0188] The mixing time in steps (a3-1) and (a3'-1) is preferably 30 seconds or longer, more preferably 60 seconds or longer, and preferably 10 minutes or shorter, more preferably 5 minutes or shorter.

[0189] In steps (a3-1) and (a3'-1), the compounding amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 part by mass or more, more preferably 0.02 part by mass or more, still more preferably 0.03 part by mass or more, and preferably 5 parts by mass or less, more preferably 2 parts by mass or less, still more preferably 1 part by mass or less, based on 100 parts by mass of the rubber component.

[0190] The additives in step (a3'-1) include the above-mentioned additives.

[0191] For the mixing method, in order to uniformly disperse each component, the mixing operation may be repeated.

[0192] The mixing temperature in steps (a3-2) and (a3'-2) is preferably 50°C or higher, more preferably 80°C or higher, and preferably 170°C or lower, more preferably 150°C or lower.

[0193] The mixing time in steps (a3-2) and (a3'-2) is preferably 30 seconds or longer, more preferably 60 seconds or longer, and preferably 10 minutes or shorter, more preferably 5 minutes or shorter.

[0194] The above-mentioned additives may be added in steps (a3-2) and (a3'-2).

[0195] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0196] Manufacturing method (b) The method for producing the rubber composition of the present invention (b) includes the following steps.

[0197] A rubber mixture containing a rubber component including a natural rubber latex coagulation, and optionally further containing additives (however, the additives are excluding the constant viscosity agent for natural rubber raw materials of the present invention), (A) The process includes mixing with the present invention's constant viscosity agent for natural rubber raw materials, Furthermore, if necessary, the process may include at least one of the following steps (B) and (C). (B) A step of mixing carbon black and / or inorganic fillers. (C) Drying process.

[0198] Specifically, the manufacturing method includes the following steps:

[0199] (b1) (b1-1) A step of mixing a rubber component containing natural rubber latex coagulation with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture. (b1-2) A step of drying the mixture obtained in (b1-1) above to obtain natural rubber from the natural rubber latex solid, and (b1-3) If necessary, a step of mixing the mixture containing natural rubber obtained in (b1-2) with carbon black and / or an inorganic filler.

[0200] (b1') (b1'-1) A step of obtaining a mixture by mixing a rubber mixture containing a rubber component including a natural rubber latex solidified product and an additive (however, the additive is excluding the constant viscosity agent for natural rubber raw materials of the present invention) with the constant viscosity agent for natural rubber raw materials of the present invention. (b1'-2) Drying the mixture obtained in (b1'-1) to obtain natural rubber from the natural rubber latex coagulum, and (b1'-3) If necessary, mixing the mixture containing natural rubber obtained in (b1'-2) with carbon black and / or an inorganic filler.

[0201] In steps (b1-1) and (b'-1), the compounding amount of the constant viscosity agent for the natural rubber raw material of the present invention is preferably 0.01 part by mass or more, more preferably 0.02 part by mass or more, still more preferably 0.03 part by mass or more, and preferably 5 parts by mass or less, more preferably 2 parts by mass or less, still more preferably 1 part by mass or less, based on 100 parts by mass of the rubber component.

[0202] The mixing temperature in steps (b1-1) and (b'-1) is preferably 50°C or higher, more preferably 80°C or higher, and preferably 170°C or lower, more preferably 15°C or lower.

[0203] The mixing time in steps (b1-1) and (b'-1) is preferably 30 seconds or longer, more preferably 60 seconds or longer, and preferably 10 minutes or shorter, more preferably 5 minutes or shorter.

[0204] The mixing method may be to repeat the mixing operation in order to uniformly disperse each component.

[0205] The additives in step (b1'-1) include the additives described above.

[0206] The drying methods in steps (b1-2) and (b1'-2) are not particularly limited as long as the volatile component is dried to 0.8% or less. For example, hot air drying is preferred. In the case of hot air drying, the drying time is preferably 1 hour to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0207] Steps (b1-3) and (b1'-3) may be carried out as necessary.

[0208] In steps (b1-3) and (b1'-3), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0209] The mixing temperature in steps (b1-3) and (b1'-3) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0210] The mixing time for steps (b1-3) and (b1'-3) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0211] The above-mentioned additives may be added in steps (b1-3) and (b1'-3).

[0212] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0213] Other specific manufacturing methods include the following steps:

[0214] (b2) (b2-1) A step of mixing a rubber component containing natural rubber latex coagulation with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture. (b2-2) A step of mixing the mixture obtained in (b2-1) with carbon black and / or an inorganic filler to obtain a mixture, and (b2-3) A step of drying the mixture obtained in (b2-2) above to obtain natural rubber from the natural rubber latex coagulation.

[0215] (b2') (b2'-1) A step of obtaining a mixture by mixing a rubber mixture containing a rubber component including a natural rubber latex coagulation product and an additive (however, the additive is excluding the constant viscosity agent for natural rubber raw materials of the present invention) with the constant viscosity agent for natural rubber raw materials of the present invention. (b2'-2) A step of mixing the mixture obtained in (b2'-1) with carbon black and / or an inorganic filler to obtain a mixture, and (b2'-3) A step of drying the mixture obtained in (b2'-2) above to obtain natural rubber from the natural rubber latex solid.

[0216] In steps (b2-1) and (b2'-1), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0217] The mixing temperature in steps (b2-1) and (b2'-1) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0218] The mixing time for steps (b2-1) and (b2'-1) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0219] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0220] The additives used in step (b2'-1) include those mentioned above.

[0221] In steps (b2-2) and (b2'-2), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0222] The mixing temperature in steps (b2-2) and (b2'-2) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0223] The mixing time for steps (b2-2) and (b2'-2) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0224] The above-mentioned additives may be added in steps (b2-2) and (b2'-2).

[0225] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0226] The drying method in steps (b2-3) and (b2'-3) is not particularly limited as long as the volatile components are dried to 0.8% or less, but hot air drying is preferred, for example. In the case of hot air drying, the drying time is preferably 1 to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0227] Other specific manufacturing methods include the following steps: (b3) (b3-1) A step of mixing a rubber component containing natural rubber latex solids with carbon black and / or an inorganic filler to obtain a mixture. (b3-2) A step of mixing the mixture obtained in (b3-1) above with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture, and (b3-3) A step of drying the mixture obtained in (b3-2) above to obtain natural rubber from the natural rubber latex coagulation.

[0228] (b3') (b3'-1) A step of obtaining a mixture by mixing a rubber component containing a natural rubber latex solidified product and an additive (except that the additive is a constant viscosity agent for natural rubber raw materials of the present invention) with carbon black and / or an inorganic filler. (b3'-2) A step of mixing the mixture obtained in (b3'-1) with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture, and (b3'-3) A step of drying the mixture obtained in (b3'-2) above to obtain natural rubber from the natural rubber latex coagulation.

[0229] In steps (b3-1) and (b3'-1), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0230] The mixing temperature in steps (b3-1) and (b3'-1) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0231] The mixing time for steps (b3-1) and (b3'-1) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0232] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0233] The additives used in step (b3'-1) include those mentioned above.

[0234] In steps (b3-2) and (b3'-2), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0235] The mixing temperature in steps (b3-2) and (b3'-2) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0236] The mixing time in steps (b3-2) and (b3'-2) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0237] The above-mentioned additives may be added in steps (b3-2) and (b3'-2).

[0238] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0239] The drying method in steps (b3-3) and (b3'-3) is not particularly limited as long as the volatile components are dried to 0.8% or less, but hot air drying is preferred, for example. In the case of hot air drying, the drying time is preferably 1 to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0240] Other specific manufacturing methods include the following steps:

[0241] (b4) (b4-1) A step of mixing a rubber component containing natural rubber latex solids with carbon black and / or an inorganic filler to obtain a mixture. (b4-2) A step of drying the mixture obtained in (b4-1) above to obtain natural rubber from the natural rubber latex coagulation, and (b4-3) A step of mixing the mixture containing natural rubber obtained in (b4-2) with the constant viscosity agent for natural rubber raw materials of the present invention.

[0242] (b4') (b4'-1) A step of obtaining a mixture by mixing a rubber mixture containing a rubber component including a natural rubber latex solidified product and an additive (however, the additive is excluding the constant viscosity agent for natural rubber raw materials of the present invention) with carbon black and / or an inorganic filler. (b4'-2) A step of drying the mixture obtained in (b4'-1) above to obtain natural rubber from the natural rubber latex solid, and (b4'-3) A step of mixing the mixture containing natural rubber obtained in (b4'-2) with the constant viscosity agent for natural rubber raw materials of the present invention.

[0243] In steps (b4-1) and (b4'-1), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0244] The mixing temperature in steps (b4-1) and (b4'-1) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0245] The mixing time for steps (b4-1) and (b4'-1) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0246] The additives used in step (b4'-1) include those mentioned above.

[0247] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0248] The drying method in steps (b4-2) and (b4'-2) is not particularly limited as long as the volatile components are dried to 0.8% or less, but hot air drying is preferred, for example. In the case of hot air drying, the drying time is preferably 1 to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0249] In steps (b4-3) and (b4'-3), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0250] The mixing temperature in steps (b4-3) and (b4'-3) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0251] The mixing time for steps (b4-3) and (b4'-3) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0252] The above-mentioned additives may be added in steps (b4-3) and (b4'-3).

[0253] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0254] Manufacturing method (c) The method for producing the rubber composition of the present invention (c) includes the following steps.

[0255] A rubber mixture containing a rubber component including natural rubber latex, and optionally further additives (however, the additives are excluding the constant viscosity agent for natural rubber raw materials of the present invention), (A) The process includes mixing with the present invention's constant viscosity agent for natural rubber raw materials, Furthermore, if necessary, the process may include at least one of the following steps: (B), (C), and (D). (B) A step of mixing carbon black and / or inorganic fillers. (C) Solidification process. (D) Drying process.

[0256] Specifically, the manufacturing method includes the following steps:

[0257] (c1) (c1-1) A step of mixing a rubber component containing latex with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture. (c1-2) A step of solidifying the mixture obtained in (c1-1) above to obtain a natural rubber latex solid from the latex, (c1-3) A step of drying the natural rubber latex solidified product obtained in (c1-2) above to obtain natural rubber from the natural rubber latex solidified product, and (c1-4) If necessary, a step of mixing the mixture containing natural rubber obtained in (c1-3) with carbon black and / or an inorganic filler.

[0258] (c1') (c1'-1) A step of obtaining a mixture by mixing a rubber mixture containing a latex component and an additive (except that the additive is the constant viscosity agent for natural rubber raw materials of the present invention) with the constant viscosity agent for natural rubber raw materials of the present invention. (c1'-2) A step of solidifying the mixture obtained in (c1'-1) above to obtain a natural rubber latex solid from the latex, (c1'-3) A step of drying the natural rubber latex solidified product obtained in (c1'-2) above to obtain natural rubber from the natural rubber latex solidified product, and (c1'-4) If necessary, a step of mixing the mixture containing natural rubber obtained in (c1'-3) with carbon black and / or an inorganic filler.

[0259] The constant viscosity agent for natural rubber raw materials of the present invention, which is compounded in steps (c1-1) and (c1'-1), may be compounded into the latex as is, or it may be compounded into the latex in the form of a dispersion prepared by dissolving the constant viscosity agent for natural rubber raw materials of the present invention in an organic solvent or oil and then adding a surfactant and water.

[0260] Examples of organic solvents for dissolving the viscosity constant agent for natural rubber raw materials of the present invention include hydrocarbon solvents, alcohol solvents, and ether solvents, with hydrocarbon solvents such as cyclohexane being preferred. The amount of organic solvent is approximately 50 to 150 parts by mass per 100 parts by mass of the viscosity constant agent for natural rubber raw materials.

[0261] Examples of surfactants to be added to the organic solvent solution of the constant viscosity agent for natural rubber raw materials of the present invention include polyoxyethylene derivatives of fatty acids, salts formed by long carbon chains terminated with carboxylate or sulfonate groups, and long-chain quaternary ammonium salts. The amount of surfactant is not particularly limited as long as the constant viscosity agent for natural rubber raw materials of the present invention is dispersed, but for example, it is about 5 to 30 parts by mass per 100 parts by mass of the constant viscosity agent for natural rubber raw materials of the present invention.

[0262] In steps (c1-1) and (c1'-1), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0263] The mixing temperature in steps (c1-1) and (c1'-1) is preferably 25°C or higher, preferably 70°C or lower, and more preferably 50°C or lower.

[0264] The mixing time for steps (c1-1) and (c1'-1) is preferably 10 seconds or more, more preferably 30 seconds or more, and 5 minutes or less, more preferably 3 minutes or less.

[0265] The additives used in step (c1'-1) include those mentioned above.

[0266] The mixing method may involve using a stirrer or similar device, and the mixing operation may be repeated to ensure that each component is uniformly dispersed.

[0267] In steps (c1-2) and (c1'-2), the method for solidifying the mixture obtained in steps (c1-1) and (c1'-1) is not particularly limited, but one method is to add a coagulant to the mixture and solidify it.

[0268] Examples of coagulants include formic acid and acetic acid.

[0269] The amount of coagulant added is such that the pH of the latex is preferably 3.7 or higher, more preferably 4.2 or higher, and preferably 5.7 or lower, more preferably 5.2 or lower.

[0270] The drying method in steps (c1-3) and (c1'-3) is not particularly limited as long as the volatile components are dried to 0.8% or less, but hot air drying is preferred, for example. In the case of hot air drying, the drying time is preferably 1 to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0271] Steps (c1-4) and (c1'-4) may be performed as needed.

[0272] In steps (c1-4) and (c1'-4), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0273] The mixing temperature in steps (c1-4) and (c1'-4) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0274] The mixing time for steps (c1-4) and (c1'-4) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0275] In steps (c1-4) and (c1'-4), other compounding agents may be added.

[0276] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0277] Other specific manufacturing methods include the following steps:

[0278] (c2) (c2-1) A step of mixing a rubber component containing latex with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture. (c2-2) A step of solidifying the mixture obtained in (c2-1) above to obtain a natural rubber latex solid from the latex, (c2-3) A step of mixing the mixture containing the natural rubber latex solidified product obtained in (c2-2) with carbon black and / or an inorganic filler to obtain a mixture, and (c2-4) A step of drying the mixture obtained in (c2-3) above to obtain natural rubber from the natural rubber latex coagulation.

[0279] (c2') (c2'-1) A step of obtaining a mixture by mixing a rubber mixture containing a latex component and an additive (except that the additive is the constant viscosity agent for natural rubber raw materials of the present invention) with the constant viscosity agent for natural rubber raw materials of the present invention. (c2'-2) A step of solidifying the mixture obtained in (c2'-1) above to obtain a natural rubber latex solid from the latex, (c2'-3) A step of mixing the mixture containing the natural rubber latex solidified product obtained in (c2'-2) with carbon black and / or an inorganic filler to obtain a mixture, and (c2'-4) A step of drying the mixture obtained in (c2'-3) above to obtain natural rubber from the natural rubber latex coagulation.

[0280] The constant viscosity agent for natural rubber raw materials of the present invention, which is compounded in steps (c2-1) and (c2'-1), may be compounded into the latex as is, or it may be compounded into the latex in the form of a dispersion prepared by dissolving the constant viscosity agent for natural rubber raw materials of the present invention in an organic solvent and then adding a surfactant and water.

[0281] Examples of organic solvents for dissolving the viscosity constant agent for natural rubber raw materials of the present invention include hydrocarbon solvents, alcohol solvents, and ether solvents, with hydrocarbon solvents such as cyclohexane being preferred. The amount of organic solvent is 50 to 150 parts by mass per 100 parts by mass of the viscosity constant agent for natural rubber raw materials.

[0282] Examples of surfactants to be added to the organic solvent solution of the constant viscosity agent for natural rubber raw materials of the present invention include polyoxyethylene derivatives of fatty acids, salts formed by long carbon chains terminated with carboxylate or sulfonate groups, and long-chain quaternary ammonium salts. The amount of surfactant is not particularly limited as long as the constant viscosity agent for natural rubber raw materials of the present invention is dispersed, but for example, it is about 5 to 30 parts by mass per 100 parts by mass of the constant viscosity agent for natural rubber raw materials of the present invention.

[0283] In steps (c2-1) and (c2'-1), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0284] The mixing temperature in steps (c2-1) and (c2'-1) is preferably 25°C or higher, preferably 80°C or lower, and more preferably 50°C or lower.

[0285] The mixing time for steps (c2-1) and (c2'-1) is preferably 10 seconds or more, more preferably 30 seconds or more, preferably 5 minutes or less, and more preferably 3 minutes or less.

[0286] The additives used in step (c2'-1) include those mentioned above.

[0287] The mixing method may involve using a stirrer or similar device, and the mixing operation may be repeated to ensure that each component is uniformly dispersed.

[0288] In steps (c2-2) and (c2'-2), the method for solidifying the mixture obtained in steps (c2-1) and (c2'-1) is not particularly limited, but one method is to add a coagulant to the mixture and solidify it.

[0289] Examples of coagulants include formic acid and acetic acid.

[0290] The amount of coagulant added is such that the pH of the latex is preferably 3.7 or higher, more preferably 4.2 or higher, and preferably 5.7 or lower, more preferably 5.2 or lower.

[0291] In steps (c2-3) and (c2'-3), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0292] The mixing temperature in steps (c2-3) and (c2'-3) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0293] The mixing time for steps (c2-3) and (c2'-3) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0294] In steps (c2-3) and (c2'-3), the above-mentioned additives may be added.

[0295] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0296] The drying method in steps (c2-4) and (c2'-4) is not particularly limited as long as the volatile components are dried to 0.8% or less, but hot air drying is preferred, for example. In the case of hot air drying, the drying time is preferably 1 to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0297] Other specific manufacturing methods include the following steps:

[0298] (c3) (c3-1) A step of mixing a rubber component containing latex with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture. (c3-2) A step of mixing the mixture obtained in (c3-1) with carbon black and / or an inorganic filler to obtain a mixture, (c3-3) A step of solidifying the mixture obtained in (c3-2) above to obtain a natural rubber latex solid from the latex, and (c3-4) A step of drying the mixture obtained in (c3-3) above to obtain natural rubber from the natural rubber latex coagulation.

[0299] (c3') (c3'-1) A step of obtaining a mixture by mixing a rubber mixture containing a latex component and an additive (except that the additive is the constant viscosity agent for natural rubber raw materials of the present invention) with the constant viscosity agent for natural rubber raw materials of the present invention. (c3'-2) A step of mixing the mixture obtained in (c3'-1) with carbon black and / or an inorganic filler to obtain a mixture. (c3'-3) A step of solidifying the mixture obtained in (c3'-2) above to obtain a natural rubber latex solid from the latex, and (c3'-4) A step of drying the mixture obtained in (c3'-3) above to obtain natural rubber from the natural rubber latex coagulation.

[0300] The constant viscosity agent for natural rubber raw materials of the present invention, which is blended in steps (c3-1) and (c3'-1), may be blended into the latex as is, or it may be blended into the latex in the form of a dispersion prepared by dissolving the constant viscosity agent for natural rubber raw materials of the present invention in an organic solvent and then adding a surfactant and water.

[0301] Examples of organic solvents for dissolving the viscosity constant agent for natural rubber raw materials of the present invention include hydrocarbon solvents, alcohol solvents, and ether solvents, with hydrocarbon solvents such as cyclohexane being preferred. The amount of organic solvent is 50 to 150 parts by mass per 100 parts by mass of the viscosity constant agent for natural rubber raw materials.

[0302] Examples of surfactants to be added to the organic solvent solution of the constant viscosity agent for natural rubber raw materials of the present invention include polyoxyethylene derivatives of fatty acids, salts formed by long carbon chains terminated with carboxylate or sulfonate groups, and long-chain quaternary ammonium salts. The amount of surfactant is not particularly limited as long as the constant viscosity agent for natural rubber raw materials of the present invention is dispersed, but for example, it is about 5 to 30 parts by mass per 100 parts by mass of the constant viscosity agent for natural rubber raw materials of the present invention.

[0303] In steps (c3-1) and (c3'-1), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0304] The mixing temperature in steps (c3-1) and (c3'-1) is preferably 25°C or higher, preferably 80°C or lower, and more preferably 50°C or lower.

[0305] The mixing time for steps (c3-1) and (c3'-1) is preferably 10 seconds or more, more preferably 30 seconds or more, preferably 5 minutes or less, and more preferably 3 minutes or less.

[0306] The additives used in step (c3'-1) include those mentioned above.

[0307] The mixing method may involve using a stirrer or similar device, and the mixing operation may be repeated to ensure that each component is uniformly dispersed.

[0308] In steps (c3-2) and (c3'-2), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0309] The mixing temperature in steps (c3-2) and (c3'-2) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0310] The mixing time for steps (c3-2) and (c3'-2) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0311] In steps (c3-2) and (c3'-2), the above-mentioned additives may be added.

[0312] The mixing method may involve using a stirrer or similar device, and the mixing operation may be repeated to ensure that each component is uniformly dispersed.

[0313] In steps (c3-3) and (c3'-3), the method for solidifying the mixture obtained in steps (c3-2) and (c3'-2) is not particularly limited, but one method is to add a coagulant to the mixture and solidify it.

[0314] Examples of coagulants include formic acid and acetic acid.

[0315] The amount of coagulant added is such that the pH of the latex is preferably 3.7 or higher, more preferably 4.2 or higher, and preferably 5.7 or lower, more preferably 5.2 or lower.

[0316] The drying method in steps (c3-4) and (c3'-4) is not particularly limited as long as the volatile components are dried to 0.8% or less, but hot air drying is preferred, for example. In the case of hot air drying, the drying time is preferably 1 to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0317] Other specific manufacturing methods include the following steps:

[0318] (c4) (c4-1) A step of mixing a rubber component containing latex with carbon black and / or an inorganic filler to obtain a mixture. (c4-2) A step of solidifying the mixture obtained in (c4-1) above to obtain a natural rubber latex solid from the latex, (c4-3) A step of drying the natural rubber latex solidified product obtained in (c4-2) above to obtain natural rubber from the natural rubber latex solidified product, and (c4-4) A step of mixing the mixture containing natural rubber obtained in (c4-3) with the constant viscosity agent for natural rubber raw materials of the present invention.

[0319] (c4′) (c4'-1) A step of mixing carbon black and / or an inorganic filler into a rubber mixture containing a latex component and an additive (however, the additive is excluding the constant viscosity agent for natural rubber raw materials of the present invention) to obtain a mixture. (c4'-2) A step of solidifying the mixture obtained in (c4'-1) above to obtain a natural rubber latex solid from the latex, (c4'-3) A step of drying the natural rubber latex solidified product obtained in (c4'-2) above to obtain natural rubber from the natural rubber latex solidified product, and (c4'-4) A step of mixing the mixture containing natural rubber obtained in (c4'-3) with the constant viscosity agent for natural rubber raw materials of the present invention.

[0320] In steps (c4-1) and (c4'-1), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0321] The mixing temperature in steps (c4-1) and (c4'-1) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0322] The mixing time for steps (c4-1) and (c4'-1) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0323] The additives used in step (c4'-1) include those mentioned above.

[0324] The mixing method may involve using a stirrer or similar device, and the mixing operation may be repeated to ensure that each component is uniformly dispersed.

[0325] In steps (c4-2) and (c4'-2), the method for solidifying the mixture obtained in steps (c4-1) and (c4'-1) is not particularly limited, but one method is to add a coagulant to the mixture and solidify it.

[0326] Examples of coagulants include formic acid and acetic acid.

[0327] The amount of coagulant added is such that the pH of the latex is preferably 3.7 or higher, more preferably 4.2 or higher, and preferably 5.7 or lower, more preferably 5.2 or lower.

[0328] The drying method in steps (c4-3) and (c4'-3) is not particularly limited as long as the volatile components are dried to 0.8% or less, but hot air drying is preferred, for example. In the case of hot air drying, the drying time is preferably 1 to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0329] In steps (c4-4) and (c4'-4), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0330] The mixing temperature in steps (c4-4) and (c4'-4) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0331] The mixing time for steps (c4-4) and (c4'-4) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0332] In steps (c4-4) and (c4'-4), the above-mentioned additives may also be added.

[0333] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0334] Other specific manufacturing methods include the following:

[0335] (c5) (c5-1) A step of mixing a rubber component containing latex with carbon black and / or an inorganic filler to obtain a mixture. (c5-2) A step of solidifying the mixture obtained in (c5-1) above to obtain a natural rubber latex solid from the latex, (c5-3) A step of mixing the mixture containing the natural rubber latex solidified product obtained in (c5-2) with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture, and (c5-4) A step of drying the mixture obtained in (c5-3) above to obtain natural rubber from the natural rubber latex coagulation.

[0336] (c5′) (c5'-1) A step of mixing carbon black and / or an inorganic filler with a rubber mixture containing a latex component and an additive (however, the additive is excluding the constant viscosity agent for natural rubber raw materials of the present invention) to obtain a mixture. (c5'-2) A step of solidifying the mixture obtained in (c5'-1) above to obtain a natural rubber latex solid from the latex, (c5'-3) A step of mixing the mixture containing the natural rubber latex solidified product obtained in (c5'-2) with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture, and (c5'-4) A step of drying the mixture obtained in (c5'-3) above to obtain natural rubber from the natural rubber latex coagulation.

[0337] In steps (c5-1) and (c5'-1), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0338] The mixing temperature in steps (c5-1) and (c5'-1) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0339] The mixing time for steps (c5-1) and (c5'-1) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0340] The additives used in step (c5'-1) include those mentioned above.

[0341] The mixing method may involve using a stirrer or similar device, and the mixing operation may be repeated to ensure that each component is uniformly dispersed.

[0342] In steps (c5-2) and (c5'-2), the method for solidifying the mixture obtained in steps (c5-1) and (c5'-1) is not particularly limited, but one method is to add a coagulant to the mixture and solidify it.

[0343] Examples of coagulants include formic acid and acetic acid.

[0344] The amount of coagulant added is such that the pH of the latex is preferably 3.7 or higher, more preferably 4.2 or higher, and preferably 5.7 or lower, more preferably 5.2 or lower.

[0345] In steps (c5-3) and (c5'-3), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0346] The mixing temperature in steps (c5-3) and (c5'-3) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0347] The mixing time for steps (c5-3) and (c5'-3) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0348] In steps (c5-3) and (c5'-3), the above-mentioned additives may also be added.

[0349] The mixing method may involve repeating the mixing operation to ensure that each component is uniformly dispersed.

[0350] The drying method in steps (c5-4) and (c5'-4) is not particularly limited as long as the volatile components are dried to 0.8% or less, but hot air drying is preferred, for example. In the case of hot air drying, the drying time is preferably 1 to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0351] Other specific manufacturing methods include the following:

[0352] (c6) (c6-1) A step of mixing a rubber component containing latex with carbon black and / or an inorganic filler to obtain a mixture. (c6-2) A step of mixing the mixture obtained in (c6-1) with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture. (c6-3) A step of solidifying the mixture obtained in (c6-2) above to obtain a natural rubber latex solid from the latex, and (c6-4) A step of drying the mixture containing the natural rubber latex solidified product obtained in (c6-3) above, in order to obtain natural rubber from the natural rubber latex solidified product.

[0353] (c6') (c6'-1) A step of obtaining a mixture by mixing carbon black and / or an inorganic filler with a rubber mixture containing a latex component and an additive (however, the additive is excluding the constant viscosity agent for natural rubber raw materials of the present invention), (c6'-2) A step of mixing the mixture obtained in (c6'-1) with the constant viscosity agent for natural rubber raw materials of the present invention to obtain a mixture. (c6'-3) A step of solidifying the mixture obtained in (c6'-2) above to obtain a natural rubber latex solid from the latex, and (c6'-4) A step of drying the mixture containing the natural rubber latex solidified product obtained in (c6'-3) above, to obtain natural rubber from the natural rubber latex solidified product.

[0354] In steps (c6-1) and (c6'-1), the amount of carbon black and / or inorganic filler added is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of rubber component.

[0355] The mixing temperature in steps (c6-1) and (c6'-1) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0356] The mixing time for steps (c6-1) and (c6'-1) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0357] The additives used in step (c6'-1) include those mentioned above.

[0358] The mixing method may involve using a stirrer or similar device, and the mixing operation may be repeated to ensure that each component is uniformly dispersed.

[0359] In steps (c6-2) and (c6'-2), the amount of the constant viscosity agent for natural rubber raw materials of the present invention is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of rubber component.

[0360] The mixing temperature in steps (c6-2) and (c6'-2) is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower.

[0361] The mixing time for steps (c6-2) and (c6'-2) is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less.

[0362] In steps (c6-2) and (c6'-2), the above-mentioned additives may be added.

[0363] The mixing method may involve using a stirrer or similar device, and the mixing operation may be repeated to ensure that each component is uniformly dispersed.

[0364] In steps (c6-3) and (c6'-3), the method for solidifying the mixture obtained in steps (c6-2) and (c6'-2) is not particularly limited, but one method is to add a coagulant to the mixture and solidify it.

[0365] Examples of coagulants include formic acid and acetic acid.

[0366] The amount of coagulant added is such that the pH of the latex is preferably 3.7 or higher, more preferably 4.2 or higher, and preferably 5.7 or lower, more preferably 5.2 or lower.

[0367] The drying method in steps (c6-4) and (c6'-4) is not particularly limited as long as the volatile components are dried to 0.8% or less, but hot air drying is preferred, for example. In the case of hot air drying, the drying time is preferably 1 to 5 hours, and the drying temperature is preferably 110°C to 150°C.

[0368] Among the methods for producing these rubber compositions, the preferred method is: Manufacturing method (a) The method for producing the rubber composition of the present invention (a) includes the following steps. A rubber mixture comprising rubber components including natural rubber, and optionally, further additives (however, the additives are excluding the natural rubber raw material constant viscosity agent of the present invention), The present invention provides a method for producing a rubber composition, comprising the step of mixing it with a constant viscosity agent for natural rubber raw materials.

[0369] [4] Modified natural rubber The modified natural rubber of the present invention is obtained by modifying at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex with a compound represented by at least one formula selected from the following general formulas (1), (2), and (3), or a salt of said compound.

[0370] [ka]

[0371] In general formula (1), X 1 , X 2 , X 3 , and X 4 These represent the same or different hydrogen atoms or hydrocarbon groups. 1 , X 2 , X 3 , and X 4 Any two of these may combine to form a cyclic structure. Each hydrocarbon group may have one or more substituents.

[0372] [ka]

[0373] In general formula (2), X 5 , X 6 , X 7 , and X 8 X represents the same or different hydrogen atom or hydrocarbon group. Each hydrocarbon group may have one or more substituents. However, among general formula (2), X 5 , X 6 , X 7 , and X 8 However, this excludes compounds that consist entirely of hydrogen atoms.

[0374] [ka]

[0375] In general formula (3), X 9 , X 10 , X11 , and X 12 These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each hydrocarbon group may have one or more substituents.

[0376] A compound represented by at least one formula selected from the above general formulas (1), (2), and (3), or a salt of said compound, is as described above. [1] Constant viscosity agent for natural rubber raw materials Apply the explanation.

[0377] The modified natural rubber of the present invention can be obtained by the reaction of crosslinking points in natural rubber with a compound represented by at least one formula selected from the above general formulas (1), (2), and (3), or a salt of said compound, and it is believed that this improves the constant viscosity of the natural rubber raw material.

[0378] [5] Method for manufacturing modified natural rubber The present invention provides a method for producing modified natural rubber, which includes the step of modifying at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex with a compound represented by at least one formula selected from the following general formulas (1), (2), and (3), or a salt of said compound.

[0379] [ka]

[0380] In general formula (1), X 1 , X 2 , X 3 , and X 4 These represent the same or different hydrogen atoms or hydrocarbon groups. 1 , X 2 , X 3 , and X 4 Any two of these may combine to form a cyclic structure. Each hydrocarbon group may have one or more substituents.

[0381] [ka]

[0382] In general formula (2), X 5 , X 6 , X 7 , and X 8 X represents the same or different hydrogen atom or hydrocarbon group. Each hydrocarbon group may have one or more substituents. However, among general formula (2), X 5 , X 6 , X 7 , and X 8 However, this excludes compounds that consist entirely of hydrogen atoms.

[0383] [ka]

[0384] In general formula (3), X 9 , X 10 , X 11 , and X 12 These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each hydrocarbon group may have one or more substituents.

[0385] A compound represented by at least one formula selected from the above general formulas (1), (2), and (3), or a salt of said compound, is as described above. [1] Constant viscosity agent for natural rubber raw materials Apply the explanation.

[0386] Methods for modification include applying heat during mixing. For example, the mixing temperature is preferably 50°C or higher, more preferably 80°C or higher, preferably 170°C or lower, and more preferably 150°C or lower. [Examples]

[0387] The present invention will be specifically described below with reference to manufacturing examples and embodiments. The embodiments are merely examples, and the present invention is not limited to these embodiments.

[0388] [1] Manufacturing of rubber compositions As shown in Table 1, natural rubber and a viscosity constant agent were blended in their respective proportions (parts by mass) and mixed to obtain a mixture. The amounts of compounds 1-5 and 4-amino-1,2,4-triazole were adjusted so that they were blended in the same molar amount per 100 parts by mass of natural rubber, based on the molecular weight of each compound. Mixing temperature: 115℃ Mixing time: 3 minutes

[0389] (Manufacturing Example 1) Manufacturing of Compound 4 N-(1-methylethylidene)-4H-1,2,4-triazole-4-amine 10.0 g of 4-amino-1,2,4-triazole was added to 200 mL of acetone and reacted at 24°C for 4 hours. The reaction mixture was concentrated to obtain the compound (14.0 g, 95% yield). 1 H-NMR (400MHz, MeOD, δppm): 8.17 (2H, s), 2.28 (3H, s), 2.01 (3H, s)

[0390] (Manufacturing Example 2) Manufacturing of Compound 5 N-(1,3-dimethylbutylidene)-4H-1,2,4-triazole-4-amine 10.0 g of 4-amino-1,2,4-triazole was added to 200 mL of methyl isobutyl ketone and reacted at 24°C for 4 hours. The reaction mixture was concentrated to obtain the compound (19.0 g, 96% yield). 1 H-NMR (500MHz, CDCl3, δppm): 8.56 (1H, s), 8.42 (1H, s), 2.43 (2H, d), 2.16 (1H, sep), 1.99 (3H, s), 1.02 (6H, d)

[0391] [ka]

[0392] [2] Constant viscosity test The Mooney viscosity was measured in accordance with ISO 289-1, and then measured again after degradation in an oven at 60°C for 7 days.

[0393] The constant viscosity was calculated using the following formula. Constant viscosity = (Mooney viscosity after thermal degradation) - (Mooney viscosity before thermal degradation)

[0394] A smaller viscosity constant value indicates lower viscosity of the natural rubber raw material and better viscosity constants.

[0395] The constant viscosity index of the rubber composition in the example was expressed as an index, with the constant viscosity value of Comparative Example 1 (rubber composition without a constant viscosity agent) set to 100, and the constant viscosity index was calculated based on the following formula.

[0396] Formula: Constant viscosity index of Examples 1-5 =[(Constant viscosity of rubber compositions in Examples 1-5) (Constant viscosity of the rubber composition of Comparative Example 1) × 100

[0397] Formula: Constant viscosity index of Comparative Example 2 =[(Constant viscosity of the rubber composition of Comparative Example 2) (Constant viscosity of the rubber composition of Comparative Example 1) × 100

[0398] A smaller viscosity index value indicates that the rubber composition has superior viscosity. The results for the viscosity index are shown in Table 1.

[0399] [Table 1]

[0400] *1: Natural rubber: Thai-made RSS#3 *2 (Compound 1): 1-amino-1H-indole: Manufactured by Combi-Blocks. *3 (Compound 2): 1-aminopyrrole: Manufactured by Combi-Blocks. *4 (Compound 3): N-(1-methylethyl)-4H-1,2,4-triazole-4-amine: Manufactured by Enamine. *5 (Compound 4): N-(1-methylethylidene)-4H-1,2,4-triazole-4-amine: See Manufacturing Example 1 *6 (Compound 5): N-(1,3-dimethylbutylidene)-4H-1,2,4-triazole-4-amine: See Manufacturing Example 2 *7: Compound described in Prior Art 1: A1137 manufactured by Tokyo Chemical Industry Co., Ltd.

Claims

1. A constant viscosity agent for natural rubber raw materials, comprising a compound represented by at least one formula selected from the following general formulas (1), (2), and (3), or a salt of said compound. 【Chemistry 1】 (In general formula (1), X １ , X ２ , X ３ , and X ４ These represent the same or different hydrogen atoms or hydrocarbon groups. １ , X ２ , X ３ , and X ４ Any two of these groups may combine to form a cyclic structure. Each of the hydrocarbon groups may have one or more substituents. 【Chemistry 2】 (In general formula (2), X ５ , X ６ , X ７ , and X ８ represent the same or different hydrogen atoms or hydrocarbon groups. The hydrocarbon groups may each have one or more substituents. However, among general formula (2), compounds in which X ５ , X ６ , X ７ , and X ８ are all hydrogen atoms are excluded.) 【Transformation 3】 (In general formula (3), X ９ , X １０ , X １１ , and X １２ These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each hydrocarbon group may have one or more substituents.

2. The above general formula (1) is X １ and X ２ The constant viscosity agent for natural rubber raw materials according to claim 1, wherein the hydrocarbon group is a compound in which these groups together form a cyclic structure.

3. The above general formula (2) is X ５ , and X ６ The constant viscosity agent for natural rubber raw materials according to claim 1, wherein at least one of the compounds is a hydrocarbon group.

4. The above general formula (3) is X ９ , and X １０ The constant viscosity agent for natural rubber raw materials according to claim 1, wherein at least one of the compounds is a hydrocarbon group.

5. The compound represented by the general formula (1) above, or a salt of said compound, is at least one compound selected from the group consisting of 1-amino-1H-indole, 1-aminopyrrole, and 9-aminocarbazole, or a salt of said compound. The compound represented by the general formula (2) above, or a salt of said compound, is at least one compound selected from the group consisting of N-(1-methylethyl)-4H-1,2,4-triazole-4-amine, N-(1-ethylpropyl)-1,2,4-triazole-4-amine, and N-(1,3-dimethylbutyl)-4H-1,2,4-triazole-4-amine, or a salt of said compound. The constant viscosity agent for natural rubber raw materials according to claim 1, wherein the compound represented by the general formula (3), or a salt of the compound, is at least one compound selected from the group consisting of N-(1-methylethylidene)-4H-1,2,4-triazole-4-amine and N-(1,3-dimethylbutylidene)-4H-1,2,4-triazole-4-amine, or a salt of the compound.

6. The constant viscosity agent for natural rubber raw materials according to claim 1, wherein the natural rubber raw material is at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex.

7. A rubber composition, A constant viscosity agent for natural rubber raw materials according to any one of claims 1 to 6, and A rubber composition comprising a rubber component containing at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulations, and latex.

8. Furthermore, the rubber composition according to claim 7, comprising carbon black and / or an inorganic filler.

9. A rubber mixture comprising a rubber component including natural rubber, and optionally an additive (however, the additive is excluding the natural rubber raw material constant viscosity agent described in any one of claims 1 to 6), A constant viscosity agent for natural rubber raw materials according to any one of claims 1 to 6 A method for producing a rubber composition, comprising the step of mixing the following.

10. A method for producing a rubber composition according to claim 9, comprising the step of mixing carbon black and / or an inorganic filler (provided that the additive is excluding the carbon black and / or inorganic filler).

11. A method for producing a rubber composition, A rubber mixture comprising a rubber component containing a natural rubber latex coagulation, and optionally further additives (however, the additives are excluding the constant viscosity agents for natural rubber raw materials described in any one of claims 1 to 6), (A) A step of mixing with the constant viscosity agent for natural rubber raw materials described in any one of claims 1 to 6, This includes, and if necessary, at least one of the following steps (B) and (C): (B) A step of mixing carbon black and / or inorganic filler, (C) Drying process, A method for producing a rubber composition.

12. A method for producing a rubber composition, A rubber mixture comprising a rubber component containing natural rubber latex, and optionally further additives (however, the additives are excluding the constant viscosity agents for natural rubber raw materials described in any one of claims 1 to 6), (A) A step of mixing with the constant viscosity agent for natural rubber raw materials described in any one of claims 1 to 6, This includes, and further, if necessary, at least one of the following steps (B), (C), and (D): (B) A step of mixing carbon black and / or inorganic filler, (C) Solidification process, (D) Drying process, A method for producing a rubber composition.

13. Modified natural rubber obtained by modifying at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex with a compound represented by at least one formula selected from the following general formulas (1), (2), and (3), or a salt of said compound. 【Chemistry 4】 (In general formula (1), X １ , X ２ , X ３ , and X ４ These represent the same or different hydrogen atoms or hydrocarbon groups. １ , X ２ , X ３ , and X ４ Any two of these groups may combine to form a cyclic structure. Each hydrocarbon group may have one or more substituents. 【Transformation 5】 (In general formula (2), X ５ , X ６ , X ７ , and X ８ X represents the same or different hydrogen atom or hydrocarbon group. Each hydrocarbon group may have one or more substituents. However, in general formula (2), X ５ , X ６ , X ７ , and X ８ (However, this excludes compounds that consist entirely of hydrogen atoms.) 【Transformation 6】 (In general formula (3), X ９ , X １０ , X １１ , and X １２ These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each hydrocarbon group may have one or more substituents.

14. A method for producing modified natural rubber, A method for producing modified natural rubber, comprising the step of modifying at least one natural rubber raw material selected from the group consisting of natural rubber, natural rubber latex coagulation, and latex with a compound represented by at least one formula selected from the following general formulas (1), (2), and (3), or a salt of said compound. 【Transformation 7】 (In general formula (1), X １ , X ２ , X ３ , and X ４ These represent the same or different hydrogen atoms or hydrocarbon groups. １ , X ２ , X ３ , and X ４ Any two of these groups may combine to form a cyclic structure. Each hydrocarbon group may have one or more substituents. 【Transformation 8】 (In general formula (2), X ５ , X ６ , X ７ , and X ８ X represents the same or different hydrogen atom or hydrocarbon group. Each hydrocarbon group may have one or more substituents. However, in general formula (2), X ５ , X ６ , X ７ , and X ８ (However, this excludes compounds that consist entirely of hydrogen atoms.) 【Chemistry 9】 (In general formula (3), X ９ , X １０ , X １１ , and X １２ These represent, either identically or differently, a hydrogen atom or a hydrocarbon group. Each hydrocarbon group may have one or more substituents.

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