Method for producing modified conjugated diene polymer, and rubber composition and vulcanized rubber composition for same

Abstract

A method for manufacturing a modified conjugated diene polymer that not only suppresses cold flow after bale forming but also has excellent filler dispersion and processability when used as a rubber composition, and excellent fuel efficiency, anti-dusting properties, and tensile strength when used as a vulcanized product, and a rubber composition and a vulcanized rubber composition comprising said modified conjugated diene polymer. A method for manufacturing a modified conjugated diene-based polymer, comprising: a polymerization process in which at least one conjugated diene monomer is polymerized in a hydrocarbon solvent in the presence of a polar substance using an organolithium initiator, or a conjugated diene monomer is copolymerized with an aromatic vinyl compound; and The method comprises a process of adding to a polymer having active ends obtained in the above polymerization process a nitrogen atom-containing coupling agent having three or more non-halogen functional groups in one molecule that react with said active ends, and a modifying agent having at least one carbonyl group and at least one substituted amino group in the molecule that reacts with said active ends, wherein the modified conjugated diene polymer is (1) Includes a coupling conjugated diene polymer with three or more couplings, (2) A coupling component containing a nitrogen atom and a nitrogen atom, (3) The Mooney viscosity measured at 100℃ is 30 or higher and 120 or lower, and (4) The shrinkage factor (g') by the GPC-light scattering method equipped with a viscometer is 0.97 or less and 0.77 or more, and (5) The shape of the chromatograph measured by gel permeation chromatography (GPC) is unimodal, and (6) A molecular weight distribution measured by the above GPC of 1.60 or more and 3.00 or less, Method for manufacturing a modified conjugated diene polymer.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a modified conjugated diene polymer, and to the rubber composition and vulcanized rubber composition thereof. Background Technology

[0002] Since the demand for lower fuel consumption in automobiles has been increasing, there is a need for improvements in the rubber materials used in automobile tires, particularly in the tire treads that come into contact with the road surface.

[0003] In recent years, due to the increasing demands for fuel efficiency regulations on automobiles, there is a demand for tires with low energy loss during driving as a required characteristic. In particular, for the rubber materials used in the tire treads that come into contact with the road surface, there is a demand for rubber materials with low rolling resistance, that is, low hysteresis loss.

[0004] In particular, as a performance requirement for heavy-duty tires used in large vehicles such as trucks or buses, there is a demand for tires that improve fuel efficiency with low energy loss, in addition to conventional characteristics such as high strength and wear resistance to support heavy loads. Specifically, for the rubber material used in the tread of heavy-duty tires, a rubber composition with high tensile strength and excellent fuel efficiency is required.

[0005] As a rubber material according to the above requirements, for example, a modified conjugated diene polymer having hydroxyl groups at the ends of polymer chains and a composition thereof, a method for manufacturing a conjugated diene polymer by reacting a hydrocarbyloxysilane compound at the ends of polymer chains and then reacting a specific compound such as a hydrocarbyloxysilane compound, and a composition are proposed (see, for example, Patent Documents 1 and 2).

[0006] However, for weight-weighted tires, rubber compositions incorporating carbon black are still suitablely used in terms of durability and wear resistance. Although there is a demand for rubber compositions that improve fuel efficiency, wear resistance, and tensile strength in compositions incorporating carbon black as a filler, there is a problem in that fuel efficiency, wear resistance, and tensile strength are not sufficiently exhibited if the dispersion state of the filler within the rubber composition is insufficient.

[0007] On the other hand, rubber products used as industrial goods also have rubber compositions incorporating carbon black suitable for use in terms of durability and processability. For example, as anti-vibration rubber for automobiles or tanks, rubber materials containing natural rubber with excellent anti-vibration properties such as compression permanent deformation and dynamic magnification have been proposed (see, for example, Patent Document 3). Prior art literature

[0008] Japanese Patent Publication No. 2017-171806, International Publication No. 03 / 046020, Pamphlet, Japanese Patent Publication No. 2004-292679 The problem to be solved

[0009] However, in recent rubber materials, the dispersibility of the filler is sometimes insufficient. If the dispersibility of the filler is insufficient in a rubber composition containing a filler, there is a problem in that the anti-dusting properties are not sufficiently expressed. In addition, conjugated diene polymers suitable for use in heavy-duty tire treads and industrial products have a problem in that the bale, which is the product shape, is prone to flowing (hereinafter referred to as "cold flowability"), making it difficult to handle the bale after storage.

[0010] Against this backdrop, there is a desire to provide a conjugated diene polymer with excellent fuel efficiency, tensile strength, and anti-vibration properties; however, there is a challenge in achieving compatibility because the processability of the rubber composition and the tensile strength and wear resistance upon vulcanization are incompatible.

[0011] Therefore, the present invention aims to provide a method for manufacturing a modified conjugated diene polymer that not only suppresses cold flow after bale forming but also has excellent filler dispersion and processability when used as a rubber composition, and excellent fuel efficiency, anti-vibration properties, and tensile strength when used as a vulcanized product, as well as a rubber composition and a vulcanized rubber composition comprising said modified conjugated diene polymer. means of solving the problem

[0012] As a result of careful research and review to solve the problems of the prior art described above, the inventors have obtained the active end of a polymer obtained after polymerizing at least one conjugated diene monomer in the presence of a polar substance using an organic lithium initiator in a hydrocarbon solvent, or copolymerizing a conjugated diene monomer with an aromatic vinyl compound, and

[0013] A nitrogen-containing coupling agent having three or more functional groups in one molecule that react with an active end containing a non-halogen, and a modifying agent having at least one carbonyl group (>C=O) and at least one substituted amino group together in the molecule that reacts with the active end, by adding

[0014] A coupling component containing three or more nitrogen atoms and a modified polymer containing nitrogen atoms are obtained, and

[0015] Mooney viscosity measured at 100℃, shrinkage factor (g') by the GPC-light scattering method equipped with a viscometer is within a specific range, and

[0016] It was discovered that a modified conjugated diene polymer, which has a specific range of molecular weight distribution and a chromatographic shape measured by gel permeation chromatography (GPC), not only suppresses cold flow but also exhibits excellent filler dispersibility and processability when used as a rubber composition, and highly combines fuel efficiency, anti-vibration properties, and tensile strength when used as a vulcanized product, thereby completing the present invention.

[0017] That is, the present invention is as follows.

[0018] <1>

[0019] As a method for manufacturing a modified conjugated diene polymer,

[0020] A polymerization process for polymerizing at least one conjugated diene monomer or copolymerizing a conjugated diene monomer with an aromatic vinyl compound in the presence of a polar substance using an organolithium initiator in a hydrocarbon solvent, and

[0021] The method comprises a process of adding to a polymer having active ends obtained in the above polymerization process a nitrogen atom-containing coupling agent having three or more non-halogen functional groups in one molecule that react with said active ends, and a modifying agent having at least one carbonyl group and at least one substituted amino group in the molecule that reacts with said active ends.

[0022] The above modified conjugated diene-based polymer is,

[0023] (1) Includes a coupling conjugated diene polymer with three or more couplings,

[0024] (2) A coupling component containing a nitrogen atom and a nitrogen atom,

[0025] (3) The Mooney viscosity measured at 100℃ is 30 or higher and 120 or lower, and

[0026] (4) The shrinkage factor (g') by the GPC-light scattering method equipped with a viscometer is 0.97 or less and 0.77 or more, and

[0027] (5) The shape of the chromatograph measured by gel permeation chromatography (GPC) is unimodal, and

[0028] (6) A molecular weight distribution measured by the above GPC of 1.60 or more and 3.00 or less,

[0029] Method for manufacturing a modified conjugated diene polymer.

[0030] <2>

[0031] The glass transition temperature of the above modified conjugated diene polymer is -110℃ to -80℃, the above <1> Method for manufacturing a modified conjugated diene-based polymer as described in

[0032] <3>

[0033] The above modified conjugated diene polymer having a 1,2-vinyl bond content in the conjugated diene unit of 10 mol% or more and 25 mol% or less, the <1> or <2> Method for manufacturing a modified conjugated diene-based polymer as described in

[0034] <4>

[0035] The aromatic vinyl bond content of the above-mentioned modified conjugated diene-based polymer is 0 mass% or more and 10 mass% or less, the above <1> inside <3> A method for manufacturing a modified conjugated diene-based polymer as described in any of the above.

[0036] <5>

[0037] The modification rate of the above-mentioned modified conjugated diene-based polymer, measured by column adsorption GPC, is 50 mass% or more, the above <1> inside <4> A method for manufacturing a modified conjugated diene-based polymer as described in any of the above.

[0038] <6>

[0039] The above modified conjugated diene polymer contains higher fatty acids in an amount of 100 ppm or more and 1000 ppm or less, the above <1> inside <5> A method for manufacturing a modified conjugated diene-based polymer as described in any of the above.

[0040] <7>

[0041] In a process of adding the coupling agent and the modifying agent to a polymer having active ends obtained in the above polymerization process, wherein the reaction time between the polymer having active ends and the modifying agent is 10 seconds or more and less than 5 minutes, <1> inside <6> A method for manufacturing a modified conjugated diene-based polymer as described in any of the above.

[0042] <8>

[0043] The above modified conjugated diene polymer contains 40 mass% or more and 90 mass% or less of a component having a structure represented by the following formula (I) and / or the following formula (II). <1> inside <7> A method for manufacturing a modified conjugated diene-based polymer as described in any of the above.

[0044]

[0045] (In formula (I), P represents a conjugated diene polymer containing at least one conjugated diene monomer, and R1 and R2 each independently represent a hydrocarbon group having 1 to 20 carbon atoms.)

[0046]

[0047] (In Formula (II), P represents a conjugated diene polymer containing at least one conjugated diene monomer, and R1 and R2 each independently represent a hydrocarbon group having 1 to 20 carbon atoms.)

[0048] <9>

[0049] It comprises a rubber component and, with respect to 100 parts by mass of the rubber component, a filler having 5.0 parts by mass or more and 150 parts by mass or less.

[0050] The above rubber component, with respect to the total amount of the above rubber component, the <1> inside <8> A rubber composition comprising 10 mass% or more of a modified conjugated diene-based polymer prepared by the method described in any of the above.

[0051] <10>

[0052] The above filler is carbon black, the above <9> Rubber composition described in

[0053] <11>

[0054] The above <8> or <10> A vulcanized rubber composition comprising the rubber composition described in Effects of the invention

[0055] According to the present invention, a method for manufacturing a modified conjugated diene polymer that not only suppresses cold flow after bale forming but also has excellent filler dispersion and processability when used as a rubber composition, and excellent fuel efficiency, dustproof properties, and tensile strength when used as a vulcanized product, and a rubber composition and a vulcanized rubber composition comprising said modified conjugated diene polymer can be provided. Specific details for implementing the invention

[0056] The following describes in detail embodiments for carrying out the present invention (hereinafter referred to as "present embodiments"), but the present invention is not limited thereto and various modifications are possible within the scope of not departing from the gist thereof.

[0057] [Method for manufacturing modified conjugated diene polymers]

[0058] The method for manufacturing a modified conjugated diene-based polymer of the present embodiment (hereinafter simply referred to as the “method for manufacturing of the present embodiment”) comprises a polymerization process in which at least one conjugated diene-based monomer is polymerized in a hydrocarbon solvent using an organolithium initiator in the presence of a polar substance, or a conjugated diene monomer is copolymerized with an aromatic vinyl compound, and

[0059] The method comprises a process of adding to a polymer having active ends obtained in the above polymerization process a nitrogen atom-containing coupling agent having three or more non-halogen functional groups in one molecule that react with said active ends, and a modifying agent having at least one carbonyl group and at least one substituted amino group in the molecule that reacts with said active ends.

[0060] The above modified conjugated diene-based polymer is,

[0061] (1) Includes a coupling conjugated diene polymer with three or more couplings,

[0062] (2) A coupling component containing a nitrogen atom and a nitrogen atom,

[0063] (3) The Mooney viscosity measured at 100℃ is 30 or higher and 120 or lower, and

[0064] (4) The shrinkage factor (g') by the GPC-light scattering method equipped with a viscometer is 0.97 or less and 0.77 or more, and

[0065] (5) The shape of the chromatograph measured by gel permeation chromatography (GPC) is unimodal, and

[0066] (6) The molecular weight distribution measured by the above GPC is 1.60 or higher and 3.00 or lower.

[0067] Polymerization Process

[0068] The polymerization process is a process of polymerizing at least one conjugated diene monomer or copolymerizing a conjugated diene monomer with an aromatic vinyl compound in the presence of a polar substance using an organolithium initiator in a hydrocarbon solvent.

[0069] (Hydrocarbon solvent)

[0070] The polymerization process of the conjugated diene polymer in the present embodiment is carried out in an inert solvent. The inert solvent is not particularly limited, but examples include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specific hydrocarbon solvents are not particularly limited, but examples include aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; and hydrocarbons including mixtures thereof.

[0071] It is desirable to treat impurities such as allenes and acetylenes with organometallic compounds before providing them to the polymerization reaction, as this tends to yield conjugated diene polymers with a high concentration of active ends, and thus tends to yield modified conjugated diene polymers with a high modification rate.

[0072] (Organic lithium initiator)

[0073] In this embodiment, at least an organic monolithium compound is used as the polymerization initiator.

[0074] Organic monolithium compounds are not particularly limited, but examples include low-molecular-weight compounds and organic monolithium compounds of solubilized oligomers.

[0075] In addition, organic monolithium compounds include, for example, compounds having a carbon-lithium bond, compounds having a nitrogen-lithium bond, and compounds having a tin-lithium bond, in terms of the bonding mode between the organic group and the lithium.

[0076] It is preferable to determine the amount of organic monolithium compound used as a polymerization initiator based on the molecular weight of the target conjugated diene polymer.

[0077] The amount of monomer, such as a conjugated diene compound, used in relation to the amount of polymerization initiator relates to the degree of polymerization. In other words, it tends to be related to the number-average molecular weight and / or weight-average molecular weight.

[0078] Therefore, to increase the molecular weight, the amount of polymerization initiator used should be reduced, and to decrease the molecular weight, the amount of polymerization initiator used should be increased.

[0079] The organic monolithium compound is preferably an alkyllithium compound having a substituted amino group, or a dialkylaminolithium, in that it is used in one method of introducing a nitrogen atom into a conjugated diene polymer.

[0080] In this case, a conjugated diene polymer having a nitrogen atom containing an amino group at the polymerization initiation end is obtained.

[0081] A substituted amino group is an amino group that does not have an active hydrogen or has a structure in which the active hydrogen is protected.

[0082] Examples of alkyl lithium compounds having an amino group that does not have an active hydrogen include, but are not particularly limited, 3-dimethylaminopropyllithium, 3-diethylaminopropyllithium, 4-(methylpropylamino)butyllithium, and 4-hexamethyleneiminobutyllithium.

[0083] Alkylithium compounds having an amino group in a structure that protects active hydrogen are not particularly limited, but examples include 3-bistrimethylsilylaminopropyllithium and 4-trimethylsilylmethylaminobutyllithium.

[0084] Examples of dialkylaminolithium include, but are not particularly limited, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium dibutylamide, lithium di-n-hexylamide, lithium diheptylamide, lithium diisopropylamide, lithium dioctylamide, lithium-di-2-ethylhexylamide, lithium didecylamide, lithium ethylpropylamide, lithium ethylbutylamide, lithium ethylbenzylamide, lithium methylphenethylamide, lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, lithium morpholide, 1-lithioazcyclooctane, 6-lithio-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane and 1-lithio-1,2,3,6-tetrahydropyridine.

[0085] These organic monolithium compounds having substituted amino groups can also be used as organic monolithium compounds of oligomers that are solubilized by reacting a small amount of polymerizable monomers, such as 1,3-butadiene, isoprene, and styrene.

[0086] As for the organic monolithium compound, it is preferably an alkyllithium compound in terms of ease of industrial availability and ease of controlling the polymerization reaction. In this case, a conjugated diene polymer having an alkyl group at the polymerization initiation end is obtained.

[0087] Examples of alkyl lithium compounds include, but are not particularly limited, n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and stilbenium.

[0088] As for alkyl lithium compounds, n-butyllithium and sec-butyllithium are preferred in terms of ease of industrial availability and ease of controlling the polymerization reaction.

[0089] These organic monolithium compounds may be used alone or in combination of two or more. In addition, they may be used in combination with other organometallic compounds.

[0090] Other organometallic compounds include, for example, alkaline earth metal compounds, other alkali metal compounds, and other organometallic compounds.

[0091] Alkaline earth metal compounds are not particularly limited, but examples include organic magnesium compounds, organic calcium compounds, and organic strontium compounds. In addition, compounds of alkaline earth metals such as alkoxides, sulfonates, carbonates, and amides may also be examples.

[0092] Examples of organomagnesium compounds include dibutylmagnesium and ethylbutylmagnesium. Examples of other organometallic compounds include organoaluminum compounds.

[0093] (Polar substances)

[0094] The polymerization process in this embodiment is carried out in the presence of a polar substance. The polar substance tends to be used as a vinylizing agent to control the amount of 1,2-vinyl bonds in the conjugated diene polymer. In addition, it tends to be effective in promoting the polymerization reaction.

[0095] As polar substances, although not particularly limited, examples include ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, 2,2-bis(2-oxolanyl)propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclideine; alkali metal alkoxide compounds such as potassium-tert-amylate, potassium-tert-butyrate, sodium-tert-butyrate, sodium amylate; and phosphine compounds such as triphenylphosphine.

[0096] These polar substances may be used as a single type or in combination of two or more types.

[0097] The amount of polar material used is not particularly limited and can be selected according to the purpose, but it is preferable that it be 0.01 mole or more and 100 mole or less per 1 mole of polymerization initiator.

[0098] These polar substances (vinylating agents) can be used as regulators of the microstructure of conjugated diene polymers in appropriate amounts depending on the desired 1,2-vinyl bond amount.

[0099] (Conjugated diene monomer)

[0100] Specific examples of the conjugated diene compound in the present embodiment are not particularly limited, but examples include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene. Among these, 1,3-butadiene and isoprene are preferred from the perspective of ease of industrial availability. These may be used individually or in combination of two or more.

[0101] (Aromatic vinyl compounds)

[0102] Examples of aromatic vinyl compounds in the present embodiment include, but are not limited to, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and diphenylethylene. Among these, styrene is preferred from the perspective of ease of industrial availability. These may be used as a single type or in combination of two or more types.

[0103] (Polymerization method)

[0104] In the polymerization process of the present embodiment, the polymerization reaction mode is not particularly limited, but examples include batch (also called "batch type") and continuous polymerization reaction modes.

[0105] In the continuous process, one or more connected reactors may be used. For example, a tubular or molded reactor equipped with a stirrer is used for the continuous process. In the continuous process, preferably, a monomer, an inert solvent, and a polymerization initiator are continuously fed into the reactor, a polymer solution containing a polymer is obtained within the reactor, and the polymer solution is continuously discharged. When the polymerization process is continuous, as described below, a coupling process or a modification process can be carried out simultaneously while continuing the polymerization reaction.

[0106] For batch reactors, for example, a molded reactor equipped with a stirrer is used. In the batch type, preferably, a monomer, an inert solvent, and a polymerization initiator are fed, and if necessary, the monomer is added continuously or intermittently during polymerization to obtain a polymer solution containing the polymer within the reactor, and the polymer solution is discharged after the polymerization is completed.

[0107] (Polymerization temperature)

[0108] In the polymerization process of the present embodiment, the polymerization temperature is preferably a temperature at which living anionic polymerization proceeds, and from the perspective of productivity, it is more preferable to be 0°C or higher, and even more preferable to be 120°C or lower. Being within this range tends to ensure a sufficient amount of reaction agent for the active end after the polymerization is completed. More preferably, it is 50°C or higher and 100°C or lower.

[0109] <Coupling and Modification Process>

[0110] The manufacturing method of the present embodiment comprises, to a polymer having active ends obtained in the polymerization process,

[0111] · A nitrogen-containing coupling agent having three or more non-halogen functional groups in one molecule that reacts with the active end of the above polymer, and

[0112] · A modifying agent having at least one carbonyl group and at least one substituted amino group in the molecule together, which reacts with the active end of the above polymer

[0113] It includes a process of adding.

[0114] In other words, the manufacturing method of the present embodiment includes a coupling process and a modification process. The order of the coupling process and the modification process is not particularly limited, and either process may be performed first, but the coupling agent and the modification agent may be added simultaneously to perform the coupling process and the modification process simultaneously.

[0115] (Coupling process)

[0116] In the manufacturing method of the present embodiment, the conjugated diene-based polymer obtained by the polymerization described above is coupled by a coupling process (hereinafter also simply referred to as the “coupling process”) by means of a coupling agent.

[0117] -Coupling Agent-

[0118] In the manufacturing method of the present embodiment, a coupling agent containing non-halogen is preferred.

[0119] When a coupling agent with a halogen active site is used, if the halogen detached after the coupling reaction remains in the manufacturing process, it causes corrosion to the process and tends to become a challenge in process management.

[0120] In the manufacturing method of the present embodiment, a nitrogen atom-containing coupling agent having three or more functional groups that react with the active end is used, and a conjugated diene polymer is coupled with said coupling agent.

[0121] A polymer coupled with a coupling agent containing nitrogen atoms having three or more functional groups in one molecule tends to suppress cold flow after bale forming, and when used in a composition containing a filler, the nitrogen atoms interact with the filler, thereby improving the dispersibility of the filler and improving fuel efficiency and dynamic magnification.

[0122] In the present embodiment, the modifying agent containing a nitrogen atom is not particularly limited, but examples include isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, and nitrogen atom-containing epoxy compounds.

[0123] Examples of isocyanate compounds that are modifiers having nitrogen atom-containing groups include, but are not particularly limited, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, polymeric type diphenylmethane diisocyanate (C-MDI), phenyl isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, butyl isocyanate, and 1,3,5-benzene triisocyanate.

[0124] Examples of isothiocyanate compounds that are modifiers having nitrogen atom-containing groups include butyl isothiocyanate, cyclohexyl isothiocyanate, phenyl isothiocyanate, 2-chlorophenyl isothiocyanate, benzyl isothiocyanate, 2,6-diisopropylphenyl isothiocyanate, and 1,4-phenylene diisothiocyanate, although they are not particularly limited.

[0125] Examples of isocyanuric acid derivatives that are modifiers having nitrogen atom-containing groups include, but are not particularly limited, 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate, 1,3,5-tris(3-triethoxysilylpropyl)isocyanurate, 1,3,5-tri(oxiran-2-yl)-1,3,5-triazinan-2,4,6-trione, 1,3,5-tris(isocyanatemethyl)-1,3,5-triazinan-2,4,6-trione, and 1,3,5-trivinyl-1,3,5-triazinan-2,4,6-trione.

[0126] As an epoxy compound that is a modifying agent having a nitrogen atom-containing group, examples include hydrocarbon compounds containing an epoxy group bonded to an amino group, although they are not particularly limited, and may also have an epoxy group bonded to an ether group. Examples of such epoxy compounds include, although they are not limited to the following, epoxy compounds represented by general formula (i).

[0127]

[0128] In the formula, R represents a divalent or higher organic group having at least one polar group selected from a divalent or higher hydrocarbon group, or a polar group having oxygen such as an ether, epoxy, or ketone, a polar group having sulfur such as a thioether or thioketone, and a polar group having nitrogen such as a tertiary amino group or an imino group.

[0129] The hydrocarbon group with two or more valences is a hydrocarbon group that may be saturated or unsaturated, straight-chain, branched, or cyclic, and includes alkylene groups, alkenylene groups, phenylene groups, etc. Preferably, it is a hydrocarbon group having 1 to 20 carbon atoms. Examples include methylene, ethylene, butylene, cyclohexylene, 1,3-bis(methylene)-cyclohexane, 1,3-bis(ethylene)-cyclohexane, o-, m-, p-phenylene, m-, p-xylene, bis(phenylene)-methane, etc.

[0130] In Equation (i), R 1 and R 4 Each represents a hydrocarbon group having 1 to 10 carbon atoms, and R 1 and R 4 They may be the same or different.

[0131] In Equation (i), R 2 and R 5 Each represents hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, and R 2 and R 5 They may be the same or different.

[0132] In Equation (i), R 3 represents a hydrocarbon group having 1 to 10 carbon atoms or a structure of formula (iv) below, where n represents an integer greater than or equal to 1, and m represents an integer greater than or equal to 0 or 1.

[0133]

[0134] In the above equation (ii), R 1 and R 2 is R of Equation (i) 1 and R 2 Defined similarly to, and R 1 and R 2 They may be the same or different.

[0135] As for the epoxy compound that is a modifying agent having a nitrogen atom-containing group, it is preferable to have an epoxy group-containing hydrocarbon group, and more preferably, to have a glycidyl group-containing hydrocarbon group.

[0136] As for the epoxy group-containing hydrocarbon group bonded to the amino group or ether group, examples include a glycidylamino group, a diglycidylamino group, or a glycidoxy group. A more preferred molecular structure is an epoxy group-containing compound having a glycidylamino group or a diglycidylamino group and a glycidoxy group, respectively, and examples include compounds represented by the following general formula (iii).

[0137]

[0138] In the above equation (iii), R is defined in the same way as R in the above equation (i), and R 6 It represents a hydrocarbon group having 1 to 10 carbon atoms or the structure of the following formula (iv).

[0139] R 6 When this hydrocarbon group is represented, it may be bonded to R to form a cyclic structure, and in that case, R 6 It may be in the form where N and R are directly bonded to each other.

[0140] In equation (iii), n represents an integer greater than or equal to 1, and m represents an integer greater than or equal to 0 or 1.

[0141]

[0142] As for the epoxy compound that is a modifying agent having a nitrogen atom-containing group, it is particularly preferably a compound having one or more diglycidylamino groups and one or more glycidoxy groups in the molecule.

[0143] In the present embodiment, the epoxy compound used as a modifying agent having a nitrogen atom-containing group is not particularly limited, but is, for example, N,N-diglycidyl-4-glycidoxycyaniline, 1-N,N-diglycidylaminomethyl-4-glycidoxy-cyclohexane, 4-(4-glycidoxyphenyl)-(N,N-diglycidyl)aniline, 4-(4-glycidoxyphenoxy)-(N,N-diglycidyl)aniline, 4-(4-glycidoxybenzyl)-(N,N-diglycidyl)aniline, 4-(N,N'-diglycidyl-2-piperazinyl)-glycidoxybenzene, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylenediamine Examples include 4,4-methylene-bis(N,N-diglycidylaniline), 1,4-bis(N,N-diglycidylamino)cyclohexane, N,N,N',N'-tetraglycidyl-p-phenylenediamine, 4,4'-bis(diglycidylamino)benzophenone, 4-(4-glycidylpiperazinyl)-(N,N-diglycidyl)aniline, 2-[2-(N,N-diglycidylamino)ethyl]-1-glycidylpyrrolidine, N,N-diglycidylaniline, 4,4'-diglycidyl-dibenzylmethylamine, N,N-diglycidylaniline, N,N-diglycidylorthotoluidine, and N,N-diglycidylaminomethylcyclohexane. Among these, N,N-diglycidyl-4-glycidoxycyaniline and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane are preferred.

[0144] In the present embodiment, as a coupling agent having a nitrogen atom-containing group, the compound having a protected amine in its molecule is not particularly limited, but examples include 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, and 2,2-diethoxy-1-butyl-1-aza-2-silacyclopentane Examples include 2,2-dimethoxy-1-methyl-1-aza-2-silacyclopentane.

[0145] In the present embodiment, the alkoxysilane compound having a tertiary amine as the coupling agent having a nitrogen atom-containing group is not particularly limited, but examples include 3-diethylaminopropyltriethoxysilane, 3-morpholinopropyltrimethoxysilane, 3-piperidinopropyltriethoxysilane, 3-(4-methyl-1-piperazino)propyltriethoxysilane, 3-(4-trimethylsilyl-1-piperazino)propyltriethoxysilane, 3-(3-trimethylsilyl-1-hexahydropyrimidinyl)propyltrimethoxysilane, 3-dimethylamino-2-(dimethylaminomethyl)propyltrimethoxysilane, bis(3-trimethoxysilylpropyl)-N-methylamine, bis(3-triethoxysilylpropyl)methylamine, tris(trimethoxysilyl)amine, Tris(3-trimethoxysilylpropyl)amine, N,N,N',N'-tetra(3-trimethoxysilylpropyl)ethylenediamine, 3-isocyanate propyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, Examples include 2,2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, 2,2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-methyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-8-(4-methylpiperazinyl)methyl-1,6-dioxa-2-silacyclooctane, and 2,2-dimethoxy-8-(N,N-diethylamino)methyl-1,6-dioxa-2-silacyclooctane.

[0146] Particularly preferred as coupling agents having nitrogen atom-containing groups, as alkoxysilane compounds having tertiary amines are tris(3-trimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-tripropoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-methyl-1-sila-2-aza [Cyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis(3-trimethoxysilylpropyl)-1,6-hexamethylenediamine, pentakis(3-trimethoxysilylpropyl)-diethylenetriamine, Tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]silane, 3-Tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-trimethoxysilylpropane, 1-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexane,1-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexane, 3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexyl-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]ether, (3-trimethoxysilylpropyl)phosphate, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]phosphate, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)phosphate and Tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]phosphate is an example.

[0147] -Coupling Process-

[0148] In the coupling process, a conjugated diene polymer is obtained by coupling a coupling reaction with the coupling agent described above to one end of the active end of the conjugated diene polymer.

[0149] The amount of coupling agent used is not particularly limited and can be selected according to the purpose, etc., but it is preferable that the amount is 0.05 moles or more and 1.50 moles or less per 1 mole of polymerization initiator, more preferable that the amount is 0.10 moles or more and 1.00 moles or less, and more preferable that the amount is 0.20 moles or more and 0.80 moles or less.

[0150] In the coupling process of the present embodiment, the reaction temperature is preferably the same as the polymerization temperature of the conjugated diene polymer, more preferably 0°C or higher and 120°C or lower, and more preferably 50°C or higher and 100°C or lower.

[0151] The reaction time in the coupling process is preferably 10 seconds or more, more preferably 30 seconds or more.

[0152] Mixing in the coupling process may be either mechanical stirring or stirring by a static mixer.

[0153] If the polymerization process is continuous, it is desirable that the coupling process is also continuous.

[0154] In the coupling process, the reactor used is, for example, a tubular type equipped with a stirrer.

[0155] The coupling agent may be diluted with an inert solvent and continuously supplied to the reactor. In the case of a batch polymerization process, the modifying agent may be introduced directly into the polymerization reactor, or the coupling process may be performed by transferring it to another reactor.

[0156] The time from the polymerization process to the coupling process should be short, preferably within 10 minutes, and more preferably within 5 minutes. In that case, a conjugated diene polymer with high coupling efficiency tends to be obtained.

[0157] The time from the polymerization process to the coupling process refers to, for example, the time from reaching the peak temperature of polymerization to the addition of the coupling agent when the polymerization process is batch-type, and the time from the addition of the coupling agent to the solution containing the conjugated diene polymer exiting the polymerization reactor when the polymerization process is continuous-type.

[0158] In this embodiment, two or more types of coupling agents may be used, and the method of adding the coupling agents in the coupling process may be simultaneous or separate.

[0159] In the present embodiment, a particularly preferred form of coupling process is that, when the polymerization process is continuous, a coupling agent is added directly to the polymerization reactor, and the coupling reaction is performed simultaneously while the polymerization reaction continues. By performing the coupling reaction simultaneously while the polymerization reaction continues, the molecular weight of the conjugated diene polymer tends to increase, and when the composition is formulated with fillers, the fracture strength and wear resistance tend to improve.

[0160] (Deformation process)

[0161] The conjugated diene polymer in this embodiment includes a “modified conjugated diene polymer” modified by a modifying agent that has at least one carbonyl group (>C=O group) and at least one substituted amino group together in the molecule reacting with the active end of the conjugated diene polymer.

[0162] (Degenerative agent)

[0163] A modifying agent having at least one carbonyl group and at least one substituted amino group together in the molecule may have the carbonyl group and the substituted amino group adjacent to each other or separated. Examples of compounds in which these functional groups are adjacent include amides, imides, ureas, and isocyanuric acids having a "-C(=O)-N<" bond. Among these, cyclic compounds are preferred, N-substituted cyclic amides and N-substituted cyclic ureas are more preferred, and N-substituted cyclic ureas are particularly preferred. Additionally, examples of compounds in which the carbonyl group and the substituted amino group are separated include N-substituted aminoketones and N-substituted aminoaldehydes, but N-substituted aminoketones are preferred.

[0164] In the present embodiment, the modifying agent having at least one carbonyl group and at least one substituted amino group together in the molecule is not particularly limited, but examples of N-substituted cyclic amides include N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, Nt-butyl-2-pyrrolidone, N-methyl-2-piperidone, N-phenyl-2-piperidone, N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, etc.

[0165] N-substituted cyclic ureas are not particularly limited, but examples include 1,3-dimethylethylene urea, 1,3-diethyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, etc.

[0166] N-substituted aminoketones are not particularly limited, but examples include 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, etc.

[0167] N-substituted aminoaldehydes are not particularly limited, but examples include 4-N,N-dimethylaminobenzaldehyde.

[0168] -Deformation Process-

[0169] In the manufacturing method of the present embodiment, the conjugated diene-based polymer obtained by the polymerization described above is modified by the modifying agent described above (hereinafter also simply referred to as the “modification process”).

[0170] In the modification process, a modified conjugated diene polymer is obtained by modifying one end of the active end of the conjugated diene polymer with the modification agent described above.

[0171] In this embodiment, two or more types of modifying agents may be used, and the method of adding the modifying agents in the modification process may be simultaneous or separate.

[0172] In this embodiment, the addition of the aforementioned coupling agent may be done simultaneously or separately.

[0173] The amount of modifying agent used is not particularly limited and can be selected according to the purpose, etc., but it is preferable that it be 0.10 moles or more and 3.00 moles or less per 1 mole of polymerization initiator, more preferable that it be 0.30 moles or more and 2.00 moles or less, and more preferable that it be 0.50 moles or more and 1.50 moles or less.

[0174] The reaction temperature in the modification process is preferably the same as the polymerization temperature of the conjugated diene polymer, more preferably 0°C or higher and 120°C or lower, and more preferably 50°C or higher and 100°C or lower.

[0175] The reaction time in the modification process, that is, the reaction time between the polymer having active ends and the modification agent, is preferably at least 10 seconds, more preferably at least 30 seconds, and more preferably at least 60 seconds. In addition, the reaction time is preferably less than 5 minutes, more preferably less than 4.5 minutes, and more preferably less than 4 minutes.

[0176] For example, in the case where the polymerization process is continuous, by setting the upper limit of the denaturation reaction time to less than 5 minutes, the response to changes in manufacturing conditions when the denaturation rate does not reach the desired denaturation rate is fast, so it tends to be easy to minimize the occurrence of non-existent products.

[0177] Mixing in the modification process may be either mechanical stirring or stirring by a static mixer.

[0178] If the polymerization process is continuous, it is desirable that the modification process is also continuous.

[0179] In the modification process, the reactor used is, for example, a tubular type equipped with a stirrer.

[0180] The modifying agent may be diluted with an inert solvent and continuously supplied to the reactor. In the case of a batch polymerization process, the modifying agent may be introduced directly into the polymerization reactor, or the modification process may be performed by transferring it to another reactor.

[0181] The time from the polymerization process to the modification process should be short, preferably within 10 minutes, and more preferably within 5 minutes. In that case, a conjugated diene polymer with high modification efficiency tends to be obtained.

[0182] The time from the polymerization process to the modification process refers to, for example, the time from reaching the peak polymerization temperature until the addition of the modifying agent when the polymerization process is batch-type, and the time from the addition of the modifying agent to the solution containing the conjugated diene polymer exiting the polymerization reactor when the polymerization process is continuous-type.

[0183] (Condensation process)

[0184] In this embodiment, after the modification process, a condensation reaction process may be further performed in the presence of a condensation accelerator.

[0185] (Hydrogenation reaction)

[0186] In the conjugated diene polymer of the present embodiment, the conjugated diene portion in the conjugated diene polymer chain may be hydrogenated.

[0187] The method for hydrogenating the conjugated diene portion of a conjugated diene-based polymer is not particularly limited, and known methods may be used.

[0188] Suitable hydrogenation methods include hydrogenation by blowing gaseous hydrogen into a polymer solution in the presence of a catalyst. The catalyst is not particularly limited, but examples include heterogeneous catalysts, such as catalysts in which precious metals are supported on porous inorganic materials; homogeneous catalysts, such as catalysts in which salts of nickel, cobalt, etc., are solubilized and reacted with organoaluminum, etc.; and catalysts using metallocenes such as titanocene. Among these, a titanocene catalyst is preferred from the perspective of being able to select mild hydrogenation conditions. Furthermore, hydrogenation of aromatic groups can be carried out by using a catalyst supported with a precious metal.

[0189] As hydrogenation catalysts, there are no specific limitations, but examples include (1) a supported heterogeneous hydrogenation catalyst in which metals such as Ni, Pt, Pd, Ru are supported on carbon, silica, alumina, diatomaceous earth, etc., (2) a so-called Ziegler-type hydrogenation catalyst using a transition metal salt such as an organic acid salt of Ni, Co, Fe, Cr, etc. or an acetylacetone salt, etc. and a reducing agent such as an organoaluminum, (3) so-called organometallic complexes such as organometallic compounds such as Ti, Ru, Rh, Zr, etc. In addition, as a hydrogenation catalyst, although not particularly limited, known hydrogenation catalysts described in, for example, Japanese Patent Publication No. Sho 42-8704, Japanese Patent Publication No. Sho 43-6636, Japanese Patent Publication No. Sho 63-4841, Japanese Patent Publication No. Hei 1-37970, Japanese Patent Publication No. Hei 1-53851, Japanese Patent Publication No. Hei 2-9041, and Japanese Patent Publication No. Hei 8-109219 may be cited. As a preferred hydrogenation catalyst, a reaction mixture of a titanocene compound and a reducing organometallic compound may be cited.

[0190] In the manufacturing method of the present embodiment, after the modification process, an inactivating agent, a neutralizing agent, etc. may be added to the polymer solution as needed.

[0191] (Inactivator)

[0192] Examples of deactivating agents include, but are not particularly limited, water; alcohols such as methanol, ethanol, and isopropanol.

[0193] (corrector)

[0194] Examples of neutralizing agents include, but are not particularly limited, carboxylic acids such as stearic acid, oleic acid, and versatic acid (a mixture of highly branched carboxylic acids with 9 to 11 carbon atoms, centered around 10); aqueous solutions of inorganic acids and carbon dioxide.

[0195] (stabilizator)

[0196] In the manufacturing method of the present embodiment, it is desirable to add a rubber stabilizer from the perspective of preventing gel formation after polymerization and improving stability during processing.

[0197] As a rubber stabilizer, known ones may be used, not limited to the following, but, for example, antioxidants such as 2,6-di-tert-butyl-4-hydroxytoluene (hereinafter also referred to as "BHT"), n-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenol)propinate, and 2-methyl-4,6-bis[(octylthio)methyl]phenol are preferred.

[0198] (Rubber softener)

[0199] In order to further improve the productivity of the conjugated diene polymer in this embodiment and the processability when the composition is formulated with fillers, a rubber softener may be added as needed.

[0200] As rubber softeners, examples include, but are not particularly limited, extension oil, liquid rubber, resin, etc.

[0201] As a method for adding a rubber softener to a conjugated diene polymer, there are no particular limitations, but a method of adding the rubber softener to a conjugated diene polymer solution, mixing, and desolvating the polymer solution containing the rubber softener is preferred.

[0202] Desirable new oils include, for example, aroma oils, naphthenic oils, and paraffin oils. Among these, from the perspective of environmental safety and from the perspective of preventing oil bleed and wet grip characteristics, an aroma substitute oil having a polycyclic aromatic (PCA) component of 3% or less according to the IP346 method is preferred. As aroma substitute oils, in addition to TDAE (Treated Distillate Aromatic Extracts) and MES (Mild Extraction Solvate) as shown in Kautschuk Gummi Kunststoffe 52(12) 799(1999), RAE (Residual Aromatic Extracts) can be cited.

[0203] Preferred liquid rubbers are not particularly limited, but examples include liquid polybutadiene, liquid styrene-butadiene rubber, etc.

[0204] As an effect of adding liquid rubber, in addition to improving processability when the composition is formulated with conjugated diene polymers and fillers, there is a tendency to improve wear resistance, low hysteresis loss, and low-temperature properties when the composition is vulcanized, in that the glass transition temperature of the composition can be shifted to the low temperature side.

[0205] Preferred resins are not particularly limited, but examples include aromatic petroleum resins, coumarin-indene resins, terpene resins, rosin derivatives (including tung oil resins), tall oil, tall oil derivatives, rosin ester resins, natural and synthetic terpene resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, mixed aliphatic-aromatic hydrocarbon resins, coumarin-indene resins, phenol resins, p-tert-butylphenol-acetylene resins, phenol-formaldehyde resins, xylene-formaldehyde resins, monoolefin oligomers, diolefin oligomers, aromatic hydrocarbon resins, aromatic petroleum resins, hydrogenated aromatic hydrocarbon resins, cyclic aliphatic hydrocarbon resins, hydrogenated hydrocarbon resins, hydrocarbon resins, hydrogenated tung oil resins, hydrogenated oil resins, hydrogenated oil resins, and esters of monofunctional or polyfunctional alcohols. These resins may be used as a single type or in combination of two or more types. When hydrogenating, all unsaturated groups may be hydrogenated, or some may remain.

[0206] As an effect of adding resin, in addition to improving processability when using a composition mixed with a conjugated diene polymer and a filler, there is a tendency to improve fracture strength when using a vulcanized material, and there is also a tendency to improve wet skid resistance in that the glass transition temperature of the composition can be shifted toward a high temperature.

[0207] The amount of extension oil, liquid rubber, or resin added as a rubber softener is not particularly limited, but with respect to 100 parts by mass of the modified conjugated diene polymer in the present embodiment, it is preferably 1 part by mass or more and 60 parts by mass or less, more preferably 5 parts by mass or more and 50 parts by mass or less, and even more preferably 10 parts by mass or more and 37.5 parts by mass or less.

[0208] When a rubber softener is added within the above range, the processability of the composition, such as a conjugated diene polymer and a filler, is improved, and the fracture strength and wear resistance of the vulcanized product tend to be improved.

[0209] (Desolvent Process)

[0210] In the manufacturing method of the present embodiment, known methods may be used to obtain the obtained conjugated diene polymer from the polymer solution. The methods are not particularly limited, but examples include a method of obtaining the polymer by separating the solvent by steam stripping, etc., filtering and separating the polymer, and then dehydrating and drying it; a method of concentrating in a flushing tank and then degassing in a vent extruder, etc.; and a method of directly degassing in a drum dryer, etc.

[0211] [Modified Conjugated Diene Polymer]

[0212] The modified conjugated diene-based polymer in this embodiment satisfies the following.

[0213] (1) Includes a coupling conjugated diene polymer with three or more couplings,

[0214] (2) A coupling component containing a nitrogen atom and a nitrogen atom,

[0215] (3) The Mooney viscosity measured at 100℃ is 30 or higher and 120 or lower, and

[0216] (4) The shrinkage factor (g') by the GPC-light scattering method equipped with a viscometer is 0.97 or less and 0.77 or more, and

[0217] (5) The shape of the chromatograph measured by gel permeation chromatography (GPC) is unimodal, and

[0218] (6) The molecular weight distribution measured by the above GPC is 1.60 or higher and 3.00 or lower.

[0219] The modified conjugated diene polymer in this embodiment is a polymer selected by reacting a coupling agent containing a nitrogen atom, in which the active end of the polymer has three or more non-halogen functional groups in one molecule, and a modifying agent having at least one carbonyl group and at least one substituted amino group in one molecule, in order to have no contamination in the process due to halogens detached by the coupling reaction as described above, suppresses cold flow after bale forming, and has excellent filler dispersibility when used as a rubber composition, and includes a branched structure of three or more branches, and also has a nitrogen atom containing a coupling component and a nitrogen atom.

[0220] (Moon's viscosity)

[0221] In the present embodiment, the modified conjugated diene polymer has a Mooney viscosity measured at 100°C that is 30 or higher and 120 or lower, preferably 35 or higher and 100 or lower, and more preferably 40 or higher and 90 or lower, in terms of productivity of the conjugated diene polymer, processability when the composition is blended with fillers, and wear resistance and fracture strength when the composition is vulcanized.

[0222] By having a Mooney viscosity of 30 or higher at 100°C, the wear resistance and fracture strength are improved when using a vulcanized material, and by having a Mooney viscosity of 120 or lower at 100°C, the impedance to the manufacture of conjugated diene polymers is suppressed, and the processability is improved when using a composition mixed with fillers, etc.

[0223] Mooney viscosity is measured by using a sample of a conjugated diene polymer formed into a plate shape by a pressure press, setting it in a device, preheating the sample at 100°C for 1 minute, rotating the rotor at 2 rpm, measuring the torque after 4 minutes, and defining the measured value as the Mooney viscosity (ML(1+4)). More specifically, it can be measured by the method described in the examples described below. The Mooney viscosity of the conjugated diene polymer can be controlled to the above-described range by controlling conditions such as the amount of polymerization initiator added and temperature conditions in the polymerization process, for example, or by adjusting the type and amount of coupling agent added in the coupling process.

[0224] (Contraction factor (g'))

[0225] In this embodiment, the modified conjugated diene polymer has a shrinkage factor (g') of 0.97 or less and 0.77 or more according to the GPC-light scattering method equipped with a viscometer. A more preferred upper limit of the shrinkage factor (g') is 0.95 or less, and even more preferably 0.93 or less.

[0226] A lower limit of the shrinkage factor (g') is more desirable at 0.80 or higher, and even more preferably at 0.83 or higher.

[0227] Modified conjugated diene polymers with a shrinkage factor (g') in this range can suppress cold flow when baled and tend to have excellent processability when vulcanized.

[0228] The shrinkage factor (g') can be measured by the method described in the examples below.

[0229] Generally, polymers having a branched structure tend to have smaller molecular sizes compared to straight-chain polymers of the same absolute molecular weight. In the present embodiment, the shrinkage factor (g') is an indicator of the ratio of the molecular size to that of a straight-chain polymer of the same absolute molecular weight. That is, as the degree of branching of the polymer increases, the shrinkage factor (g') tends to decrease.

[0230] In this embodiment, intrinsic viscosity is used as an indicator of molecular size, and for a linear polymer, intrinsic viscosity [η] = 10 -3.883 ×M 0.771 According to the relationship, and in the above formula, M is the absolute molecular weight.

[0231] The shrinkage factor (g') at each absolute molecular weight of the modified conjugated diene polymer is calculated, and the average value of the shrinkage factors (g') is taken as the shrinkage factor (g') of the modified conjugated diene polymer.

[0232] Here, "branching" refers to the formation of a polymer by directly or indirectly bonding to a single polymer. Additionally, "degree of branching" is the number of polymers directly or indirectly bonded to one branch. For example, if three conjugated diene polymer chains are indirectly bonded to each other through the aforementioned coupling agent residue, the degree of branching is 3.

[0233] In the modified conjugated diene system of the present embodiment, the structure is a mixture of a branched component coupled by a coupling agent and a straight-chain component modified by a modifying agent, and the shrinkage factor (g') is a value representing the state in which these polymers are mixed.

[0234] Since the shrinkage factor (g') tends to depend on the degree of branching, the shrinkage factor (g') can be controlled to 0.97 or less and 0.77 or more by appropriately adjusting the type or amount of coupling agent in the coupling process of the conjugated diene polymer and the type or amount of modifying agent in the modification process. More specifically, it can be controlled by the method described in the examples described below.

[0235] (Molecular weight distribution)

[0236] The conjugated diene polymer in this embodiment has a unimodal chromatographic shape when measured by a gel permeation chromatograph (GPC). "Unimodal" chromatographic shape means that the chromatographic shape of the gel permeation chromatograph (GPC) measured by the method described in the following examples indicates that the peak originating from the polymer is a single peak, and that there are no valleys in the peak shape.

[0237] Control of the GPC chromatographic shape of conjugated diene polymers can be achieved, for example, by adopting a continuous polymerization method and appropriately controlling the type or amount of coupling agent added in the coupling process and the type or amount of modifying agent added in the modification process.

[0238] More specifically, this can be achieved by the method described in the embodiments below.

[0239] In the present embodiment, the conjugated diene polymer has a molecular weight distribution (Mw / Mn), expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), which is 1.60 or higher and 3.00 or lower.

[0240] Conjugated diene polymers with a molecular weight distribution in this range tend to have excellent wear resistance and fracture strength when a composition incorporating fillers, etc., is vulcanized. More preferably, the molecular weight distribution is 1.65 or higher and 2.70 or lower, and even more preferably 1.70 or higher and 2.50 or lower.

[0241] The number average molecular weight, weight average molecular weight, and molecular weight distribution of a conjugated diene polymer can be measured by the method described in the examples below. The number average molecular weight, weight average molecular weight, and molecular weight distribution of the conjugated diene polymer can be controlled to the above-described range by controlling conditions such as temperature conditions in the polymerization process, for example, or by appropriately adjusting the type or amount of coupling agent in the coupling process and the type or amount of modifying agent in the modification process.

[0242] (Glass transition temperature (Tg))

[0243] In the present embodiment, the glass transition temperature of the conjugated diene polymer is preferably within the range of -110°C to -80°C in order to exhibit excellent fuel efficiency, dust prevention performance, and tensile strength when the composition is formulated with fillers, etc. A more preferred lower limit of the glass transition temperature of the conjugated diene polymer is -105°C or higher, more preferably -103°C or higher, and even more preferably -100°C or higher.

[0244] In addition, the upper limit of the more desirable glass transition temperature is -82°C or lower, more preferably -84°C or lower, and even more preferably -86°C or lower.

[0245] The glass transition temperature tends to increase as the amount of 1,2-vinyl bonds and aromatic vinyl bonds described later increases, and can be controlled by controlling the amount of 1,2-vinyl bonds and aromatic vinyl bonds to an appropriate range. More specifically, this is described in the examples described later.

[0246] The glass transition temperature of a conjugated diene polymer is measured using differential scanning calorimetry (DSC) in accordance with ISO 22768:2017. Specifically, the DSC curve is recorded while increasing the temperature within a predetermined temperature range, and the inflection point of the DSC differential curve is taken as the glass transition temperature. Specifically, it can be measured by the method described in the examples described below.

[0247] When the glass transition temperature is set to a specific range, the fracture strength and wear resistance tend to improve when the composition is formulated with fillers, etc.

[0248] [1,2 vinyl binding amount]

[0249] In the present embodiment, the 1,2-vinyl bond content of the conjugated diene polymer is preferably 25 mol% or less, more preferably 23 mol% or less, even more preferably 22 mol% or less, and even more preferably 20 mol% or less.

[0250] The lower limit of the 1,2-vinyl binding amount is not specifically limited, but is more preferably 7 mol% or more, even more preferably 10 mol% or more, and even more preferably 12 mol% or more.

[0251] Specifically, in this embodiment, the 1,2-vinyl bond content of the conjugated diene polymer is preferably 10 mol% or more and 25 mol% or less, and more preferably 12 mol% or more and 23 mol% or less, in order to set the glass transition temperature described above to an appropriate range.

[0252] The microstructure of a conjugated diene polymer can be measured using a Fourier transform infrared spectrophotometer by the method described in the examples below.

[0253] In order to keep the 1,2-vinyl bonding amount within the aforementioned specific range, it can be controlled by the polymerization temperature and the amount of polar material added during the polymerization process. Specifically, if the polymerization temperature is set high, the 1,2-vinyl bonding amount tends to decrease. Furthermore, if the amount of polar compound added increases, in addition to increasing the 1,2-vinyl bonding amount, it is also effective in promoting the polymerization reaction; however, when the composition is formulated with fillers, the fracture strength and wear resistance tend to deteriorate, so it is necessary to control the 1,2-vinyl bonding amount within a specific range by adjusting the amount of polar material added. More specifically, this is described in the examples to be described later.

[0254] When the amount of 1,2-vinyl binding is set to a specific range, the fracture strength and wear resistance tend to improve when the composition is formulated with fillers, etc.

[0255] [Aromatic vinyl binding amount]

[0256] In the present embodiment, the aromatic vinyl bond amount of the conjugated diene polymer is preferably 0 mass% or more and 10 mass% or less. The upper limit of the aromatic vinyl bond amount of the conjugated diene polymer, which is more preferably 7 mass% or less, more preferably 6 mass% or less, and even more preferably 5 mass% or less.

[0257] Specifically, in the present embodiment, the aromatic vinyl bond content of the conjugated diene polymer is preferably 0 mass% or more and 10 mass% or less, and more preferably 0 mass% or more and 5 mass% or less, in order to set the glass transition temperature described above to an appropriate range.

[0258] The amount of aromatic vinyl bonding can be controlled by adjusting the addition ratio of the conjugated diene monomer and the aromatic vinyl compound in the aforementioned polymerization process. More specifically, this is described in the examples to be described later.

[0259] The amount of aromatic vinyl bonds in a conjugated diene polymer can be measured using an ultraviolet spectrophotometer by the method described in the examples below.

[0260] By setting the amount of aromatic vinyl bonding to a specific range, the fracture strength and wear resistance tend to improve when the composition is formulated with fillers, etc.

[0261] [Degeneration Rate]

[0262] In the present embodiment, the conjugated diene polymer preferably has a modification rate of 50 mass% or more as measured by column adsorption GPC, in order to improve filler dispersibility and processability when used in a rubber composition. Although the term "modification rate" may be used in this specification, "modification rate" is the mass ratio of the conjugated diene polymer having nitrogen atom-containing functional groups to the total amount of the conjugated diene polymer.

[0263] The denaturation rate can be measured by chromatography capable of separating the coupling component containing functional groups, and the denaturation component from the non-denaturation component.

[0264] As a method using this chromatography, a method for quantifying by using a column for gel permeation chromatography packed with polar materials such as silica that adsorb specific functional groups, and using an internal standard of non-adsorbed components for comparison (column adsorption GPC method) can be cited.

[0265] More specifically, the denaturation rate is obtained by measuring the amount of adsorption to the silica column from the difference between the chromatogram measured by a polystyrene-based gel column and the chromatogram measured by a silica-based column, of a sample solution containing the sample and a low molecular weight internal standard polystyrene.

[0266] More specifically, the denaturation rate can be measured by the method described in the example.

[0267] In the conjugated diene polymer of the present embodiment, the modification rate can be controlled by adjusting the amount of nitrogen atom-containing coupling agent and the modification agent added and the reaction method, and thereby the modification rate can be controlled to 50 mass% or more.

[0268] (High-grade fatty acids)

[0269] In the modified conjugated diene polymer of the present embodiment, it is preferable to include a higher fatty acid in an amount of 100 ppm or more and 1000 ppm or less from the perspective of suppressing polymer adhesion during the manufacturing process. More preferably, it is 200 ppm or more and 800 ppm or less, and even more preferably, 300 ppm or more and 600 ppm or less.

[0270] Higher fatty acids are preferably fatty acids having 12 to 24 carbon atoms, and saturated fatty acids are more preferable from the perspective of thermal stability. As higher fatty acids, known ones may be used, not limited to the following, but examples include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, etc.

[0271] In the modified conjugated diene-based polymer of the present embodiment, the preferred form of addition of the higher fatty acid is to add it in a state dissolved in the same solvent as the polymerization solvent in the polymer solution, and it is more preferable to add it in the polymer solution after the modification reaction.

[0272] In addition to the aforementioned effect as a neutralizing agent, the high-grade fatty acid has the effect of suppressing the adhesion of the polymer to the manufacturing process when the polymer is obtained by separating the solvent, for example by steam stripping, filtering and fractionating the polymer, and then dehydrating and drying it. By doing so, it is possible to suppress the incorporation of polymers with degraded quality, such as gelation or discoloration caused by retention in the process, and thus produce high-quality modified conjugated diene polymers.

[0273] [Structure of Modified Conjugated Diene Polymers]

[0274] In the present embodiment, the conjugated diene polymer preferably comprises 40 mass% or more and 90 mass% or less of a component having an amino group and an amide group represented by the following formula (I) and / or the following formula (II) in order to improve filler dispersion when used as a rubber composition and to improve fuel efficiency, anti-vibration properties, and tensile strength when used as a vulcanized product.

[0275] The lower limit of the amount of the component having an amino group and an amide group represented by the following formula (I) and / or the following formula (II) is more preferably 50 mass% or more, more preferably 55 mass% or more, and even more preferably 60 mass% or more.

[0276] The upper limit of the amount of the component having an amino group and an amide group represented by the following formula (I) and / or the following formula (II) is not particularly limited, but is more preferably 87 mass% or less, even more preferably 84 mass% or less, and even more preferably 82 mass% or less.

[0277]

[0278] (In formula (I), P represents a conjugated diene polymer containing at least one conjugated diene monomer, and R1 and R2 each independently represent a hydrocarbon group having 1 to 20 carbon atoms.)

[0279]

[0280] (In Formula (II), P represents a conjugated diene polymer containing at least one conjugated diene monomer, and R1 and R2 each independently represent a hydrocarbon group having 1 to 20 carbon atoms.)

[0281] By having terminal groups as described above, when used as a filler, particularly in a rubber composition containing carbon black, the terminal groups interact or bond with the functional groups on the surface of the carbon black, so that the dispersion of carbon black in the rubber composition tends to be improved, and when used as a vulcanized product, it is excellent in fuel efficiency and magnification.

[0282] In the present embodiment, the modifying agent represented by formula (I) is not particularly limited, but examples include 1,3-diethyl-2-imidazolinone, 1,3-dimethyl-2-imidazolinone, 1,3-dipropyl-2-imidazolinone, 1-methyl-3-ethyl-2-imidazolinone, 1-methyl-3-propyl-2-imidazolinone, 1-methyl-3-butyl-2-imidazolinone, 1,3-dihydro-1,3-dimethyl-2H-imidazole-2-one, etc.

[0283] In the present embodiment, the modifying agent represented by formula (II) is not particularly limited, but examples include 1,3-diethyl-2-imidazolidinone, 1,3-dimethyl-2-imidazolidinone, 1,3-dipropyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1-methyl-3-propyl-2-imidazolidinone, etc.

[0284] (Rubber composition)

[0285] The rubber composition of the present embodiment comprises a rubber component and a filler in an amount of 5.0 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the rubber component, and

[0286] The above rubber component is a rubber composition comprising 10 mass% or more of the modified conjugated diene polymer in the present embodiment relative to the total amount of the rubber component.

[0287] The rubber composition of the present embodiment can be used in combination with rubber components other than modified conjugated diene polymers. Additionally, as a filler, both carbon black and fillers other than carbon black can be used, but carbon black is preferred as a filler in terms of durability and wear resistance.

[0288] (Rubber components other than modified conjugated diene polymers)

[0289] Examples of such rubber components include, but are not particularly limited, conjugated diene polymers or their hydrogenated derivatives, random copolymers of conjugated diene compounds and vinyl aromatic compounds or their hydrogenated derivatives, block copolymers of conjugated diene compounds and vinyl aromatic compounds or their hydrogenated derivatives, non-diene polymers, and natural rubber.

[0290] Specific rubber components are not particularly limited, but examples include butadiene rubber or its hydrogenated derivative, isoprene rubber or its hydrogenated derivative, styrene-butadiene rubber or its hydrogenated derivative, styrene-butadiene block copolymer or its hydrogenated derivative, styrene-isoprene block copolymer or its hydrogenated derivative, styrene-based elastomers, acrylonitrile-butadiene rubber or its hydrogenated derivative.

[0291] Examples of non-diene polymers include, but are not particularly limited, olefin elastomers such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, ethylene-octene rubber, butyl rubber, butyl bromide rubber, acrylic rubber, fluororubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β-unsaturated nitrile-acrylic acid ester-conjugated diene copolymer rubber, urethane rubber, and polysulfide rubber.

[0292] Natural rubber is not particularly limited, but examples include smoked sheets RSS3 to 5, SMR, and epoxidized natural rubber.

[0293] The various rubber components described above may be modified rubbers imparted with polar functional groups such as hydroxyl groups and amino groups. When used for tires, butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber are preferably used.

[0294] The weight-average molecular weight of the rubber component is preferably 2,000 or more and 2,000,000 or less, and more preferably 5,000 or more and 1,500,000 or less, from the perspective of the balance of performance and processing characteristics. In addition, low molecular weight rubbery polymers, so-called liquid rubber, may be used. These rubbery polymers may be used as a single type or two or more types may be used in combination.

[0295] In the present embodiment, when the rubber composition comprises the modified conjugated diene polymer and the rubber component described below, the content ratio (mass ratio) of the modified conjugated diene polymer to the rubber component is preferably 10 / 90 or more and 100 / 0 or less as (modified conjugated diene polymer / rubber component), more preferably 20 / 80 or more and 90 / 10 or less, and even more preferably 40 / 60 or more and 80 / 20 or less.

[0296] Accordingly, the rubber component comprises, with respect to the total amount (100 parts by mass) of the rubber component, a modified conjugated diene polymer, preferably 10 parts by mass or more and 100 parts by mass or less, more preferably 20 parts by mass or more and 90 parts by mass or less, and even more preferably 40 parts by mass or more and 80 parts by mass or less.

[0297] If the content ratio of (modified conjugated diene polymer / rubber component) is within the above range, the wear resistance and tensile strength are excellent when made into a vulcanized rubber composition, and the balance of fuel efficiency and wet skid resistance and dustproof performance are excellent.

[0298] (Carbon Black)

[0299] The carbon black included in the rubber composition of the present embodiment is not particularly limited, but examples include carbon black of each class such as SRF, FEF, HAF, ISAF, and SAF. Among these, a carbon black with a nitrogen adsorption specific surface area of ​​50 m² 2 Carbon black with an oil absorption capacity of 80 mL / 100 g or less and a dibutyl phthalate (DBP) absorption capacity of 80 mL / 100 g or less is preferred.

[0300] In the rubber composition of the present embodiment, the carbon black content is preferably 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the rubber component, more preferably 25 parts by mass or more and 125 parts by mass or less, and even more preferably 30 parts by mass or more and 100 parts by mass or less.

[0301] In the cross-linked rubber composition of the present embodiment, the carbon black content is preferably 10 parts by mass or more per 100 parts by mass of the rubber component from the perspective of exhibiting performance required for industrial use, such as hardness or dustproof properties, and is preferably 150 parts by mass or less per 100 parts by mass of the rubber component from the perspective of dispersibility.

[0302] (Fillings other than carbon black)

[0303] The rubber composition of the present embodiment may include fillers other than carbon black.

[0304] As fillers other than carbon black, examples include silica-based inorganic fillers, metal oxides, and metal hydroxides, although they are not particularly limited. Among these, silica is preferred.

[0305] The filler may be used as a single type or in combination with two or more types.

[0306] As for the silica-based inorganic filler, there are no particular limitations and known ones may be used, but solid particles containing SiO2 or Si3Al as constituent units are preferred, and solid particles containing SiO2 or Si3Al as the main component of the constituent units are more preferred. Here, the main component refers to a component contained in the silica-based inorganic filler in an amount of 50 mass% or more, preferably 70 mass% or more, and more preferably 80 mass% or more.

[0307] Specific silica-based inorganic fillers are not particularly limited, but examples include inorganic fibrous materials such as silica, clay, talc, mica, diatomite, wollastonite, montmorillonite, zeolite, and glass fiber. Additionally, silica-based inorganic fillers with hydrophobic surfaces and mixtures of silica-based inorganic fillers and non-silica-based inorganic fillers may be used. Among these, silica and glass fiber are preferred from the perspective of strength and wear resistance, and silica is more preferred. Examples of silica include dry silica, wet silica, and synthetic silicate silica. Among these silicas, wet silica is preferred.

[0308] In terms of obtaining practically good wear resistance and fracture strength of crosslinked rubber compositions, the nitrogen adsorption specific surface area obtained by the BET adsorption method of silica-based inorganic fillers is 100 m 2 / g or more than 300m 2 It is desirable that it be / g or less, and 170m 2 / g or more 250m 2 It is more desirable that it be / g or less. In addition, if necessary, a relatively small specific surface area (e.g., a specific surface area of ​​200 m²) 2 silica-based inorganic fillers (less than / g) and those with a relatively large specific surface area (e.g., 200 m²) 2 A silica-based inorganic filler (at least 1 / g) can be used in combination.

[0309] The content of silica-based inorganic filler in the cross-linked rubber composition is preferably 50 mass% or less with respect to the total amount of filler per 100 mass parts of rubber components including a conjugated diene polymer, more preferably 30 mass% or less, and even more preferably 20 mass% or less.

[0310] The lower limit content of silica-based inorganic filler in the cross-linked rubber composition is preferably 15 mass% or less with respect to the total amount of filler per 100 mass parts of rubber components including a conjugated diene polymer, more preferably 10 mass% or less, and more preferably 5 mass% or less.

[0311] In the rubber composition of the present embodiment, the term "metal oxide" refers to a solid particle having the chemical formula MxOy (where M represents a metal atom, and x and y each independently represent integers from 1 to 6) as the main component of the constituent unit.

[0312] Examples of metal oxides include, but are not particularly limited, alumina, titanium oxide, magnesium oxide, and zinc oxide.

[0313] As for metal hydroxides, examples include aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide, although they are not particularly limited.

[0314] (Vulcanized rubber composition)

[0315] The rubber composition of the present embodiment can be made into a vulcanized rubber composition by vulcanizing. In other words, the vulcanized rubber composition of the present embodiment comprises the rubber composition of the present embodiment containing a modified conjugated diene polymer, and is a composition obtained by vulcanizing the said rubber composition.

[0316] (Silanic coupling agent)

[0317] The vulcanized rubber composition of the present embodiment may include a silane coupling agent when silica is incorporated as a filler. The silane coupling agent has the function of closely coordinating the interaction between the rubber component and the inorganic filler, and is preferably a compound having a group of affinity or bonding ability to the rubber component and the silica-based inorganic filler, respectively, and having a sulfur bonding portion and an alkoxysilyl group or a silanol group portion in one molecule. Examples of such compounds are not particularly limited, but include bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, and bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide.

[0318] In the vulcanized rubber composition of the present embodiment, the content of the silane coupling agent is preferably 0.1 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the silica-based inorganic filler described above, more preferably 0.5 parts by mass or more and 20 parts by mass or less, and even more preferably 1.0 parts by mass or more and 15 parts by mass or less. If the content of the silane coupling agent is within the above range, the additive effect caused by the silane coupling agent tends to be made more pronounced.

[0319] (Rubber softener)

[0320] The vulcanized rubber composition of the present embodiment may include a rubber softener in order to improve its processability.

[0321] The amount of rubber softener added is expressed as the total amount of rubber softener added when making a cross-linked rubber composition, based on 100 parts by mass of a rubber component containing the conjugated diene polymer described above, and the amount of rubber softener contained in the conjugated diene polymer or other rubbery polymer described above.

[0322] Mineral oil, or liquid or low-molecular-weight synthetic softeners are suitable as rubber softeners.

[0323] Mineral oil-based rubber softeners, referred to as process oils or extender oils, used to promote the softening, expansion, and processing of rubber, are mixtures of aromatic rings, naphthenic rings, and paraffin chains. Those in which the number of carbon atoms in the paraffin chains accounts for 50% or more of the total carbons are called paraffinic, those in which the number of carbon atoms in the naphthenic rings accounts for 30% or more and 45% or less of the total carbons are called naphthenic, and those in which the number of carbon atoms in the aromatic rings accounts for more than 30% of the total carbons are called aromatic. In the case where the conjugated diene polymer in the present embodiment is a copolymer of a conjugated diene compound and a vinyl aromatic compound, it is preferable for the rubber softener used to have an appropriate aromatic content, as this tends to have good affinity with the copolymer.

[0324] In the vulcanized rubber composition of the present embodiment, the content of the rubber softener is preferably 0 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the rubber component, more preferably 5 parts by mass or more and 90 parts by mass or less, and even more preferably 10 parts by mass or more and 80 parts by mass or less. By having a content of the rubber softener of 100 parts by mass or less with respect to 100 parts by mass of the rubber component, there is a tendency to suppress bleed-out and suppress stickiness on the surface of the rubber composition.

[0325] (Method for manufacturing a vulcanized rubber composition)

[0326] The method for manufacturing the rubber composition of the present embodiment is not particularly limited, but may include, for example, a method of melt-kneading additives such as conjugated diene polymers, other rubbery polymers, carbon black, silica-based inorganic fillers or other fillers, silane coupling agents, and rubber softeners using a general mixer such as an open roll, Banbury mixer, kneader, single-screw extruder, twin-screw extruder, or multi-screw extruder, or a method of removing the solvent by heating after melting and mixing each component. Among these, the melt-kneading method using a roll, Banbury mixer, kneader, or extruder is preferred in terms of productivity and good mixability. In addition, both a method of mixing the rubber components, other fillers, silane coupling agents, and additives in one go and a method of mixing in multiple steps are applicable.

[0327] The vulcanized rubber composition of the present embodiment may be a cross-linked rubber composition that has undergone vulcanization treatment with a vulcanizing agent (hereinafter, it may also be referred to as a "vulcanized composition"). As for the vulcanizing agent, it is not particularly limited, but examples include radical generating agents such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur compounds. Sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, polymeric polysulfide compounds, etc. In the rubber composition of the present embodiment, the content of the vulcanizing agent is preferably 0.01 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the rubber component, and more preferably 0.1 parts by mass or more and 15 parts by mass or less. As for the vulcanization method, a conventionally known method may be applied, and the vulcanization temperature is preferably 120°C or more and 200°C or less, and more preferably 140°C or more and 180°C or less.

[0328] During vulcanization, a vulcanization accelerator may be used as needed. As a vulcanization accelerator, conventionally known materials may be used and are not particularly limited, but examples include sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, thiourea-based, and dithiocarbamate-based vulcanization accelerators. Additionally, as a vulcanization aid, there are no particularly limited examples, but zinc oxide and stearic acid may be used. The content of the vulcanization accelerator is preferably 0.01 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the rubber component, and more preferably 0.1 parts by weight or more and 15 parts by weight or less.

[0329] In the vulcanized rubber composition of the present embodiment, various additives such as other softeners and fillers, heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, and lubricants may be used in addition to those described above, to the extent that the purpose of the present invention is not impaired. As other softeners, known softeners may be used. As other fillers, specifically, although not particularly limited, examples include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. As the heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, and lubricants described above, known materials may be used for each.

[0330] The rubber composition of the present embodiment is suitably used as a rubber composition for tires. That is, the tire of the present embodiment contains the rubber composition of the present embodiment.

[0331] The rubber composition for tires is not particularly limited, but can be used in various parts of tires such as fuel-efficient tires, all-season tires, high-performance tires, studless tires, and tires for heavy-duty vehicles, such as treads, carcasses, sidewalls, and bead sections. In particular, the rubber composition for tires is suitable for use as treads for fuel-efficient tires, high-performance tires, and tires for heavy-duty vehicles because, when vulcanized, it exhibits an excellent balance of wear resistance, fracture strength, low hysteresis loss, and wet skid resistance.

[0332] In addition, the rubber composition of the present embodiment has industrial applicability as, in addition to tires, anti-vibration rubber, anti-vibration rubber, conveyor belts, shoe soles such as outsoles for shoes, weather strips for automobiles, packing or gaskets, sealing materials, waterproof sheets, engine mounts, air springs, rubber gloves, medical and sanitary supplies, industrial hoses for various uses, battery cases, adhesives, wire insulation, window frame rubber, rubber plugs, rubber rollers, and materials for various industrial products.

[0333] [Example]

[0334] The present embodiment will be described in more detail below with reference to specific examples and comparative examples, but the present embodiment is not limited in any way to the following examples and comparative examples.

[0335] Various physical properties in the examples and comparative examples were measured by the method shown below.

[0336] (Physical Property 1) Mooney Viscosity

[0337] A conjugated diene polymer or a conjugated diene polymer modified with a substituted amino group-containing modifying agent (hereinafter also referred to as "modified conjugated diene polymer" and together with the conjugated diene polymer as "(modified) conjugated diene polymer") was used as a sample, and Mooney viscosity was measured using an L-type rotor in accordance with ISO 289 using a Mooney viscometer (product name "VR1132" manufactured by Seisakusho Uejima).

[0338] The measurement temperature was set to 100℃.

[0339] First, the sample was preheated at the test temperature for 1 minute, then the rotor was rotated at 2 rpm, and the torque after 4 minutes was measured and set as Mooney viscosity (ML (physical property 1)).

[0340] (Physical Property 2) Microstructure of Conjugated Diene Polymers

[0341] In cases where the conjugated diene polymer is polybutadiene, the (modified) conjugated diene polymer was used as the sample, and 50 mg of the sample was dissolved in 10 mL of carbon disulfide to prepare the measurement sample. Using a solution cell, the infrared spectrum was measured from 600 to 1000 cm⁻¹. -1 The 1,2-vinyl bond content (mol%) of the conjugated diene polymer was determined by measuring within the range and using the absorbance at a given wavenumber according to the formula of Morero's method (the method described in D. Morero, A. Santambrogio, L. Porri, F. Clampelli: Chim. e Ind., 41, 758 (1959)). (Measurement device: Fourier transform infrared spectrophotometer "FT-IR230" manufactured by Nihon Bunko Co., Ltd.)

[0342] In the case where the conjugated diene polymer is a styrene-butadiene copolymer, measurements were performed in the same manner as in the case of the aforementioned polybutadiene, and the microstructure of the butadiene portion, i.e., the amount of 1,2-vinyl bonds (mol%), was determined according to the calculation formula of Hampton's method (method described in R.R. Hampton, Analytical Chemistry 21, 923 (1949)) based on the absorbance at a predetermined wavenumber.

[0343] (Physical Property 3) Amount of Binded Styrene

[0344] A conjugated diene polymer was used as a sample, and 100 mg of the sample was mixed with 100 mL of chloroform and dissolved to form a measurement sample. The amount of bound styrene (mass%) relative to 100 mass% of the modified conjugated diene polymer sample was measured based on the amount of absorption of ultraviolet light at the wavelength (around 254 nm) by the phenyl group of styrene (spectrophotometer “UV-2450” manufactured by Shimadzu Seisakusho Co., Ltd.).

[0345] (Physical Property 4) Glass Transition Temperature

[0346] Using a conjugated diene polymer as a sample, DSC measurements were performed using a differential scanning calorimeter (NETZSCH “DSC3500”) in accordance with ISO 22768:2006. DSC curves were recorded while increasing the temperature from -130°C at 20°C / min under a flow of 50 mL / min of helium, and the inflection point of the DSC differential curve was set as the glass transition temperature (Tg).

[0347] (Physical Property 5) Shrinkage Factor (g')

[0348] Using a modified conjugated diene polymer as a sample, a GPC measuring device (Malvern trade name "GPCmax VE-2001") consisting of three connected columns packed with polystyrene gel was used for measurement. Measurements were performed using three detectors connected in sequence: a light scattering detector, an RI detector, and a viscosity detector (Malvern trade name "TDA305"). Based on standard polystyrene, the absolute molecular weight was determined from the results of the light scattering detector and the RI detector, and the intrinsic viscosity was determined from the results of the RI detector and the viscosity detector. For the linear polymer, the intrinsic viscosity [η] = 10 -3.883 ×M 0.771 The shrinkage factor (g') was calculated as the ratio of the intrinsic viscosity corresponding to each molecular weight, using the method described above. 5 mmol / L of triethylamine-containing THF was used as the eluent. The columns used were the TSKgel G4000HXL, TSKgel G5000HXL, and TSKgel G6000HXL manufactured by Dosoh Co., Ltd. 20 mg of the sample for measurement was dissolved in 10 mL of THF to prepare the measurement solution, 100 μL of the measurement solution was injected into the GPC measuring device, and measurements were performed under conditions of an oven temperature of 40°C and a THF flow rate of 1 mL / min.

[0349] (Physical property 6) Molecular weight

[0350] Measurement Condition 1:

[0351] (Modified) conjugated diene polymer was used as a sample, and a GPC measuring device (product name “HLC-8320GPC”) with three columns packed with polystyrene gel was used, and a chromatogram was measured using an RI detector (product name “HLC8020”). Based on the calibration curve obtained using standard polystyrene, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (Mw / Mn) were determined.

[0352] 5 mmol / L triethylamine-containing THF (tetrahydrofuran) was used as the eluent. Three columns of the product name “TSKgel SuperMultiporeHZ-H” manufactured by Dosoh Co., Ltd. were connected, and a guard column of the product name “TSKguardcolumn SuperMP(HZ)-H” manufactured by Dosoh Co., Ltd. was connected in front of them.

[0353] 10 mg of the sample for measurement was dissolved in 10 mL of THF to make the measurement solution, 10 μL of the measurement solution was injected into a GPC measuring device, and measurements were performed under conditions of an oven temperature of 40℃ and a THF flow rate of 0.35 mL / min.

[0354] Among the various samples measured under the above-described measurement condition 1, samples in which the molecular weight distribution (Mw / Mn) value was less than 1.6 were measured again under the following measurement condition 2. Samples measured under measurement condition 1 in which the molecular weight distribution value was 1.6 or higher were measured under measurement condition 1.

[0355] Measurement Condition 2:

[0356] A conjugated diene polymer or a coupling conjugated diene polymer was used as a sample, and a chromatogram was measured using a GPC measuring device consisting of three connected columns filled with polystyrene gel, and the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were determined based on a calibration curve using standard polystyrene.

[0357] The eluent used was 5 mmol / L triethylamine-containing THF. The columns used were guard column: "TSKguardcolumn SuperH-H" manufactured by Dosoh Co., Ltd., and columns: "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000" manufactured by Dosoh Co., Ltd.

[0358] An RI detector (product name “HLC8020” manufactured by Tosho Co., Ltd.) was used under conditions of an oven temperature of 40℃ and a THF flow rate of 0.6 mL / min. 10 mg of the sample for measurement was dissolved in 20 mL of THF to make the measurement solution, and 20 μL of the measurement solution was injected into a GPC measuring device for measurement.

[0359] For samples that were measured under measurement condition 1 and had a molecular weight distribution value of less than 1.6, they were measured under measurement condition 2.

[0360] (Physical Property 7) Modification Rate

[0361] (Modification) The modification rate in conjugated diene polymers was measured as follows by the column adsorption GPC method. Using a coupling conjugated diene polymer as a sample, the measurement was performed by applying the characteristic of adsorbing modified basic polymer components onto a GPC column packed with silica gel.

[0362] The amount of adsorption to the silica column was measured from the difference between the chromatogram measured by the polystyrene-based column and the chromatogram measured by the silica-based column for a sample solution containing the sample and low molecular weight internal standard polystyrene, and the modification rate was calculated.

[0363] Specifically, as shown below. In addition, for samples in which the molecular weight distribution value was 1.6 or higher when measured under measurement condition 1 of the above-described (physical property 4), the following measurement condition 3 was applied, and for samples in which the molecular weight distribution value was less than 1.6, the following measurement condition 4 was applied.

[0364] Preparation of sample solution: 10 mg of sample and 5 mg of standard polystyrene were dissolved in 20 mL of THF to make the sample solution.

[0365] Measurement Condition 3: GPC measurement conditions using a polystyrene-based column:

[0366] The product name “HLC-8320GPC” manufactured by Tosho Co., Ltd. was used, 5 mmol / L of triethylamine-containing THF was used as the eluent, 10 μL of the sample solution was injected into the device, and a chromatogram was obtained using an RI detector under conditions of a column oven temperature of 40°C and a THF flow rate of 0.35 mL / min. Three columns manufactured by Tosho Co., Ltd., product name “TSKgel SuperMultiporeHZ-H” were connected, and a guard column manufactured by Tosho Co., Ltd., product name “TSKguardcolumn SuperMP(HZ)-H” was connected upstream of them.

[0367] Measurement Condition 4:

[0368] THF containing 5 mmol / L of triethylamine was used as the eluent, and 20 μL of the sample solution was injected into the device for measurement. The columns used were: guard column: Tosoh Co., Ltd. trade name "TSKguardcolumn SuperH-H"; and columns: Tosoh Co., Ltd. trade names "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000". Under conditions of a column oven temperature of 40°C and a THF flow rate of 0.6 mL / min, measurements were taken using an RI detector (Tosoh Co., Ltd. HLC8020) to obtain a chromatogram.

[0369] GPC measurement conditions using a silica-based column: The product name “HLC-8320GPC” manufactured by Tosho Co., Ltd. was used, THF was used as the eluent, 50 μL of the sample solution was injected into the device, and a chromatogram was obtained using an RI detector under conditions of a column oven temperature of 40°C and a THF flow rate of 0.5 ml / min. The columns used were the product names “Zorbax PSM-1000S”, “PSM-300S”, and “PSM-60S” connected, and the product name “DIOL 4.6×12.5 mm 5 micron” was connected as a guard column upstream thereof.

[0370] Method for calculating the modification rate: The total peak area of ​​the chromatogram using a polystyrene-based column was set to 100, the peak area of ​​the sample was set to P1, the peak area of ​​the standard polystyrene was set to P2, the total peak area of ​​the chromatogram using a silica-based column was set to 100, the peak area of ​​the sample was set to P3, and the peak area of ​​the standard polystyrene was set to P4, and the modification rate (%) was calculated from the following formula.

[0371] Modification Rate (%) = [1 - (P2 × P3) / (P1 × P4)] × 100

[0372] (However, P1+P2=P3+P4=100)

[0373] [Example 1] Modified conjugated diene polymer (Sample 1)

[0374] Two polymerization reactors were connected, each having a volume of 10L, a ratio of internal height (L) to diameter (D) of 4.0 (L / D), an inlet at the bottom, an outlet at the top, and a stirring device, and a molding pressure vessel having a jacket for temperature control.

[0375] 1,3-butadiene, from which moisture had been removed beforehand, was mixed at a rate of 30.8 g / min, and n-hexane at a rate of 189.3 g / min. In a static mixer installed in the middle of the piping supplying this mixed solution to the inlet of the reactor, n-butyllithium for inactivating residual impurities was added and mixed at a rate of 0.072 mmol / min, and then continuously supplied to the bottom of the reactor. In addition, 2,2-bis(2-oxolanyl)propane as a polar substance was supplied at a rate of 0.027 mmol / min, and n-butyllithium as a polymerization initiator was supplied at a rate of 0.205 mmol / min to the bottom of the first reactor, which was vigorously mixed with a stirrer, and the reactor temperature was maintained at 78°C.

[0376] A polymer solution was continuously discharged from the top of the first reactor and continuously supplied to the bottom of the second reactor to continue the reaction at 78°C, and was also supplied to a static mixer from the top of the second reactor. When the polymerization was sufficiently stable, 1,3-butadiene polymerization was performed, and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (abbreviated as "A" in the table) was added as a coupling agent from the bottom of the second reactor at a rate of 0.014 mmol / min, and a polymerization reaction and a coupling reaction were carried out to obtain a conjugated diene polymer having a coupling structure. Furthermore, when the polymerization reaction and the coupling reaction were stable, a small amount of the conjugated diene polymer solution before the addition of the modifier was discharged, and an antioxidant (BHT) was added at a rate of 0.2 g per 100 g of polymer, after which the solvent was removed, and the Mooney viscosity of the conjugated diene polymer was measured. The measurement results are shown in Table 1.

[0377] Next, 1,3-dimethylimidazolidinone (abbreviated as "E" in the table) was continuously added as a modifier to the polymer solution discharged from the outlet of the reactor at a rate of 0.217 mmol / min, mixed using a static mixer, and carried out a modification reaction. At this time, the time until the modifier was added to the polymer solution discharged from the outlet of the reactor was 4.8 minutes, the temperature was 76°C, the residence time of the static mixer (reaction time between the conjugated diene polymer and the modifier) ​​was 4.2 minutes, and the difference between the temperature during the polymerization process and the temperature until the addition of the modifier was 2°C.

[0378] Next, an antioxidant (BHT) was continuously added to the modified polymer solution at a rate of 0.055 g / min (n-hexane solution) such that the amount was 0.2 g per 100 g of polymer, and the modification reaction was terminated. Afterward, the solvent was removed by steam stripping to obtain a modified conjugated diene polymer (Sample 1) containing a tetrahedral structure, and various physical properties of the sample were measured. The measurement results are shown in Table 1.

[0379] [Examples 2 to 9] Modified conjugated diene polymers (Samples 2 to 9)

[0380] Modified conjugated diene polymers (Samples 2 to 9) were obtained in the same manner as in Example 1, except that the manufacturing conditions of Example 1 were changed to the manufacturing conditions of Examples 2 to 9 shown in Table 1. Various physical properties of the samples were measured. The measurement results are shown in Table 1. In the table, "B," "C," and "F," indicated as coupling agents and modifying agents, respectively represent the following compounds.

[0381] 「B」: 2-Dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane

[0382] 「C」: tris(3-trimethoxysilylpropyl)amine

[0383] 「F」: N-methyl-2-pyrrolidone

[0384] [Comparative Example 1] Conjugated diene polymer (Sample 10)

[0385] Two polymerization reactors were connected, each having a volume of 10L, a ratio of internal height (L) to diameter (D) of 4.0 (L / D), an inlet at the bottom, an outlet at the top, and a stirring device, and a molding pressure vessel having a jacket for temperature control.

[0386] 1,3-butadiene, from which moisture had been removed beforehand, was mixed at a rate of 30.8 g / min, and n-hexane at a rate of 189.3 g / min. In a static mixer installed in the middle of the piping supplying this mixed solution to the inlet of the reactor, n-butyllithium for inactivating residual impurities was added and mixed at a rate of 0.072 mmol / min, and then continuously supplied to the bottom of the reactor. In addition, 2,2-bis(2-oxolanyl)propane as a polar substance was supplied at a rate of 0.027 mmol / min, and n-butyllithium as a polymerization initiator was supplied at a rate of 0.205 mmol / min to the bottom of the first reactor, which was vigorously mixed with a stirrer, and the reactor temperature was maintained at 78°C.

[0387] The polymer solution was continuously discharged from the top of the first reactor and continuously supplied to the bottom of the second reactor to continue the reaction at 78°C, and was also supplied to a static mixer from the top of the second reactor. When the polymerization reaction was sufficiently stable, a small amount of the conjugated diene polymer solution was discharged, and an antioxidant (BHT) was added at a concentration of 0.2 g per 100 g of polymer. After removing the solvent, the Mooney viscosity of the conjugated diene polymer was measured. The measurement results are shown in Table 2.

[0388] Next, an antioxidant (BHT) was continuously added to the polymer solution at a rate of 0.055 g / min (n-hexane solution) such that the amount was 0.2 g per 100 g of polymer. Subsequently, the solvent was removed by steam stripping to obtain a modified conjugated diene polymer (Sample 10), and various physical properties were measured. The measurement results are shown in Table 2.

[0389] [Comparative Examples 2 to 3] Conjugated diene polymers (Samples 11 and 12)

[0390] The manufacturing conditions of Comparative Example 1 were changed to the manufacturing conditions of Comparative Examples 2 and 3 shown in Table 2. When the polymerization reaction was sufficiently stable, a coupling agent was added from the bottom of the second reactor, and a polymerization reaction and a coupling reaction were carried out to obtain a conjugated diene polymer having a coupling structure. Subsequently, without adding a modifying agent, conjugated diene polymers (Samples 11 and 12) were obtained in the same manner as in Comparative Example 1, and various physical properties were measured. The measurement results are shown in Table 2.

[0391] [Comparative Example 4] Modified conjugated diene polymer (Sample 13)

[0392] A modified conjugated diene polymer (Sample 13) was obtained in the same manner as Comparative Example 1, except that the manufacturing conditions of Comparative Example 1 were changed to the manufacturing conditions of Comparative Example 4 shown in Table 2, and at the point when the polymerization reaction was sufficiently stable, a modifying agent was added and a polymerization reaction and a modification reaction to obtain a conjugated diene polymer were performed, and various physical properties were measured. The measurement results are shown in Table 2.

[0393] [Comparative Examples 5 to 7] Modified conjugated diene polymers (Samples 14 to 16)

[0394] The manufacturing conditions of Comparative Example 1 were changed to the manufacturing conditions of Comparative Examples 5 to 7 shown in Table 2. When the polymerization reaction was sufficiently stable, a coupling agent was added from the bottom of the second reactor, and a polymerization reaction and coupling reaction were carried out to obtain a conjugated diene polymer having a coupling structure. Subsequently, when the polymerization reaction and coupling reaction were sufficiently stable, the polymer solution discharged from the outlet of the reactor was supplied to a static mixer, and a modification agent was added to carry out a modification reaction. Except for this, modified conjugated diene polymers (Samples 14 to 16) were obtained in the same manner as Comparative Example 1, and various physical properties were measured. The measurement results are shown in Table 2.

[0395] "D" in the table, representing a coupling agent, indicates the following compounds.

[0396] 「D」: Tetramethoxysilane

[0397] [Comparative Example 8] Modified conjugated diene polymer (Sample 17)

[0398] A molding pressure vessel having a stirrer, which is a molding reactor equipped with a stirrer, and a jacket for temperature control, having a volume of 10L and a ratio (L / D) of the internal height (L) to the diameter (D) of 4.0, was used as a polymerization reactor.

[0399] 1050 g of 1,3-butadiene and 4780 g of n-hexane, from which moisture had been removed beforehand, were fed into a reactor and mixed by stirring. Then, 0.01 mmol of 2,2-bis(2-oxolanyl)propane was added to the reactor as a polar substance, and the temperature of the reactor was controlled to 45°C while stirring continued.

[0400] After confirming that the internal temperature of the reactor stabilized at 45°C while stirring, the hot water in the reactor jacket was drained, and 10.66 mmol of n-butyllithium was added as a polymerization initiator to start the polymerization reaction. After the polymerization started, the internal temperature of the reactor began to rise slowly and reached 97°C after 23 minutes, at which point peaking was performed.

[0401] After 2 minutes from picking, 0.53 mmol of 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (abbreviated as "A" in the table) was added as a coupling agent and a coupling reaction was carried out for 5 minutes. Then, 8.53 mmol of 1,3-dimethylimidazolidinone (abbreviated as "E" in the table) was added as a modifying agent and a modification reaction was carried out for 5 minutes (reaction time between the conjugated diene polymer and the modifying agent: 5 minutes).

[0402] After the denaturation reaction, 10.00 mmol of ethyl alcohol was added to completely stop the reaction.

[0403] Next, an antioxidant (BHT) was added to the polymer solution at a concentration of 0.2 g per 100 g of polymer. Subsequently, the solvent was removed by steam stripping to obtain a modified conjugated diene polymer (Sample 17) containing a tetrahedral structure, and various physical properties of the sample were measured. The measurement results are shown in Table 2.

[0404] [Comparative Example 9] Conjugated diene polymer (Sample 18)

[0405] Hysis BR manufactured by UBE Elastomer Co., Ltd., trade name “UBEPOL BR150” (Moonie viscosity (100℃): 43, 1,2-vinyl binding amount: 1 mol%) was prepared as sample 18.

[0406]

[0407]

[0408] [Examples 10 to 18, Comparative Examples 10 to 18]

[0409] Samples 1 to 18 shown in Tables 1 and 2 were used as raw rubbers, and rubber compositions containing each raw rubber were obtained according to the formulations shown below.

[0410] (Rubber component)

[0411] · Conjugated diene polymers (Samples 1 to 18)

[0412] : 60 mass parts

[0413] · Natural Rubber RSS #3

[0414] : 40 parts by mass

[0415] (Mixing conditions)

[0416] The amount of each compounding agent added was expressed as a number of parts by mass per 100 parts by mass of the rubber component.

[0417] · Carbon Black (Tokai Carbon's product name "Syst KH (N550)")

[0418] : 50.0 parts by mass

[0419] ·SRAE oil (product name "Process NC140" manufactured by JX Nikko Nisseki Energy)

[0420] : 10.0 parts by mass

[0421] · Zinc oxide: 5.0 parts by mass

[0422] · Stearic acid: 1.0 part by mass

[0423] · Anti-aging agent (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine): 2.0 parts by mass

[0424] · Sulfur: 2.5 parts by mass

[0425] · Vulcanization accelerator: N-(tert-butyl)-2-benzothiazolesulfenamide)

[0426] : 1.5 parts by mass

[0427] · Total: 172.0 mass parts

[0428] (Mixing method)

[0429] A rubber composition was obtained by kneading the above-described materials by the following method. A closed mixer (capacity 0.3L) equipped with a temperature control device was used, and as a first stage of mixing, raw rubber (samples 1 to 18), carbon black, SRAE oil, zinc oxide, and stearic acid were mixed under conditions of a filling rate of 65% and a rotor rotation speed of 30 to 50 rpm. At this time, the temperature of the closed mixer was controlled, and each rubber composition (compound) was obtained at a discharge temperature of 155 to 160℃.

[0430] Next, as a second stage of mixing, the mixture obtained above was cooled to room temperature, an anti-aging agent was added, and the mixture was mixed again to improve the dispersion of carbon black. In this case as well, the discharge temperature of the mixture was adjusted to 155 to 160°C by controlling the temperature of the mixer. After cooling, as a third stage of mixing, sulfur and a vulcanization accelerator were added and mixed in an open roll set to 70°C. Subsequently, the mixture was molded and vulcanized using a vulcanization press at 160°C for 30 minutes. The rubber composition before vulcanization and the rubber composition after vulcanization were evaluated. Specifically, they were evaluated by the following method. The results are shown in Tables 3 and 4.

[0431] (Evaluation 1) Cold flowability

[0432] Samples 1 to 18 were placed on bales, cut to a size of L×W×H = 40mm×40×mm×50mm, a 1kg load was placed on them, and they were left to stand for 24 hours under an environment of 40℃. After 24 hours, the height (H) of the samples was measured, the average retention rate of the two test points was calculated, and the result of Comparative Example 18 was indexed with the result of Comparative Example 18 set to 100. A higher index indicates better cold flowability. The results are shown in Tables 3 and 4.

[0433] (Evaluation 2) Mixture Pattern Viscosity

[0434] Using the mixture obtained above after the second stage of mixing and before the third stage of mixing as a sample, a Mooney viscometer was used to measure the viscosity after preheating at 130°C for 1 minute in accordance with ISO 289, followed by rotating the rotor at 2 revolutions per minute for 4 minutes. The result of Comparative Example 18 was indexed with 100. A lower index indicates better processability. The results are shown in Tables 3 and 4.

[0435] (Evaluation 3) Sheet Status

[0436] The mixture obtained above after the second stage of mixing and before the third stage of mixing was used as a sample, and the edge and surface condition of a rubber composition sheet that was passed through three times using a 10-inch open roll temperature-controlled to 70°C under conditions of a guide width of 200 mm and a clearance of 2.5 mm were judged visually as follows. The results are shown in Tables 3 and 4.

[0437] ◎: Edges and surface are smooth, O: Edges are slightly rough but surface is smooth, △: Edges are very rough and surface roughness is visible, ×: Edges and surface are very rough, making sheet forming difficult.

[0438] (Evaluation 4) Tensile Strength

[0439] Tensile strength was measured in accordance with the tensile test method of JIS K6251, and the result of Comparative Example 18 was indexed with 100. A higher index indicates better tensile strength. The results are shown in Tables 3 and 4.

[0440] (Rating 5) Pain Effect

[0441] Storage modulus (G') measured at a strain of 0.1% in torsion mode at a temperature of 50°C and a frequency of 10 Hz using the "ARES" viscoelasticity tester manufactured by Rheometrics Scientific 0.1 ) and storage modulus (G') measured at 10% strain 10The difference ΔG'(G') from ) 0.1 -G' 10 The Paine effect was calculated and indexed with the result of Comparative Example 18 set to 100. A lower index indicates better dispersion of the filler. The results are shown in Tables 3 and 4.

[0442] (Rating 6) Fuel Economy

[0443] Using the "ARES" viscoelasticity tester manufactured by Rheometrics Scientific, tanδ measured in torsion mode at a temperature of 50°C, a frequency of 10 Hz, and a deformation of 3% was used as an indicator of fuel efficiency, and the result of Comparative Example 18 was indexed with 100. A lower index indicates better fuel efficiency. The results are shown in Tables 3 and 4.

[0444] (Evaluation 7) Wear resistance

[0445] Using an Akron wear tester (manufactured by Yasuda Seki Seisakusho Co., Ltd.), the amount of wear was measured at a load of 44.4 N and 1,000 rotations in accordance with JIS K6264-2, and the result of Comparative Example 18 was indexed to 100. A lower index indicates better wear resistance. The results are shown in Tables 3 and 4.

[0446] (Evaluation 8) Same magnification

[0447] Using MTS ACUMEN3 and in accordance with JIS K6385, the static spring constant and dynamic spring constant of the crosslinked rubber composition were measured, the dynamic magnification ratio (dynamic spring constant / static spring constant) was calculated, and the result of Comparative Example 18 was set to 100 and indexed. A smaller index indicates superior vibration damping properties. The results are shown in Tables 3 and 4.

[0448] As shown in Tables 3 and 4, it was confirmed that Examples 10 to 18, compared to Comparative Examples 10 to 18, have excellent cold flow resistance, low Mooney viscosity when vulcanized, good processability, low pain effect when vulcanized, and excellent balance of performance in terms of fuel efficiency, tensile strength, and kinetics.

[0449]

[0450]

Claims

Claim 1 A method for preparing a modified conjugated diene polymer comprises: a polymerization process in which at least one conjugated diene monomer is polymerized in a hydrocarbon solvent in the presence of a polar substance using an organolithium initiator, or a conjugated diene monomer is copolymerized with an aromatic vinyl compound; and a process of adding to a polymer having active ends obtained in the polymerization process a coupling agent containing a nitrogen atom having three or more non-halogen functional groups in one molecule that react with said active ends, and a modifying agent having at least one carbonyl group and at least one substituted amino group in the molecule that reacts with said active ends. The modified conjugated diene polymer comprises (1) a coupling conjugated diene polymer having three or more branches, (2) a coupling component containing a nitrogen atom and a nitrogen atom, (3) a Mooney viscosity measured at 100°C of 30 or more and 120 or less, and (4) a shrinkage factor (g') by the GPC-light scattering method equipped with a viscometer of 0.97 A method for preparing a modified conjugated diene polymer, wherein the molecular weight is 0.77 or higher, (5) the shape of the chromatograph measured by gel permeation chromatography (GPC) is monomodal, (6) and the molecular weight distribution measured by the GPC is 1.60 or higher and 3.00 or lower. Claim 2 A method for manufacturing a modified conjugated diene polymer according to claim 1, wherein the glass transition temperature of the modified conjugated diene polymer is -110°C to -80°C. Claim 3 A method for manufacturing a modified conjugated diene polymer according to claim 1, wherein the amount of 1,2-vinyl bonds in the conjugated diene units of the modified conjugated diene polymer is 10 mol% or more and 25 mol% or less. Claim 4 A method for manufacturing a modified conjugated diene polymer according to claim 1, wherein the aromatic vinyl bond content of the modified conjugated diene polymer is 0 mass% or more and 10 mass% or less. Claim 5 A method for manufacturing a modified conjugated diene polymer according to claim 1, wherein the modification rate of the modified conjugated diene polymer measured by column adsorption GPC is 50 mass% or more. Claim 6 A method for manufacturing a modified conjugated diene polymer according to claim 1, wherein the modified conjugated diene polymer contains a higher fatty acid at a concentration of 100 ppm or more and 1000 ppm or less. Claim 7 A method for preparing a modified conjugated diene polymer according to claim 1, wherein the reaction time of the process of adding the coupling agent and the modifying agent to the polymer having active ends obtained in the polymerization process is 10 seconds or more and less than 5 minutes for the polymer having active ends and the modifying agent. Claim 8 A method for preparing a modified conjugated diene polymer according to claim 1, wherein the modified conjugated diene polymer contains 40 mass% or more and 90 mass% or less of a component having a structure represented by the following formula (I) and / or the following formula (II). (In formula (I), P represents a conjugated diene polymer containing at least one conjugated diene monomer, and R1 and R2 each independently represent a hydrocarbon group having 1 to 20 carbon atoms.) (In Formula (II), P represents a conjugated diene polymer containing at least one conjugated diene monomer, and R1 and R2 each independently represent a hydrocarbon group having 1 to 20 carbon atoms.) Claim 9 A rubber composition comprising a rubber component and a filler having an amount of 5.0 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the rubber component, wherein the rubber component comprises 10% by mass or more of a modified conjugated diene polymer prepared by the method described in any one of claims 1 to 8, with respect to the total amount of the rubber component. Claim 10 A rubber composition according to claim 9, wherein the filler is carbon black. Claim 11 A vulcanized rubber composition comprising the rubber composition described in claim 9.

Images