Conjugated diene polymer, conjugated diene polymer composition, cross-linked rubber, and tire

Abstract

Provided is a conjugated-diene-based polymer at least including units of a conjugated diene monomer, wherein high-molecular-weight components have a shrinkage factor of 0.4-0.8 and have a degree of adsorption onto silica of 75% or less and medium-molecular-weight components have a degree of adsorption of 40-100%.

Description

[Technical Field]

[0001] The present invention relates to a conjugated diene polymer, a conjugated diene polymer composition, a cross-linked rubber product, and a tire, and more particularly to a conjugated diene polymer that can give a cross-linked rubber product that is excellent in processability and fuel economy, and a conjugated diene polymer composition, a cross-linked rubber product, and a tire obtained using such a conjugated diene polymer. [Background technology]

[0002] In recent years, with the increasing interest in environmental issues, polymer compositions used in automobile tires are also required to have excellent fuel economy. Polymer compositions used for automobile tires include, for example, polymer compositions containing a conjugated diene polymer such as polybutadiene or a butadiene-styrene copolymer, and a filler such as carbon black or silica.

[0003] For example, Patent Document 1 discloses a method in which, when a polymerization initiator is added to a monomer containing a conjugated diene compound in a hydrocarbon solvent to obtain a polymerization solution containing a conjugated diene-based polymer, the polymerization initiator is further added in one or more divided portions during the polymerization reaction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-172548 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the conjugated diene polymer obtained by the technology of Patent Document 1, the fuel saving properties can be improved by blending silica or the like as a filler, but the processability is insufficient, and therefore, improvement of the processability has been desired.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a conjugated diene polymer that can give a cross-linked rubber product that is excellent in processability and fuel economy. Another object of the present invention is to provide a conjugated diene polymer composition, a cross-linked rubber product, and a tire obtainable using such a conjugated diene polymer, and to provide a method for producing such a conjugated diene polymer. [Means for solving the problem]

[0007] As a result of intensive research to achieve the above object, the present inventors have found that the above object can be achieved by adjusting the shrinkage factor and silica adsorption rate of the high molecular weight component constituting the conjugated diene-based polymer, and the silica adsorption rate of the medium molecular weight component, to specific ranges, and have thus completed the present invention.

[0008] That is, according to the present invention, there is provided a conjugated diene-based polymer containing at least a conjugated diene monomer unit, The shrinkage factor of the polymer is 0.4 to 0.8, The adsorption rate of the high molecular weight substance to silica is 75% or less, A conjugated diene polymer is provided, the adsorption rate of which of the medium molecular weight components to silica is 40 to 100%.

[0009] In the conjugated diene polymer of the present invention, the shrinkage factor of the medium molecular weight polymer is preferably 0.8 to 1.2. In the conjugated diene polymer of the present invention, the adsorption rate of the high molecular weight component to silica is preferably 10 to 70%. The conjugated diene polymer of the present invention preferably has two or more peak values ​​of molecular weight. The conjugated diene polymer of the present invention is preferably a copolymer having the conjugated diene monomer units and aromatic vinyl monomer units. In the conjugated diene polymer of the present invention, the molecular weight Mp of the low molecular weight component _LOW is preferably in the range of 100,000 to 190,000.

[0010] According to the present invention, there is provided a conjugated diene polymer composition containing the above conjugated diene polymer and a filler. Furthermore, according to the present invention, there are provided a cross-linked rubber product obtained by cross-linking the conjugated diene polymer composition, and a tire including such a cross-linked rubber product.

[0011] Furthermore, according to the present invention, there is provided a method for producing a polymer having an active terminal, comprising: a first step of polymerizing a monomer containing a conjugated diene compound in an inert solvent in the presence of a polymerization initiator to obtain a solution containing a polymer chain having an active terminal; a second step of forming coupled polymer chains by performing a coupling reaction on some of the polymer chains having active ends obtained in the first step, thereby obtaining a solution containing the polymer chains having active ends and the coupled polymer chains; a third step of further polymerizing a monomer containing a conjugated diene compound onto a polymer chain having an active terminal after the coupling reaction in the second step, The present invention provides a method for producing a conjugated diene polymer, wherein in at least one of the first step and the third step, a monomer containing a vinyl compound having a functional group capable of interacting with silica is used as the monomer to be polymerized in addition to a conjugated diene compound.

[0012] In the method for producing a conjugated diene-based polymer of the present invention, it is preferable to additionally add a polymerization initiator at any timing among the middle of the polymerization in the first step, the start of the polymerization in the third step, and the middle of the polymerization in the third step. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a conjugated diene polymer that can give a cross-linked rubber product that has excellent processability and excellent fuel economy. Furthermore, according to the present invention, it is also possible to provide a conjugated diene polymer composition, a cross-linked rubber product, and a tire obtained using such a conjugated diene polymer, and to provide a method for producing such a conjugated diene polymer. [Brief explanation of the drawings]

[0014] [Figure 1] 1(A) and 1(B) are graphs showing examples of GPC charts in the case where the conjugated diene polymer of the present invention exhibits a unimodal distribution. [Figure 2] 2(A) and 2(B) are graphs showing examples of GPC charts in the case where the conjugated diene polymer of the present invention exhibits a bimodal distribution. [Figure 3] 3(A) and 3(B) are graphs showing examples of GPC charts when the conjugated diene polymer of the present invention exhibits a bimodal distribution. [Figure 4] 4(A) and 4(B) are graphs showing examples of GPC charts when the conjugated diene-based polymer of the present invention exhibits a trimodal distribution. [Figure 5] 5(A) and 5(B) are graphs showing examples of GPC charts in the case where the conjugated diene polymer of the present invention exhibits a tetramodal distribution. [Figure 6] FIG. 6 is an example of a graph showing the relationship between molecular weight and intrinsic viscosity [η] measured by 3D-GPC, intrinsic viscosity [η] 0 of a linear polymer, and shrinkage factor g′. [Figure 7] FIG. 7 is a graph schematically showing the results of GPC measurement obtained using a styrene-based column and a silica-based column. DETAILED DESCRIPTION OF THE INVENTION

[0015] <Conjugated diene polymer> The conjugated diene polymer of the present invention is a conjugated diene polymer containing at least a conjugated diene monomer unit, The shrinkage factor of the polymer is 0.4 to 0.8, The adsorption rate of the high molecular weight substance to silica is 75% or less, The adsorption rate of the medium molecular weight substance to silica is 40 to 100%.

[0016] The conjugated diene polymer of the present invention contains conjugated diene monomer units, and examples of conjugated diene compounds for forming the conjugated diene monomer units include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferred, and 1,3-butadiene is more preferred.

[0017] Furthermore, the conjugated diene polymer of the present invention is preferably a copolymer having conjugated diene monomer units and aromatic vinyl monomer units. Examples of aromatic vinyl compounds for forming the aromatic vinyl monomer units include styrene, methylstyrene, ethylstyrene, t-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, chlorostyrene, bromostyrene, methoxystyrene, dimethylaminomethylstyrene, dimethylaminoethylstyrene, diethylaminomethylstyrene, diethylaminoethylstyrene, cyanoethylstyrene, and vinylnaphthalene. Among these, styrene is preferred. The content of the aromatic vinyl monomer units in the conjugated diene polymer of the present invention is preferably 3 to 50% by weight, more preferably 4 to 50% by weight, based on 100% by weight of the total amount of all monomers. By setting the content of the aromatic vinyl monomer units within the above range, the fuel economy of the resulting cross-linked rubber can be further improved.

[0018] Furthermore, the conjugated diene polymer of the present invention preferably contains, in addition to the conjugated diene monomer units and aromatic vinyl monomer units, units of a vinyl compound containing a functional group capable of interacting with silica.

[0019] The vinyl compound that contains functional groups that can interact with silica and that can form the unit of the vinyl compound that contains functional groups that can interact with silica can be any compound that contains a functional group that can interact with silica and a vinyl group, and is not particularly limited.Here, the functional group that can interact with silica is the functional group that can form a covalent bond between this functional group and the silica surface, or can form intermolecular forces that are weaker than covalent bonds (for example, ion-dipole interaction, dipole-dipole interaction, hydrogen bond, van der Waals force, etc.).The functional group that can interact with silica is not particularly limited, but can include nitrogen atom-containing functional groups, silicon atom-containing functional groups, oxygen atom-containing functional groups, etc.Among these, silicon atom-containing functional groups are preferred because of their high interaction with silica.

[0020] As a preferred embodiment of the vinyl compound containing a functional group capable of interacting with silica, a vinyl compound containing a silicon atom-containing functional group can be suitably used, for example, a compound represented by the following general formula (1): [ka] In the above general formula (1), X 1 represents a chemical single bond or a hydrocarbylene group, and X 2 , X 3 and X 4 each independently represents a substituted amino group, a hydrocarbyloxy group, or a hydrocarbyl group which may have a substituent.

[0021] In the above general formula (1), X 1 is a chemical single bond or a hydrocarbylene group, preferably a chemical single bond. Examples of the hydrocarbylene group include an alkylene group, an alkenediyl group, an arylene group, and a group in which an arylene group and an alkylene group are bonded together. Examples of alkylene groups include methylene, ethylene, and trimethylene groups. Examples of alkenediyl groups include vinylene and ethylene-1,1-diyl groups. Examples of arylene groups include phenylene, naphthylene, and biphenylene groups. Examples of groups in which an arylene group and an alkylene group are bonded include groups in which a phenylene group and a methylene group are bonded, and groups in which a phenylene group and an ethylene group are bonded. X 1 When is a hydrocarbylene group, X 1 is preferably an arylene group, more preferably a phenylene group.

[0022] In the above general formula (1), X 2 , X 3 and X 4 X each independently represents a substituted amino group, a hydrocarbyloxy group, or a hydrocarbyl group which may have a substituent. 2 , X 3 and X 4 At least one of X is preferably a substituted amino group; 2 , X 3 and X 4 It is more preferable that two of them are substituted amino groups.

[0023] X 2 , X 3 and X 4 As the substituted amino group which can constitute the above, a group represented by the following general formula (2) is preferred. [ka] In the above general formula (2), R 1 and R 2 may or may not be bonded to each other, and R 1 and R 2 If they are not bonded to each other, R 1 and R 2 each independently represents a hydrocarbyl group or a trihydrocarbylsilyl group which may have a substituent, and R 1 and R 2When and are bonded to each other, R 1 and R 2 represents a hydrocarbylene group which may contain at least one atom selected from a nitrogen atom, an oxygen atom, a sulfur atom and a silicon atom.

[0024] R 1 and R 2 Examples of hydrocarbyl groups that can constitute the above include chain alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, and n-octyl; cyclic alkyl groups such as cyclopentyl and cyclohexyl; and aryl groups such as phenyl, benzyl, and naphthyl. Among these, chain alkyl groups are preferred, and methyl or ethyl groups are more preferred. R 1 and R 2 When the hydrocarbyl group that can constitute the above has a substituent, examples thereof include hydrocarbyl groups having a hydrocarbyloxy group as a substituent, and examples of the hydrocarbyl group having a hydrocarbyloxy group as a substituent include alkoxyalkyl groups such as a methoxymethyl group, an ethoxymethyl group, and a methoxyethyl group; and aryloxyalkyl groups such as a phenoxymethyl group.

[0025] R 1 and R 2 Specific examples of the trihydrocarbylsilyl group that can constitute the above group include trialkylsilyl groups such as trimethylsilyl group, triethylsilyl group, and tert-butyldimethylsilyl group.

[0026] R 1 and R 2 When and are bonded to each other, R 1 and R 2Examples of the hydrocarbylene group that can constitute R include alkylene groups such as trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, decamethylene, dodecamethylene, and 2,2,4-trimethylhexane-1,6-diyl; and alkenediyl groups such as pentan-2-ene-1,5-diyl. 1 and R 2 When the hydrocarbylene group that can constitute the formula (I) contains at least one selected from a nitrogen atom, an oxygen atom, a sulfur atom, and a silicon atom, examples of the hydrocarbylene group containing at least one selected from a nitrogen atom, an oxygen atom, a sulfur atom, and a silicon atom include a group represented by -CH=N-CH=CH-, a group represented by -CH=N-CH2-CH2-, a group represented by -CH2-CH2-O-CH2-CH2-, a group represented by -CH2-CH2-S-CH2-CH2-, a group represented by -CH2-CH2-SiH2-CH2-CH2-, a group represented by -CH2-CH2-SiMe2-CH2-CH2-, and a group represented by -CH2-CH2-SiEt2-CH2-CH2-. R 1 and R 2 is an alkyl group, or R 1 and R 2 and preferably bond to each other to form an alkylene group, and R 1 and R 2 is more preferably an alkyl group, and R 1 and R 2 is more preferably a methyl group or an ethyl group.

[0027] In the above general formula (2), R 1 and R 2When is a hydrocarbyl group, specific examples of the group represented by the above general formula (2) include dialkylamino groups such as dimethylamino group, diethylamino group, ethylmethylamino group, di-n-propylamino group, diisopropylamino group, di-n-butylamino group, diisobutylamino group, di-sec-butylamino group, and di-tert-butylamino group; diarylamino groups such as diphenylamino group; etc. Among these, dialkylamino groups are preferred, and dimethylamino group, diethylamino group, and di-n-butylamino group are more preferred.

[0028] In the above general formula (2), R 1 and R 2 When the group represented by the general formula (2) is a hydrocarbyl group having a hydrocarbyloxy group as a substituent, specific examples of the group represented by the general formula (2) include di(alkoxyalkyl)amino groups such as di(methoxymethyl)amino and di(ethoxymethyl)amino.

[0029] In the above general formula (2), R 1 and R 2 When is a trihydrocarbylsilyl group, specific examples of the group represented by the above general formula (2) include trialkylsilyl group-containing amino groups such as a bis(trimethylsilyl)amino group, a bis(tert-butyldimethylsilyl)amino group, and an N-trimethylsilyl-N-methylamino group.

[0030] In the above general formula (2), R 1 and R 2 and (b) are bonded to each other to form a hydrocarbylene group, specific examples of the group represented by the above general formula (2) include 1-alkyleneimino groups such as a 1-trimethyleneimino group, a 1-pyrrolidino group, a 1-piperidino group, a 1-hexamethyleneimino group, a 1-heptamethyleneimino group, a 1-octamethyleneimino group, a 1-decamethyleneimino group, and a 1-dodecamethyleneimino group.

[0031] In the above general formula (2), R 1 and R 2and are bonded to each other to form a hydrocarbylene group containing a nitrogen atom and / or an oxygen atom, specific examples of the group represented by the above general formula (2) include a 1-imidazolyl group, a 4,5-dihydro-1-imidazolyl group, and a morpholino group.

[0032] As the group represented by the above general formula (2), a dialkylamino group or a 1-alkyleneimino group is preferred, a dialkylamino group is more preferred, and a dimethylamino group, a diethylamino group or a di-n-butylamino group is even more preferred.

[0033] In the above general formula (1), X 2 , X 3 and X 4 Examples of hydrocarbyloxy groups that can constitute the above formula include alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, and tert-butoxy; and aryloxy groups such as phenoxy and benzyloxy.

[0034] In the above general formula (1), X 2 , X 3 and X 4 Examples of hydrocarbyl groups that can constitute the above formula include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl; and aryl groups such as phenyl, 4-methyl-1-phenyl, and benzyl. X 2 , X 3 and X 4 When the hydrocarbyl group that can constitute the above has a substituent, examples thereof include hydrocarbyl groups having a hydrocarbyloxy group as the substituent, and examples thereof include alkoxyalkyl groups such as a methoxymethyl group, an ethoxymethyl group, and an ethoxyethyl group.

[0035] In the above general formula (1), X 1 is a chemical single bond, and X 2 , X 3 and X 4Specific examples of vinyl compounds containing a silicon atom-containing functional group represented by the above general formula (1), when one of the groups is a substituted amino group, include (dialkylamino)dialkylvinylsilanes such as (dimethylamino)dimethylvinylsilane, (ethylmethylamino)dimethylvinylsilane, (di-n-propylamino)dimethylvinylsilane, (diisopropylamino)dimethylvinylsilane, (dimethylamino)diethylvinylsilane, (ethylmethylamino)diethylvinylsilane, (di-n-propylamino)diethylvinylsilane, and (diisopropylamino)diethylvinylsilane; [bis(trimethylsilyl)amino]dimethylvinylsilane, [bis(t-butyldimethylsilyl)amino]dimethylvinylsilane, [bis(trimethylsilyl)amino]diethylvinylsilane, and [bis(t-butyldimethylsilyl)amino]diethylvinylsilane; (trialkylsilyl)amino]dialkylvinylsilane; (dialkylamino)di(alkoxyalkyl)vinylsilanes such as (dimethylamino)di(methoxymethyl)vinylsilane, (dimethylamino)di(methoxyethyl)vinylsilane, (dimethylamino)di(ethoxymethyl)vinylsilane, (dimethylamino)di(ethoxyethyl)vinylsilane, (diethylamino)di(methoxymethyl)vinylsilane, (diethylamino)di(methoxyethyl)vinylsilane, (diethylamino)di(ethoxymethyl)vinylsilane, and (diethylamino)di(ethoxyethyl)vinylsilane; cyclic aminodialkylvinylsilane compounds such as pyrrolidinodimethylvinylsilane, piperidinodimethylvinylsilane, hexamethyleneiminodimethylvinylsilane, 4,5-dihydroimidazolyldimethylvinylsilane, and morpholinodimethylvinylsilane; and the like.

[0036] In the above general formula (1), X 1 is a hydrocarbylene group, and X 2 , X 3 and X 4Specific examples of vinyl compounds containing a silicon atom-containing functional group represented by the above general formula (1), when one of the groups is a substituted amino group, include (dimethylamino)dimethyl-4-vinylphenylsilane, (dimethylamino)dimethyl-3-vinylphenylsilane, (diethylamino)dimethyl-4-vinylphenylsilane, (diethylamino)dimethyl-3-vinylphenylsilane, (di-n-propylamino)dimethyl-4-vinylphenylsilane, (di-n-propylamino)dimethyl-3-vinylphenylsilane, (di-n-butylamino)dimethyl-4-vinylphenylsilane, (di-n-butylamino)dimethyl- and (dialkylamino)dialkylvinylphenylsilanes such as (dialkylamino)diethyl-3-vinylphenylsilane, (dimethylamino)diethyl-4-vinylphenylsilane, (dimethylamino)diethyl-3-vinylphenylsilane, (diethylamino)diethyl-4-vinylphenylsilane, (diethylamino)diethyl-3-vinylphenylsilane, (di-n-propylamino)diethyl-4-vinylphenylsilane, (di-n-propylamino)diethyl-3-vinylphenylsilane, (di-n-butylamino)diethyl-4-vinylphenylsilane, and (di-n-butylamino)diethyl-3-vinylphenylsilane.

[0037] In the above general formula (1), X 1 is a chemical single bond, and X 2 , X 3 and X 4Specific examples of vinyl compounds containing silicon atom-containing functional groups represented by the above general formula (1) in the case where two of them are substituted amino groups include bis(dialkylamino)alkylvinylsilanes such as bis(dimethylamino)methylvinylsilane, bis(diethylamino)methylvinylsilane, bis(di-n-propylamino)methylvinylsilane, bis(di-n-butylamino)methylvinylsilane, bis(dimethylamino)ethylvinylsilane, bis(diethylamino)ethylvinylsilane, bis(di-n-propylamino)ethylvinylsilane, and bis(di-n-butylamino)ethylvinylsilane; bis[bis(trimethylsilyl)amino]methylvinylsilane, bis[bis(tert-butyldimethylsilyl)amino]methylvinylsilane, bis[bis(trimethylsilyl)amino]ethylvinylsilane, and bis[bis(tert-butyldimethylsilyl)amino]ethylvinylsilane. bis[bis(trialkylsilyl)amino]alkylvinylsilanes; bis(dialkylamino)alkoxyalkylsilanes such as bis(dimethylamino)methoxymethylvinylsilane, bis(dimethylamino)methoxyethylvinylsilane, bis(dimethylamino)ethoxymethylvinylsilane, bis(dimethylamino)ethoxyethylvinylsilane, bis(diethylamino)methoxymethylvinylsilane, bis(diethylamino)methoxyethylvinylsilane, bis(diethylamino)ethoxymethylvinylsilane, and bis(dimethylamino)ethoxyethylvinylsilane; bis(cyclic amino)alkylvinylsilane compounds such as bis(pyrrolidino)methylvinylsilane, bis(piperidino)methylvinylsilane, bis(hexamethyleneimino)methylvinylsilane, bis(4,5-dihydroimidazolyl)methylvinylsilane, and bis(morpholino)methylvinylsilane; and the like.

[0038] In the above general formula (1), X 1 is a hydrocarbylene group, and X 2 , X 3 and X 4Specific examples of vinyl compounds containing silicon atom-containing functional groups represented by the above general formula (1) when two of them are substituted amino groups include bis(dimethylamino)methyl-4-vinylphenylsilane, bis(dimethylamino)methyl-3-vinylphenylsilane, bis(diethylamino)methyl-4-vinylphenylsilane, bis(diethylamino)methyl-3-vinylphenylsilane, bis(di-n-propylamino)methyl-4-vinylphenylsilane, bis(di-n-propylamino)methyl-3-vinylphenylsilane, bis(di-n-butylamino)methyl-4-vinylphenylsilane, bis(di-n-butylamino)methyl- and bis(dialkylamino)alkylvinylphenylsilanes such as bis(dimethylamino)ethyl-3-vinylphenylsilane, bis(dimethylamino)ethyl-4-vinylphenylsilane, bis(dimethylamino)ethyl-3-vinylphenylsilane, bis(diethylamino)ethyl-4-vinylphenylsilane, bis(diethylamino)ethyl-3-vinylphenylsilane, bis(di-n-propylamino)ethyl-4-vinylphenylsilane, bis(di-n-propylamino)ethyl-3-vinylphenylsilane, bis(di-n-butylamino)ethyl-4-vinylphenylsilane, and bis(di-n-butylamino)ethyl-3-vinylphenylsilane.

[0039] In the above general formula (1), X 1 is a chemical single bond, and X 2 , X 3 and X 4 Specific examples of vinyl compounds containing silicon atom-containing functional groups represented by the above general formula (1) when three of the groups are substituted amino groups include tris(dialkylamino)vinylsilanes such as tris(dimethylamino)vinylsilane, tris(diethylamino)vinylsilane, tris(di-n-propylamino)vinylsilane, and tris(di-n-butylamino)vinylsilane.

[0040] In the above general formula (1), X 1 is a hydrocarbylene group, and X 2 , X 3 and X 4Specific examples of vinyl compounds containing silicon atom-containing functional groups represented by the above general formula (1) when three of the groups are substituted amino groups include tris(dialkylamino)vinylphenylsilanes such as tris(dimethylamino)-4-vinylphenylsilane, tris(dimethylamino)-3-vinylphenylsilane, tris(diethylamino)-4-vinylphenylsilane, tris(diethylamino)-3-vinylphenylsilane, tris(di-n-propylamino)-4-vinylphenylsilane, tris(di-n-propylamino)-3-vinylphenylsilane, tris(di-n-butylamino)-4-vinylphenylsilane, and tris(di-n-butylamino)-3-vinylphenylsilane.

[0041] In the above general formula (1), X 1 is a chemical single bond, and X 2 , X 3 and X 4 Specific examples of vinyl compounds containing a silicon atom-containing functional group represented by the above general formula (1), when none of the functional groups is a substituted amino group, include trialkoxyvinylsilanes such as trimethoxyvinylsilane, triethoxyvinylsilane, and tripropoxyvinylsilane; dialkoxyalkylvinylsilanes such as methyldimethoxyvinylsilane and methyldiethoxyvinylsilane; dialkoxyarylvinylsilanes such as di(tert-pentoxy)phenylvinylsilane and di(tert-butoxy)phenylvinylsilane; monoalkoxydialkylvinylsilanes such as dimethylmethoxyvinylsilane; monoalkoxydiarylvinylsilanes such as tert-butoxydiphenylvinylsilane and tert-pentoxydiphenylvinylsilane; monoalkoxyalkylarylvinylsilanes such as tert-butoxymethylphenylvinylsilane and tert-butoxyethylphenylvinylsilane; and substituted alkoxyvinylsilane compounds such as tris(β-methoxyethoxy)vinylsilane.

[0042] Among the compounds represented by the general formula (1), X 1 is preferably a chemical single bond, and X1 is a chemical single bond and X 2 , X 3 and X 4 Among these, compounds in which two are substituted amino groups are more preferred, and X 1 is a chemical single bond and X 2 , X 3 and X 4 Among these, compounds in which two of the groups are dialkylamino groups are particularly preferred.

[0043] Among the compounds represented by the general formula (1), bis(dimethylamino)methylvinylsilane, bis(diethylamino)methylvinylsilane, and bis(di-n-butylamino)methylvinylsilane are preferred, with bis(diethylamino)methylvinylsilane being particularly preferred.

[0044] Furthermore, examples of vinyl compounds containing a functional group capable of interacting with silica other than the compound represented by the general formula (1) above include bis(trialkylsilyl)aminostyrenes such as 4-N,N-bis(trimethylsilyl)aminostyrene and 3-N,N-bis(trimethylsilyl)aminostyrene; and bis(trialkylsilyl)aminoalkylstyrenes such as 4-bis(trimethylsilyl)aminomethylstyrene, 3-bis(trimethylsilyl)aminomethylstyrene, 4-bis(trimethylsilyl)aminoethylstyrene, and 3-bis(trimethylsilyl)aminoethylstyrene.

[0045] When the compound represented by the above general formula (1) is used as the vinyl compound containing a functional group capable of interacting with silica, a unit represented by the following general formula (3) is introduced into the conjugated diene polymer of the present invention as a unit of the vinyl compound containing a functional group capable of interacting with silica. [ka] In the above general formula (3), X 5 represents a chemical single bond or a hydrocarbylene group, and X 6 , X 7 and X8 each independently represents a hydroxyl group, a substituted amino group, a hydrocarbyloxy group, or a hydrocarbyl group which may have a substituent.

[0046] In the unit represented by the general formula (3), X 5 represents X in the compound represented by the general formula (1). 1 In the unit represented by the general formula (3), X 6 , X 7 and X 8 represents X in the compound represented by the general formula (1). 2 , X 3 and X 4 Therefore, in the unit represented by the general formula (3), X 5 , X 6 , X 7 and X 8 represents X in the compound represented by the general formula (1). 1 , X 2 , X 3 and X 4 In addition, the compound represented by the general formula (1) may be the same as X 2 , X 3 and X 4 In the case where at least one of X is a substituted amino group or a hydrocarbyloxy group, the substituted amino group or the hydrocarbyloxy group can be hydrolyzed in any step and at any timing to form X 2 , X 3 and X 4 At least one of the groups may be a hydroxyl group.

[0047] In the conjugated diene polymer of the present invention, the content of the vinyl compound unit containing a functional group capable of interacting with silica is preferably 0.001 to 10,000% by weight, and more preferably 0.001 to 3,000% by weight, based on 100% by weight of the total amount of all monomers. By setting the content of the vinyl compound unit containing a functional group capable of interacting with silica within the above range, the fuel economy of the resulting cross-linked rubber product can be further improved while maintaining sufficient processability.

[0048] The conjugated diene polymer of the present invention may also contain other monomer units in addition to the conjugated diene monomer units, aromatic vinyl monomer units, and vinyl compound units containing functional groups capable of interacting with silica. Examples of other compounds constituting such other monomer units include linear olefin compounds such as ethylene, propylene, and 1-butene; cyclic olefin compounds such as cyclopentene and 2-norbornene; and non-conjugated diene compounds such as 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene.

[0049] Furthermore, in the conjugated diene polymer of the present invention, the high molecular weight polymer has a shrinkage factor of 0.4 to 0.8, the high molecular weight polymer has an adsorption rate to silica of 75% or less, and the medium molecular weight polymer has an adsorption rate to silica of 40 to 100%.

[0050] Here, the low molecular weight component, the medium molecular weight component, and the high molecular weight component that constitute the conjugated diene polymer of the present invention will be described. _LOW , medium molecular weight P _MID , high molecular weight substance P _HIGH The present invention will be described with reference to Figures 1 to 5. Figures 1 to 5 are graphs that schematically show examples of GPC charts obtained by performing gel permeation chromatography measurements using a styrene column on the conjugated diene polymer of the present invention.

[0051] First, the case where the conjugated diene polymer of the present invention has one maximum value in the molecular weight distribution measured by gel permeation chromatography, i.e., a unimodal distribution, as shown in FIG. 1(A) will be described.

[0052] As shown in FIG. 1(B), when the molecular weight distribution is unimodal, the molecular weight at which the molecular weight distribution has a maximum value is first determined as the medium molecular weight component P _MID Molecular weight Mp _MID In addition, the peak intensity S at the molecular weight where the molecular weight distribution shows a maximum value is MID For half the strength (i.e., 1 / 2S MID ) the molecular weight on the lower molecular weight side is called low molecular weight P _LOW Molecular weight Mp _LOW On the other hand, the peak intensity S at the molecular weight where the molecular weight distribution shows a maximum value MID For half the strength (i.e., 1 / 2S MID ) the molecular weight on the higher molecular weight side is called the high molecular weight P _HIGH Molecular weight Mp _HIGH Let's say.

[0053] 2(A) shows a molecular weight distribution measured by gel permeation chromatography that has two maximum values, i.e., a bimodal distribution. The distribution shown in FIG. 2(A) shows a bimodal distribution in which, of the two peaks containing the maximum values, the area of ​​the peak on the lower molecular weight side is larger than the area of ​​the peak on the higher molecular weight side.

[0054] As shown in FIG. 2(B), in the case where the distribution is bimodal and the peak area on the low molecular weight side is larger, the molecular weight at which the molecular weight distribution shows a maximum value in the peak on the low molecular weight side with a larger peak area is referred to as the middle molecular weight component P. _MID Molecular weight Mp _MID In addition, the molecular weight at which the molecular weight distribution reaches a maximum value in the peak on the high molecular weight side with a small peak area is defined as the high molecular weight component P _HIGH Molecular weight Mp _HIGHThen, in the peak on the low molecular weight side with a large peak area, the peak intensity S at the molecular weight at which the molecular weight distribution shows a maximum value is MID For half the strength (i.e., 1 / 2S MID ) the molecular weight on the lower molecular weight side is called low molecular weight P _LOW Molecular weight Mp _LOW Let's say.

[0055] On the other hand, Figure 3(A) shows an embodiment of a molecular weight distribution measured by gel permeation chromatography that has two maxima, i.e., a bimodal distribution, in which, of the two peaks containing the maxima, the peak area on the high molecular weight side is larger than the peak area on the low molecular weight side.

[0056] As shown in FIG. 3(B), in the case of a bimodal distribution in which the peak area on the high molecular weight side is larger, the molecular weight at which the molecular weight distribution shows a maximum value in the peak on the high molecular weight side with a larger peak area is referred to as the middle molecular weight component P. _MID Molecular weight Mp _MID In addition, the molecular weight at which the molecular weight distribution reaches a maximum value in the peak on the low molecular weight side with a small peak area is defined as the low molecular weight component P _LOW Molecular weight Mp _LOW Then, in the peak on the high molecular weight side with a large peak area, the peak intensity S at the molecular weight at which the molecular weight distribution shows a maximum value is MID For half the strength (i.e., 1 / 2S MID ) the molecular weight on the higher molecular weight side is called the high molecular weight P _HIGH Molecular weight Mp _HIGH Let's say.

[0057] FIG. 4(A) shows an embodiment in which the molecular weight distribution measured by gel permeation chromatography has three maximum values, that is, a trimodal distribution.

[0058] As shown in FIG. 4(B), in the case of an embodiment having a trimodal distribution, the three molecular weights at which the molecular weight distribution has a maximum value are designated, from the low molecular weight side, as low molecular weight components P _LOW Molecular weight Mp _LOW , medium molecular weight P _MID Molecular weight Mp _MID , and high molecular weight substance P _HIGH Molecular weight Mp _HIGH Let's say.

[0059] FIG. 5(A) shows an embodiment in which the molecular weight distribution measured by gel permeation chromatography has four maximum values, that is, a quadrupole distribution.

[0060] As shown in Figure 5(B), in the case of an embodiment having a quadruple distribution, a combination of three consecutive peaks is selected from the four peaks showing the four maximum values, and the combination with the largest total peak area of ​​the three consecutive peaks is selected. In the embodiment shown in Figure 5(B), three consecutive peaks including the peak located on the highest molecular weight side are selected. Then, for the selected three consecutive peaks, the molecular weights at which the molecular weight distribution shows the maximum value are determined from the lowest molecular weight side as the low molecular weight components P. _LOW Molecular weight Mp _LOW , medium molecular weight P _MID Molecular weight Mp _MID , and high molecular weight substance P _HIGH Molecular weight Mp _HIGH 5(A) and 5(B), an embodiment having four maximum values, i.e., an embodiment having a tetramodal distribution, has been described, but in the case of an embodiment having five or more maximum values, i.e., an embodiment having a pentamodal or more distribution, the peak having the largest total peak area of ​​three consecutive peaks is selected in the same manner, and the low molecular weight component P _LOW Molecular weight Mp _LOW , medium molecular weight P _MID Molecular weight Mp _MID , and high molecular weight substance P _HIGH Molecular weight Mp _HIGH Determine.

[0061] Low molecular weight P_LOW Molecular weight Mp _LOW is preferably in the range of 50,000 to 200,000, more preferably in the range of 60,000 to 190,000, even more preferably in the range of 60,000 to 180,000, and particularly preferably in the range of 70,000 to 160,000. _LOW Molecular weight Mp _LOW By setting the value within the above range, the processability of the obtained cross-linked rubber product can be further improved while the fuel economy of the cross-linked rubber product can be improved.

[0062] Medium molecular weight P _MID Molecular weight Mp _MID is preferably in the range of 210,000 to 600,000, more preferably in the range of 300,000 to 500,000, and even more preferably in the range of 330,000 to 450,000. _MID Molecular weight Mp _MID By setting the value within the above range, the processability of the obtained cross-linked rubber product can be further improved while the fuel economy of the cross-linked rubber product can be improved.

[0063] High molecular weight P _HIGH Molecular weight Mp _HIGH is preferably in the range of 610,000 to 1,400,000, more preferably in the range of 700,000 to 1,300,000, and even more preferably in the range of 740,000 to 1,200,000. _HIGH Molecular weight Mp _HIGH By setting the value of the hardness to within the above range, it is possible to improve the abrasion resistance and mechanical strength while improving the processability.

[0064] In addition, the weight average molecular weight Mw of the entire conjugated diene polymer of the present invention _TOTAL The weight average molecular weight Mw of the entire conjugated diene polymer is preferably in the range of 300,000 to 900,000, more preferably in the range of 350,000 to 800,000, further preferably in the range of 400,000 to 700,000, and particularly preferably in the range of 420,000 to 600,000. _TOTALBy setting the value within the above range, the processability of the obtained cross-linked rubber product can be further improved while the fuel economy of the cross-linked rubber product can be improved.

[0065] The overall molecular weight distribution of the conjugated diene polymer of the present invention, expressed as the ratio (Mw / Mn) of the overall weight average molecular weight (Mw) to the number average molecular weight (Mn), is preferably 1.1 to 3.0, more preferably 1.2 to 2.5, and particularly preferably 1.2 to 2.2.

[0066] The molecular weights mentioned above can be determined as polystyrene equivalent values ​​by gel permeation chromatography using a styrene column. _LOW Molecular weight Mp _LOW , medium molecular weight P _MID Molecular weight Mp _MID , and high molecular weight substance P _HIGH Molecular weight Mp _HIGH Specifically, it can be determined according to the method described above with reference to FIGS.

[0067] The method for making the molecular weight distribution of the conjugated diene polymer of the present invention bimodal or more is not particularly limited, but examples thereof include a method of adding a polymerization initiator during polymerization when synthesizing the conjugated diene polymer by polymerizing a monomer, and a method of carrying out a coupling reaction on the polymer chain obtained by polymerization. In this case, for example, by selecting the timing and amount of adding the polymerization initiator, the timing of carrying out the coupling reaction, the type of coupling agent used, etc., it is possible to obtain a low molecular weight polymer P. _LOW Molecular weight Mp _LOW , medium molecular weight P _MID Molecular weight Mp _MID , and high molecular weight substance P _HIGH Molecular weight Mp _HIGH can be controlled.

[0068] From the viewpoint of further improving processability and fuel economy, the conjugated diene polymer of the present invention preferably has a bimodal or higher molecular weight distribution (having two or more peaks), and more preferably a trimodal distribution (having three peaks). In the present invention, a maximum value is defined as a value that exhibits an intensity three times or more higher than the nearest minimum value, and peaks including such a maximum value are counted in the number of peaks. In other words, even if a maximum value is shown, a value that exhibits an intensity less than three times higher than the nearest minimum value is not considered to be a maximum value that forms a peak.

[0069] The conjugated diene polymer of the present invention is a high molecular weight polymer P _HIGH The shrinkage factor of the high molecular weight P _HIGH The adsorption rate of the medium molecular weight P to silica is 75% or less. _MID The adsorption rate of silica is 40 to 100%.

[0070] Here, the high molecular weight substance P _HIGH The contraction factor is a high molecular weight substance P _HIGH The intrinsic viscosity [η] of a conjugated diene polymer is measured using a GPC apparatus (3D-GPC) equipped with a viscosity detector, a light scattering detector, and a differential refractive index (RI) detector, using tetrahydrofuran as a solvent, and the ratio of the measured intrinsic viscosity to the standard intrinsic viscosity [η] can be calculated. Specifically, the conjugated diene polymer is subjected to 3D-GPC measurement, and the high molecular weight polymer P is determined from the measurement results. _HIGH Molecular weight Mp _HIGH The intrinsic viscosity [η] is calculated, and the shrinkage factor g' can be calculated from the calculated intrinsic viscosity [η] and the standard intrinsic viscosity [η]0 according to the equation g'=[η] / [η]0. The standard intrinsic viscosity [η]0 is a calculated value of the intrinsic viscosity of a conjugated diene polymer that does not have a branched structure (intrinsic viscosity of a linear polymer), and the lower the value of the shrinkage factor g', the higher the degree of branching tends to be.

[0071] FIG. 6 shows an example of a graph showing the relationship between molecular weight and intrinsic viscosity [η], standard intrinsic viscosity [η]0, and shrinkage factor g' measured by 3D-GPC. Also shown in FIG. 6 is a chart showing the molecular weight distribution measured by GPC. _HIGH As shown in Figure 6, the shrinkage factor of the high molecular weight P _HIGH Molecular weight Mp _HIGH The intrinsic viscosity [η] measured by 3D-GPC and the standard intrinsic viscosity [η]0 are used to calculate the ratio (η / η0) between them.

[0072] In the conjugated diene polymer of the present invention, the high molecular weight polymer P _HIGH The shrinkage factor of the polymer P is in the range of 0.4 to 0.8, preferably 0.4 to 0.7, and more preferably 0.4 to 0.6. _HIGH If the shrinkage factor is too low, the mechanical strength will be poor. _HIGH If the shrinkage factor is too high, the processability will be reduced. _HIGH The method for adjusting the shrinkage factor to the above range is not particularly limited, but examples include a method in which a polymer chain obtained by polymerization is subjected to a coupling reaction using a tri- or higher functional coupling agent.

[0073] In the conjugated diene polymer of the present invention, the medium molecular weight component P _MID The shrinkage factor of the high molecular weight P _HIGH Similar to the shrinkage factor of the medium molecular weight P _MID Molecular weight Mp _HIGH The intrinsic viscosity [η] measured by 3D-GPC and the standard intrinsic viscosity [η]0 can be calculated by calculating the ratio (η / η0) between them. _MID The shrinkage factor of the medium molecular weight polymer P is not particularly limited, but is preferably 0.8 to 1.2, more preferably 0.8 to 1.0, and even more preferably 0.8 to 0.9. _MID By setting the shrinkage factor within the above range, the processability can be further improved.

[0074] The conjugated diene polymer of the present invention is a high molecular weight polymer P _HIGH and medium molecular weight P _MID That is, the conjugated diene polymer of the present invention has a high molecular weight P _HIGH The adsorption rate of the medium molecular weight P to silica is 75% or less. _MID The adsorption rate of the polymer P to silica is in the range of 40 to 100%. _HIGH and medium molecular weight P _MID The adsorption rate of the conjugated diene polymer to silica can be calculated, for example, by subjecting the conjugated diene polymer to GPC measurement using a styrene column and GPC measurement using a silica column, based on the results of these measurements, according to the following formula (1): Adsorption rate to silica (%) = (1 - (area A of the material measured by GPC using a silica column) Si / Area B of standard polystyrene measured by GPC using a silica column Si ) × (area of ​​standard polystyrene measured by GPC using a styrene column B sty / Area A of the material measured by GPC using a styrene column sty ))×100 (1) Here, Fig. 7 is a graph showing the results of GPC measurement using a styrene-based column and a silica-based column. As shown in Fig. 7, in the GPC measurement using a styrene-based column, no adsorption occurs, whereas in the GPC measurement using a silica-based column, a part of the polymer chain is adsorbed to the silica, resulting in a difference between the results. In the present invention, the high molecular weight P obtained by such a measurement _HIGH Adsorption rate of P on silica and medium molecular weight P _MID This defines the adsorption rate of silica.

[0075] For GPC measurements using styrene columns, two 5000 molecular weight standard polystyrene columns (7.5 mm ID x 300 mm, Agilent Technologies) were used. A column oven (CTO-20A, Shimadzu Corporation) and an RI detector (RID-10A, Shimadzu Corporation) were used at 35°C. The mobile phase was a mixture of tetrahydrofuran and 2-(ethylamino)ethanol at a flow rate of 1.0 mL / min. Alternatively, three PLgel Mini MIXED-C columns (4.6 mm ID x 250 mm, Agilent Technologies) or three PLgel MIXED-C columns (7.5 mm ID x 300 mm, Agilent Technologies) could also be used. In addition, GPC measurements using silica-based columns were performed using standard polystyrene with a molecular weight of 5000. Three columns were used: one Zorbax PSM1000-S (6.2 x 250 mm, Agilent Technologies), one Zorbax PSM-300 (6.2 x 250 mm, Agilent Technologies), and one Zorbax PSM60-S (6.2 x 250 mm, Agilent Technologies). Measurements were performed using a column oven (CTO-20A, Shimadzu Corporation) set at 35°C and an RI detector (RID-10A, Shimadzu Corporation), with tetrahydrofuran as the mobile phase and a flow rate of 0.7 mL / min.

[0076] And the high molecular weight substance P _HIGH Adsorption rate of P on silica and _MID Specifically, the adsorption rate of the compound to silica is determined as follows.

[0077] That is, when the conjugated diene polymer of the present invention has a unimodal distribution as shown in FIG. 1(A), the medium molecular weight component P _MID The adsorption rate of Mp shown in Figure 1(B) is _LOW From, Mp _HIGH The area between the middle molecular weight substance P_MID The adsorption rate of Mp shown in Figure 1(B) is _LOW From, Mp _HIGH Area A between Si , A sty (i.e., Mp _LOW From, Mp _HIGH Area A between Si , and Mp by GPC measurement using a styrene column _LOW From, Mp _HIGH Area between both areas A sty ) and calculate the area A Si , A sty The polymer P can be calculated by the above formula (1). _HIGH The adsorption rate of Mp shown in Figure 1(B) is _HIGH From, Mp _1%_HIGH (Mp _1%_HIGH is the maximum intensity (S in Fig. 1(B)). MID The area between the molecular weights (P) and (P) is determined as the object of measurement. _HIGH The adsorption rate of Mp shown in Figure 1(B) is _HIGH From, Mp _1%_HIGH Area A between Si , A sty Calculate the area A Si , A sty It can be calculated using the above formula (1).

[0078] Furthermore, as shown in FIG. 2(A), when the distribution is bimodal and the peak area on the low molecular weight side is larger, it is considered to be a medium molecular weight component P. _MID The adsorption rate of Mp shown in Figure 2(B) _LOW From, Mp _谷 (Mp _谷 is Mp _MID and Mp _HIGH The area A between Si , A sty Calculate the area A Si , A styThe polymer P can be calculated by the above formula (1). _HIGH The adsorption rate of Mp shown in Figure 2(B) _谷 From, Mp _1%_HIGH (Mp _1%_HIGH is the maximum intensity (S in Figure 2(B)). MID ) and the molecular weight that shows 1 / 100 of the intensity of the molecular weight located on the high molecular weight side) Si , A sty Calculate the area A Si , A sty It can be calculated using the above formula (1).

[0079] Furthermore, as shown in FIG. 3(A), when the distribution is bimodal and the peak area on the high molecular weight side is larger, it is considered that the middle molecular weight component P _MID The adsorption rate of silica is shown in Figure 3(B) _谷 (Mp _谷 is Mp _LOW and Mp _MID From the molecular weight at which the minimum value is found between _HIGH Area A between Si , A sty Calculate the area A Si , A sty The polymer P can be calculated by the above formula (1). _HIGH The adsorption rate of silica is shown in Figure 3(B) _HIGH From, Mp _1%_HIGH (Mp _1%_HIGH is the maximum intensity (S in Figure 3(B)). MID ) and the molecular weight that shows 1 / 100 of the intensity of the molecular weight located on the high molecular weight side) Si , A sty Calculate the area A Si , A sty It can be calculated using the above formula (1).

[0080] Furthermore, as shown in FIG. 4(A), when the distribution has a trimodal distribution, the medium molecular weight P _MID The adsorption rate of silica is shown in Figure 4(B) as Mp _谷_1(Mp _谷_1 is Mp _LOW and Mp _MID From the molecular weight at which the minimum value is found between _谷_2 (Mp _谷_2 is Mp _MID and Mp _HIGH The area A between Si , A sty Calculate the area A Si , A sty The polymer P can be calculated by the above formula (1). _HIGH The adsorption rate of silica is shown in Figure 4(B) as Mp _谷_2 From, Mp _1%_HIGH (Mp _1%_HIGH is the maximum intensity (S in Figure 4(B)). MID ) and the molecular weight that shows 1 / 100 of the intensity of the molecular weight located on the high molecular weight side) Si , A sty Calculate the area A Si , A sty It can be calculated using the above formula (1).

[0081] Furthermore, as shown in FIG. 5(A), when the distribution has four peaks, the medium molecular weight P _MID The adsorption rate of Mp _谷_2 (Mp _谷_2 is Mp _LOW and Mp _MID From the molecular weight at which the minimum value is found between _谷_3 (Mp _谷_3 is Mp _MID and Mp _HIGH The area A between Si , A sty Calculate the area A Si , A sty The polymer P can be calculated by the above formula (1). _HIGH The adsorption rate of Mp _谷_3 From, Mp _1%_HIGH (Mp _1%_HIGH is the maximum intensity (S in Figure 5(B)).MID ) and the molecular weight that shows 1 / 100 of the intensity of the molecular weight located on the high molecular weight side) Si , A sty Calculate the area A Si , A sty In the case of an embodiment having five or more maximum values, i.e., an embodiment having a five- or more-modal distribution, the amount of the medium-molecular-weight polymer P can be calculated in the same manner as in the case of a four-modal distribution. _MID Adsorption rate of P on silica and high molecular weight P _HIGH The adsorption rate of the compound to silica can be determined. In either embodiment, the molecular weight range used to calculate the area is measured using a styrene-based column, and the area is calculated using the range showing the molecular weight determined using the styrene-based column in the GPC chart measured using the silica-based column. The area can be calculated by confirming the elution time showing each molecular weight and integrating it with respect to the elution time.

[0082] High molecular weight P _HIGH The adsorption rate of the polymer P to silica is 75% or less, preferably 10 to 70%, and more preferably 10 to 60%. _HIGH If the adsorption rate of the polymer P to silica is too high, the processability will be reduced. _HIGH The method for adjusting the adsorption rate of the polymer P to silica to the above range is not particularly limited, but _HIGH and a method of adjusting the amount and type of units of a vinyl compound having a functional group capable of interacting with silica, which is contained in the above.

[0083] In addition, the medium molecular weight P _MID The adsorption rate of the medium molecular weight compound P to silica is 40 to 100%, preferably 50 to 100%, and more preferably 50 to 80%. _MID If the adsorption rate of the medium molecular weight compound P to silica is too low, the effect of improving fuel economy cannot be obtained. _MID The method for adjusting the adsorption rate of the medium molecular weight compound P to silica to the above range is not particularly limited, but _MIDand a method of adjusting the amount and type of units of a vinyl compound having a functional group capable of interacting with silica, which is contained in the above.

[0084] In the conjugated diene polymer of the present invention, the low molecular weight component P _LOW , medium molecular weight P _MID , and high molecular weight substance P _HIGH The content ratio of the low molecular weight compound P is not particularly limited. _LOW The content of the medium molecular weight compound P is preferably 5 to 20% by weight, more preferably 8 to 17% by weight. _MID The content of the polymer P is preferably 30 to 70% by weight, more preferably 50 to 60% by weight. _HIGH The content of the low molecular weight component P is preferably 20 to 60% by weight, more preferably 25 to 40% by weight. _LOW , medium molecular weight P _MID , and high molecular weight substance P _HIGH The content ratio can be calculated as follows:

[0085] That is, when the conjugated diene polymer of the present invention has a unimodal distribution as shown in FIG. 1(A), the low molecular weight component P _LOW The content ratio of Mp _1%_LOW (Mp _1%_LOW is the maximum intensity (S in Fig. 1(B)). MID ) and is located on the low molecular weight side), Mp _LOW The area between _LOW The area of ​​the medium molecular weight component P _MID The content ratio of Mp shown in Figure 1(B) _LOW From, Mp _HIGH The area between the medium molecular weight P _MID Furthermore, the area of ​​the high molecular weight substance P _HIGH The content ratio of Mp shown in Figure 1(B) _HIGH From, Mp _1%_HIGH The area between the high molecular weight molecules P _HIGH This is calculated by taking the area of

[0086] As shown in FIG. 2(A), when the distribution is bimodal and the peak area on the low molecular weight side is larger, it is considered to be a low molecular weight component P _LOW The content ratio of Mp _1%_LOW (Mp _1%_LOW is the maximum intensity (S in Figure 2(B)). MID ) and is located on the low molecular weight side), Mp _LOW The area between _LOW The area of ​​the medium molecular weight component P _MID The content ratio of Mp shown in Figure 2(B) _LOW From, Mp _谷 The area between the medium molecular weight P _MID Furthermore, the area of ​​the high molecular weight substance P _HIGH The content ratio of Mp shown in Figure 2(B) _谷 From, Mp _1%_HIGH The area between the high molecular weight molecules P _HIGH This is calculated by taking the area of

[0087] As shown in FIG. 3(A), when the distribution is bimodal and the peak area on the high molecular weight side is larger, it is considered that the low molecular weight component P _LOW The content ratio of Mp _1%_LOW (Mp _1%_LOW is the maximum intensity (S in Figure 3(B)). MID ) and is located on the low molecular weight side), Mp _谷 The area between _LOW The area of ​​the medium molecular weight component P _MID The content ratio of Mp shown in Figure 3(B) _谷 From, Mp _HIGH The area between the medium molecular weight P _MID Furthermore, the area of ​​the high molecular weight substance P _HIGH The content ratio of Mp shown in Figure 3(B) _HIGH From, Mp _1%_HIGH The area between the high molecular weight molecules P _HIGH This is calculated by taking the area of

[0088] As shown in FIG. 4(A), when the distribution is trimodal, the low molecular weight P _LOW The content ratio of Mp _1%_LOW (Mp _1%_LOW is the maximum intensity (S in Figure 4(B)). MID ) and is located on the low molecular weight side), Mp _谷_1 The area between _LOW The area of ​​the medium molecular weight component P _MID The content ratio of Mp shown in FIG. _谷_1 From, Mp _谷_2 The area between the medium molecular weight P _MID Furthermore, the area of ​​the high molecular weight substance P _HIGH The content ratio of Mp shown in FIG. _谷_2 From, Mp _1%_HIGH The area between the high molecular weight molecules P _HIGH This is calculated by taking the area of

[0089] As shown in FIG. 5(A), when the distribution is quadrupole, the low molecular weight P _LOW The content ratio of Mp _1%_LOW (Mp _1%_LOW is the maximum intensity (S in Figure 5(B)). MID ) and is located on the low molecular weight side), Mp _谷_2 The area between _LOW The area of ​​the medium molecular weight component P _MID The content ratio of Mp shown in FIG. _谷_2 From, Mp _谷_3 The area between the medium molecular weight P _MID Furthermore, the area of ​​the high molecular weight substance P _HIGH The content ratio of Mp shown in FIG. _谷_3 From, Mp _1%_HIGH The area between the high molecular weight molecules P _HIGHIn this case, the area can also be calculated by checking the elution time indicating each molecular weight and integrating the area with respect to the elution time.

[0090] The vinyl bond content in the conjugated diene monomer units (for example, isoprene monomer units and 1,3-butadiene monomer units) in the entire conjugated diene polymer of the present invention is preferably 1 to 90% by weight, more preferably 3 to 85% by weight, and particularly preferably 5 to 80% by weight. By setting the vinyl bond content in the conjugated diene monomer units in the entire conjugated diene polymer within the above range, better fuel economy can be achieved.

[0091] The Mooney viscosity (ML 1+4 , 100°C) is preferably 20 to 100, more preferably 30 to 90, and particularly preferably 35 to 80. When the conjugated diene polymer is used as an oil-extended rubber, it is preferable that the Mooney viscosity of the oil-extended rubber be in the above range.

[0092] The glass transition temperature (Tg) of the conjugated diene polymer of the present invention is not particularly limited, but is preferably 20 to −110° C., and more preferably 10 to −70° C. The glass transition temperature of the conjugated diene rubber used in the present invention can be appropriately adjusted, for example, by adjusting the content of aromatic vinyl monomer units in the conjugated diene polymer and the vinyl bond content in the conjugated diene monomer units.

[0093] <Method of producing conjugated diene polymer> The method for producing a conjugated diene polymer of the present invention comprises the steps of: a first step of polymerizing a monomer including a conjugated diene compound in an inert solvent in the presence of a polymerization initiator to obtain a solution containing a polymer chain having an active terminal; a second step of forming coupled polymer chains by performing a coupling reaction on some of the polymer chains having active ends obtained in the first step, thereby obtaining a solution containing the polymer chains having active ends and the coupled polymer chains; a third step of further polymerizing a monomer containing a conjugated diene compound onto a polymer chain having an active terminal after the coupling reaction in the second step, In at least one of the first step and the third step, the monomer used for polymerization is a monomer containing a vinyl compound containing a functional group capable of interacting with silica in addition to a conjugated diene compound.

[0094] The first step is a step of polymerizing a monomer containing a conjugated diene compound in an inert solvent in the presence of a polymerization initiator to obtain a solution containing a polymer chain having an active end.

[0095] The inert solvent used in the polymerization is not particularly limited as long as it is one commonly used in solution polymerization and does not inhibit the polymerization reaction. Specific examples of the inert solvent include linear or branched aliphatic hydrocarbons such as propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, propene, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, and n-heptane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as benzene, ethylbenzene, toluene, and xylene; and ether compounds such as tetrahydrofuran and diethyl ether. These inert solvents may be used alone or in combination of two or more. The amount of the inert solvent used is not particularly limited, but is, for example, an amount that results in a monomer concentration of 1 to 50% by weight, preferably 5 to 40% by weight.

[0096] The polymerization initiator used in the polymerization is not particularly limited as long as it can polymerize a monomer containing a conjugated diene compound to give a conjugated diene polymer chain having an active terminal. Specific examples include polymerization initiators using organic alkali metal compounds, organic alkaline earth metal compounds, and lanthanide metal compounds as the main catalyst. Examples of organic alkali metal compounds include organic monolithium compounds such as n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, ethyllithium, n-propyllithium, isopropyllithium, tert-octyllithium, n-decyllithium, 2-naphthyllithium, 2-butylphenyllithium, 4-phenylbutyllithium, hexyllithium, cyclopentyllithium, the reaction product of diisopropenylbenzene with butyllithium, and stilbenelithium; dilithiomethane; 1,4 Examples of suitable organic compounds include organic polyvalent lithium compounds such as 1,4-dilithiobutane, 1,4-dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, 1,3,5-tris(lithiomethyl)benzene, the reaction product of sec-butyllithium with diisopropenylbenzene, the reaction product of n-butyllithium with 1,3-butadiene and divinylbenzene, and the reaction product of n-butyllithium with a polyacetylene compound; organic sodium compounds such as sodium naphthalene; organic potassium compounds such as potassium naphthalene; organic rubidium compounds; and organic cesium compounds. Other examples include alkoxides, sulfonates, carbonates, and amides of lithium, sodium, and potassium. These compounds may also be used in combination with other organic metal compounds. Furthermore, known organic alkali metal compounds such as those disclosed in U.S. Pat. No. 5,708,092, British Patent No. 2,241,239, and U.S. Pat. No. 5,527,753 may also be used.

[0097] The amount of the polymerization initiator used is not particularly limited, but is usually in the range of 1 to 50 mmol, preferably 1.2 to 20 mmol, and more preferably 2 to 15 mmol per 1000 g of monomer.

[0098] The polymerization temperature is usually in the range of -80 to +150°C, preferably 0 to 100°C, and more preferably 30 to 90°C. The polymerization method can be either batch or continuous. However, when copolymerizing a conjugated diene compound with an aromatic vinyl compound, the batch method is preferred because it is easy to control the randomness of the bonds between the conjugated diene monomer units and the aromatic vinyl monomer units. The bonding pattern of each monomer can be various, such as block, tapered, or random. Among these, the random bonding pattern is preferred. By using a random bonding pattern, the low heat buildup of the resulting cross-linked rubber can be further improved.

[0099] Furthermore, when polymerizing a monomer containing a conjugated diene compound, a polar compound may be added to the inert organic solvent to adjust the vinyl bond content in the conjugated diene monomer units in the resulting conjugated diene polymer chain. Examples of polar compounds that can be used include ether compounds, tertiary amines, phosphine compounds, alkali metal alkoxides, and alkali metal phenoxides. Examples of ether compounds include cyclic ethers such as tetrahydrofuran, tetrahydropyran, and 1,4-dioxane; aliphatic monoethers such as diethyl ether and dibutyl ether; aliphatic diethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether; aliphatic triethers such as diethylene glycol diethyl ether and diethylene glycol dibutyl ether; and aromatic ethers such as diphenyl ether, anisole, 1,2-dimethoxybenzene, and 3,4-dimethoxytoluene. Examples of tertiary amines include triethylamine, tripropylamine, tributylamine, 1,1,2,2-tetramethylethylenediamine, N,N-diethylaniline, pyridine, and quinoline. Examples of phosphine compounds include trimethylphosphine, triethylphosphine, and triphenylphosphine. Examples of alkali metal alkoxides include sodium tert-butoxide, potassium tert-butoxide, sodium tert-pentoxide, and potassium tert-pentoxide. Examples of alkali metal phenoxides include sodium phenoxide and potassium phenoxide. These polar compounds may be used alone or in combination of two or more. The amount of polar compound used may be determined depending on the desired vinyl bond content, and is preferably 0.001 to 100 mol, and more preferably 0.01 to 10 mol, per mol of the polymerization initiator. When the amount of polar compound used is within this range, it is easy to adjust the vinyl bond content in the conjugated diene monomer units, and problems due to deactivation of the polymerization initiator are unlikely to occur.

[0100] In the first step, the monomer used for polymerization may contain at least a conjugated diene compound, but from the viewpoint of making the conjugated diene polymer have conjugated diene monomer units and aromatic vinyl monomer units, it is preferable to use an aromatic vinyl compound. Furthermore, the monomer used for polymerization may contain a vinyl compound containing a functional group capable of interacting with silica, but from the viewpoint of further improving the processability of the conjugated diene polymer, it is preferable not to use a vinyl compound containing a functional group capable of interacting with silica in the first step, but to use it in the third step described below.

[0101] The second step is a step of forming coupled polymer chains by performing a coupling reaction on some of the polymer chains having active ends obtained in the first step, thereby obtaining a solution containing the polymer chains having active ends and the coupled polymer chains.

[0102] The coupling agent is not particularly limited, but examples thereof include silicon tetrachloride, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, tin tetrachloride, methyltrichlorotin, dimethyldichlorotin, trimethylchlorotin, tetramethoxysilane, methyltrimethoxysilane, dimethoxydimethylsilane, methyltriethoxysilane, ethyltrimethoxysilane, dimethoxydiethylsilane, diethoxydimethylsilane, tetraethoxysilane, ethyltriethoxysilane, diethoxydiethylsilane, bis(trichlorosilyl)methane, 1,2-bis(trichlorosilyl)ethane, 1,3-bis(trichlorosilyl)propane, 1,4-bis(trichlorosilyl)butane, 1,5-bis(trichlorosilyl)pentane, and 1,6-bis(trichlorosilyl)hexane. Among these, the high molecular weight component P contained in the obtained conjugated diene polymer is particularly preferred. _HIGHFrom the viewpoints of being able to keep the shrinkage factor within a specific range and to appropriately improve mechanical properties while effectively suppressing a decrease in processability due to high molecular weight, it is preferable to use a trifunctional or higher functional coupling agent, and it is even more preferable to use a tetrafunctional or higher functional coupling agent.

[0103] The amount of coupling agent used is not particularly limited, but from the viewpoint of subjecting only a portion of the polymer chains having active ends obtained in the first step to a coupling reaction, it is preferable that the amount of coupling agent used is less than 1 mole, preferably 0.03 to 0.4 moles, and more preferably 0.05 to 0.3 moles, calculated as functional groups of the coupling agent, per mole of the polymerization initiator used in the first step. By using an amount of coupling agent within the above range, fuel economy can be further improved. By adding a coupling agent, polymer chains having active ends undergo a coupling reaction at the active ends, and as a result, the active ends of the polymer chains that have undergone the coupling reaction disappear, leaving them without active ends.

[0104] The third step is a step in which, after the coupling reaction in the second step, a monomer containing a conjugated diene compound is further polymerized onto the polymer chain having an active end.

[0105] In the third step, the monomer used for polymerization may contain at least a conjugated diene compound. However, from the viewpoint of forming a conjugated diene-based polymer having conjugated diene monomer units and aromatic vinyl monomer units, it is preferable to use an aromatic vinyl compound. Furthermore, in the third step, the monomer used for polymerization preferably contains a vinyl compound containing a functional group capable of interacting with silica. By using a vinyl compound containing a functional group capable of interacting with silica in the third step, it is possible to preferentially introduce units of the vinyl compound containing a functional group capable of interacting with silica into polymer chains other than those subjected to the coupling reaction in the second step. This effectively increases the silica adsorption rate of polymer chains other than those subjected to the coupling reaction, resulting in improved processability and improved fuel economy.

[0106] Furthermore, the polymerization in the third step may be carried out in an inert solvent, and the inert solvent is not particularly limited, and the same inert solvents as those exemplified in the first step described above can be used. The polymerization temperature and polymerization mode are also not particularly limited, and may be the same as those in the first step described above. The bonding mode of each monomer may be various, such as block, tapered, or random. Among these, the random bonding mode is preferred. By using a random bonding mode, the low heat buildup properties of the resulting cross-linked rubber can be further improved.

[0107] Furthermore, in the production method of the present invention, it is preferable to additionally add the polymerization initiator either during the polymerization in the first step, or at the start of the polymerization in the third step, or during the polymerization in the third step. The timing of additionally adding the polymerization initiator and the number of times the polymerization initiator is additionally added are not particularly limited and may be determined depending on the molecular weight distribution of the conjugated diene polymer to be obtained. In the production method of the present invention, it is preferable to additionally add the polymerization initiator either during the polymerization in the first step, or at the start of the polymerization in the third step, or during the polymerization in the third step, but it is more preferable to additionally add the polymerization initiator at the start of the polymerization in the third step or during the polymerization in the third step. The amount of the additionally added polymerization initiator is not particularly limited, but is preferably 0.1 to 0.7 mol, more preferably 0.2 to 0.6 mol, per mol of the polymerization initiator used at the start of the polymerization.

[0108] It is preferable that the above-mentioned first, second, and third steps are carried out as continuous steps. For example, it is preferable to carry out a coupling reaction by adding a coupling agent in the second step while continuing the polymerization reaction in the first step, and then to carry out the polymerization reaction in the third step.

[0109] After the polymerization reaction in the third step is completed, a polymerization terminator such as an alcohol such as methanol, ethanol, or isopropanol, or water is added to the polymerization system to inactivate the active terminals, thereby obtaining a solution of a conjugated diene polymer.

[0110] If desired, antioxidants such as phenolic stabilizers, phosphorus-based stabilizers, and sulfur-based stabilizers, crumb inhibitors, and scale inhibitors may be added to the reaction solution of the conjugated diene polymer obtained as described above. The polymerization solvent is then separated from the reaction solution by direct drying or steam stripping, and a solid conjugated diene rubber is recovered. If desired, an extender oil may be added to convert the conjugated diene polymer into an oil-extended rubber. Examples of extender oils include paraffinic, aromatic, and naphthenic petroleum-based softeners, vegetable-based softeners, and fatty acids. When a petroleum-based softener is used, it is preferable that the polycyclic aromatic content extracted by the IP346 method (a testing method of the Institute of Petroleum, UK) be less than 3%. When an extender oil is used, the amount used is typically 5 to 100 parts by weight per 100 parts by weight of the conjugated diene polymer.

[0111] Furthermore, examples of the phenol-based stabilizer to be added to the solution of the conjugated diene polymer of the present invention include 1'-hydroxy[2,2'-ethylidenebis[4,6-bis(1,1-dimethylpropyl)benzene]]-1-yl acrylate, 2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl acrylate, 2,6-di-tert-butyl-p-cresol, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 4,6-bis(octathiomethyl)-o-cresol. Examples of sulfur-based stabilizers include didodecyl-3,3'-thiodipropionate, 2,2-bis[[3-(dodecylthio)propionic acid]3-oxopropyloxy]methyl]-1,3-propanediyl, ditridecyl-3,3'-thiodipropionate, etc. Examples of phosphorus-based stabilizers include tris(2,4-di-tert-butylphenyl)phosphite, etc.

[0112] The stabilizers may be used alone or in combination of two or more. For example, a phenolic stabilizer may be used in combination with another stabilizer. Examples of combinations of two stabilizers include a combination of 2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl acrylate and 2,2-bis[[3-(dodecylthio)propionic acid]methyl]-1,3-propanediyl, a combination of 1'-hydroxy[2,2'-ethylidenebis[4,6-bis(1,1-dimethylpropyl)benzene]]-1-yl acrylate and 2,2-bis[[3-(dodecylthio)propionic acid]methyl]-1,3-propanediyl, a combination of 4,6-bis(octathiomethyl)-o-cresol and 2,6-di-tert-butyl-p-cresol, Examples of the combination include a combination of 4,6-bis(octathiomethyl)-o-cresol and 2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl acrylate, a combination of 4,6-bis(octathiomethyl)-o-cresol and 1'-hydroxy[2,2'-ethylidenebis[4,6-bis(1,1-dimethylpropyl)benzene]]-1-yl acrylate, a combination of 4,6-bis(octathiomethyl)-o-cresol and 2,2-bis[[3-(dodecylthio)-1-oxopropyloxy]methyl]-1,3-propanediyl bis[3-(dodecylthio)propionic acid], and a combination of 4,6-bis(octathiomethyl)-o-cresol and didodecyl-3,3'-thiodipropionate.

[0113] Examples of combinations of three stabilizers include a combination of 4,6-bis(octathiomethyl)-o-cresol, 1'-hydroxy[2,2'-ethylidenebis[4,6-bis(1,1-dimethylpropyl)benzene]]-1-yl acrylate, and didodecyl-3,3'-thiodipropionate, and a combination of 4,6-bis(octathiomethyl)-o-cresol, 2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl acrylate, and 2,2-bis[[3-(dodecylthio)-1-oxopropyloxy]methyl]-1,3-propanediyl bis[3-(dodecylthio)propionic acid]. , a combination of 4,6-bis(octathiomethyl)-o-cresol, 2,6-di-tert-butyl-p-cresol, and 2,2-bis[[3-(dodecylthio)propionic acid]methyl]-1,3-propanediyl; and a combination of 4,6-bis(octathiomethyl)-o-cresol, 1'-hydroxy[2,2'-ethylidenebis[4,6-bis(1,1-dimethylpropyl)benzene]]-1-yl acrylate, and 2,2-bis[[3-(dodecylthio)propionic acid]methyl]-1,3-propanediyl.

[0114] Furthermore, from the viewpoint of further enhancing affinity for fillers such as silica, the conjugated diene polymer of the present invention may be one in which the polymer chain end is modified with a heteroatom-containing functional group. The heteroatom-containing functional group is not particularly limited as long as it is a group containing a heteroatom, but a group containing at least one heteroatom selected from a nitrogen atom, an oxygen atom, and a silicon atom is preferred, and from the viewpoint of affinity for silica, a group containing a silicon atom is particularly preferred.

[0115] The heteroatom-containing functional group can be introduced into the polymer chain end of the conjugated diene rubber, for example, by reacting a heteroatom-containing compound with the active end of the conjugated diene polymer chain having the active end that has been subjected to the third step. Examples of the heteroatom-containing compound include compounds having silicon atoms, and alkoxysilane compounds or vinylsilane compounds are preferred, with alkoxysilane compounds having an amino group or vinylsilane compounds having an amino group being more preferred.

[0116] Examples of alkoxysilane compounds having an amino group include [3-(dimethylamino)propyl]trimethoxysilane, [3-(diethylamino)propyl]trimethoxysilane, [3-(dimethylamino)propyl]triethoxysilane, [3-(diethylamino)propyl]triethoxysilane, [3-(ethylmethylamino)propyl]trimethoxysilane, [3-(ethylmethylamino)propyl]triethoxysilane, [3-(dimethylamino)propyl]methyldimethoxysilane, and [3-(diethylamino)propyl] Methyldimethoxysilane, [3-(dimethylamino)propyl]ethyldimethoxysilane, [3-(diethylamino)propyl]ethyldimethoxysilane, [(3-methyl-3-ethylamino)propyl]methyldimethoxysilane, [(3-methyl-3-ethylamino)propyl]ethyldimethoxysilane, [3-(dimethylamino)propyl]methyldiethoxysilane, [3-(diethylamino)propyl]methyldiethoxysilane, [3-(dimethylamino)propyl]ethyldiethoxysilane, [3-(diethylamino)propyl ]ethyldiethoxysilane, [3-(ethylmethylamino)propyl]methyldiethoxysilane, [3-(ethylmethylamino)propyl]ethyldiethoxysilane, [3-(benzylmethylamino)propyl]trimethoxysilane, [3-(benzylmethylamino)propyl]triethoxysilane, {3-[di(methoxymethyl)amino]propyl}trimethoxysilane, {3-[di(methoxyethyl)amino]propyl}trimethoxysilane, {3-[di(methoxymethyl)amino]propyl}triethoxysilane, {3-[di(methyl)amino]propyl}triethoxysilane, (triethoxyethyl)amino]propyl}triethoxysilane, {3-[di(ethoxyethyl)amino]propyl}trimethoxysilane, {3-[di(ethoxymethyl)amino]propyl}trimethoxysilane, {3-[di(ethoxyethyl)amino]propyl]triethoxysilane, {3-[di(ethoxymethyl)amino]propyl}triethoxysilane, {3-[N,N-bis(trimethylsilyl)amino]propyl}trimethoxysilane, {3-[N,N-bis(trimethylsilyl)amino]propyl}triethoxysilane, {3-[N,N-bis(t-butyldimethylsilyl)amino]propyl}trimethoxysilane, {3-[N,N-bis(t-butyldimethylsilyl)amino]propyl}triethoxysilane, {3-[N,N-bis(trimethylsilyl)amino]propyl}methyldimethoxysilane, {3-[N,N-bis(trimethylsilyl)amino]propyl}methyldiethoxysilane, {3-[N,N-bis(t-butyldimethylsilyl)amino]propyl}methyldimethoxysilane, {3-[N,N-bis(t-butyldimethylsilyl)amino]propyl}methyldimethoxysilane Examples include [3-(ethylmethylamino)propyl]methyldiethoxysilane, [3-(ethylmethylamino)propyl]trimethoxysilane, [3-(ethylmethylamino)propyl]triethoxysilane, [3-(ethylmethylamino)propyl]methyldimethoxysilane, [3-(ethylmethylamino)propyl]ethyldimethoxysilane, [3-(ethylmethylamino)propyl]methyldiethoxysilane, and [3-(ethylmethylamino)propyl]ethyldiethoxysilane. Among these, [3-(dimethylamino)propyl]trimethoxysilane, [3-(diethylamino)propyl]trimethoxysilane, [3-(dimethylamino)propyl]triethoxysilane, and [3-(diethylamino)propyl]triethoxysilane are preferably used.

[0117] Examples of vinylsilane compounds having an amino group include bis(dimethylamino)methylvinylsilane, bis(diethylamino)methylvinylsilane, bis(n-propylamino)methylvinylsilane, bis(di(n-butyl)amino)methylvinylsilane, bis(dimethylamino)ethylvinylsilane, bis(diethylamino)ethylvinylsilane, bis(dipropylamino)ethylvinylsilane, and bis(dibutylamino)ethylvinylsilane.

[0118] In addition, as the compound having a silicon atom, a siloxane compound can also be suitably used. The siloxane compound is not particularly limited as long as it has a siloxane structure (-Si-O-) as the main chain, but organosiloxanes having organic groups on the side chains are preferred, and polyorganosiloxanes represented by the following general formula (4) are more preferred. [ka] In the above general formula (4), R 3 ~R 10 is an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, which may be the same or different. X 9 and X 12 is any group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and an epoxy group-containing group having 4 to 12 carbon atoms, and these may be the same or different. X 10 is an alkoxy group having 1 to 5 carbon atoms or a group containing an epoxy group and having 4 to 12 carbon atoms, and X 10 When there are multiple X's, they may be the same or different. 11 is a group containing 2 to 20 repeating units of alkylene glycol, and X 11 When there are a plurality of m, they may be the same or different. m is an integer of 1 to 200, n is an integer of 0 to 200, k is an integer of 0 to 200, and m+n+k is 1 or more.

[0119] In the polyorganosiloxane represented by the general formula (4), R 3 ~R 10 , X 9 and X 12Examples of alkyl groups having 1 to 6 carbon atoms that can constitute the above include methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl, and cyclohexyl groups. Examples of aryl groups having 6 to 12 carbon atoms include phenyl and methylphenyl groups. Among these, methyl and ethyl groups are preferred from the viewpoint of ease of production of the polyorganosiloxane itself.

[0120] In addition, in the polyorganosiloxane represented by the general formula (4), X 9 , X 10 and X 12 Examples of the alkoxy group having 1 to 5 carbon atoms that can constitute the above include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group. Among these, from the viewpoint of ease of production of the polyorganosiloxane itself, a methoxy group and an ethoxy group are preferred.

[0121] Furthermore, in the polyorganosiloxane represented by the general formula (4), X 9 , X 10 and X 12 Examples of the epoxy group-containing group having 4 to 12 carbon atoms that can constitute the above include groups represented by the following general formula (5). -Z 1 -Z 2 -E (5) In the above general formula (5), Z 1 is an alkylene group or alkylarylene group having 1 to 10 carbon atoms, and Z 2 is a methylene group, a sulfur atom, or an oxygen atom, and E is a hydrocarbon group having 2 to 10 carbon atoms and an epoxy group.

[0122] The group represented by the general formula (5) includes Z 2 is preferably an oxygen atom, and Z 2 is an oxygen atom and E is a glycidyl group, and Z 1 is an alkylene group having 1 to 3 carbon atoms, and Z 2It is particularly preferred that is an oxygen atom and E is a glycidyl group.

[0123] In addition, in the polyorganosiloxane represented by the general formula (4), X 9 and X 12 Among the above, X is preferably a group containing an epoxy group and having 4 to 12 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. 10 Among the above, an epoxy group-containing group having 4 to 12 carbon atoms is preferred as X. 9 and X 12 is an alkyl group having 1 to 6 carbon atoms, and X 10 is more preferably a group containing an epoxy group and having 4 to 12 carbon atoms.

[0124] In addition, in the polyorganosiloxane represented by the general formula (4), X 11 That is, the group containing 2 to 20 repeating units of alkylene glycol is preferably a group represented by the following general formula (6). [ka] In the general formula (6), t is an integer of 2 to 20, and X 13 is an alkylene group or alkylarylene group having 2 to 10 carbon atoms, and R 11 is a hydrogen atom or a methyl group, and X 14 is an alkoxy group or an aryloxy group having 1 to 10 carbon atoms. Among these, t is an integer of 2 to 8, and X 13 is an alkylene group having 3 carbon atoms, and R 11 is a hydrogen atom and X 14 is preferably a methoxy group.

[0125] In the polyorganosiloxane represented by the general formula (4), m is an integer of 1 to 200, preferably an integer of 20 to 150, and more preferably an integer of 30 to 120. When m is 1 to 200, the polyorganosiloxane represented by the general formula (4) itself becomes easier to produce, and its viscosity does not become too high, making it easier to handle.

[0126] In the polyorganosiloxane represented by the general formula (4), n is an integer of 0 to 200, preferably an integer of 0 to 150, and more preferably an integer of 0 to 120. k is an integer of 0 to 200, preferably an integer of 0 to 150, and more preferably an integer of 0 to 130. The total number of m, n, and k is 1 or more, preferably 3 to 400, more preferably 20 to 300, and particularly preferably 30 to 250. When the total number of m, n, and k is 1 or more, the reaction between the polyorganosiloxane represented by the general formula (4) and the conjugated diene polymer chain having an active terminal proceeds easily. Furthermore, when the total number of m, n, and k is 400 or less, the polyorganosiloxane represented by the general formula (4) itself is easily produced, and its viscosity does not become too high, making it easy to handle.

[0127] The method for reacting a conjugated diene polymer chain having an active end with a heteroatom-containing compound is not particularly limited, but examples include a method of mixing them in a solvent in which each of them is soluble. Examples of the solvent used in this reaction include those exemplified as inert solvents that can be used in the first step. In this case, a simple and preferred method is to add the heteroatom-containing compound to the polymerization solution obtained through the third step. In this case, the heteroatom-containing compound may be dissolved in an inert solvent and added to the polymerization system. The reaction temperature is not particularly limited, but is usually 0 to 120°C. The reaction time is also not particularly limited, but is usually 1 minute to 1 hour.

[0128] When reacting a conjugated diene polymer chain having an active terminal with a heteroatom-containing compound, the amount of the heteroatom-containing compound used is preferably 0.1 to 100 mol, more preferably 0.3 to 50 mol, per mol of the total amount of polymerization initiators used in the polymerization. When the amount of the heteroatom-containing compound used is within the above range, fuel economy can be further improved.

[0129] <Conjugated Diene Polymer Composition> The conjugated diene polymer composition of the present invention is a composition containing the above-mentioned conjugated diene polymer of the present invention and a filler.

[0130] The conjugated diene polymer composition of the present invention may contain a polymer other than the above-mentioned conjugated diene polymer of the present invention. Examples of other polymers include natural rubber (which may be modified natural rubber such as epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), deproteinized natural rubber (DPNR), highly purified natural rubber (UPNR), and grafted natural rubber), polyisoprene rubber, emulsion-polymerized styrene-butadiene copolymer rubber, solution-polymerized styrene-butadiene copolymer rubber, polybutadiene rubber (which may be high cis-BR or low cis-BR, or which may be polybutadiene rubber containing crystalline fibers made of 1,2-polybutadiene polymer), styrene-isoprene copolymer rubber, butadiene-isoprene copolymer rubber, styrene-isoprene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylonitrile-styrene-butadiene copolymer rubber, butyl rubber (IIR), ethylene-propylene copolymer, chloroprene rubber, nitrile-chloroprene rubber, and nitrile-isoprene rubber, which are other than the above-mentioned conjugated diene rubbers. Among these, natural rubber, polyisoprene rubber, polybutadiene rubber, and solution-polymerized styrene-butadiene copolymer rubber are preferred. Natural rubber is more preferred. These polymers can be used alone or in combination of two or more, such as natural rubber and polybutadiene rubber, or natural rubber and styrene-butadiene copolymer rubber.

[0131] In the conjugated diene polymer composition of the present invention, the conjugated diene polymer of the present invention preferably accounts for 10 to 100% by weight, and particularly preferably 50 to 100% by weight, of the polymer components in the conjugated diene polymer composition. By including the conjugated diene rubber of the present invention in the polymer components in such a ratio, the composition can achieve sufficiently excellent fuel economy.

[0132] Examples of fillers include silica, calcium silicate, aluminum silicate, carbon black, calcium carbonate, talc, aluminum hydroxide, alumina, clay, and mica. Among these, carbon black and silica are preferred, and silica is more preferred, because they can further improve fuel economy. These can be used alone or in combination of two or more.

[0133] Examples of silica include dry process white carbon, wet process white carbon, colloidal silica, precipitated silica, calcium silicate, and aluminum silicate. Among these, wet process white carbon, which is mainly composed of hydrous silica, is preferred. Carbon-silica dual phase filler, in which silica is supported on the surface of carbon black, may also be used. These silicas may be used alone or in combination of two or more. The nitrogen adsorption specific surface area of ​​the silica used (measured by the BET method in accordance with ASTM D3037-81) is preferably 20 to 400 m 2 / g, more preferably 50 to 220 m 2 / g, particularly preferably 80 to 170m 2 The pH of the silica is preferably 5 to 10.

[0134] As the silica, various commercially available silicas can be used, for example, "Hi-Sil 210," "Hi-Sil 233," and "Hi-Sil 243LD" manufactured by PPG Industries; "Zeosil 1115MP," "Zeosil 1165MP," and "Zeosil 165GR" manufactured by Solvay; "ULTRASIL VN2" and "ULTRASIL VN3" manufactured by EVONIK; and "NIPSIL VN3," "NIPSIL AQ," "NIPSIL ER," and "NIPSIL RS-150" manufactured by Tosoh Silica Corporation.

[0135] Examples of carbon black include furnace black, acetylene black, thermal black, channel black, and graphite. Examples of channel black include EPC, MPC, and CC. Examples of furnace carbon black include SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF, and ECF. Examples of thermal black include FT and MT. Each carbon black can be used alone or in combination of two or more types.

[0136] The amount of filler blended in the conjugated diene polymer composition of the present invention is preferably 10 to 250 parts by weight, more preferably 15 to 150 parts by weight, and even more preferably 20 to 130 parts by weight, per 100 parts by weight of the polymer components in the conjugated diene polymer composition. By blending the amount of silica within the above range, it is possible to further improve fuel economy while maintaining sufficient processability.

[0137] The conjugated diene polymer composition of the present invention may further contain a silane coupling agent from the viewpoint of further improving fuel economy. The silane coupling agent is not particularly limited, and various silane coupling agents can be used. In the present invention, sulfide-based, mercapto-based, protected mercapto-based (e.g., those having a carbonylthio group), thiocyanate-based, vinyl-based, amino-based, methacrylate-based, glycidoxy-based, nitro-based, epoxy-based, or chloro-based silane coupling agents can be suitably used. Specific examples of the silane coupling agent include bis(3-(triethoxysilyl)propyl)disulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-(triethoxysilyl)propyl)tetrasulfide, γ-mercaptopropyltriethoxysilane, 3-[ Examples of suitable silanes include ethoxybis(3,6,9,12,15-pentaoxaoctacosan-1-yloxy)silyl)-1-propanethiol, 3-octanoylthio-1-propyl-triethoxysilane, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, γ-trimethoxysilylpropylbenzothiazyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-thiocyanatepropyltriethoxysilane, vinyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 3-trimethoxysilylpropyl methacrylate monosulfide, γ-glycidoxypropyltriethoxysilane, 3-nitropropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-chloropropyltrimethoxysilane. Other silane coupling agents that can be used include NXT-Z100, NXT-Z30, NXT-Z45, NXT-Z60, NXT-Z45, and NXT manufactured by Momentive Performance Materials, and Si69, Si75, and VP Si363 manufactured by Evonik Degussa. These silane coupling agents can be used alone or in combination of two or more. Alternatively, one or more of these silane coupling agents can be oligomerized in advance and used in the oligomerized state.The amount of the silane coupling agent to be added is preferably 0.1 to 30 parts by weight, more preferably 1 to 15 parts by weight, based on 100 parts by weight of the filler.

[0138] The conjugated diene polymer composition of the present invention preferably further contains a crosslinking agent. Examples of crosslinking agents include sulfur-containing compounds such as sulfur and sulfur halides, organic peroxides, quinone dioximes, organic polyamine compounds, and alkylphenol resins having methylol groups. Among these, sulfur is preferably used. The amount of the crosslinking agent is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 4 parts by weight, per 100 parts by weight of the polymer components in the conjugated diene polymer composition.

[0139] Furthermore, in addition to the above components, the conjugated diene polymer composition of the present invention may contain required amounts of additives such as a crosslinking accelerator, a crosslinking activator, an antioxidant, an activator, a process oil, a plasticizer, a lubricant, and a tackifier, according to a conventional method.

[0140] When sulfur or a sulfur-containing compound is used as the crosslinking agent, it is preferable to use a crosslinking accelerator and a crosslinking activator in combination. Examples of crosslinking accelerators include sulfenamide-based crosslinking accelerators, guanidine-based crosslinking accelerators, thiourea-based crosslinking accelerators, thiazole-based crosslinking accelerators, thiuram-based crosslinking accelerators, dithiocarbamic acid-based crosslinking accelerators, and xanthogenic acid-based crosslinking accelerators. Among these, those containing sulfenamide-based crosslinking accelerators are preferred. These crosslinking accelerators are used alone or in combination of two or more. The amount of crosslinking accelerator blended is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 4 parts by weight, per 100 parts by weight of the polymer components in the conjugated diene polymer composition.

[0141] Examples of crosslinking activators include higher fatty acids such as stearic acid, zinc oxide, etc. These crosslinking activators may be used alone or in combination of two or more. The amount of the crosslinking activator to be added is preferably 0.05 to 20 parts by weight, and particularly preferably 0.5 to 15 parts by weight, per 100 parts by weight of the polymer component in the conjugated diene polymer composition.

[0142] To obtain the conjugated diene polymer composition of the present invention, the components may be kneaded according to a conventional method. For example, the components excluding thermally unstable components such as crosslinking agents and crosslinking accelerators are kneaded with a conjugated diene rubber, and then the kneaded mixture is mixed with thermally unstable components such as crosslinking agents and crosslinking accelerators to obtain the desired composition. The kneading temperature for the components excluding thermally unstable components and the conjugated diene rubber is preferably 80 to 200°C, more preferably 120 to 180°C, and the kneading time is preferably 30 seconds to 30 minutes. The kneaded mixture is usually cooled to 100°C or below, preferably 80°C or below, before mixing with the thermally unstable components.

[0143] <Rubber cross-linked products> The cross-linked rubber of the present invention is obtained by cross-linking the above-mentioned conjugated diene polymer composition of the present invention. The cross-linked rubber product of the present invention can be produced by using the conjugated diene polymer composition of the present invention, for example, molding the composition into a desired shape using a molding machine such as an extruder, injection molding machine, compressor, or roll, and then heating to cause a cross-linking reaction and fix the shape as a cross-linked rubber product. In this case, cross-linking may be carried out after molding or simultaneously with molding. The molding temperature is usually 10 to 200°C, preferably 25 to 120°C. The cross-linking temperature is usually 100 to 200°C, preferably 130 to 190°C, and the cross-linking time is usually 1 minute to 24 hours, preferably 2 minutes to 12 hours, and particularly preferably 3 minutes to 6 hours.

[0144] Depending on the shape, size, etc. of the cross-linked rubber product, even if the surface is cross-linked, the inside may not be sufficiently cross-linked, so secondary cross-linking may be carried out by further heating.

[0145] The heating method may be appropriately selected from common methods used for crosslinking rubber, such as press heating, steam heating, oven heating, and hot air heating.

[0146] The cross-linked rubber product of the present invention obtained in this manner is excellent in fuel economy because it is obtained using the conjugated diene polymer of the present invention described above. Therefore, by taking advantage of its excellent fuel economy, the cross-linked rubber product of the present invention can be used in a variety of applications, such as materials for various tire parts such as cap tread, base tread, carcass, sidewall, and bead portions in tires; materials for hoses, belts, mats, anti-vibration rubber, and various other industrial products; impact modifiers for resins; resin film cushioning agents; shoe soles; rubber shoes; golf balls; and toys. In particular, the cross-linked rubber product of the present invention is suitable as a tire material because of its excellent fuel economy. [Example]

[0147] The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In the following, "parts" are by weight unless otherwise specified. Tests and evaluations were carried out according to the following methods.

[0148] <1. Mooney viscosity (ML 1+4 )> The Mooney viscosity of the conjugated diene polymer was measured at 100°C in accordance with JIS K6300 (1994).

[0149] <2. Styrene unit content and vinyl bond content> According to JIS K6239 (2007), 1 The content (wt %) of styrene units in the conjugated diene polymer and the amount (mol %) of vinyl bonds in the conjugated diene units were determined by H-NMR.

[0150] <3.Weight average molecular weight (Mw)> The weight average molecular weight (Mw) of the entire conjugated diene polymer was measured by gel permeation chromatography (GPC) under the following conditions (1) to (8). (GPC equipment and software) (i) Liquid transfer pump: LC-20AD (Shimadzu Corporation) (ii) Degasser: DGU-20A3 (Shimadzu Corporation) (iii) Autosampler: SIL-20A HT (Shimadzu Corporation) (iv) Column oven: CTO-20A (Shimadzu Corporation) (v) Refractive index detector (RID): RID-10A (Shimadzu Corporation) (vi) System controller: CBM-20A (Shimadzu Corporation) (vii) Measurement and analysis software: LC solution ver. 1.24 SP1 (viii) Measurement conditions GPC column: Plus Pore series Poly Pore 7.5mm ID x 300mm (Agilent Technologies) 2 columns Mobile phase: 25 mg of 2-(ethylamino)ethanol (Fujifilm Wako Chemical Co., Ltd., special grade) added to 3 L of tetrahydrofuran (Kanto Chemical Co., Ltd., special grade, stabilizer-free) Flow rate: 1mL / min Column oven temperature: 35°C Detection: Refractive index detector (RID) RID cell temperature: 35℃ Sample solution injection volume: 100 μL GPC column calibration standard: PStQuick Kit-H (Tosoh Corporation) (ix) Sample solution preparation conditions Solvent: Tetrahydrofuran (Kanto Chemical Co., Ltd., special grade, stabilizer-free) Sample solution concentration: 0.5 mg / mL Automatic dissolution shaker: DF-8020 (Tosoh Corporation) Dissolution conditions: 10 mg of sample and 20 mL of solvent were placed in a screw vial, sealed, and stirred at room temperature for 120 minutes at a stirring speed of 60 reciprocations per minute using a DF-8020. Filtration was carried out using a syringe equipped with a filtration filter. Filtration filter: Millex-LG, pore size 0.2 μm, hydrophilic, PTFE, filter diameter 25 mm (Merck)

[0151] <4.Low molecular weight P _LOW , medium molecular weight P _MID , high molecular weight P _HIGH Molecular weight of Based on the GPC chart of the conjugated diene polymer obtained in "3. Weight average molecular weight (Mw)" above, the low molecular weight P _LOW Molecular weight Mp _LOW , medium molecular weight P _MID Molecular weight Mp _MID , and high molecular weight substance P _HIGH Molecular weight Mp _HIGH asked for. The conjugated diene polymers obtained in Synthesis Examples 1 to 5 and the conjugated diene polymers obtained by blending used in Examples 4 to 6 all had a trimodal distribution (i.e., the GPC charts were as shown in Fig. 4(A) and Fig. 4(B)). Therefore, the molecular weights at the pick-up tops of each peak were determined from the low molecular weight side as follows: low molecular weight component P _LOW Molecular weight Mp _LOW , medium molecular weight P _MID Molecular weight Mp _MID , and high molecular weight substance P _HIGH Molecular weight Mp _HIGH It was decided.

[0152] <5.Low molecular weight P _LOW , medium molecular weight P _MID , high molecular weight P _HIGH Content ratio> Based on the GPC chart of the conjugated diene polymer obtained in "3. Weight average molecular weight (Mw)" above, the low molecular weight P was determined according to the method described above. _LOW Content ratio of medium molecular weight P _MID The content ratio of the polymer P_HIGH The content ratio was calculated. The conjugated diene polymers obtained in Synthesis Examples 1 to 5 and the conjugated diene polymers obtained by blending in Examples 4 to 6 all had a trimodal distribution (i.e., the GPC charts were as shown in Figures 4(A) and 4(B)). _LOW The content ratio of Mp _1%_LOW From this, Mp shown in Figure 4(B) _谷_1 Calculated based on the area between _MID The content ratio of Mp shown in FIG. _谷_1 From, Mp _谷_2 The high molecular weight P is calculated based on the area between _HIGH The content ratio of Mp shown in FIG. _谷_2 From, Mp _1%_HIGH It was calculated based on the area between

[0153] <6. Medium molecular weight P _MID , high molecular weight P _HIGH Contraction factor> The conjugated diene polymer was dissolved in tetrahydrofuran as a solvent at a concentration of 20 mg / 10 ml, and measurement was carried out using a GPC apparatus (3D-GPC) (Malvern, trade name: "OMNISEC") equipped with a viscosity detector, a light scattering detector, and an RI detector. To calibrate the light scattering detector (LS) and the viscosity detector (VISC) and to correct for the delay volume between the detectors, Malvern's polystyrene standard substance, Polycal TDS-PS-N (weight average molecular weight Mw 104,349, polydispersity 1.04), was used at a solution concentration of 1 mg / ml. The refractive index increment (dn / dc) of the sample in tetrahydrofuran was set to 0.152 ml / g. The dn / dc of the polystyrene standard substance was set to 0.185 ml / g. To calculate the absolute molecular weight and intrinsic viscosity ([η]; unit: dl / g) from the data of each detector, Malvern's data processing software, OmniSEC (version 4.7), was used, following the literature "Size The calculation was carried out with reference to "Exclusion Chromatography, Springer (1999)." The refractive index increment is the rate of change in refractive index relative to a change in concentration. The intrinsic viscosity [η] obtained by the above measurement and the intrinsic viscosity [η]0 of the linear polymer obtained by calculation were used to calculate the intrinsic viscosity of the medium molecular weight polymer P measured using a light scattering detector (LS). _MID Molecular weight Mp _MID , and high molecular weight substance P _HIGH Molecular weight Mp _HIGH By calculating the shrinkage factor g'=[η] / [η]0, the medium molecular weight P _MID Contraction factor g' and high molecular weight substance P _HIGH The shrinkage factor g' was calculated. Here, the intrinsic viscosity [η]0 of the linear polymer was calculated using the following formula. [η]0 = 10 -3.883 × M 0.771 (dl / g) where M is the absolute molecular weight. <Measurement conditions> Measurement equipment: Malvern OMNISEC Detectors: Light scattering detector, RI detector, UV detector, viscosity detector GPC columns: Tosoh TSKgel G4000HXL, TSKgel G5000HXL, TSKgel G6000HXL Sample solution concentration: 20mg / 10ml Solvent: Tetrahydrofuran (Kanto Chemical Co., Ltd., special grade, stabilizer-free) Injection volume: 100μl Measurement temperature: 40℃ Dissolution conditions: Stir at room temperature for 2 hours Mobile phase: Tetrahydrofuran containing 0.3 vol% 2-ethylaminoethanol (Kanto Chemical Co., Ltd., special grade, stabilizer-free) Mobile phase flow rate: 1ml / min

[0154] <7. Medium molecular weight P _MID , high molecular weight P _HIGH Adsorption rate to silica> Based on the GPC chart of the conjugated diene polymer obtained in "3. Weight average molecular weight (Mw)" above, the medium molecular weight P_ MID The molecular weight range showing high molecular weight P_ HIGH The molecular weight range in which the medium molecular weight P _MID , high molecular weight P _HIGH The adsorption rate of the compound to silica was calculated using the results of GPC measurement using a styrene-based column under the following conditions and the results of GPC measurement using a silica-based column. The conditions for GPC measurement using a styrene-based column were as follows. (GPC equipment and software) (i) Liquid transfer pump: LC-20AD (Shimadzu Corporation) (ii) Degasser: DGU-20A3 (Shimadzu Corporation) (iii) Autosampler: SIL-20A HT (Shimadzu Corporation) (iv) Column oven: CTO-20A (Shimadzu Corporation) (v) Refractive index detector (RID): RID-10A (Shimadzu Corporation) (vi) System controller: CBM-20A (Shimadzu Corporation) (vii) Measurement and analysis software: LC solution ver. 1.24 SP1 (viii) Measurement conditions GPC column: Plus Pore series Poly Pore 7.5mm ID x 300mm (Agilent Technologies) 2 columns Mobile phase: 25 mg of 2-(ethylamino)ethanol (Fujifilm Wako Chemical Co., Ltd., special grade) added to 3 L of tetrahydrofuran (Kanto Chemical Co., Ltd., special grade, stabilizer-free) Flow rate: 1mL / min Column oven temperature: 35°C Detection: Refractive index detector (RID) RID cell temperature: 35℃ Sample solution injection volume: 100 μL GPC column calibration standard: PStQuick Kit-H (Tosoh Corporation) (ix) Sample solution preparation conditions Solvent: 5 mg of standard polystyrene A5000 (manufactured by Tosoh Corporation) with a molecular weight of 5000 was added to 20 mL of tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd., special grade, stabilizer-free) as an internal standard. Sample solution concentration: 0.5 mg / mL Automatic dissolution shaker: DF-8020 (Tosoh Corporation) Dissolution conditions: 10 mg of sample and 20 mL of solvent were placed in a screw vial, sealed, and stirred at room temperature for 120 minutes at a stirring speed of 60 reciprocations per minute using a DF-8020. Filtration was carried out using a syringe equipped with a filtration filter. Filtration filter: Millex-LG, pore size 0.2 μm, hydrophilic, PTFE, filter diameter 25 mm (Merck) The conditions for GPC measurement using a silica column were as follows: (GPC equipment and software) (i) Liquid transfer pump: LC-20AD (Shimadzu Corporation) (ii) Degasser: DGU-20A3 (Shimadzu Corporation) (iii) Autosampler: SIL-20A HT (Shimadzu Corporation) (iv) Column oven: CTO-20A (Shimadzu Corporation) (v) Refractive index detector (RID): RID-10A (Shimadzu Corporation) (vi) System controller: CBM-20A (Shimadzu Corporation) (vii) Measurement and analysis software: LC solution ver. 1.24 SP1 (viii) Measurement conditions GPC columns: Zorbax PSM1000-S (6.2 x 250 mm, Agilent Technologies) x 1, Zorbax PSM-300 (6.2 x 250 mm, Agilent Technologies) x 1, Zorbax PSM60-S (6.2 x 250 mm, Agilent Technologies) x 1 Mobile phase: Tetrahydrofuran (Kanto Chemical Co., Ltd., special grade, stabilizer-free) Flow rate: 0.7mL / min Column oven temperature: 35°C Detection: Refractive index detector (RID) RID cell temperature: 35℃ Sample solution injection volume: 100 μL GPC column calibration standard: PStQuick Kit-H (Tosoh Corporation) (ix) Sample solution preparation conditions Solvent: 5 mg of standard polystyrene A5000 (manufactured by Tosoh Corporation) with a molecular weight of 5000 was added to 20 mL of tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd., special grade, stabilizer-free) as an internal standard. Sample solution concentration: 0.5 mg / mL Automatic dissolution shaker: DF-8020 (Tosoh Corporation) Dissolution conditions: 10 mg of sample and 20 mL of solvent were placed in a screw vial, sealed, and stirred at room temperature for 120 minutes at a stirring speed of 60 reciprocations per minute using a DF-8020. Filtration was carried out using a syringe equipped with a filtration filter. Filtration filter: Millex-LG, pore size 0.2 μm, hydrophilic, PTFE, filter diameter 25 mm (Merck)

[0155] From the measurement results, the medium molecular weight component P was calculated using the following formula (2):_MID The adsorption rate of the polymer P to silica was calculated using the following formula (3): _HIGH The adsorption rates of each compound on silica were calculated.

[0156] Medium molecular weight P _MID Adsorption rate (%) of silica = {1-(b1×c1) / (a1×d1)}×100 (2) a1: Medium molecular weight P measured by GPC using a styrene column _MID Area (%) b1: Area (%) of internal standard polystyrene using a styrene-based column c1: Medium molecular weight P measured by GPC using a silica column _MID Area (%) d1: Area (%) of internal standard polystyrene using a silica-based column

[0157] High molecular weight P _HIGH Adsorption rate (%) of silica = {1-(b2 × c2) / (a2 × d2)} × 100 (3) a2: High molecular weight P measured by GPC using a styrene column _HIGH Area (%) b2: Area (%) of internal standard polystyrene using a styrene-based column c2: High molecular weight P measured by GPC using a silica column _HIGH Area (%) d2: Area (%) of internal standard polystyrene using a silica-based column

[0158] The conjugated diene polymers obtained in Synthesis Examples 1 to 5 and the conjugated diene polymers obtained by blending used in Examples 4 to 6 all had a trimodal distribution (i.e., the GPC charts were as shown in Fig. 4(A) and Fig. 4(B)). _谷_1 From, Mp _谷_2 The area between the medium molecular weight P _MID The area of ​​Mp shown in Figure 4(B) _谷_2 From, Mp _1% The area between the high molecular weight molecules P _HIGH The area was set at .

[0159] <8. Compound Mooney viscosity (ML 1+4 )> The Mooney viscosity (compound Mooney viscosity) of the conjugated diene polymer composition was measured at 100° C. in accordance with JIS K6300 (1994).

[0160] <9. Fuel efficiency> Test specimens were punched out from the cross-linked rubber sheet into strips measuring 1 or 2 mm in width and 40 mm in length, and subjected to testing. The loss tangent (tan δ(30°C)) of the test specimens was measured at a temperature of 30°C using a viscoelasticity measuring device (Ueshima Seisakusho Co., Ltd.) under conditions of a frequency of 10 Hz, an initial extension of 10%, and a strain amplitude of 0.25%.

[0161] [Synthesis Example 1] A 30 L stainless steel polymerization reactor equipped with a stirrer was cleaned and dried, and the atmosphere inside the reactor was replaced with dry nitrogen. Next, 12.24 kg of industrial hexane (Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 3.51 kg of cyclohexane, 608 g of 1,3-butadiene, 743 g of styrene, 9.12 mL of tetrahydrofuran, 0.75 mL of ethylene glycol diethyl ether, and 2.24 mL of ethylene glycol dibutyl ether were added to the polymerization reactor. Next, a small amount of a hexane solution of n-butyllithium (n-BuLi) was added as a scavenger to detoxify impurities that could deactivate the polymerization initiator. Then, an n-hexane solution containing 12.17 mmol of n-BuLi was added to the polymerization reactor to initiate the polymerization reaction. During the polymerization reaction, the temperature inside the polymerization reactor was adjusted to 65°C, the solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm, and 20 minutes after the start of polymerization, 1,3-butadiene and styrene were continuously fed into the polymerization reactor.

[0162] After 80 minutes of polymerization, an n-hexane solution containing 1.17 mmol of silicon tetrachloride (SiCl4) was added to the polymerization reactor and the polymerization was continued for 10 minutes. Next, an n-hexane solution containing 5.76 mmol of bis(diethylamino)methylvinylsilane and 2.52 mmol of n-BuLi was added to the polymerization reactor and the polymerization was continued for 160 minutes. During the total polymerization time of 4 hours and 40 minutes, 1,3-butadiene was continuously fed into the polymerization reactor over 200 minutes and styrene over 115 minutes. The total amount of 1,3-butadiene fed was 1039 g and the total amount of styrene fed was 310 g.

[0163] While maintaining the temperature inside the polymerization reactor at 65°C, the polymerization solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm. 15.01 mmol of the modifier [3-(diethylamino)propyl]trimethoxysilane was added to the polymerization solution and stirred for 15 minutes. Next, an n-hexane solution containing 30.00 mmol of n-BuLi was added to the polymerization solution and stirred for 15 minutes. Next, 20 mL of a hexane solution containing 2.8 mL of methanol was added to the polymerization reactor, and the polymerization solution was stirred for 5 minutes.

[0164] The stirred material was removed from the polymerization reactor, and a portion of the stirred material was dried at room temperature for 24 hours to evaporate most of the volatile matter. The resulting mixture was then further dried under reduced pressure at 55°C for 12 hours to obtain a polymer sample for measurement. The vinyl bond amount, styrene unit content, molecular weight (weight average molecular weight (Mw)), and low molecular weight P content were then measured. _LOW , medium molecular weight P _MID , and high molecular weight substance P _HIGH molecular weight), medium molecular weight P _MID and high molecular weight substance P _HIGH The shrinkage factor of the medium molecular weight P _MID and high molecular weight substance P _HIGH The adsorption rate of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33

[0165] The stirred mixture was removed from the polymerization reactor, and 10.8 g of 4,6-bis(octylthiomethyl)-o-cresol (manufactured by BASF, trade name: Irganox 1520L, manufactured by BASF) and 675 g of extender oil (manufactured by Japan Energy Corporation, trade name: JOMO Process NC-140) were added to obtain a mixture. Most of the volatile matter in the obtained mixture was evaporated at room temperature for 24 hours, and the mixture was further dried under reduced pressure at 55°C for 12 hours to obtain a conjugated diene polymer (A1).

[0166] [Synthesis Example 2] A 30 L stainless steel polymerization reactor equipped with a stirrer was cleaned and dried, and the atmosphere inside the reactor was replaced with dry nitrogen. Next, 12.24 kg of industrial hexane (Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 3.51 kg of cyclohexane, 608 g of 1,3-butadiene, 743 g of styrene, 9.12 mL of tetrahydrofuran, 0.75 mL of ethylene glycol diethyl ether, and 2.24 mL of ethylene glycol dibutyl ether were added to the polymerization reactor. Next, a small amount of a hexane solution of n-butyllithium (n-BuLi) was added as a scavenger to detoxify impurities that could deactivate the polymerization initiator. Then, an n-hexane solution containing 10.27 mmol of n-BuLi was added to the polymerization reactor to initiate the polymerization reaction. During the polymerization reaction, the temperature inside the polymerization reactor was adjusted to 65°C, the solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm, and 20 minutes after the start of polymerization, 1,3-butadiene and styrene were continuously fed into the polymerization reactor.

[0167] After 80 minutes of polymerization, an n-hexane solution containing 0.65 mmol of 1,6-bis(trichlorosilyl)hexane was added to the polymerization reactor and the polymerization was continued for 10 minutes. Next, an n-hexane solution containing 5.76 mmol of bis(diethylamino)methylvinylsilane and 5.77 mmol of n-BuLi was added to the polymerization reactor and the polymerization was continued for 160 minutes. During the total polymerization time of 4 hours and 40 minutes, 1,3-butadiene was continuously fed into the polymerization reactor over 200 minutes and styrene over 115 minutes. The total amount of 1,3-butadiene fed was 1,039 g and the total amount of styrene fed was 310 g.

[0168] While maintaining the temperature inside the polymerization reactor at 65°C, the polymerization solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm. 18.21 mmol of the modifier [3-(diethylamino)propyl]trimethoxysilane was added to the polymerization solution and stirred for 15 minutes. Next, an n-hexane solution containing 36.40 mmol of n-BuLi was added to the polymerization solution and stirred for 15 minutes. Next, 20 mL of a hexane solution containing 3.2 mL of methanol was added to the polymerization reactor, and the polymerization solution was stirred for 5 minutes.

[0169] The stirred product was removed from the polymerization reactor, and a portion of the stirred product was dried at room temperature for 24 hours to evaporate most of the volatile components, and then further dried under reduced pressure at 55°C for 12 hours to obtain a polymer sample for measurement, which was subjected to the same measurements as in Synthesis Example 1. The results are shown in Table 1.

[0170] The stirred mixture was removed from the polymerization reactor, and 10.8 g of 4,6-bis(octylthiomethyl)-o-cresol (manufactured by BASF, trade name: Irganox 1520L, manufactured by BASF) and 675 g of extender oil (manufactured by Japan Energy Corporation, trade name: JOMO Process NC-140) were added to obtain a mixture. Most of the volatile matter in the obtained mixture was evaporated at room temperature for 24 hours, and the mixture was further dried under reduced pressure at 55°C for 12 hours to obtain a conjugated diene polymer (A2).

[0171] [Synthesis Example 3] A 20 L stainless steel polymerization reactor equipped with a stirrer was cleaned and dried, and the atmosphere inside the reactor was replaced with dry nitrogen. Next, 8.16 kg of industrial hexane (Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 2.34 kg of cyclohexane, 405 g of 1,3-butadiene, 495 g of styrene, 6.08 mL of tetrahydrofuran, 0.50 mL of ethylene glycol diethyl ether, and 1.50 mL of ethylene glycol dibutyl ether were added to the polymerization reactor. Next, a small amount of a hexane solution of n-butyllithium (n-BuLi) was added as a scavenger to detoxify impurities that could deactivate the polymerization initiator. Then, an n-hexane solution containing 6.86 mmol of n-BuLi was added to the polymerization reactor to initiate the polymerization reaction. During the polymerization reaction, the temperature inside the polymerization reactor was adjusted to 65°C, the solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm, and 20 minutes after the start of polymerization, 1,3-butadiene and styrene were continuously fed into the polymerization reactor.

[0172] After 80 minutes of polymerization, an n-hexane solution containing 0.43 mmol of 1,6-bis(trichlorosilyl)hexane was added to the polymerization reactor and the polymerization was continued for 10 minutes. Next, an n-hexane solution containing 3.84 mmol of bis(diethylamino)methylvinylsilane and 3.84 mmol of n-BuLi was added to the polymerization reactor and the polymerization was continued for 160 minutes. During the total polymerization time of 4 hours and 50 minutes, 1,3-butadiene was continuously fed into the polymerization reactor over 200 minutes and styrene over 115 minutes. The total amount of 1,3-butadiene fed was 693 g and the total amount of styrene fed was 207 g.

[0173] While maintaining the temperature inside the polymerization reactor at 65°C, the polymerization solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm. 3.24 mmol of 2-butanol was added to the polymerization solution and stirred for 15 minutes. Next, 7.29 mmol of the modifier [3-(diethylamino)propyl]trimethoxysilane was added to the polymerization solution and stirred for 15 minutes. After that, an n-hexane solution containing 14.6 mmol of n-BuLi was added to the polymerization solution and stirred for 15 minutes. Next, 20 mL of a hexane solution containing 1.6 mL of methanol was added to the polymerization reactor, and the polymerization solution was stirred for 5 minutes.

[0174] The stirred product was removed from the polymerization reactor, and a portion of the stirred product was dried at room temperature for 24 hours to evaporate most of the volatile components, and then further dried under reduced pressure at 55°C for 12 hours to obtain a polymer sample for measurement, which was subjected to the same measurements as in Synthesis Example 1. The results are shown in Table 1.

[0175] The stirred mixture was removed from the polymerization reactor, and 7.2 g of 4,6-bis(octylthiomethyl)-o-cresol (manufactured by BASF, trade name: Irganox 1520L, manufactured by BASF) and 450 g of extender oil (manufactured by Japan Energy Corporation, trade name: JOMO Process NC-140) were added to obtain a mixture. Most of the volatile matter in the obtained mixture was evaporated at room temperature for 24 hours, and the mixture was further dried under reduced pressure at 55°C for 12 hours to obtain a conjugated diene polymer (A3).

[0176] [Synthesis Example 4] A 20 L stainless steel polymerization reactor equipped with a stirrer was cleaned and dried, and the atmosphere inside the reactor was replaced with dry nitrogen. Next, 8.16 kg of industrial hexane (Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 2.34 kg of cyclohexane, 405 g of 1,3-butadiene, 495 g of styrene, 6.08 mL of tetrahydrofuran, 0.50 mL of ethylene glycol diethyl ether, and 1.50 mL of ethylene glycol dibutyl ether were charged into the polymerization reactor. Next, a small amount of a hexane solution of n-butyllithium (n-BuLi) was charged into the polymerization reactor as a scavenger to detoxify impurities that could deactivate the polymerization initiator. Then, an n-hexane solution containing 1.25 mmol of n-BuLi was charged into the polymerization reactor to initiate the polymerization reaction. During the polymerization reaction, the temperature inside the polymerization reactor was adjusted to 65°C, the solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm, and 20 minutes after the start of polymerization, 1,3-butadiene and styrene were continuously fed into the polymerization reactor.

[0177] After 40 minutes of polymerization, an n-hexane solution containing 3.75 mmol of n-BuLi was added to the polymerization reactor and the polymerization was continued for 35 minutes. Next, 3.84 mmol of bis(diethylamino)methylvinylsilane was added to the polymerization reactor and the polymerization was continued for 35 minutes. After that, an n-hexane solution containing 5.00 mmol of n-BuLi was added to the polymerization reactor and the polymerization was continued for 140 minutes. During the total polymerization time of 4 hours and 40 minutes, 1,3-butadiene was continuously fed into the polymerization reactor over 200 minutes and styrene over 115 minutes. The total amount of 1,3-butadiene fed was 693 g and the total amount of styrene fed was 207 g.

[0178] While maintaining the temperature inside the polymerization reactor at 65°C, the polymerization solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm. 15.0 mmol of the modifier [3-(diethylamino)propyl]trimethoxysilane was added to the polymerization solution and stirred for 15 minutes. Next, an n-hexane solution containing 26.25 mmol of n-BuLi was added to the polymerization solution and stirred for 15 minutes. Next, 20 mL of a hexane solution containing 2.23 mL of methanol was added to the polymerization reactor, and the polymerization solution was stirred for 5 minutes.

[0179] The stirred product was removed from the polymerization reactor, and a portion of the stirred product was dried at room temperature for 24 hours to evaporate most of the volatile components, and then further dried under reduced pressure at 55°C for 12 hours to obtain a polymer sample for measurement, which was subjected to the same measurements as in Synthesis Example 1. The results are shown in Table 1.

[0180] The stirred mixture was removed from the polymerization reactor, and 7.2 g of 4,6-bis(octylthiomethyl)-o-cresol (manufactured by BASF, trade name: Irganox 1520L, manufactured by BASF) and 450 g of extender oil (manufactured by Japan Energy Corporation, trade name: JOMO Process NC-140) were added to obtain a mixture. Most of the volatile matter in the obtained mixture was evaporated at room temperature for 24 hours, and the mixture was further dried under reduced pressure at 55°C for 12 hours to obtain a conjugated diene polymer (B1).

[0181] [Synthesis Example 5] A 20 L stainless steel polymerization reactor equipped with a stirrer was cleaned and dried, and the atmosphere inside the reactor was replaced with dry nitrogen. Next, 8.16 kg of industrial hexane (Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 2.34 kg of cyclohexane, 405 g of 1,3-butadiene, 495 g of styrene, 6.08 mL of tetrahydrofuran, 0.50 mL of ethylene glycol diethyl ether, and 1.50 mL of ethylene glycol dibutyl ether were charged into the polymerization reactor. Next, a small amount of a hexane solution of n-butyllithium (n-BuLi) was charged into the polymerization reactor as a scavenger to detoxify impurities that could deactivate the polymerization initiator. Then, an n-hexane solution containing 1.25 mmol of n-BuLi was charged into the polymerization reactor to initiate the polymerization reaction. During the polymerization reaction, the temperature inside the polymerization reactor was adjusted to 65°C, the solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm, and 20 minutes after the start of polymerization, 1,3-butadiene and styrene were continuously fed into the polymerization reactor.

[0182] After 40 minutes of polymerization, an n-hexane solution containing 3.75 mmol of n-BuLi was added to the polymerization reactor and the polymerization was continued for 35 minutes. Next, 3.84 mmol of bis(diethylamino)methylvinylsilane was added to the polymerization reactor and the polymerization was continued for 35 minutes. After that, an n-hexane solution containing 5.00 mmol of n-BuLi was added to the polymerization reactor and the polymerization was continued for 140 minutes. During the total polymerization time of 4 hours and 40 minutes, 1,3-butadiene was continuously fed into the polymerization reactor over 200 minutes and styrene over 115 minutes. The total amount of 1,3-butadiene fed was 693 g and the total amount of styrene fed was 207 g.

[0183] While maintaining the temperature inside the polymerization reactor at 65°C, the polymerization solution inside the polymerization reactor was stirred at a stirring speed of 130 rpm. 20.0 mmol of the modifier [3-(diethylamino)propyl]trimethoxysilane was added to the polymerization solution and stirred for 15 minutes. Next, an n-hexane solution containing 26.25 mmol of n-BuLi was added to the polymerization solution and stirred for 15 minutes. Next, 20 mL of a hexane solution containing 2.77 mL of methanol was added to the polymerization reactor, and the polymerization solution was stirred for 5 minutes.

[0184] The stirred product was removed from the polymerization reactor, and a portion of the stirred product was dried at room temperature for 24 hours to evaporate most of the volatile components, and then further dried under reduced pressure at 55°C for 12 hours to obtain a polymer sample for measurement, which was subjected to the same measurements as in Synthesis Example 1. The results are shown in Table 1.

[0185] The stirred material in the polymerization reactor was removed and divided into two equal weight portions. 3.6 g of 4,6-bis(octylthiomethyl)-o-cresol (manufactured by BASF, trade name: Irganox 1520L, manufactured by BASF) and 225 g of extender oil (manufactured by Japan Energy Corporation, trade name: JOMO Process NC-140) were added to one portion to obtain a mixture. The majority of the volatile matter in the resulting mixture was evaporated at room temperature for 24 hours, and the mixture was further dried under reduced pressure at 55°C for 12 hours to obtain a conjugated diene polymer (B2).

[0186] [Synthesis Example 6] To the remaining stirred mixture divided into two in Synthesis Example 5, 3.6 g of "Irganox 1520L (Irganox 1520L: 4,6-bis(octylthiomethyl)-o-cresol, manufactured by BASF)", 1.8 g of "Sumilizer GM (2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl acrylate, manufactured by Sumitomo Chemical Co., Ltd.)", 0.9 g of "Sumilizer TP-D (2,2-bis[[3-(dodecylthio)propionic acid]2,2-bis[[3-(dodecylthio)-1-oxopropyloxy]methyl]-1,3-propanediyl, manufactured by Sumitomo Chemical Co., Ltd.)", and 225 g of extender oil (manufactured by Japan Energy Corporation, trade name: JOMO Process NC-140) were added to obtain a mixture. Most of the volatile matter in the mixture was evaporated at room temperature for 24 hours, and the mixture was further dried under reduced pressure at 55° C. for 12 hours to obtain a conjugated diene polymer (B3).

[0187] Table 1 shows the properties of the conjugated diene polymers obtained in Synthesis Examples 1 to 6.

[0188] [Table 1]

[0189] <Preparation of Conjugated Diene Polymer Composition and Fabrication of Cross-Linked Rubber Sheet> Materials other than sulfur and the vulcanization accelerator were kneaded in a Labo Plastomill at 150°C for 5 minutes in the blending ratios (parts by weight) shown in Table 2 to prepare conjugated diene polymer compositions according to Examples 1 to 6 and Comparative Examples 1 to 3. The obtained conjugated diene polymer compositions were then used to measure the compound Mooney viscosity according to the method described above. The results are shown in Table 2. In Examples 4 to 6, two types of conjugated diene polymers were mixed, but a mixture of two types of conjugated diene polymers was separately prepared, and a medium molecular weight polymer P was obtained according to the method described above. _MID and high molecular weight substance P _HIGH The shrinkage factor of the medium molecular weight P _MID and high molecular weight substance P _HIGH The adsorption rate of HCl on silica was measured. Next, sulfur and a vulcanization accelerator were added to the obtained conjugated diene polymer composition, which was then formed into a sheet at 50°C using a 6-inch roll, and the sheet was heated at 160°C for 35 to 40 minutes to crosslink, thereby producing cross-linked rubber sheets according to Examples 1 to 6 and Comparative Examples 1 to 3. The results are shown in Table 2.

[0190] [Table 2]

[0191] The materials shown in Table 2 are as follows: Silica: EVONIK, product name "Ultrasil VN3-GR" Oil: JOMO Process NC-140, manufactured by JXTG Nippon Oil & Energy Corporation Silane coupling agent: bis(3-(triethoxysilyl)propyl)tetrasulfide (manufactured by Degussa, trade name "Si69") Carbon black: Cabot Japan, product name "N339" Zinc oxide: Zinc oxide type 2, manufactured by Seido Chemical Industry Co., Ltd. Antioxidant: 6PPD, N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., product name "Nocrac 6C") Stearic acid: NOF Corporation's product name "Beads Stearic Acid Camellia" Wax: Ouchi Shinko Chemical Industry Co., Ltd., product name "Sunnock N" Processing aid: Struktol EF44, manufactured by Struktol Vulcanization accelerator (1): N-cyclohexyl-2-benzothiazolyl sulfenamide, product name "Noccela CZ-G" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Vulcanization accelerator (2): Diphenyl guanidine (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., product name "Noccela D") Sulfur: Tsurumi Chemical Co., Ltd., product name "Sulfur 325 mesh"

[0192] Table 2 shows the compound Mooney viscosity (A) and fuel economy performance (B) results for each example and comparative example. The smaller the compound Mooney viscosity (A) value, the better the processability. The smaller the fuel economy performance (B) value, the better the fuel economy.

[0193] As shown in Table 2, the high molecular weight P _HIGH The shrinkage factor of the high molecular weight P _HIGH The adsorption rate of the medium molecular weight P to silica is 75% or less. _MID The conjugated diene polymers having an adsorption rate of 40 to 100% to silica were blended with silica or the like as a filler to form a conjugated diene polymer composition. When the compound Mooney viscosity (A) was multiplied by the fuel-saving performance (B) when the resulting cross-linked rubber was formed, the value ((A) × (B)) was low, and the processability and fuel-saving performance were well-balanced and excellent (Examples 1 to 6). On the other hand, high molecular weight P _HIGH The shrinkage factor of the high molecular weight substance P is more than 0.8. _HIGH Conjugated diene polymers having an adsorption rate of more than 75% to silica had a high value ((A) × (B)) obtained by multiplying the compound Mooney viscosity (A) and the fuel saving performance (B), and were inferior in processability and fuel saving performance (Comparative Examples 1 to 3). In Table 2, the value ((A) x (B)) obtained by multiplying the compound Mooney viscosity (A) and the fuel economy performance (B) is shown as an index (the larger the index, the better) with the result of Comparative Example 1 set to 100.

Claims

1. A conjugated diene-based polymer containing at least a conjugated diene monomer unit, The shrinkage factor of the polymer is 0.4 to 0.8, the adsorption rate of the high molecular weight substance to silica is 75% or less; The adsorption rate of the medium molecular weight substance to silica is 40 to 100%; Contains aromatic vinyl monomer units, The polymer chain contains a coupling polymer chain obtained by a coupling reaction using a trifunctional or higher functional coupling agent, Contains units of a vinyl compound containing a functional group capable of interacting with silica, The conjugated diene polymer, wherein the vinyl compound is a compound represented by the following general formula (1): 【Chemistry 6】 (In the above general formula (1), X １ represents a chemical single bond or a hydrocarbylene group, and X ２ , X ３ and X ４ each independently represents a substituted amino group, a hydrocarbyloxy group, or a hydrocarbyl group which may have a substituent, and two of X 2 , X 3 , and X 4 are substituted amino groups.

2. 2. The conjugated diene polymer according to claim 1, wherein the shrinkage factor of the medium molecular weight polymer is 0.8 to 1.

2.

3. 3. The conjugated diene polymer according to claim 1, wherein the high molecular weight component has an adsorption rate of 10 to 70% on silica.

4. 4. The conjugated diene polymer according to claim 1, which has two or more peak values ​​of molecular weight.

5. Molecular weight of low molecular weight substance Mp ＿ＬＯＷ The conjugated diene polymer according to any one of claims 1 to 4, wherein the molecular weight of the conjugated diene polymer is in the range of 70,000 to 190,000.

6. A conjugated diene polymer composition comprising the conjugated diene polymer according to any one of claims 1 to 5 and a filler.

7. A cross-linked rubber product obtained by cross-linking the conjugated diene polymer composition according to claim 6.

8. A tire comprising the cross-linked rubber according to claim 7.

9. a first step of polymerizing monomers including a conjugated diene compound and an aromatic vinyl compound in an inert solvent in the presence of a polymerization initiator to obtain a solution containing a polymer chain having an active terminal; a second step of forming coupled polymer chains by performing a coupling reaction using a tri- or higher functional coupling agent on some of the polymer chains having active ends obtained in the first step, thereby obtaining a solution containing the polymer chains having active ends and the coupled polymer chains; a third step of further polymerizing a monomer containing a conjugated diene compound onto a polymer chain having an active terminal after the coupling reaction in the second step, A method for producing a conjugated diene polymer, wherein in at least one of the first step and the third step, a monomer containing a vinyl compound having a functional group capable of interacting with silica in addition to a conjugated diene compound is used as the monomer to be polymerized, and the vinyl compound is a compound represented by the following general formula (1): 【Chemistry 7】 (In the above general formula (1), X １ represents a chemical single bond or a hydrocarbylene group, and X ２ , X ３ and X ４ each independently represents a substituted amino group, a hydrocarbyloxy group, or a hydrocarbyl group which may have a substituent.

10. 10. The method for producing a conjugated diene-based polymer according to claim 9, wherein the polymerization initiator is additionally added at any one of the following timings: during the polymerization in the first step, at the start of the polymerization in the third step, and during the polymerization in the third step.

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