Conjugated-diene-based polymer, conjugated-diene-based polymer composition, crosslinked rubber object, and tire

Abstract

A conjugated-diene-based polymer comprising conjugated-diene monomer units and aromatic vinyl monomer units, wherein the difference between the content (AL) of the aromatic vinyl monomer units in low-molecular-weight components (L) of the conjugated-diene-based polymer and the content (AH) of the aromatic vinyl monomer units in high-molecular-weight components (H) of the conjugated-diene-based polymer, (content (AL) of aromatic vinyl monomer units)-(content (AH) of aromatic vinyl monomer units), is 2 wt% or greater.

Description

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

[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 has excellent processability and can give a cross-linked rubber product that is excellent in wet grip performance, handling stability, tensile strength, and elongation, and a conjugated diene polymer composition, a cross-linked rubber product, and a tire obtained using such a conjugated diene polymer.

[0002] In recent years, automobile tires have been required to have excellent wet grip properties and steering stability from the viewpoint of safety. Polymer compositions used for automobile tires include, for example, polymer compositions containing conjugated diene polymers such as polybutadiene and butadiene-styrene copolymers, and fillers such as carbon black and silica.

[0003] Patent Document 1 discloses a conjugated diene polymer that satisfies the following (1) to (4) as a conjugated diene polymer used to provide such a tire. (1) The molecular weight distribution curve obtained by gel permeation chromatography (GPC) measurement has two or more peaks. (2) The molecular weight distribution curve contains a peak (A) having a peak molecular weight of 500,000 to 2,500,000 and a peak (B) having a peak molecular weight of 150,000 to 600,000. (3) The total area of ​​the peak (A) and the area of ​​the peak (B) accounts for 70% or more of the entire molecular weight distribution curve. (4) The absolute value of the difference between the glass transition temperature (Tg(A)) of the conjugated diene polymer contained in the peak (A) and the glass transition temperature (Tg(B)) of the conjugated diene polymer contained in the peak (B) is 2°C to 30°C.

[0004] International Publication No. 2018 / 147312

[0005] The conjugated diene polymer obtained by the technique of Patent Document 1 above does not have sufficient processability, and the cross-linked rubber obtained using the same leaves room for improvement in wet grip properties.

[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-based polymer that has excellent processability and can give a cross-linked rubber product that is excellent in wet grip performance, handling stability, tensile strength, and elongation. Another object of the present invention is to provide a conjugated diene-based polymer composition, a cross-linked rubber product, and a tire obtained using such a conjugated diene-based polymer, and to provide a method for producing such a conjugated diene-based polymer.

[0007] As a result of intensive research conducted by the present inventors to achieve the above object, it has been found that, in a conjugated diene polymer containing a conjugated diene monomer unit and an aromatic vinyl monomer unit, the content ratio (A) of the aromatic vinyl monomer unit contained in a low-molecular-weight component (L) constituting the conjugated diene polymer is Ｌ ) and the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ The present inventors have found that the above object can be achieved by controlling the difference ΔA between the σ and the σ within a specific range, and have thus completed the present invention.

[0008] That is, the present invention provides the following inventions: [1] A conjugated diene polymer containing conjugated diene monomer units and aromatic vinyl monomer units, wherein the content ratio (A) of the aromatic vinyl monomer units contained in a low-molecular-weight component (L) constituting the conjugated diene polymer is 0.01 to 0.01. Ｌ ) and the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ ) and the difference ΔA "Difference ΔA = content ratio of aromatic vinyl monomer unit (A Ｌ )-aromatic vinyl monomer unit content (A Ｈ[2] The conjugated diene copolymer according to [1], wherein the number of peaks in a molecular weight distribution curve obtained by gel permeation chromatography measurement is two or more, the peak top molecular weight of the low molecular weight peak (LP) is 80,000 to 200,000, and the ionic strength is 70% or less. [3] The conjugated diene polymer according to [2], wherein the peak top molecular weight of the low molecular weight peak (LP) is 100,000 to 190,000. [4] The conjugated diene polymer according to [2] or [3], wherein the proportion of polymer components constituting the low molecular weight peak (LP) is 10 to 65% by weight. [5] The conjugated diene polymer according to any one of [2] to [4], wherein the total weight average molecular weight (Mw) is 300,000 to 900,000. [6] A conjugated diene polymer composition containing the conjugated diene polymer according to any one of [1] to [5] and a filler. [7] A cross-linked rubber obtained by cross-linking the conjugated diene polymer composition according to [6]. [8] A tire comprising the cross-linked rubber product according to [7]. [9] A method for producing the conjugated diene polymer according to any one of [1] to [5], comprising: a first step of copolymerizing monomers comprising a conjugated diene monomer and an aromatic vinyl monomer in a solvent in the presence of a polymerization initiator; a second step of adding a polymerization terminator in an amount sufficient to deactivate 10 to 95 mol % of the active polymerization ends contained in the polymerization reaction system when the polymerization conversion rate is 5% or more but less than 95%, thereby deactivating a portion of the active polymerization ends and continuing the polymerization reaction; and a third step of adding a polymerization terminator to terminate the polymerization reaction after the polymerization conversion rate has reached 95% or more.

[10] A method for producing the conjugated diene polymer according to [9], wherein the entire amount of the aromatic vinyl monomer to be used in the polymerization reaction is added to the polymerization reaction system before the start of the polymerization reaction.

[11] The method for producing a conjugated diene polymer according to [9] or

[10] , wherein, when the total amount of the conjugated diene monomer and the aromatic vinyl monomer copolymerizable with the conjugated diene monomer used in the polymerization reaction is taken as 100% by weight, a total of 40 to 70% by weight of the conjugated diene monomer and the aromatic vinyl monomer copolymerizable with the conjugated diene monomer is added to the polymerization reaction system before the start of the polymerization reaction.

[12] The method for producing a conjugated diene polymer according to any one of [9] to

[11] , wherein the amount of the polymerization terminator added in the second step is an amount that deactivates 20 to 95 mol % of the active polymerization terminals contained in the polymerization reaction system.

[13] The method for producing a conjugated diene polymer according to any one of [9] to

[12] , wherein the timing for adding the polymerization terminator in the second step is at a stage where the polymerization conversion rate is 15 to 75%.

[0009] According to the present invention, it is possible to provide a conjugated diene-based polymer that has excellent processability and can give a cross-linked rubber product that is excellent in wet grip performance, handling stability, tensile strength, and elongation. Furthermore, according to the present invention, it is also possible to provide a conjugated diene-based polymer composition, a cross-linked rubber product, and a tire obtained using such a conjugated diene-based polymer, and to provide a method for producing such a conjugated diene-based polymer.

[0010] <Conjugated diene polymer> The conjugated diene polymer of the present invention is a conjugated diene polymer containing conjugated diene monomer units and aromatic vinyl monomer units, and the content ratio (A) of the aromatic vinyl monomer units contained in the low-molecular-weight component (L) constituting the conjugated diene polymer is Ｌ ) and the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ ) and the difference ΔA "Difference ΔA = content ratio of aromatic vinyl monomer unit (A Ｌ )-aromatic vinyl monomer unit content (A Ｈ )) is 2% by weight or more.

[0011] 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. The content of the conjugated diene monomer units in the conjugated diene polymer of the present invention is preferably 50 to 92 wt %, more preferably 50 to 90 wt %, and even more preferably 56 to 88 wt %, based on 100 wt % of the total amount of all monomers. The content of the conjugated diene monomer units in the conjugated diene polymer of the present invention may be, for example, 70 to 88 wt %, or may be 56 to 68 wt %.

[0012] 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 8 to 50 wt%, more preferably 10 to 50 wt%, and even more preferably 12 to 44 wt%, based on 100 wt% of the total amount of all monomers. By ensuring that the content of the aromatic vinyl monomer units falls within the above range, the wet grip properties and handling stability of the resulting cross-linked rubber can be further improved. The content of the aromatic vinyl monomer units in the conjugated diene polymer of the present invention may be, for example, 12 to 30 wt%, or may be 32 to 44 wt%.

[0013] Furthermore, the conjugated diene polymer of the present invention may contain, 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.

[0014] 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 may suitably be used, for example, a compound represented by the following general formula (1): 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.

[0015] In the above general formula (1), X １ is a chemical single bond or a hydrocarbylene group, preferably a chemical single bond. Examples of hydrocarbylene groups include alkylene groups, alkenediyl groups, arylene groups, and groups in which an arylene group and an alkylene group are bonded. Examples of alkylene groups include methylene groups, ethylene groups, and trimethylene groups. Examples of alkenediyl groups include vinylene groups and ethylene-1,1-diyl groups. Examples of arylene groups include phenylene groups, naphthylene groups, 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.

[0016] In the above general formula (1), 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. ２ , X ３ and X ４ At least one of X is preferably a substituted amino group; ２ , X ３ and X ４It is more preferable that two of them are substituted amino groups.

[0017] 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. In the above general formula (2), R １ and R ２ may or may not be bonded to each other, R １ and R ２ When 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 ２ When 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.

[0018] R １ and R ２ Examples of hydrocarbyl groups that can constitute R 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. 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 the substituent, and examples of the hydrocarbyl group having a hydrocarbyloxy group as the substituent include alkoxyalkyl groups such as a methoxymethyl group, an ethoxymethyl group, and a methoxyethyl group; and aryloxyalkyl groups such as a phenoxymethyl group.

[0019] R１ 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.

[0020] R １ and R ２ and are bonded to each other, R １ and R ２ Examples of the hydrocarbylene group that can constitute R include alkylene groups such as a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a decamethylene group, a dodecamethylene group, and a 2,2,4-trimethylhexane-1,6-diyl group; and alkenediyl groups such as a pentan-2-ene-1,5-diyl group. １ and R ２ When the hydrocarbylene group that can constitute the above group contains at least one selected from a nitrogen atom, an oxygen atom, a sulfur atom, and a silicon atom, the hydrocarbylene group containing at least one selected from a nitrogen atom, an oxygen atom, a sulfur atom, and a silicon atom includes a group represented by -CH=N-CH=CH-, -CH=N-CH ２ -CH ２ a group represented by -, -CH ２ -CH ２ -O-CH ２ -CH ２ a group represented by -, -CH ２ -CH ２ -S-CH ２ -CH ２ a group represented by -, -CH ２ -CH ２ -SiH ２ -CH ２ -CH ２ a group represented by -, -CH ２ -CH ２ -SiMe ２ -CH ２ -CH ２ a group represented by -, -CH ２ -CH ２ -SiEt ２ -CH ２ -CH２ - and the like. 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.

[0021] In the above general formula (2), R １ and R ２ When is a hydrocarbyl group, specific examples of the group represented by general formula (2) above 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.

[0022] In the above general formula (2), R １ and R ２ is a hydrocarbyl group having a hydrocarbyloxy group as a substituent, specific examples of the group represented by the above general formula (2) include di(alkoxyalkyl)amino groups such as di(methoxymethyl)amino group and di(ethoxymethyl)amino group.

[0023] In the above general formula (2), R １ and R ２ 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.

[0024] In the above general formula (2), R１ 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.

[0025] In the above general formula (2), R １ and R ２ and 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.

[0026] 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.

[0027] 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.

[0028] In the above general formula (1), X ２ , X ３ and X ４ Examples of hydrocarbyl groups that can constitute X 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. ２ , X ３ and X ４When 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.

[0029] 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), in which 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.

[0030] 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), in which 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.

[0031] 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), in which two of the groups 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(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.

[0032] 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.

[0033] 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) in the case where 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.

[0034] 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 general formula (1) above, in the case where 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.

[0035] In the above general formula (1), X １ is a chemical single bond, and X ２ , X ３ and X ４ Among these, specific examples of vinyl compounds containing a silicon atom-containing functional group represented by the above general formula (1), when none of them is a substituted amino group, include trialkoxyvinylsilanes such as trimethoxyvinylsilane, triethoxyvinylsilane, tripropoxyvinylsilane, etc.; dialkoxyalkylvinylsilanes such as methyldimethoxyvinylsilane, methyldiethoxyvinylsilane, etc.; dialkoxyarylvinylsilanes such as di(tert-pentoxy)phenylvinylsilane, di(tert-butoxy)phenylvinylsilane, etc.; monoalkoxydialkylvinylsilanes such as dimethylmethoxyvinylsilane; monoalkoxydiarylvinylsilanes such as tert-butoxydiphenylvinylsilane, tert-pentoxydiphenylvinylsilane, etc.; monoalkoxyalkylarylvinylsilanes such as tert-butoxymethylphenylvinylsilane, tert-butoxyethylphenylvinylsilane, etc.; and substituted alkoxyvinylsilane compounds such as tris(β-methoxyethoxy)vinylsilane.

[0036] Among the compounds represented by the general formula (1), X １ is preferably a chemical single bond, and X １is 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, 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.

[0037] 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.

[0038] 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.

[0039] When the compound represented by the 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. In the above general formula (3), X ５ represents a chemical single bond or a hydrocarbylene group, and X ６ , X ７ and X ８ each independently represents a hydroxyl group, a substituted amino group, a hydrocarbyloxy group, or a hydrocarbyl group which may have a substituent.

[0040] 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.

[0041] 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 the total amount of all monomers being 100% by weight. 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 obtained cross-linked rubber product can be further improved while maintaining sufficient processability.

[0042] 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.

[0043] The bonding pattern of each monomer unit in the conjugated diene polymer of the present invention can be various bonding patterns such as block, tapered, random, etc., but a random bonding pattern is preferred. By using a random bonding pattern, the fuel economy of the obtained cross-linked rubber can be further improved.

[0044] Furthermore, the conjugated diene polymer of the present invention preferably contains a modifying group, and more preferably contains a modifying group (terminal modified group) obtained by modifying the end of the polymer chain of the conjugated diene polymer with a modifying agent. In this specification, the "conjugated diene polymer containing a modifying group" may be one in which at least a portion of the polymer chain constituting the conjugated diene polymer contains a modifying group, that is, one in which a portion of the polymer chain constituting the conjugated diene polymer does not contain a modifying group.

[0045] The modifying group preferably contains a functional group capable of interacting with silica, from the viewpoint of appropriately increasing affinity for fillers such as silica and further improving the wet grip properties and handling stability of the resulting cross-linked rubber. Here, the functional group capable of interacting with silica is a functional group that can form a covalent bond between the functional group and the silica surface, or can form an intermolecular force weaker than a covalent bond (e.g., ion-dipole interaction, dipole-dipole interaction, hydrogen bond, van der Waals force, etc.). The interaction formed between silica and the functional group is preferably a covalent bond or an intermolecular force weaker than a covalent bond (e.g., ion-dipole interaction, dipole-dipole interaction, hydrogen bond, van der Waals force, etc.), and from the viewpoint of easily controlling the ionic strength index within a suitable range, weak intermolecular forces (e.g., ion-dipole interaction, dipole-dipole interaction, hydrogen bond, van der Waals force, etc.) are more preferred. The functional group capable of interacting with silica is not particularly limited, but examples thereof include a nitrogen atom-containing functional group, a silicon atom-containing functional group, and an oxygen atom-containing functional group.

[0046] As the modifier for forming the modifying group, from the viewpoint of high interaction with silica, silicon atom-containing modifier and nitrogen atom-containing modifier are preferred, and silicon atom-containing modifier is more preferred.Silicon atom-containing modifiers include, for example, siloxane compounds and hydrocarbyloxysilane compounds.Among these, hydrocarbyloxysilane compounds having nitrogen atom-containing functional groups are preferred.

[0047] Examples of nitrogen atom-containing modifiers include N,N-disubstituted aminoalkyl(meth)acrylamides such as dimethylaminoethyl acrylamide, diethylaminoethyl acrylamide, dimethylaminopropyl acrylamide, diethylaminopropyl acrylamide, dimethylaminobutyl acrylamide, diethylaminobutyl acrylamide, dimethylaminoethyl methacrylamide, diethylaminoethyl methacrylamide, dimethylaminopropyl methacrylamide, diethylaminopropyl methacrylamide, dimethylaminobutyl methacrylamide, and diethylaminobutyl methacrylamide; and pyrrolidone compounds such as N-phenyl-2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and 1-cyclohexyl-2-pyrrolidone.

[0048] Examples of hydrocarbyloxysilane compounds having a nitrogen atom-containing functional group include amino group-containing alkoxysilane compounds such as [3-(dimethylamino)propyl]trimethoxysilane, [3-(diethylamino)propyl]trimethoxysilane, [3-(dimethylamino)propyl]triethoxysilane, [3-(diethylamino)propyl]triethoxysilane, [3-(ethylmethylamino)propyl]trimethoxysilane, and [3-(ethylmethylamino)propyl]triethoxysilane.

[0049] In addition, the conjugated diene polymer of the present invention has a low molecular weight component (L) and a low molecular weight component (L) containing an aromatic vinyl monomer unit (A Ｌ ) and the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ ) and the difference ΔA "Difference ΔA = content ratio of aromatic vinyl monomer unit (A Ｌ )-aromatic vinyl monomer unit content (A Ｈ )) is 2% by weight or more.

[0050] In the present invention, A ＨThe high molecular weight component (H) when calculating A is a polymer component detected in the RI elution curve c(t) obtained by subjecting the conjugated diene polymer of the present invention to gel permeation chromatography (GPC) measurement using a UV detector and an RI detector, at an elution time t5 to t50 where the area integrated from the shortest elution time is 5 to 50% when the total area of ​​c(t) is taken as 100%. Ｌ The low-molecular-weight component (L) when calculating (L) refers to a polymer component detected in an RI elution curve c(t) obtained by subjecting the conjugated diene-based polymer of the present invention to gel permeation chromatography (GPC) measurement using a UV detector and an RI detector, at an elution time t50 to t95 where the area integrated from the shortest elution time is 50 to 95% when the total area of ​​c(t) is taken as 100%.

[0051] In the present invention, the content ratio of the aromatic vinyl monomer unit contained in each of the low molecular weight component (L) and the high molecular weight component (H) is set within a specific range, and this makes it possible to obtain a conjugated diene polymer that has excellent processability and can give a cross-linked rubber product that is excellent in wet grip performance, handling stability, tensile strength and elongation.

[0052] Specifically, the content ratio of aromatic vinyl monomer units contained in the low molecular weight component (L) (A Ｌ ) and the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ ) and the difference ΔA "Difference ΔA = content ratio of aromatic vinyl monomer unit (A Ｌ )-aromatic vinyl monomer unit content (A ＨThe difference ΔA may be adjusted depending on the proportion of aromatic vinyl monomer units contained in the entire conjugated diene polymer. When the proportion of aromatic vinyl monomer units contained in the entire conjugated diene polymer is 8% by weight or more and less than 20% by weight, the difference ΔA is preferably 2% by weight to 12% by weight, more preferably 4% by weight to 9% by weight. When the proportion of aromatic vinyl monomer units contained in the entire conjugated diene polymer is 20% by weight or more and less than 32% by weight, the difference ΔA is preferably 5% by weight to 17% by weight, more preferably 7% by weight to 13% by weight. When the proportion of aromatic vinyl monomer units contained in the entire conjugated diene polymer is 32% by weight to 50% by weight, the difference ΔA is preferably 2% by weight to 42% by weight, more preferably 3% by weight to 35% by weight.

[0053] Specific methods for measuring the difference ΔA include the methods described in Examples below. The method for making the difference ΔA fall within the above range is not particularly limited, and examples thereof include a method in which, when copolymerizing monomers containing a conjugated diene monomer and an aromatic vinyl monomer, a polymerization terminator is added in an amount that deactivates 10 to 95 mol % of the active polymerization terminals contained in the polymerization reaction system at a polymerization conversion rate of 5% or more but less than 95%, thereby deactivating a portion of the active polymerization terminals and then continuing the polymerization reaction.

[0054] The conjugated diene polymer of the present invention preferably has two or more peaks in a molecular weight distribution curve obtained by gel permeation chromatography (GPC) measurement, and the peak top molecular weight (Mp) of the low molecular weight peak (LP) is preferably 80,000 to 200,000. The number of peaks is preferably 2 to 7, and more preferably 3 to 5.

[0055] In the conjugated diene polymer of the present invention, the peak with the largest area among the peaks detected at a peak-top molecular weight of 400,000 or less in the molecular weight distribution curve obtained by gel permeation chromatography (GPC) measurement is referred to as the low molecular weight peak (LP). Furthermore, among the peaks remaining after excluding the low molecular weight peak (LP) and having a peak-top molecular weight exceeding 400,000, the peak with the largest area is referred to as the high molecular weight peak (HP). In the present invention, the peak-top molecular weight (Mp) of the low molecular weight peak (LP) is preferably 80,000 to 200,000, more preferably 90,000 to 200,000, and even more preferably 100,000 to 190,000. By setting the peak-top molecular weight (Mp) of the low molecular weight peak (LP) within the above range, processability, wet grip performance, and handling stability can be further improved. Furthermore, the peak-top molecular weight (Mp) of the high molecular weight peak (HP) is preferably 450,000 to 1,300,000, more preferably 450,000 to 1,200,000, and even more preferably 500,000 to 1,100,000. The peak top molecular weight is a molecular weight converted into standard polystyrene.

[0056] In the conjugated diene polymer of the present invention, the proportion of the polymer component constituting the low molecular weight peak (LP) is preferably 10 to 65% by weight, more preferably 15 to 65% by weight, and even more preferably 20 to 65% by weight. By setting the proportion of the polymer component constituting the low molecular weight peak (LP) within the above range, processability, wet grip performance, and handling stability can be further improved. In the conjugated diene polymer of the present invention, the proportion of the polymer component constituting the high molecular weight peak (HP) is preferably 35 to 90% by weight, more preferably 35 to 85% by weight, and even more preferably 35 to 80% by weight.

[0057] The peak top molecular weight of the low molecular weight peak (LP), the peak top molecular weight of the high molecular weight peak (HP), the proportion of polymer components constituting the low molecular weight peak (LP), and the proportion of polymer components constituting the high molecular weight peak (HP) can be measured by the method described in the examples below.

[0058] The conjugated diene polymer of the present invention preferably has an overall weight average molecular weight (Mw) of 300,000 to 900,000, more preferably 350,000 to 800,000, and even more preferably 410,000 to 730,000, and an overall weight average molecular weight (Mw / Mn) of 1.3 to 5.0, more preferably 1.5 to 4.0, and even more preferably 1.7 to 3.5. The overall weight average molecular weight (Mw) and the overall weight average molecular weight (Mw / Mn) can be determined in polystyrene equivalent terms by gel permeation chromatography (GPC) measurement, and can be measured by the method described in the Examples below.

[0059] The conjugated diene polymer of the present invention preferably has an ionic strength index of 70% or less. The ionic strength index is a value calculated according to the following formula (I) based on the results of gel permeation chromatography (GPC) measurements using a styrene column and gel permeation chromatography (GPC) measurements using a cation exchange column, performed on a sample solution containing the conjugated diene polymer and internal standard polystyrene (molecular weight 5000). Ionic strength index (%)={1-(A ＣＸ / B ＣＸ ) × (B ｓｔｙ / A ｓｔｙ )}×100 (I) A ＣＸ B: Peak area of ​​the molecular weight distribution curve of the conjugated diene polymer measured by GPC using a cation exchange column ＣＸ B: Peak area of ​​the internal standard polystyrene peak measured by GPC using a cation exchange column ｓｔｙ A: Peak area of ​​the internal standard polystyrene peak measured by GPC using a styrene column ｓｔｙ : Peak area of ​​the molecular weight distribution curve of the conjugated diene polymer measured by GPC using a styrene column Wherein, A ＣＸ and A ｓｔｙIn the definition above, the peak area of ​​the molecular weight distribution curve of the conjugated diene polymer refers to the peak area of ​​the molecular weight distribution curve obtained by excluding the region of molecular weight less than 5000 from the obtained molecular weight distribution curve and further excluding the peak of the internal standard polystyrene. In addition, a column using a styrene-divinylbenzene-based gel packing material is considered to be a styrene-based column.

[0060] The GPC measurement using a styrene column and the GPC measurement using a cation exchange column can be carried out under the conditions described in the examples below.

[0061] If the conjugated diene polymer contains impurities such as oil, an error may occur in the measured value of the ionic strength index. In such a case, the conjugated diene polymer may be subjected to Soxhlet extraction or the like as necessary to remove impurities, and then the ionic strength index may be measured.

[0062] In GPC measurement using a cation exchange column, an ionic interaction occurs between some polymer chains in the conjugated diene polymer and the surface of the cation exchange column. Therefore, the greater the proportion of polymer chains in the conjugated diene polymer that cause ionic interaction, and the stronger the ionic interaction of the polymer chains, the lower the peak intensity attributable to the polymer chains in the molecular weight distribution curve obtained using the cation exchange column, compared with the molecular weight distribution curve obtained using a styrene column, and the larger the ionic strength index calculated by the above formula (I) tends to be.

[0063] The conjugated diene polymer of the present invention preferably has an ionic strength index of 70% or less, more preferably 60% or less, and even more preferably 45% or less. The lower limit of the ionic strength index is not particularly limited, but is preferably 0.5% or more. By setting the ionic strength index within the above range, it is possible to further increase the tensile strength while realizing excellent processability.

[0064] The ionic strength index can be controlled by adjusting the proportion of polymer chains in the conjugated diene polymer that have a functional group (for example, a cationic group such as an amino group) that interacts with a cation exchange column, the position of the functional group in the polymer chain (for example, whether the functional group is in the polymer chain or at the end of the polymer chain), the molecular structure in the vicinity of the functional group, the proportion of the functional group, etc.

[0065] 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, even more preferably 5 to 80% by weight, and particularly preferably 25 to 75% by weight. By setting the vinyl bond content in the conjugated diene monomer units in the entire conjugated diene polymer within the above range, it is possible to achieve even better wet grip performance.

[0066] The Mooney viscosity (ML １＋４ , 125°C) is preferably 20 to 100, more preferably 25 to 90, and particularly preferably 30 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 within the above range.

[0067] 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.

[0068] <Method for producing conjugated diene polymer> The method for producing a conjugated diene polymer of the present invention comprises: a first step of copolymerizing monomers including a conjugated diene monomer and an aromatic vinyl monomer in a solvent in the presence of a polymerization initiator; a second step of adding a polymerization terminator in an amount that deactivates 10 to 95 mol % of the active polymerization ends contained in the polymerization reaction system when the polymerization conversion rate is 5% or more but less than 95%, thereby deactivating a portion of the active polymerization ends and continuing the polymerization reaction; and a third step of adding a polymerization terminator to terminate the polymerization reaction after the polymerization conversion rate has reached 95% or more.

[0069] The first step is a step of copolymerizing monomers including a conjugated diene monomer and an aromatic vinyl monomer in a solvent in the presence of a polymerization initiator.

[0070] The solvent used in the polymerization is one typically used in solution polymerization, and is not particularly limited as long as it does not inhibit the polymerization reaction. Specific examples of inert solvents 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.

[0071] The polymerization initiator used in the polymerization is not particularly limited as long as it can polymerize monomers including a conjugated diene monomer and an aromatic vinyl monomer to give a conjugated diene polymer chain having an active terminal. Specific examples thereof include polymerization initiators using an organic alkali metal compound, an organic alkaline earth metal compound, a lanthanide metal compound, or the like as a 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, a reaction product of diisopropenylbenzene with butyllithium, and stilbenelithium; dilithiomethane, 1,4 Examples of suitable organic polyvalent lithium compounds include 1,4-dilithiobutane, 1,4-dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, 1,3,5-tris(lithiomethyl)benzene, a reaction product of sec-butyllithium with diisopropenylbenzene, a reaction product of n-butyllithium with 1,3-butadiene and divinylbenzene, and a 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, potassium, and the like. These compounds may also be used in combination with other organometallic compounds. Furthermore, known organic alkali metal compounds disclosed in U.S. Pat. No. 5,708,092, British Patent No. 2,241,239, U.S. Pat. No. 5,527,753, and the like, can also be used.

[0072] 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, more preferably 2 to 15 mmol, per 1000 g of monomer.

[0073] 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, but when copolymerizing a conjugated diene compound and an aromatic vinyl compound, the batch method is preferred because it is easier 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. Of these, the random bonding pattern is preferred. By using a random bonding pattern, the low heat buildup properties of the resulting cross-linked rubber can be further improved.

[0074] Furthermore, when polymerizing monomers including a conjugated diene monomer and an aromatic vinyl monomer, a polar compound may be added to the inert organic solvent in order 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, more preferably 0.01 to 10 mol, per mol of the polymerization initiator. When the amount of the polar compound used is within this range, it is easy to adjust the vinyl bond content in the conjugated diene monomer unit, and problems due to deactivation of the polymerization initiator are unlikely to occur.

[0075] The second step is a step in which, when the polymerization conversion rate is 5% or more but less than 95%, a polymerization terminator is added in an amount that deactivates 10 to 95 mol% of the active polymerization terminals contained in the polymerization reaction system, thereby deactivating a portion of the active polymerization terminals, and then continuing the polymerization reaction.

[0076] That is, in the production method of the present invention, copolymerization (first step) of monomers containing a conjugated diene monomer and an aromatic vinyl monomer is initiated in a solvent in the presence of a polymerization initiator, and then a polymerization terminator is added at a predetermined timing. By adding the polymerization terminator, some of the polymer chains having active polymerization ends contained in the polymerization reaction system are deactivated, while the polymerization reaction continues for the polymer chains having active polymerization ends that have not been deactivated. By employing such a process, the content ratio (A Ｌ ) and the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ ) can be appropriately controlled.

[0077] The polymerization reaction terminator is not particularly limited as long as it can react with the polymerization active terminals and make them inactive in the polymerization reaction, and examples thereof include water and alcohol. Specific examples of alcohols include methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, and 2-methyl-2-propanol, and among these, 1-butanol is preferred. These may be used alone or in combination of two or more.

[0078] Further, examples of other terminators include preferred silicon atom-containing terminators and nitrogen atom-containing terminators, with nitrogen atom-containing terminators being more preferred. Examples of nitrogen atom-containing terminators include N,N-disubstituted aminoalkyl(meth)acrylamides, such as dimethylaminoethylacrylamide, diethylaminoethylacrylamide, dimethylaminopropylacrylamide, diethylaminopropylacrylamide, dimethylaminobutylacrylamide, diethylaminobutylacrylamide, dimethylaminoethylmethacrylamide, diethylaminoethylmethacrylamide, dimethylaminopropylmethacrylamide, diethylaminopropylmethacrylamide, dimethylaminobutylmethacrylamide, and diethylaminobutylmethacrylamide, which are more preferred than nitrogen atom-containing terminators having an N—H bond. Other nitrogen atom-containing terminators include pyrrolidone compounds such as N-phenyl-2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and 1-cyclohexyl-2-pyrrolidone. Examples of silicon atom-containing terminators include siloxane compounds and hydrocarbyloxysilane compounds. Examples of silicon atom-containing terminators include amino group-containing alkoxysilane compounds such as [3-(dimethylamino)propyl]trimethoxysilane, [3-(diethylamino)propyl]trimethoxysilane, [3-(dimethylamino)propyl]triethoxysilane, [3-(diethylamino)propyl]triethoxysilane, [3-(ethylmethylamino)propyl]trimethoxysilane, and [3-(ethylmethylamino)propyl]triethoxysilane. These terminators may be used alone or in combination of two or more.

[0079] The timing for adding the polymerization reaction terminator may be when the polymerization conversion rate is 5% or more but less than 95%, but from the viewpoint of more appropriately controlling the difference ΔA, it is preferably when the polymerization conversion rate is 10 to 85%, more preferably when the polymerization conversion rate is 15 to 75%, and even more preferably when the polymerization conversion rate is 20 to 65%. The polymerization conversion rate is the ratio of actually polymerized monomers to all monomers constituting the finally obtained conjugated diene-based copolymer.

[0080] In the second step, the amount of the polymerization terminator used is an amount that deactivates 10 to 95 mol % of the active polymerization terminals contained in the polymerization reaction system, and from the viewpoint of more appropriately controlling the difference ΔA, it is preferably an amount that deactivates 15 to 95 mol %, more preferably an amount that deactivates 20 to 95 mol %, and even more preferably an amount that deactivates 30 to 95 mol %. The amount of active polymerization terminals deactivated by the addition of the polymerization terminator can usually be determined from the amount (mol %) of the polymerization terminator added relative to the amount of the polymerization initiator.

[0081] In the production method of the present invention, in the first step and the second step, monomers including a conjugated diene monomer and an aromatic vinyl monomer are copolymerized. In this case, with regard to the aromatic vinyl monomer, from the viewpoint of more appropriately controlling the difference ΔA, it is preferable to start polymerization in a state where the entire amount of the aromatic vinyl monomer to be used in the polymerization reaction has been added to the polymerization reaction system before the start of the polymerization reaction.

[0082] Furthermore, with regard to the conjugated diene monomer, from the viewpoint of more appropriately controlling the difference ΔA, when the total amount of the conjugated diene monomer and the aromatic vinyl monomer copolymerizable with the conjugated diene monomer to be used in the polymerization reaction is taken as 100% by weight, it is preferable to start the polymerization in a state where 40 to 70% by weight of the conjugated diene monomer and the aromatic vinyl monomer copolymerizable with the conjugated diene monomer are added to the polymerization reaction system before the start of the polymerization reaction, and it is more preferable to start the polymerization in a state where 45 to 65% by weight of the total amount 100% by weight is added to the polymerization reaction system before the start of the polymerization reaction. In this case, the remainder of the conjugated diene monomer and aromatic vinyl monomer copolymerizable with the conjugated diene monomer used in the polymerization reaction is added after the initiation of the polymerization reaction, and in this case, when the remainder of the conjugated diene monomer and aromatic vinyl monomer copolymerizable with the conjugated diene monomer used in the polymerization reaction is taken as 100 wt%, preferably 5 to 50 wt%, more preferably 7 to 30 wt%, of the conjugated diene monomer and aromatic vinyl monomer copolymerizable with the conjugated diene monomer used in the polymerization reaction to be added after the initiation of the polymerization reaction is taken as 100 wt%, it is preferable to add to the polymerization reaction system preferably 50 to 95 wt%, more preferably 70 to 93 wt%, of the conjugated diene monomer and aromatic vinyl monomer copolymerizable with the conjugated diene monomer used in the polymerization reaction to be added after the initiation of the polymerization reaction is taken as 100 wt%, and then the polymerization reaction is added to the polymerization reaction system after the addition of the polymerization reaction terminator to deactivate a portion of the polymer chains having active polymerization ends.

[0083] The third step is a step of adding a polymerization terminator to terminate the polymerization reaction after the polymerization conversion rate reaches 95% or more. The timing for terminating the polymerization reaction is preferably when the polymerization conversion rate reaches 95 to 100%.

[0084] The polymerization terminator used in the third step is not particularly limited, but the same compounds as those used in the second step can be used, and the same compound as that used in the second step or a different compound can be used.

[0085] Furthermore, in the third step, before adding the polymerization terminator to terminate the polymerization reaction, a coupling agent may be added to the polymerization reaction system to carry out a coupling reaction on the polymer chain having the polymerization active terminal.

[0086] 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.

[0087] The amount of the coupling agent used is not particularly limited, but is preferably 0.01 to 0.50 mol, more preferably 0.03 to 0.30 mol, per 1 mol of the active polymerization terminal that has not been deactivated after the addition of the polymerization terminator in the second step.

[0088] In the production method of the present invention, a modifying agent may be added to the polymerization reaction system before adding a polymerization terminator to terminate the polymerization reaction, thereby introducing a modifying group into the polymer chain having an active polymerization terminal. As the modifying agent, those described above as modifiers for forming a modifying group that can be contained in the conjugated diene-based polymer of the present invention can be used.

[0089] 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 UK's Institute of Petroleum) 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.

[0090] Furthermore, examples of the phenolic 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.

[0091] 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)propionic acid]-1-oxopropyloxy]methyl]-1,3-propanediyl, and a combination of 4,6-bis(octathiomethyl)-o-cresol and didodecyl-3,3'-thiodipropionate.

[0092] 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]3-oxopropyloxy]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]3-bis[[3-(dodecylthio)propionic acid]3-oxopropyloxy]methyl]-1,3-propanediyl.

[0093] <Conjugated Diene Polymer Composition> The conjugated diene polymer composition of the present invention is a composition containing the above-described conjugated diene polymer of the present invention and a filler.

[0094] The conjugated diene polymer composition of the present invention may contain rubber other than the above-mentioned conjugated diene polymer of the present invention. Examples of rubbers other than conjugated diene 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. Among these, natural rubber, polyisoprene rubber, polybutadiene rubber, and solution-polymerized styrene-butadiene copolymer rubber are preferred, and polybutadiene rubber and natural rubber are 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.

[0095] 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, more preferably 50 to 100% by weight, and particularly preferably 75 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, it is possible to achieve sufficiently excellent wet grip performance and handling stability.

[0096] The conjugated diene polymer composition of the present invention preferably contains a resin. Examples of the resin include cyclopentadiene resins, aromatic resins, terpene resins, petroleum resins, and acrylic resins. The resin may be hydrogenated. These may be used alone or in combination of two or more.

[0097] The content of the resin is not particularly limited, but from the viewpoint of improving processability and handling stability while not deteriorating abrasion resistance and the like, it is preferably 3 to 50 parts by weight, and more preferably 5 to 30 parts by weight, per 100 parts by weight of the rubber component.

[0098] The conjugated diene polymer composition of the present invention preferably contains a liquid diene polymer. Examples of the liquid diene polymer include liquid isoprene rubber, liquid butadiene rubber, liquid styrene butadiene rubber, liquid ethylene propylene rubber, liquid nitrile rubber, liquid chloroprene rubber, liquid acrylic rubber, and liquid epichlorohydrin rubber. Among these, liquid isoprene rubber, liquid butadiene rubber, and liquid styrene butadiene rubber are preferred. The main chain or terminal of the liquid diene polymer may be modified with a polar group. These may be used alone or in combination of two or more.

[0099] The weight average molecular weight of the liquid diene polymer is preferably 1,000 or more, more preferably 2,000 or more, and even more preferably 3,000 or more. The weight average molecular weight of the liquid diene polymer is preferably 100,000 or less, more preferably 90,000 or less, and even more preferably 80,000 or less. The weight average molecular weight of the liquid rubber is a standard polystyrene-equivalent value obtained by gel permeation chromatography (GPC) measurement.

[0100] The content of the liquid diene polymer is preferably 1 part by weight or more and less than 100 parts by weight based on 100 parts by weight of the rubber component.

[0101] 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.

[0102] 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 170 m ２ The pH of the silica is preferably 5 to 10.

[0103] As the silica, for example, various commercially available silicas can be used, such as "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.

[0104] 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.

[0105] 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, even more preferably 20 to 130 parts by weight, and particularly preferably 45 to 80 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.

[0106] The conjugated diene polymer composition of the present invention may further contain a silane coupling agent from the viewpoint of further improving wet grip performance and handling stability. The silane coupling agent is not particularly limited, and various silane coupling agents can be used, but 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-[ 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-thiocyanatopropyl triethoxysilane, vinyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 3-trimethoxysilylpropyl methacrylate monosulfide, γ-glycidoxypropyltriethoxysilane, 3-nitropropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-chloropropyltrimethoxysilane. Other examples 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. Furthermore, one or more of these silane coupling agents may 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, per 100 parts by weight of the filler.

[0107] 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 a methylol group. Among these, sulfur is preferably used. The amount of the crosslinking agent to be added 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.

[0108] 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.

[0109] 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 component in the conjugated diene polymer composition.

[0110] Examples of crosslinking activators include higher fatty acids such as stearic acid; zinc oxide; and the like. 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.

[0111] 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 a crosslinking agent and crosslinking accelerator 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 mixed with the thermally unstable components after cooling to 100°C or less, preferably 80°C or less.

[0112] <Rubber Cross-Linked Product> The cross-linked rubber product of the present invention is obtained by cross-linking the conjugated diene polymer composition of the present invention described above. 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, to mold 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 in advance 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.

[0113] Depending on the shape, size, etc. of the cross-linked rubber, the surface may be cross-linked but the interior may not be sufficiently cross-linked, so secondary cross-linking may be carried out by further heating.

[0114] 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.

[0115] The cross-linked rubber product of the present invention obtained in this manner is obtained using the conjugated diene-based polymer of the present invention described above, and therefore is excellent in wet grip performance, handling stability, tensile strength, and elongation. Therefore, by taking advantage of its excellent properties, the cross-linked rubber product of the present invention can be used in a variety of applications, such as, for example, materials for various tire parts such as cap tread, base tread, carcass, sidewall, and bead portion 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 wet grip performance, handling stability, tensile strength, and elongation.

[0116] 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.

[0117] <Content of Styrene Units, Amount of Vinyl Bonds> The content (wt%) of styrene units and the amount (mol%) of vinyl bonds in the conjugated diene monomer units are determined according to JIS K6239:2007. １ It was determined by H-NMR.

[0118] <Mooney Viscosity of Conjugated Diene Polymer> The Mooney viscosity (ML1+4) of the modified conjugated diene polymer was measured in accordance with JIS K6300-1:2013 under the following conditions: Test temperature: 100°C or 125°C Rotor type: L-type Testing machine used: Shimadzu Mooney Viscometer SMV-300J, manufactured by Shimadzu Corporation

[0119] <Total Weight Average Molecular Weight (Mw), Total Molecular Weight Distribution (Mw / Mn), Number of Peaks in Molecular Weight Distribution Curve, Peak-Top Molecular Weight of Each Peak, and Area of ​​Components Constituting Each Peak> Gel permeation chromatography (GPC) using an RI detector was performed on sample solutions containing modified conjugated diene polymers (1) to (17), and molecular weight distribution curves of the modified conjugated diene polymers were obtained. Based on the obtained molecular weight distribution curves of the modified conjugated diene polymers, the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the entire modified conjugated diene polymer were determined. The weight average molecular weight (Mw) and number average molecular weight (Mn) were determined in terms of polystyrene. Specific measurement conditions for GPC were as follows: Measuring instrument: High-performance liquid chromatograph (manufactured by Tosoh Corporation, trade name "HLC-8320") Column: Two polystyrene columns manufactured by Tosoh Corporation, trade name "TSKgel Super HM-H", were connected in series. Detector: Differential refractive index (RI) Eluent: Tetrahydrofuran (Kanto Chemical Co., Ltd., special grade, stabilizer-free) to which 0.9 vol% 2-(ethylamino)ethanol (Fujifilm Wako Chemical Co., Ltd., special grade) was added. Column temperature: 40°C Flow rate: 0.6 mL / min Sample solution concentration: 1.0 mg / mL Sample solution solvent: Tetrahydrofuran (Kanto Chemical Co., Ltd., special grade, stabilizer-free) Sample solution injection volume: 5 μL Molecular weight calculation method: Ten types of standard polystyrenes with known molecular weights were analyzed by GPC, and the common logarithm of the molecular weight was plotted against the retention time of each standard polystyrene. A third-order polynomial approximation equation was calculated from the obtained plot to create a calibration curve. A conjugated diene-based polymer was analyzed by GPC, and the polystyrene-equivalent molecular weight of the conjugated diene-based polymer was determined from the obtained retention time and the calibration curve.Standard polystyrene: F-700, F-288, F-128, F-80, F-40, F-20, F-4, F-2, A-5000, A-2500 (all manufactured by Tosoh Corporation, trade name "TSKgel Standard Polystyrene"). Furthermore, the molecular weight distribution curve of the obtained modified conjugated diene polymer was divided into regions sandwiched between the baseline or minimum values ​​and each having a single maximum value, and the peak area of ​​each divided region was determined. The number of regions having a peak area of ​​1% or more, when the peak area of ​​the entire molecular weight distribution curve of the modified conjugated diene polymer was taken as 100%, was calculated as the number of molecular weight peaks. Furthermore, for the peaks in each divided region (limited to regions having a peak area of ​​1% or more), the peak top molecular weight (the molecular weight showing the maximum value in each region) and peak area ratio were calculated. Of the peaks detected at a peak top molecular weight of 400,000 or less, the peak having the largest area was defined as the low molecular weight peak (LP), and of the remaining peaks excluding the low molecular weight peak (LP) and having a peak top molecular weight exceeding 400,000, the peak having the largest area was defined as the high molecular weight peak (HP).The peak top molecular weights (molecular weight showing the maximum value in each region, MP) and peak area ratios of the low molecular weight peak (LP) and the high molecular weight peak (HP) were then determined.

[0120] <Difference in the content ratio of aromatic vinyl monomer units (difference ΔA=(content ratio of aromatic vinyl monomer units contained in the low molecular weight component (L) (A Ｌ )) - (the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ)))> Sample solutions containing the modified conjugated diene polymers (1) to (17) were subjected to GPC measurement using a UV detector and an RI detector to obtain a UV elution curve u(t) and an RI elution curve c(t) versus elution time t. Here, the UV elution curve u(t) and the RI elution curve c(t) refer to curves obtained excluding the region of molecular weight less than 5,000 and further excluding the peak of the internal standard polystyrene. The concentration increments (dn / dc) of the refractive index of the solutes of the aromatic vinyl monomer and the non-aromatic vinyl monomer (conjugated diene monomer) were set to 0.185 mL / mg and 0.13 mL / mg, respectively, and the extinction coefficients (dA / dc) of the aromatic vinyl monomer and the non-aromatic vinyl monomer (conjugated diene monomer) were set to 1 and 0, respectively, and the content curve a(t) of the aromatic vinyl monomer unit was obtained from the ratio u(t) / c(t) of the UV elution curve to the RI elution curve. When the total area of ​​c(t) was set to 100%, the elution times t5, t50, and t95 at which the integrated area from the shorter elution time reached 5%, 50%, and 95%, respectively, were calculated. The content ratio (A) of the aromatic vinyl monomer unit contained in the high molecular weight component (H) with the shorter elution time was calculated. Ｈ ), and the content ratio of aromatic vinyl monomer units contained in the low molecular weight component (L) having a long elution time (A Ｌ ) were calculated according to the following formulas (1) and (2), respectively. The difference ΔA in the content ratio of the aromatic vinyl monomer unit is calculated as follows: "difference ΔA = (content ratio of the aromatic vinyl monomer unit contained in the low molecular weight component (L) (A)" Ｌ )) - (the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ )))

[0121] GPC measurements using a UV detector and an RI detector were carried out under the following conditions. (GPC apparatus and software) (i) LC apparatus: HLC-8220GPC (manufactured by Tosoh Corporation) (ii) Detector: UV-8220 (manufactured by Tosoh Corporation) and TDA302 (with built-in RI detector, manufactured by Viscotek) connected in series (iii) Analysis software: OmniSEC ver. 5.12 (iv) Measurement conditions GPC column: Plus Pore series Poly Pore 7.5 mm ID x 300 mm (manufactured by Agilent Technologies) x 2 Mobile phase: 25 g of 2-(ethylamino)ethanol (manufactured by Fujifilm Wako Chemical Co., Ltd., special grade) was added to 3 L of tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd., special grade, stabilizer-free). Flow rate: 1 mL / min Column oven temperature: 35°C Detection: Refractive index detector (RID), UV detector RID cell temperature: 35°C UV detection wavelength: 260 nm Sample solution injection volume: 100 μL Standard substance for GPC column calibration: PStQuick Kit-H (manufactured by Tosoh Corporation) Standard substance for calibration of vinyl aromatic monomer content (vinyl aromatic monomer content 100 wt%): F-10 (manufactured by Tosoh Corporation) Standard substance for delay volume correction of UV detector and RI detector: F-10 (manufactured by Tosoh Corporation) (v) Conditions for preparing sample solution Solvent: To 20 mL of tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd., special grade, stabilizer-free), 5 mg of standard polystyrene A5000 (manufactured by Tosoh Corporation) having a molecular weight of 5000 was added 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 with the DF-8020 at a stirring speed of 60 reciprocations per minute at room temperature for 120 minutes. Filtration was carried out using a syringe equipped with a filtration filter. Filtration filter: Millex-LG, pore size 0.45 μm, hydrophilic, PTFE, filter diameter 25 mm (Merck)

[0122] <Ionic Strength Index> A sample solution containing the modified conjugated diene polymers (1) to (17) and an internal standard polystyrene was subjected to GPC measurement using a styrene column and GPC measurement using a cation exchange column, and the ionic strength index was calculated based on the results of these measurements according to the following formula (3): Ionic Strength Index (%) = {1 - (A ＣＸ / B ＣＸ ) × (B ｓｔｙ / A ｓｔｙ )}×100 (3) A ＣＸ B: Peak area of ​​the molecular weight distribution curve of the conjugated diene polymer measured by GPC using a cation exchange column ＣＸ B: Peak area of ​​the internal standard polystyrene peak measured by GPC using a cation exchange column ｓｔｙ A: Peak area of ​​the internal standard polystyrene peak measured by GPC using a styrene column ｓｔｙ : Peak area of ​​the molecular weight distribution curve of the conjugated diene polymer measured by GPC using a styrene column Wherein, A ＣＸ Call A ｓｔｙ In the definition above, the molecular weight distribution curve of the modified conjugated diene polymer refers to a molecular weight distribution curve obtained by excluding the region of molecular weight less than 5,000 from the obtained molecular weight distribution curve and further excluding the peak of the internal standard polystyrene.

[0123] GPC measurements using a styrene-based column were carried out under the following conditions: (GPC apparatus and software) (i) Solution 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: Two Plus Pore series Poly Pore 7.5 mm ID x 300 mm (manufactured by Agilent Technologies) Mobile phase: 25 g of 2-(ethylamino)ethanol (manufactured by Fujifilm Wako Chemical Co., Ltd., special grade) was added to 3 L of tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd., special grade, stabilizer-free). Flow rate: 1 mL / min Column oven temperature: 35°C Detection: Refractive index detector (RID) RID cell temperature: 35°C Sample solution injection volume: 100 μL Standard substance for GPC column calibration: PStQuick Kit-H (Tosoh Corporation) (ix) Sample solution preparation conditions Solvent: To 20 mL of tetrahydrofuran (Kanto Chemical Co., Ltd., special grade, stabilizer-free), 5 mg of standard polystyrene A5000 (Tosoh Corporation) with a molecular weight of 5000 was added 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 with the DF-8020 at a stirring rate of 60 reciprocations per minute at room temperature for 120 minutes. Filtration was performed using a syringe equipped with a filtration filter. Filtration filter: Millex-LG, pore size 0.45 μm, hydrophilic, PTFE, filter diameter 25 mm (manufactured by Merck)

[0124] GPC measurements using a cation exchange column were carried out under the following conditions. The measurement solution used in the GPC measurements using a cation exchange column was the same as the measurement solution used in the GPC measurements using the styrene-based column. (GPC apparatus and software) (i) Solution 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: Inertcil CX (4.6 × 250 mm, manufactured by GL Sciences) x 2 Mobile phase: tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd., special grade, stabilizer-free) Flow rate: 0.7 mL / min Column oven temperature: 35°C Detection: refractive index detector (RID) RID cell temperature: 35°C Sample solution injection amount: 100 μL Standard substance for GPC column calibration: PStQuick Kit-H (manufactured by Tosoh Corporation) (ix) Sample solution preparation conditions Solvent: To 20 mL of tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd., special grade, stabilizer-free), 5 mg of standard polystyrene A5000 (manufactured by Tosoh Corporation) having a molecular weight of 5000 was added 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 with the DF-8020 at a stirring speed of 60 reciprocations per minute at room temperature for 120 minutes. Filtration was carried out using a syringe equipped with a filtration filter. Filtration filter: Millex-LG, pore size 0.45 μm, hydrophilic, PTFE, filter diameter 25 mm (Merck)

[0125] Compound Mooney viscosity (ML １＋４), Processability> The Mooney viscosity (compound Mooney viscosity) of the conjugated diene polymer composition was measured at 130°C in accordance with JIS K6300 (1994). The compound Mooney viscosity measurement results were calculated as an index with the compound Mooney viscosity of an example having a similar aromatic vinyl unit content set to 100, and the processability value was defined as that. Specifically, the results of Comparative Examples 1 to 3 were calculated with the index of Example 1 set to 100, the results of Example 2 and Comparative Examples 4 to 6 were calculated with the index of Example 3 set to 100, the results of Example 4 and Comparative Examples 7 to 9 were calculated with the index of Example 5 set to 100, and the results of Example 6 and Comparative Example 10 were calculated with the index of Example 7 set to 100, and the processability value was defined as that. A higher processability value means that the resulting rubber composition has better processability.

[0126] <Loss tangent (tan δ (0°C), wet grip property> Test specimens in the shape of strips having a width of 1 mm or 2 mm and a length of 40 mm were punched out from the cross-linked rubber sheet and used for testing. The loss tangent (tan δ (0°C)) of the test specimens was measured at a temperature of 0°C using a viscoelasticity measuring device (manufactured by Ueshima Seisakusho Co., Ltd.) under conditions of a frequency of 10 Hz, an initial elongation of 10%, and a strain amplitude of 2.50%. The measurement results of loss tangent (tan δ (0°C)) were calculated using an index with the loss tangent (tan δ (0°C)) of an example having an approximate content of aromatic vinyl units set to 100, and this was taken as the value of wet grip performance. Specifically, the results of Comparative Examples 1 to 3 were calculated using an index with Example 1 set to 100, the results of Example 3 and Comparative Examples 4 to 6 were calculated using an index with Example 2 set to 100, the results of Example 5 and Comparative Examples 7 to 9 were calculated using an index with Example 4 set to 100, and the results of Example 7 and Comparative Example 10 were calculated using an index with Example 6 set to 100, and these were taken as the value of wet grip performance. A higher wet grip performance value means that the obtained cross-linked rubber product has better wet grip properties.

[0127] <Storage Modulus (E'(60°C)), Steering Stability> Test specimens were punched out from the cross-linked rubber sheet into strips having a width of 1 mm or 2 mm and a length of 40 mm, and subjected to testing. The storage modulus (E'(60°C)) of the test specimens was measured at a temperature of 60°C under conditions of a frequency of 10 Hz, an initial elongation of 10%, and a strain amplitude of 1.00% using a viscoelasticity measuring device (manufactured by Ueshima Seisakusho Co., Ltd.). The measurement results of the storage modulus (E'(60°C)) were calculated as an index, with the storage modulus (E'(60°C)) in an example having a similar content of aromatic vinyl units set to 100, and this was used as the value of steering stability. Specifically, the results of Comparative Examples 1 to 3 were calculated using an index with Example 1 set to 100, the results of Example 3 and Comparative Examples 4 to 6 were calculated using an index with Example 2 set to 100, the results of Example 4 and Comparative Examples 7 to 9 were calculated using an index with Example 5 set to 100, and the results of Example 6 and Comparative Example 10 were calculated using an index with Example 7 set to 100, and these were used as values ​​of handling stability. A larger value of handling stability means that the obtained cross-linked rubber product is more excellent in handling stability.

[0128] <Tensile Strength and Elongation> Using a cross-linked rubber sheet, the tensile strength (MPa) and elongation (%) at break were measured under the following conditions in accordance with JIS K6251:2010. The measurement results of tensile strength and elongation were calculated as an index with the tensile strength and elongation of examples having similar aromatic vinyl unit contents set to 100. Specifically, the results of Comparative Examples 1 to 3 were calculated using an index of 100 for Example 1, the results of Example 3 and Comparative Examples 4 to 6 were calculated using an index of 100 for Example 2, the results of Example 5 and Comparative Examples 7 to 9 were calculated using an index of 100 for Example 4, and the results of Example 7 and Comparative Example 10 were calculated using an index of 100 for Example 6. The larger the index values ​​for tensile strength and elongation, the more excellent the strength properties of the resulting cross-linked rubber product. - Test piece preparation method: After preparing a sheet by press crosslinking, punching processing was performed. - Test piece shape: Dumbbell No. 3 - Test piece collection direction: Parallel to the grain direction - Number of test pieces: 3 - Measurement temperature: 23°C - Test speed: 500 mm / min - Testing machine used: TENSOMETER 10k manufactured by ALPHA TECHNOLOGIES - Testing machine capacity: Load cell type 1kN

[0129] Synthesis Example 1 A 20 L autoclave equipped with a stirrer was charged under a nitrogen atmosphere with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 2.34 kg of cyclohexane, 452 g of 1,3-butadiene, 194 g of styrene, 8.02 mL of tetrahydrofuran, and 0.75 mL of ethylene glycol dibutyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 1.98 mmol of n-butyllithium, and polymerization was initiated at 45°C. The temperature was raised from 45°C to 70°C over 80 minutes and then maintained at 70°C. Ten minutes after the start of the polymerization reaction, 239 g of 1,3-butadiene was continuously added over 80 minutes. Furthermore, 90 minutes after the start of the polymerization reaction, 400 g of 1,3-butadiene was continuously added over 80 minutes. When the polymerization conversion reached 49% (95 minutes after the start of the polymerization reaction), 5.80 mmol of normal butyllithium was added. The temperature at this point was raised from 60°C to 70°C over 65 minutes, and the temperature was maintained at 70°C. Thereafter, 200 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion had reached a range of 95% to 100%, 0.39 mmol of silicon tetrachloride was added and the reaction was allowed to proceed for 20 minutes. Thereafter, 11.17 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 20 minutes. Thereafter, 16.76 mmol of normal butyllithium was added and the reaction was allowed to proceed for 20 minutes. Thereafter, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants, respectively, per 100 parts of the modified conjugated diene polymer, to obtain a polymer solution.Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55° C. for 12 hours to obtain a modified conjugated diene polymer (1).

[0130] Synthesis Example 2 A 20 L autoclave equipped with a stirrer was charged with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL) under a nitrogen atmosphere, 2.34 kg of cyclohexane, 512 g of 1,3-butadiene, 220 g of styrene, 8.02 mL of tetrahydrofuran, and 0.65 mL of ethylene glycol dibutyl ether. A small amount of n-butyllithium was added to the autoclave as a scavenger to detoxify impurities that may deactivate the polymerization. Then, 1.98 mmol of n-butyllithium was added, and polymerization was initiated at 45°C. The temperature was raised from 45°C to 70°C over 157 minutes and then maintained at 70°C. Five minutes after the start of the polymerization reaction, 271 g of 1,3-butadiene was continuously added over 80 minutes. Furthermore, 85 minutes after the start of the polymerization reaction, 453 g of 1,3-butadiene was continuously added over 80 minutes. When the polymerization conversion reached 60% (115 minutes after the start of the polymerization reaction), 4.62 mmol of normal butyllithium was added. The temperature at this point was raised from 60°C to 70°C over 42 minutes and maintained at 70°C. Thereafter, 185 minutes after the start of the polymerization reaction, it was confirmed that the polymerization conversion had reached a range of 95% to 100%, and then 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the conjugated diene polymer, respectively, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (2).

[0131] Synthesis Example 3 A 20 L autoclave equipped with a stirrer was charged with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL) under a nitrogen atmosphere, 2.34 kg of cyclohexane, 512 g of 1,3-butadiene, 220 g of styrene, 8.02 mL of tetrahydrofuran, and 0.65 mL of ethylene glycol dibutyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 1.68 mmol of n-butyllithium, and polymerization was initiated at 45°C. The temperature was raised from 45°C to 70°C over 144 minutes and then maintained at 70°C. Five minutes after the start of the polymerization reaction, 271 g of 1,3-butadiene was continuously added over 80 minutes. Furthermore, 85 minutes after the start of the polymerization reaction, 453 g of 1,3-butadiene was continuously added over 80 minutes. When the polymerization conversion reached 51% (102 minutes after the start of the polymerization reaction), 6.72 mmol of normal butyllithium was added. The temperature at this point was raised from 60°C to 70°C over 42 minutes and maintained at 70°C. Then, 185 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion had reached a range of 95% to 100%, 1.68 mmol of N-(3-dimethylaminopropyl)acrylamide was added and the reaction was allowed to proceed for 15 minutes. Then, 6.72 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 15 minutes. Then, 10.08 mmol of normal butyllithium was added and the reaction was allowed to proceed for 15 minutes. Then, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the conjugated diene polymer, respectively, to obtain a polymer solution.Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55° C. for 12 hours to obtain a modified conjugated diene polymer (3).

[0132] Synthesis Example 4 A 20 L autoclave equipped with a stirrer was charged with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL) under a nitrogen atmosphere, 2.34 kg of cyclohexane, 591 g of 1,3-butadiene, 253 g of styrene, 8.02 mL of tetrahydrofuran, and 0.80 mL of ethylene glycol dibutyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 10.90 mmol of n-butyllithium, and polymerization was initiated at 45°C. The temperature was raised from 45°C to 70°C over 80 minutes and then maintained at 70°C. Ten minutes after the start of the polymerization reaction, 312 g of 1,3-butadiene was continuously added over 80 minutes. When the polymerization conversion rate reached 48% (55 minutes after the start of the polymerization reaction), 10.15 mmol of 1-butanol was added. Furthermore, 90 minutes after the start of the polymerization reaction, 523 g of 1,3-butadiene was continuously added over 80 minutes. Thereafter, 320 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion rate had reached a range of 95% to 100%, 0.05 mmol of silicon tetrachloride was added and the reaction was allowed to proceed for 10 minutes. Subsequently, 1.00 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 20 minutes. Subsequently, 1.5 mmol of normal butyllithium was added and the reaction was allowed to proceed for 15 minutes. Subsequently, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants, respectively, per 100 parts of the modified conjugated diene polymer, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (4).

[0133] Synthesis Example 5 A 20 L autoclave equipped with a stirrer was charged under a nitrogen atmosphere with 9.02 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 1.36 kg of cyclohexane, 477.4 g of 1,3-butadiene, 374.7 g of styrene, 8.02 mL of tetrahydrofuran, and 4.48 mL of ethylene glycol diethyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 1.58 mmol of n-butyllithium, and polymerization was initiated at 45°C. The temperature was raised from 45°C to 60°C over 60 minutes and then maintained at 60°C. Five minutes after the start of the polymerization reaction, 233.5 g of 1,3-butadiene was continuously added over 80 minutes. When the polymerization conversion rate reached 49% (68 minutes after the start of the polymerization reaction), 6.32 mmol of normal butyllithium was added. The temperature at this point was raised from 60°C to 70°C over 92 minutes, and the temperature was maintained at 70°C. Furthermore, 85 minutes after the start of the polymerization reaction, 414.4 g of 1,3-butadiene was continuously added over 80 minutes. Thereafter, 215 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion rate had reached a range of 95% to 100%, 11.85 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 15 minutes. Thereafter, 17.77 mmol of normal butyllithium was added and the reaction was allowed to proceed for 10 minutes. Thereafter, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (5).

[0134] Synthesis Example 6 A 20 L autoclave equipped with a stirrer was charged with 9.02 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL) under a nitrogen atmosphere, 1.36 kg of cyclohexane, 477.4 g of 1,3-butadiene, 374.7 g of styrene, 8.02 mL of tetrahydrofuran, and 4.48 mL of ethylene glycol diethyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 1.99 mmol of n-butyllithium, and polymerization was initiated at 45°C. The temperature was raised from 45°C to 60°C over 60 minutes and then maintained at 60°C. Five minutes after the start of the polymerization reaction, 233.5 g of 1,3-butadiene was continuously added over 80 minutes. Furthermore, 85 minutes after the start of the polymerization reaction, 414.4 g of 1,3-butadiene was continuously added over 80 minutes. When the polymerization conversion reached 66% (102 minutes after the start of the polymerization reaction), 5.61 mmol of normal butyllithium was added. The temperature at this point was raised from 60°C to 70°C over 58 minutes, and the temperature was maintained at 70°C. Thereafter, 200 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion had reached a range of 95% to 100%, 11.41 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 15 minutes. Thereafter, 17.11 mmol of normal butyllithium was added and the reaction was allowed to proceed for 10 minutes. Thereafter, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator, to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (6).

[0135] Synthesis Example 7 The atmosphere in a 30 L stainless steel polymerization reactor equipped with a stirrer was replaced with dry nitrogen. Next, 10.2 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 712 g of 1,3-butadiene, 388 g of styrene, 8.02 mL of tetrahydrofuran, and 3.36 mL of ethylene glycol diethyl ether were charged into the polymerization reactor. To preliminarily detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger. 7.87 mmol of piperidine was then added and stirred for 1 minute. An n-hexane solution containing 11.24 mmol of n-butyllithium was then charged into the polymerization reactor, and polymerization was initiated at a stirring speed of 160 rpm and 31°C. 764 g of 1,3-butadiene and 168 g of styrene were continuously added over 90 minutes. Fifteen minutes after the start of polymerization, 9.2 mmol of bis(diethylamino)methylvinylsilane was added. 90 minutes after the start of polymerization, 168 g of 1,3-butadiene was continuously added. Then, 120 minutes after the start of polymerization, 1.25 mmol of tin tetrachloride was added, and the mixture was allowed to react for 15 minutes. Then, 11.1 mmol of N-(3-dimethylaminopropyl)acrylamide was added, and the mixture was allowed to react for 10 minutes. Then, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator, to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (7).

[0136] Synthesis Example 8 A 20 L autoclave equipped with a stirrer was charged with 9.02 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL) under a nitrogen atmosphere, 1.36 kg of cyclohexane, 477.4 g of 1,3-butadiene, 374.7 g of styrene, 8.02 mL of tetrahydrofuran, and 4.48 mL of ethylene glycol diethyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 8.98 mmol of n-butyllithium, and polymerization was initiated at 45°C. The temperature was raised from 45°C to 70°C over 100 minutes and then maintained at 70°C. Five minutes after the start of the polymerization reaction, 233.5 g of 1,3-butadiene was continuously added over 80 minutes. When the polymerization conversion rate reached 47% (30 minutes after the start of the polymerization reaction), 5.47 mmol of 1-butanol was added. Furthermore, 85 minutes after the start of the polymerization reaction, 414.4 g of 1,3-butadiene was continuously added over 80 minutes. Thereafter, 255 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion rate had reached a range of 95% to 100%, 21.68 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was carried out for 15 minutes. Subsequently, 32.52 mmol of normal butyllithium was added and the reaction was carried out for 10 minutes. Subsequently, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (8).

[0137] Synthesis Example 9 A 20 L autoclave equipped with a stirrer was charged with 9.02 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL) under a nitrogen atmosphere, 1.36 kg of cyclohexane, 477.4 g of 1,3-butadiene, 374.7 g of styrene, 8.02 mL of tetrahydrofuran, and 4.48 mL of ethylene glycol diethyl ether. A small amount of n-butyllithium was added to the autoclave as a scavenger to detoxify impurities that may deactivate the polymerization. Then, 6.82 mmol of n-butyllithium was added, and polymerization was initiated at 45°C. The temperature was raised from 45°C to 70°C over 100 minutes and then maintained at 70°C. Five minutes after the start of the polymerization reaction, 233.5 g of 1,3-butadiene was continuously added over 80 minutes. When the polymerization conversion rate reached 50% (37 minutes after the start of the polymerization reaction), 4.70 mmol of 1-butanol was added. Furthermore, 85 minutes after the start of the polymerization reaction, 414.4 g of 1,3-butadiene was continuously added over 80 minutes. Thereafter, 255 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion rate had reached a range of 95% to 100%, 17.27 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 15 minutes. Subsequently, 25.91 mmol of normal butyllithium was added and the reaction was allowed to proceed for 10 minutes. Subsequently, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (9).

[0138] Synthesis Example 10: A 20 L autoclave equipped with a stirrer was charged with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL) under a nitrogen atmosphere, 2.34 kg of cyclohexane, 250 g of 1,3-butadiene, 466 g of styrene, 8.02 mL of tetrahydrofuran, and 20.86 mL of ethylene glycol diethyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger. Then, 1.94 mmol of n-butyllithium was added, and polymerization was initiated at 35°C. The temperature was raised from 35°C to 60°C over 60 minutes and then maintained at 60°C. After the polymerization reaction began, 150 g of 1,3-butadiene was continuously added over 75 minutes. When the polymerization conversion reached 56% (70 minutes after the start of the polymerization reaction), 5.00 mmol of n-butyllithium was added. The temperature was raised from 60°C to 70°C over 100 minutes. Furthermore, 75 minutes after the start of the polymerization reaction, 300 g of 1,3-butadiene was continuously added over 75 minutes. Thereafter, 170 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion rate had reached a range of 95% to 100%, 0.35 mmol of silicon tetrachloride was added and the reaction was allowed to proceed for 10 minutes. Thereafter, 4.94 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 15 minutes. Thereafter, 7.40 mmol of normal butyllithium was added and the reaction was allowed to proceed for 15 minutes. Thereafter, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution.Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55° C. for 12 hours to obtain a modified conjugated diene polymer (10).

[0139] Synthesis Example 11 A 20 L autoclave equipped with a stirrer was charged under a nitrogen atmosphere with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 2.34 kg of cyclohexane, 369.6 g of 1,3-butadiene, 688.9 g of styrene, 8.02 mL of tetrahydrofuran, and 18.54 mL of ethylene glycol diethyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 1.81 mmol of n-butyllithium, and polymerization was initiated at 40°C. The temperature was raised from 40°C to 60°C over 60 minutes and then maintained at 60°C. After the polymerization reaction began, 221.8 g of 1,3-butadiene was continuously added over 75 minutes. When the polymerization conversion reached 53% (60 minutes after the start of the polymerization reaction), 5.44 mmol of normal butyllithium was added. The temperature was raised from 60°C to 70°C over 100 minutes. Furthermore, 75 minutes after the start of the polymerization reaction, 443.5 g of 1,3-butadiene was continuously added over 75 minutes. Thereafter, 170 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion had reached a range of 95% to 100%, 0.36 mmol of silicon tetrachloride was added and the reaction was allowed to proceed for 10 minutes. Subsequently, 8.71 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 15 minutes. Subsequently, 13.07 mmol of normal butyllithium was added and the reaction was allowed to proceed for 15 minutes. Subsequently, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution.Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55° C. for 12 hours to obtain a modified conjugated diene polymer (11).

[0140] Synthesis Example 12 The atmosphere in a 20 L stainless steel polymerization reactor equipped with a stirrer was replaced with dry nitrogen. Next, 10.2 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 357 g of 1,3-butadiene, 244 g of styrene, 11.25 mL of tetrahydrofuran, and 10.94 mL of ethylene glycol diethyl ether were charged into the polymerization reactor. Next, an n-hexane solution containing 1.60 mmol of n-butyllithium was charged into the polymerization reactor, and the mixture was stirred at a stirring speed of 130 rpm and an internal temperature of 65°C. While continuously feeding 238 g of 1,3-butadiene and 162 g of styrene to the mixture, the mixture was stirred for an additional 4 hours under the above conditions, to obtain a polymerization solution. Next, 0.19 mmol of silicon tetrachloride was added to the resulting polymerization solution and stirred for 15 minutes. Then, 0.36 mmol of dimethylaminopropylacrylamide was added and stirred for 15 minutes. Then, 20 mL of a hexane solution containing 0.81 mL of methanol was added, and the polymerization solution was stirred for an additional 5 minutes. To this solution, 4.5 g of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM), 2.3 g of pentaerythrityl tetrakis(3-laurylthiopropionate) (Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D), and 375 g of extender oil (ENEOS Corporation, trade name: Process NC140) were added to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55° C. for 12 hours to obtain a modified conjugated diene polymer (12).

[0141] Synthesis Example 13 A 20 L autoclave equipped with a stirrer was charged under a nitrogen atmosphere with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 2.34 kg of cyclohexane, 369.6 g of 1,3-butadiene, 688.9 g of styrene, 8.02 mL of tetrahydrofuran, and 18.5 mL of ethylene glycol diethyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 10.51 mmol of n-butyllithium, and polymerization was initiated at 35°C. The temperature was raised from 35°C to 70°C over 90 minutes and then maintained at 70°C. After the initiation of the polymerization reaction, 221.8 g of 1,3-butadiene was continuously added over 75 minutes. When the polymerization conversion reached 63% (35 minutes after the start of the polymerization reaction), 7.57 mmol of 1-butanol was added. Furthermore, 75 minutes after the start of the polymerization reaction, 443.5 g of 1,3-butadiene was continuously added over 75 minutes. Thereafter, 240 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion had reached a range of 95% to 100%, 0.11 mmol of silicon tetrachloride was added and the reaction was allowed to proceed for 10 minutes. Next, 15.77 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 15 minutes. Thereafter, 23.7 mmol of normal butyllithium was added and the reaction was allowed to proceed for 15 minutes. Thereafter, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (13).

[0142] Synthesis Example 14 A 20 L autoclave equipped with a stirrer was charged with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL) under a nitrogen atmosphere, 2.34 kg of cyclohexane, 369.6 g of 1,3-butadiene, 688.9 g of styrene, 8.02 mL of tetrahydrofuran, and 18.5 mL of ethylene glycol diethyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 7.09 mmol of n-butyllithium, and polymerization was initiated at 35°C. The temperature was raised from 35°C to 70°C over 90 minutes and then maintained at 70°C. After the initiation of the polymerization reaction, 119 g of 1,3-butadiene was continuously added over 40 minutes. When the polymerization conversion reached 51% (25 minutes after the start of the polymerization reaction), 4.32 mmol of 1-butanol was added. Furthermore, 40 minutes after the start of the polymerization reaction, 546.3 g of 1,3-butadiene was continuously added over 160 minutes. Thereafter, 240 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion had reached a range of 95% to 100%, 0.07 mmol of silicon tetrachloride was added and the reaction was allowed to proceed for 10 minutes. Next, 10.64 mmol of [3-(diethylamino)propyl]trimethoxysilane was added and the reaction was allowed to proceed for 15 minutes. Thereafter, 15.96 mmol of normal butyllithium was added and the reaction was allowed to proceed for 15 minutes. Thereafter, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.80 parts and 0.40 parts of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (14).

[0143] Synthesis Example 15 A 20 L autoclave equipped with a stirrer was charged under a nitrogen atmosphere with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 2.34 kg of cyclohexane, 427.0 g of 1,3-butadiene, 702.0 g of styrene, 8.14 mL of tetrahydrofuran, 0.622 mL of ethylene glycol diethyl ether, and 1.309 mL of ethylene glycol dibutyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added to the autoclave as a scavenger, followed by the addition of 6.31 mmol of n-butyllithium, and polymerization was initiated at 40°C. The temperature was raised from 40°C to 65°C over 30 minutes and then maintained at 65°C. After the initiation of the polymerization reaction, 604 g of 1,3-butadiene was continuously added over 90 minutes. Furthermore, 90 minutes after the start of the polymerization reaction, 67.0 g of 1,3-butadiene was continuously added over 40 minutes. Then, 165 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion rate had reached 95% to 100%, 1.28 mmol of 1,6-bis(trichlorosilyl)hexane was added. After allowing the reaction to proceed for 15 minutes, 3.61 mmol of N-(3-dimethylaminopropyl)acrylamide was added. Subsequently, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene polymer. To this solution, 0.56 parts and 25.0 parts of Irganox 1520L (manufactured by BASF) and extender oil (manufactured by ENEOS Corporation, product name: Process NC140) were added as antioxidants, respectively, per 100 parts of the modified conjugated diene polymer, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55° C. for 12 hours to obtain a modified conjugated diene polymer (15).

[0144] Synthesis Example 16 A 20 L autoclave equipped with a stirrer was charged under a nitrogen atmosphere with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 2.34 kg of cyclohexane, 427.0 g of 1,3-butadiene, 702.0 g of styrene, 8.14 mL of tetrahydrofuran, 0.622 mL of ethylene glycol diethyl ether, and 1.309 mL of ethylene glycol dibutyl ether. A small amount of n-butyllithium was added to the autoclave as a scavenger to detoxify impurities that may deactivate the polymerization. Then, 6.31 mmol of n-butyllithium was added, and polymerization was initiated at 40°C. The temperature was raised from 40°C to 65°C over 30 minutes and then maintained at 65°C. After the initiation of the polymerization reaction, 604 g of 1,3-butadiene was continuously added over 90 minutes. When the polymerization conversion reached 23% (28 minutes after the start of the polymerization reaction), 1.9 mmol of N-(3-dimethylaminopropyl)acrylamide was added. Furthermore, 90 minutes after the start of the polymerization reaction, 67.0 g of 1,3-butadiene was continuously added over 40 minutes. Thereafter, 165 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion had reached a range of 95% to 100%, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator to obtain a solution containing a modified conjugated diene polymer. To this solution, 0.56 parts and 25.0 parts of Irganox 1520L (manufactured by BASF) and extender oil (manufactured by ENEOS Corporation, trade name: Process NC140) were added as antioxidants, respectively, relative to 100 parts of the modified conjugated diene polymer, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the solution was further dried under reduced pressure at 55° C. for 12 hours to obtain a modified conjugated diene polymer (16).

[0145] Synthesis Example 17 A 20 L autoclave equipped with a stirrer was charged under a nitrogen atmosphere with 8.16 kg of industrial hexane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Hexane (general product), density 0.68 g / mL), 2.34 kg of cyclohexane, 427.0 g of 1,3-butadiene, 702.0 g of styrene, 8.14 mL of tetrahydrofuran, 0.622 mL of ethylene glycol diethyl ether, and 1.309 mL of ethylene glycol dibutyl ether. To detoxify impurities that may deactivate the polymerization, a small amount of n-butyllithium was added as a scavenger to the autoclave. Then, 6.31 mmol of piperidine and 6.31 mmol of n-butyllithium were added, and polymerization was initiated at 40°C. The temperature was raised from 40°C to 65°C over 30 minutes and then maintained at 65°C. After the initiation of the polymerization reaction, 604 g of 1,3-butadiene was continuously added over 90 minutes. Six minutes after the start of the polymerization reaction, 2.26 mmol of bis(diethylamino)methylvinylsilane was added. When the polymerization conversion reached 28% (28 minutes after the start of the polymerization reaction), 1.9 mmol of N-(3-dimethylaminopropyl)acrylamide was added. Furthermore, 90 minutes after the start of the polymerization reaction, 67.0 g of 1,3-butadiene was continuously added over 40 minutes. Thereafter, 165 minutes after the start of the polymerization reaction, after confirming that the polymerization conversion had reached a range of 95% to 100%, 4.73 mmol of N-(3-dimethylaminopropyl)acrylamide was added. Thereafter, 1.5 equivalents of methanol relative to the total amount of lithium in the autoclave were added as a polymerization terminator, to obtain a solution containing a modified conjugated diene-based polymer. To this solution, 0.56 parts and 25.0 parts of Irganox 1520L (manufactured by BASF) and extender oil (manufactured by ENEOS Corporation, trade name: Process NC140) were added as antioxidants relative to 100 parts of the modified conjugated diene polymer, respectively, to obtain a polymer solution. Most of the volatile matter in the obtained polymerization solution was evaporated at room temperature for 24 hours, and the resulting solution was further dried under reduced pressure at 55°C for 12 hours to obtain a modified conjugated diene polymer (17).

[0146] Table 1 shows the properties of the modified conjugated diene polymers (1) to (17) obtained in Synthesis Examples 1 to 17.

[0147]

[0148] [Preparation of Rubber Compositions; Example 1, Comparative Examples 1-3] Rubber compositions were prepared using the modified conjugated diene polymers (1)-(4) obtained in Synthesis Examples 1-4 according to the following method. That is, in a 250 mL Labo Plastomill, the modified conjugated diene polymer was masticated for 30 seconds, and then the components shown as Compounding Ingredient 1 in Table 2 were added in the proportions shown in Table 2. After kneading for 1 minute 30 seconds, the components shown as Compounding Ingredient 2 in Table 2 were added in the proportions shown in Table 2. After kneading for an additional 2 minutes 30 seconds or more, the temperature was maintained for 1 minute after reaching 150°C, and the rubber composition after primary kneading was then released from the Labo Plastomill. Next, a temperature of 110°C was set in the 250 mL Labo Plastomill, and the rubber composition after primary kneading was kneaded for 3 minutes, after which the rubber composition after secondary kneading was released from the Labo Plastomill. Next, the rubber composition after the secondary kneading was wound around an open roll set at 50°C, and each component shown as a vulcanization component in Table 2 was added in the blending ratio shown in Table 2, and these were kneaded to obtain a sheet-like uncrosslinked rubber composition. The compound Mooney viscosity (ML1+4) of the obtained uncrosslinked rubber composition was evaluated according to the above-mentioned method. The results are shown in Table 3.

[0149] Furthermore, the uncrosslinked rubber composition obtained above was heated at 160°C for 30 to 35 minutes to crosslink it, thereby obtaining a cross-linked rubber sheet. The obtained cross-linked rubber sheet was evaluated for wet grip performance, handling stability, tensile strength, and elongation according to the methods described above. The results are shown in Table 3.

[0150] [Preparation of Rubber Compositions; Examples 2 to 7, Comparative Examples 4 to 10] Rubber compositions were prepared using the modified conjugated diene polymers (5) to (17) obtained in Synthesis Examples 5 to 17 according to the following method. That is, in a 250 mL Labo Plastomill, the modified conjugated diene polymer was masticated for 30 seconds. Next, the components shown as Compounding Ingredient 1 in Table 2 were added in the proportions shown in Table 2 and kneaded for 1 minute 30 seconds. After that, the components shown as Compounding Ingredient 2 in Table 2 were added in the proportions shown in Table 2 and kneaded for an additional 1 minute 30 seconds or more. After the temperature reached 150°C and kneading for an additional 1 minute 30 seconds, the rubber composition after primary kneading was released from the Labo Plastomill. Next, a temperature of 110°C was set in a 250 mL Labo Plastomill, and the rubber composition after primary kneading was kneaded for 3 minutes. After that, the rubber composition after secondary kneading was released from the Labo Plastomill. Next, the rubber composition after the secondary kneading was wound around an open roll set at 50°C, and each component shown as a vulcanization component in Table 2 was added in the blending ratio shown in Table 2, and these were kneaded to obtain a sheet-like uncrosslinked rubber composition. The compound Mooney viscosity (ML1+4) of the obtained uncrosslinked rubber composition was evaluated according to the above-mentioned method. The results are shown in Table 3.

[0151] Furthermore, the uncrosslinked rubber composition obtained above was heated at 160°C for 20 to 25 minutes to crosslink it, thereby obtaining a cross-linked rubber sheet. The obtained cross-linked rubber sheet was evaluated for wet grip performance, handling stability, tensile strength, and elongation according to the methods described above. The results are shown in Table 3.

[0152] The materials shown in Table 2 are as follows: BR: butadiene rubber (manufactured by Nippon Zeon Corporation, "Nipol BR1220") Silica: manufactured by Rhodia, trade name "Zeosil 1165MP" Oil: manufactured by Nippon Oil Corporation, trade name "Aromax T-DAE" Silane coupling agent 1: bis(3-(triethoxysilyl)propyl)tetrasulfide, manufactured by Evonik, trade name "Si69 (registered trademark)" Silane coupling agent 2: bis(3-(triethoxysilyl)propyl)disulfide, manufactured by Evonik, trade name "Si75 (registered trademark)" Zinc oxide: manufactured by Seido Chemical Industry Co., Ltd., trade name "Zinc Oxide Type 2" Stearic acid: manufactured by NOF Corporation, trade name "Beads Stearic Acid Tsubaki" Antioxidant: 6PPD, N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name "Nocrac 6C") Sulfur: manufactured by Tsurumi Chemical Co., Ltd., trade name "Sulfur 325 Mesh" Vulcanization accelerator (1): N-cyclohexyl-2-benzothiazylsulfenamine (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name "Noccela CZ-G") Vulcanization accelerator (2): diphenylguanidine (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name "Noccela D")

[0153]

[0154] As is clear from Tables 1 to 3, the content ratio (A) of the aromatic vinyl monomer unit contained in the low molecular weight component (L) constituting the conjugated diene polymer Ｌ ) and the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ ) and the difference ΔA "Difference ΔA = content ratio of aromatic vinyl monomer unit (A Ｌ )-aromatic vinyl monomer unit content (A Ｈ It can be confirmed that a conjugated diene copolymer having a ratio of 2% by weight or more of "(R)-2-(H ...

Claims

1. A conjugated diene polymer containing conjugated diene monomer units and aromatic vinyl monomer units, The content ratio (A) of aromatic vinyl monomer units contained in the low molecular weight component (L) that constitutes the conjugated diene polymer. Ｌ ) and the content ratio of aromatic vinyl monomer units contained in the high molecular weight component (H) (A Ｈ ) Difference ΔA "Difference ΔA = Content ratio of aromatic vinyl monomer units (A Ｌ ) - Content ratio of aromatic vinyl monomer units (A Ｈ A conjugated diene copolymer having 2% by weight or more of )

2. The number of peaks in the molecular weight distribution curve obtained by gel permeation chromatography is two or more. The peak top molecular weight of the low molecular weight peak (LP) is between 80,000 and 200,000. The conjugated diene polymer according to claim 1, wherein the ionic strength is 70% or less.

3. The conjugated diene polymer according to claim 2, wherein the peak top molecular weight of the low molecular weight peak (LP) is 100,000 to 190,000.

4. The conjugated diene polymer according to claim 2, wherein the proportion of polymer components constituting the low molecular weight peak (LP) is 10 to 65% by weight.

5. The conjugated diene polymer according to claim 2, wherein the overall weight-average molecular weight (Mw) is 300,000 to 900,000.

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

7. A rubber crosslinked product obtained by crosslinking the conjugated diene polymer composition described in claim 6.

8. A tire comprising the rubber crosslinking material described in claim 7.

9. A method for producing a conjugated diene polymer according to any one of claims 1 to 5, A first step involves copolymerizing a monomer containing a conjugated diene monomer and an aromatic vinyl monomer in a solvent in the presence of a polymerization initiator. In the second step, at a stage where the polymerization conversion rate is 5% or more but less than 95%, a polymerization reaction arresting agent is added in an amount that inactivates 10 to 95 mol% of the polymerization active ends contained in the polymerization reaction system, thereby inactivating a portion of the polymerization active ends, and then the polymerization reaction is continued. A method for producing a conjugated diene polymer, comprising a third step of adding a polymerization reaction arresting agent to stop the polymerization reaction after the polymerization conversion rate reaches 95% or more.

10. A method for producing a conjugated diene polymer according to claim 9, wherein the entire amount of aromatic vinyl monomers used in the polymerization reaction is added to the polymerization reaction system before the start of the polymerization reaction.

11. A method for producing a conjugated diene polymer according to claim 9, wherein, when the total amount of the conjugated diene monomer used in the polymerization reaction and the aromatic vinyl monomer copolymerizable with the conjugated diene monomer is 100% by weight, the conjugated diene monomer and the aromatic vinyl monomer copolymerizable with the conjugated diene monomer together amount to 40 to 70% by weight and are added to the polymerization reaction system before the start of the polymerization reaction.

12. A method for producing a conjugated diene polymer according to claim 9, wherein the amount of polymerization reaction terminating agent added in the second step is such that 20 to 95 mol% of the polymerization active ends contained in the polymerization reaction system are deactivated.

13. A method for producing a conjugated diene polymer according to claim 9, wherein the timing of adding the polymerization reaction termination agent in the second step is at a stage where the polymerization conversion rate is 15 to 75%.