JP6816919B2 - Rubber composition and tires - Google Patents

Description

The present invention relates to a rubber composition having more highly compatible wet grip, low heat generation and wear resistance, and a tire using the same.

In recent years, due to the social demand for reducing the load on the global environment, the demand for fuel efficiency and long life of automobiles is becoming more severe. In order to meet such demands, it is required to reduce rolling resistance and improve wear resistance in terms of tire performance.
As a method for reducing the rolling resistance of a tire, in addition to a method for optimizing the tire structure, it is the most common method to improve low heat generation by using a material having less heat generation as a rubber composition. ing. As an example of this method, a rubber composition in which silica is blended with a rubber component containing a block copolymer and a diene-based rubber and a terminal-modified diene-based rubber for silica which are incompatible with each other has been proposed (Patented). Reference 1).

Japanese Unexamined Patent Publication No. 2012-172000

The rubber composition described in Patent Document 1 can improve low rolling resistance and wear resistance. However, it is required to improve tire performance at an even higher level. An object of the present invention is to provide a rubber composition capable of achieving both wet grip property, low heat generation property and wear resistance to a higher degree.

The gist of the present invention is as follows.
[1] A rubber component A containing a natural rubber and a modified conjugated diene (co) polymer having a glass transition temperature of −50 ° C. or lower, a rubber component B having a glass transition temperature of −35 ° C. or higher, and a reinforcing filler. The modified conjugated diene (co) polymer is a functional group in the vicinity of the silanol group and the silanol group at the molecular terminal of the conjugated diene (co) polymer, and the silanol group and the reinforcement thereof. It has a functional group that promotes the reaction with the sex filler, and two peaks based on each of the rubber component A and the rubber component B are observed in the temperature dispersion curve of tan δ by the dynamic viscoelasticity test. A rubber composition characterized by the above.
[2] The rubber composition according to [1], wherein the rubber component A is contained in an amount of 50% by mass or more based on the total mass of the rubber component A and the rubber component B.
[3] The rubber composition according to [1] or [2], wherein the ratio of the natural rubber to the rubber component A is 10% by mass or more and 80% by mass or less based on the total mass of the rubber component A.
[4] A tire containing the rubber composition according to any one of [1] to [3].

According to the present invention, it is possible to provide a rubber composition having more highly compatible wet grip property, low heat generation property and wear resistance.

[Rubber composition]
The rubber composition according to the embodiment of the present invention comprises a rubber component A containing natural rubber and a modified conjugated diene (co) polymer having a glass transition temperature of −50 ° C. or lower, and a rubber component having a glass transition temperature of −35 ° C. or higher. B and a reinforcing filler are blended, and the modified conjugated diene (co) polymer has a silanol group and a functional group in the vicinity of the silanol group at the molecular end of the conjugated diene (co) polymer. It has a silanol group and a functional group that promotes the reaction of the reinforcing filler, and in the temperature dispersion curve of tan δ by the dynamic viscoelasticity test, the rubber component A and the rubber component B It is characterized in that two peaks based on each are observed.
The temperature dispersion curve of the rubber component tan δ was obtained by using a viscoelasticity tester ARES manufactured by Leometrics Co., Ltd., with a strain of 0.1%, a frequency of 45 Hz, a measurement temperature range of 65 ° C. to -100 ° C., and a temperature rise. It can be measured at a speed of 1 ° C./min.

[Rubber component A]
The rubber component A applicable to the rubber composition according to the present embodiment contains natural rubber and a modified conjugated diene (co) polymer having a glass transition temperature of −50 ° C. or lower.
The ratio of natural rubber in the rubber component A is preferably 10% by mass or more and 80% by mass or less, and more preferably 40% by mass or more and 60% by mass or less based on the total mass of the rubber component A. When the ratio of natural rubber in the rubber component A is in the above range, good low heat generation can be obtained.
By including natural rubber in the rubber component A, it is possible to improve the wear resistance of the tire formed by using the rubber composition.
Among the rubber components A, the glass transition temperature of the modified conjugated diene (co) polymer is −50 ° C. or lower, preferably −60 ° C. or lower. Further, it is preferable that the glass transition temperature of the rubber component A is set lower than the glass transition temperature of the rubber component B described later.
Since the rubber component A contains a modified conjugated diene (co) polymer, when silica is used as the reinforcing filler described later, the dispersibility of the silica in the rubber component A is enhanced. , It is dispersed in the rubber component A having a relatively low glass transition point. As a result, the increase in tan δ at 60 ° C. caused by blending silica can be suppressed, and the rolling performance of the tire obtained by using the rubber composition can be improved.
Further, it is known that the glass transition temperature rises as the amount of styrene and vinyl contained in the rubber component increases. It is considered that the amount of styrene contributes more to the increase in the glass transition temperature than the amount of vinyl. Therefore, in this embodiment, an index of (styrene amount + 1/2 vinyl amount) is used.
Based on the above viewpoint, the (styrene amount + 1/2 vinyl amount) of the modified conjugated diene (co) polymer applicable to the rubber composition according to the present embodiment is preferably 35% by mass or less, preferably 20% by mass. More preferably, it is less than%. When the amount of styrene + 1/2 vinyl of the modified conjugated diene (co) polymer is 35% by mass or less, the glass transition temperature of the modified conjugated diene (co) polymer can be set to −50 ° C. or less.
Further, if it has the above-mentioned properties, the rubber component A shows a peak at a temperature different from that of the rubber component B described later in the temperature dispersion curve of tan δ of the rubber composition. Further, since the rubber component A contains the modified conjugated diene (co) polymer, the reinforcing filler is unevenly distributed in the modified conjugated diene (co) polymer in the rubber component A, and is satisfactorily distributed in the rubber component A. Can be dispersed.
In the rubber composition according to the present embodiment, the rubber component A is preferably contained in an amount of 50% by mass or more, more preferably 60% by mass or more, based on the total mass of the rubber component A and the rubber component B. More preferably, it is 80% by mass or more. From the viewpoint of maintaining the wear resistance of the rubber composition, the upper limit of the ratio of the rubber component A is 95% by mass.

<Modified conjugated diene (co) polymer with glass transition temperature of -50 ° C or less>
Examples of the modified conjugated diene (co) polymer having a glass transition temperature of −50 ° C. or lower that can be used for the rubber component A of the rubber composition according to the present embodiment described above include the following.
That is, a characteristic group that produces a silanol group by hydrolysis is applied to the active site of the conjugated diene (co) polymer having an active site, and (i) an addition reaction or a substitution reaction is carried out at the active site in the vicinity of the characteristic group. A functional group that binds the organic silane compound to the conjugated diene (co) polymer and promotes the reaction between the silanol group and the reinforcing filler after the reaction, or (ii) the silanol group and the reinforcing filler. A modification reaction step of reacting an organic silane compound having a functional group that promotes the reaction with, a hydrolysis step performed after the modification reaction step is completed, and preferably a condensation reaction further carried out in the presence of a condensation accelerator. It is a (co) polymer produced by going through a reaction step.
In the present embodiment, it is preferable that the characteristic group that produces a silanol group by the hydrolysis is an alkoxysilane group, and 10% or more of the characteristic group produces a silanol group by the hydrolysis.
In the present invention, what is described as a conjugated diene (co) polymer includes a conjugated diene polymer and a conjugated diene copolymer.

The characteristic group that produces a silanol group by the hydrolysis needs to become a silanol group by the reaction when reacting with a reinforcing filler, particularly silica, but if it is a silanol group from the beginning, the reactivity with silica is It becomes higher, the dispersibility of silica in the rubber composition is improved, and the low heat generation property of the rubber composition is improved, which is a great effect. Further, when the characteristic group that produces a silanol group by hydrolysis is an alkoxy group, a volatile organic compound (VOC, particularly alcohol) is generated, but a silanol group is not generated, which is preferable in terms of working environment.

In the present invention, "the functional group exists in the vicinity of the characteristic group that produces a silanol group" means that the functional group preferably has 1 to 20 carbon atoms from the characteristic group among the organic silane compounds. Within the range (which may be via a silicon atom), more preferably within the range of 1 to 15 carbon atoms (which may be via a silicon atom), and even more preferably within the range of 1 to 12 carbon atoms (which may be via a silicon atom). In the range (may be via silicon atom), particularly preferably in the range of 1 to 10 in carbon number (may be via silicon atom), and more particularly preferably in the range of 1 to 5 in carbon number (via silicon atom). It means that it exists in (also good).
The "neighborhood" in the case of "a silanol group and a functional group in the vicinity of the silanol group" is also synonymous with the above.

In the present embodiment, a characteristic group that produces a silanol group by the hydrolysis and an organic silane compound and the conjugated diene (co) weight by (i) addition or substitution reaction to the active site in the vicinity of the characteristic group. An organic having a functional group that binds to the coalescence and promotes the reaction between the silanol group and the reinforcing filler after the reaction, or (ii) a functional group that promotes the reaction between the silanol group and the reinforcing filler. The silane compound is preferably an organic silane compound represented by the following general formula (1) or the following general formula (2).

ここで、Ｒ^１は単結合又は炭素数１〜２０の二価の炭化水素基；Ｒ^２及びＲ^３はそれぞれ独立に水素原子又は炭素数１〜２０の一価の炭化水素基；−ＯＬ^１は加水分解によりＳｉと共にシラノール基を生成する加水分解性官能基；Ａ^１は前記活性部位に付加もしくは置換反応を行う事によって前記有機シラン化合物と前記共役ジエン（共）重合体とを結合させ、且つ該反応後に前記シラノール基と前記補強性充填材との反応を促進する官能基であり、ｍは１〜１０の整数である。なお、「Ｒ^１は単結合」とは、例えば、上記一般式（１）において、Ａ^１とＳｉが直接単結合にて結合することをいう。以下、Ｒ^４、Ｒ^５、Ｒ^６及びＡ^４の場合も同様である。

Here, R ¹ is a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms; R ² and R ³ are independently hydrogen atoms or a monovalent hydrocarbon group having 1 to 20 carbon atoms; -OL ¹ the hydrolyzable functional group forms a silanol group with Si through hydrolysis; a ¹ is coupled with said organic silane compound and the conjugated diene (co) polymer by performing an addition or substitution reaction with the active site, Moreover, it is a functional group that promotes the reaction between the silanol group and the reinforcing filler after the reaction, and m is an integer of 1 to 10. In addition, "R ¹ is a single bond" means, for example, in the above general formula (1) that A ¹ and Si are directly bonded by a single bond. Hereinafter, the same applies to the cases of R ⁴ , R ⁵ , R ⁶ and A ⁴ .

ここで、Ｒ^４は単結合又は炭素数１〜２０の炭化水素基；Ｒ^５及びＲ^６はそれぞれ独立に単結合、水素原子又は炭素数１〜２０の炭化水素基；−ＯＬ^２は加水分解によりＳｉと共にシラノール基を生成する加水分解性官能基；Ａ^２は前記活性部位と反応する官能基又は前記活性部位に付加もしくは置換反応を行う事によって前記有機シラン化合物と前記共役ジエン（共）重合体とを結合させる官能基；Ｂ及びＤはそれぞれ独立に前記シラノール基と前記補強性充填材との反応を促進する官能基を少なくとも一つ含む基であり；ｐ及びｑはそれぞれ独立に０〜５の整数であり、（ｐ＋ｑ）が１以上であり、ｎは１〜１０の整数である。

Here, R ⁴ is a single bond or a hydrocarbon group having 1 to 20 carbon atoms; R ⁵ and R ⁶ are independently single bonds, and a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms; -OL ² is hydrolyzed. Hydrophilic functional group that produces a silanol group together with Si; A ² is a functional group that reacts with the active site or a conjugated diene (co) weight of the organic silane compound by adding or substituting the active site. Functional groups that bind to the coalescence; B and D are groups that each independently contain at least one functional group that promotes the reaction of the silanol group with the reinforcing filler; p and q are independently 0 to 0, respectively. It is an integer of 5, (p + q) is 1 or more, and n is an integer of 1 to 10.

Here, as the hydrolyzable functional group that produces a silanol group together with Si by hydrolysis, for example, an alkoxy group having 1 to 20 carbon atoms, a phenoxy group, a benzyloxy group, −OM _{(1 / x),} or the like is preferable. Can be mentioned. Of these, an alkoxy group having 1 to 20 carbon atoms is more preferable, and an alkoxy group having 1 to 12 carbon atoms is particularly preferable. Specific examples of the alkoxy group having 1 to 20 carbon atoms include a metosiki group, an etoshiki group, a propoxy group, an isopropoxy group, an n-butoxy group, and a tert-butoxy group.
In the above formula-OM _{(1 / x)} , M is a Group 1 element excluding hydrogen (ie, an alkali metal); a Group 2-12 element; a Group 13 element excluding boron; an element excluding carbon and silicon. Group 14 element; a metal atom selected from Group 15 elements and rare earth elements excluding nitrogen, phosphorus and arsenic, and x is the valence of the metal atom. Group 2 elements are Be, Mg and alkaline earth metals. Among these metal atoms, alkali metals, Mg, alkaline earth metals, Sn, Al, Ti and Fe are more preferable, and Li, Na, K, Mg, Ca, Ba, Sn, Al, Ti and Fe are particularly preferable. ..

In the general formula (1), the organic silane compound and the conjugated diene (co) polymer are bonded by performing an addition or substitution reaction to the active site, and after the reaction, the silanol group and the reinforcing packing are carried out. the functional group a ¹ to promote the reaction between the wood, for example, (including glycidoxy group) (thio) epoxy group, (thio) isocyanate group, a nitrile group (cyano group), a pyridyl group, N- alkyl pyrrolide alkylsulfonyl Group, N-alkylimidazolyl group, N-alkylpyrazolyl group, (thio) ketone group, (thio) aldehyde group, imine residue, amide group, ketimine group, isocyanuric acid triester residue, 1 to 20 carbon atoms ( Thio) carboxylic acid hydrocarbyl ester residue, residue of (thio) carboxylic acid metal salt having 1 to 20 carbon atoms, carboxylic acid anhydride residue having 1 to 20 carbon atoms, carboxylic acid halide residue having 1 to 20 carbon atoms. Examples include groups or dihydrocarbyl carbonate residues. As the halogen of the carboxylic acid halide residue having 1 to 20 carbon atoms, chlorine, bromine or fluorine is preferable. As the carboxylic acid anhydride residue having 1 to 20 carbon atoms, a maleic anhydride residue, a phthalic anhydride residue, an acetic anhydride residue and the like are preferable. These are groups that bind to the active site of the conjugated diene (co) polymer and also promote the reaction with silica.

In the general formula (2), a functional group that reacts with the active site or a functional group A ² that binds the organic silane compound and the conjugated diene (co) polymer by performing an addition or substitution reaction to the active site. As the following formula (2-a)
-R ^d SiX ₃ ... (2-a)
Wherein, ^{R d} represents a single bond, an alkylene group or ^-OR e substituted or unsubstituted 1 to 10 carbon atoms ^{(R e} is substituted or unsubstituted alkylene having 1 to 10 carbon atoms.) Indicates, X represents a halogen atom or an alkoxy group having 1 to 10 carbon atoms, and a plurality of Xs may be the same or different. ], Or a (thio) epoxy group, a (thio) isocyanate group, a nitrile group, an imidazolyl group, a ketimine group, a (thio) ketone group, a protected first or second amino group, or the like. Can be done.

Further, in the production of the modified conjugated diene (co) polymer used in the present invention, the functional group A ² that reacts with the active site of the conjugated diene (co) polymer is a functional group that can chemically react with the active site. refers to a ^2, for example, an alkoxy group having 1 to 20 carbon atoms, a phenoxy group, a benzyloxy group, a halogen group are preferably exemplified. An alkoxy group having 1 to 20 carbon atoms is more preferable, and an alkoxy group having 1 to 12 carbon atoms is particularly preferable. Specific examples of the alkoxy group having 1 to 20 carbon atoms include a metoshiki group, an etoshiki group, a propyloxy group, an isopropyloxy group, an n-butoxy group, and a tert-butoxy group. As the halogen, chlorine, bromine or fluorine is preferable.

Further, in the general formula (2), the groups B and D containing at least one functional group that promotes the reaction between the silanol group and the reinforcing filler are independently, for example, a first amino group and a second. Amino group, protected primary or secondary amino group, tertiary amino group, cyclic amino group, oxazolyl group, imidazolyl group, aziridinyl group, (thio) ketone group, (thio) aldehyde group, amide group, (thio) Epoxy group (including glycidoxy group), (thio) isocyanate group, nitrile group (cyano group), pyridyl group, N-alkylpyrrolidonyl group, N-alkylimidazolyl group, N-alkylpyrazolyl group, imino group, amide group , Ketimine group, imine residue, isocyanuric acid triester residue, (thio) carboxylic acid hydrocarbyl ester residue having 1 to 20 carbon atoms, residue of (thio) carboxylic acid metal salt having 1 to 20 carbon atoms, carbon number Examples thereof include carboxylic acid anhydride residues of 1 to 20, carboxylic acid halide residues of 1 to 20 carbon atoms, dihydrocarbyl carbonate residues, or functional groups represented by the general formula -E-FG.
Here, E is an imino group, a divalent imine residue, a divalent pyridine residue or a divalent amide residue, and F is an alkylene group having 1 to 20 carbon atoms, a phenylene group or an aralkylene having 8 to 20 carbon atoms. Group, G is a primary amino group, a secondary amino group, a protected primary or secondary amino group, a tertiary amino group, a cyclic amino group, an oxazolyl group, an imidazolyl group, an aziridinyl group, a ketimine group, a nitrile group (cyano). Group), amide group, pyridine group or (thio) isocyanate group.
Specific examples of the functional group represented by the general formula -E-F-G include, for example, -NH-C ₂ H _4- NH ₂ , -NH-C ₂ H _4- N (CH ₃ ) ₂ , and these. Examples thereof include a functional group in which −C ₂ H ₄ − is replaced with − C ₆ H ₁₂ − or a phenylene group.

In the general formula (2), the silicon-containing group in which a halogen atom or an alkoxy group is bonded to the silicon atom and the -R ^d SiX ₃ group represented by the formula (2-a) are active of the conjugated diene (co) polymer. The (thio) epoxy group, (thio) isocyanate group, nitrile group, imidazolyl group, ketimine group, (thio) ketone group or protected first or second amino group is a silica. It is a group that promotes the reaction with.

When a functional group that promotes the reaction between the silanol group and the reinforcing filler is present in the vicinity of the silanol group, the reaction between the hydroxy group, the silanol group and the silanol group on the silica surface and the reinforcing filler is carried out. It is conceivable that a stable structure is formed by the three atoms having unpaired electrons (oxygen atom, sulfur atom or nitrogen atom) in the functional group to be promoted, and the reactivity of the silanol group with silica is improved. As a result, the low heat build-up of the rubber composition of the present invention using the modified conjugated diene (co) polymer of the present invention is improved.

In the above general formula (1) and the above general formula (2), a hydrocarbon having 1 to 20 carbon atoms, which is R ⁵ when R ¹ , R ⁴ , p is 1 or R ⁶ when q is 1. Specific examples of the groups include methylene group, ethylene group, propane-1,3-diyl group, butane-1,3-diyl group, butane-1,4-diyl group, pentane-1,3-diyl group, and pentane. -1,5-diyl group, hexane-1,3-diyl group, hexane-1,6-diyl group, heptane-1,3-diyl group, heptane-1,7-diyl group, octane-1,8- Examples thereof include a diyl group, a nonan-1,9-diyl group, a decane-1,10-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group and the like. Of these, the propane-1,3-diyl group is particularly preferred.
Here, R ⁵ when p is 0 and R ⁶ when q is 0 are hydrogen atoms or monovalent hydrocarbon groups having 1 to 20 carbon atoms, similarly to R ² and R ³ . That is, the valence of R ⁵ is (p + 1), and the valence of R ⁶ is (q + 1).

Further, in the above general formula (1) and the above general formula (2), R ⁵ when R ² , R ³ , p is 0 or R ⁶ when q is 0 has 1 to 20 carbon atoms. Specific examples of the monovalent hydrocarbon group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group and n. -Heptyl group, n-octyl group, stearyl group and the like can be mentioned. Of these, a methyl group or an ethyl group is particularly preferable.

Specific examples of the organic silane compound represented by the above general formula (1) include (2-glycidoxyethyl) dimethylmethoxysilane and (2-glycidoxyethyl) diethylmethoxy as (thio) epoxy group-containing silane compounds. Silane, (2-glycidoxyethyl) dimethylethoxysilane, (2-glycidoxyethyl) diethylethoxysilane, (3-glycidoxypropyl) dimethylmethoxysilane, (3-glycidoxypropyl) diethylmethoxysilane, (3-glycidoxypropyl) dimethylethoxysilane, (3-glycidoxypropyl) diethylethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (dimethyl) methoxysilane, 2- (3,4-epoxycyclohexyl) ) Ethyl (diethyl) methoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (dimethyl) ethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (diethyl) ethoxysilane and thioepoxy groups in these compounds It can be mentioned that it is replaced with a base. Among these, in particular, (3-glycidoxypropyl) dimethylmethoxysilane, (3-glycidoxypropyl) diethylmethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (dimethyl) methoxysilane and 2- ( 3,4-Epoxycyclohexyl) ethyl (diethyl) methoxysilane is suitable.

Further, as another specific example of the organic silane compound represented by the above general formula (1), as an imine residue-containing silane compound, N- (1,3-dimethylbutylidene) -3- (dimethylethoxysilyl)-. 1-Propanamine, N- (1,3-dimethylbutylidene) -3- (diethylethoxysilyl) -1-propaneamine, N- (1-methylethylidene) -3- (dimethylethoxysilyl) -1-propane Amine, N- (1-methylethylidene) -3- (diethylethoxysilyl) -1-propaneamine, N-ethylidene-3- (dimethylethoxysilyl) -1-propaneamine, N-ethylidene-3- (diethylethoxy) Cyril) -1-propanamine, N- (1-methylpropanol) -3- (dimethylethoxysilyl) -1-propaneamine, N- (1-methylpropanol) -3- (diethylethoxysilyl) -1 − Propaneamine, N- (4-N, N-dimethylaminobenzylidene) -3- (Dimethylethoxysilyl) -1-propaneamine, N- (4-N, N-dimethylaminobenzylidene) -3- (diethylethoxy) Cyril) -1-propaneamine, N- (cyclohexylidene) -3- (dimethylethoxysilyl) -1-propaneamine, N- (cyclohexylidene) -3- (diethylethoxysilyl) -1-propaneamine, etc. Can be mentioned. Among these, N- (1-methylpropanol) -3- (dimethylethoxysilyl) -1-propaneamine, N- (1-methylpropanolden) -3- (diethylethoxysilyl) -1-propane, in particular. Amine, N- (1,3-dimethylbutylidene) -3- (dimethylethoxysilyl) -1-propaneamine and N- (1,3-dimethylbutylidene) -3- (diethylethoxysilyl) -1-propane Amine is preferred.

As another specific example of the organic silane compound represented by the above general formula (1), 1- [3- (dimethylethoxysilyl) propyl] -4,5-dihydroimidazole, 1 as an imino (amidine) group-containing compound. -[3- (diethylethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- (dimethylmethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- (diethylmethoxysilyl) propyl ] -4,5-Dihydroimidazole, 3- [10- (dimethylethoxysilyl) decyl] -4-oxazoline, 3- [10- (diethylethoxysilyl) decyl] -4-oxazoline, 3- (1-hexamethylene) Imino) Propyl (Dimethylethoxy) Silane, 3- (1-Hexamethylene Imino) Propyl (Diethylethoxy) Silane, (1-Hexamethylene Imino) Methyl (Dimethylmethoxy) Silane, (1-Hexamethylene Imino) Methyl (diethylmethoxy) ) Silane, 1- [3- (dimethylethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- (diethylethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- (dimethyl) Methoxysilyl) propyl] -4,5-dihydroimidazole and 1- [3- (diethylmethoxysilyl) propyl] -4,5-dihydroimidazole can be mentioned, and among these, 3- (1- (1-) Hexamethylene imino) propyl (dimethylethoxy) silane, 3- (1-hexamethylene imino) propyl (diethylethoxy) silane, (1-hexamethylene imino) methyl (dimethylmethoxy) silane, (1-hexamethylene imino) methyl ( Diethylmethoxy) silane, 1- [3- (dimethylethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- (diethylethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- [3- (Dimethylmethoxysilyl) propyl] -4,5-dihydroimidazole and 1- [3- (diethylmethoxysilyl) propyl] -4,5-dihydroimidazole can be preferably mentioned.

Then, as another specific example of the organic silane compound represented by the above general formula (1), as the carboxylic acid ester group-containing compound, (3-methacryloyloxypropyl) dimethylethoxysilane, (3-methacryloyloxypropyl). Diethylethoxysilane, (3-methacryloyloxypropyl) dimethylmethoxysilane, (3-methacryloyloxypropyl) diethylmethoxysilane, (3-methacryloyloxypropyl) dimethylisopropoxysilane, (3-methacryloyloxypropyl) diethyl Examples thereof include isopropoxysilane, and among these, (3-methacryloyloxypropyl) dimethylmethoxysilane and (3-methacryloyloxypropyl) diethylmethoxysilane are preferable.

Further, as another specific example of the organic silane compound represented by the above general formula (1), as the isocyanate group-containing compound, (3-isocyanatopropyl) dimethylmethoxysilane, (3-isocyanatopropyl) diethylmethoxysilane, Examples thereof include (3-isocyanatopropyl) dimethylethoxysilane, (3-isocyanatopropyl) diethylethoxysilane, (3-isocyanatopropyl) dimethylisopropoxysilane, and (3-isocyanatopropyl) diethylisopropoxysilane. Of these, (3-isocyanatopropyl) dimethylethoxysilane and (3-isocyanatopropyl) diethylethoxysilane are preferred.

Further, as another specific example of the organic silane compound represented by the above general formula (1), as a carboxylic acid anhydride-containing compound, 3- (dimethylethoxy) silylpropyl succinic anhydride and 3- (diethylethoxy) silyl are used. Examples thereof include propyl succinic anhydride, 3- (dimethylmethoxy) silylpropyl succinic anhydride, 3- (diethylmethoxy) silylpropyl succinic anhydride, and the like, and among these, 3- (dimethylethoxy) silyl is preferable. Propyl succinic anhydride and 3- (diethylethoxy) silyl propyl succinic anhydride.

As the organic silane compound represented by the above general formula (2), a trialkylsilyl group whose protecting group is represented by −SiR ^a R ^b R ^c (where ^Ra , R ^b and R ^c have independently carbon atoms). Examples thereof include hydrocarbyloxysilane compounds having a protected primary amino group, which are 1 to 12 alkyl groups, preferably a methyl group, an ethyl group, a propyl group, a propyl group or a butyl group). Specific examples of the hydrocarbyloxysilane compound having a protected primary amino group include N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, and N. , N-bis (trimethylsilyl) aminoethylmethyldimethoxysilane, N, N-bis (trimethylsilyl) aminoethylmethyldiethoxysilane and the like can be preferably mentioned. Of these, N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane or N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane is particularly preferable.

As another example of the organic silane compound represented by the above general formula (2), the protecting group is -SiR ^a R ^b R trialkylsilyl group represented by ^{c (R} a, ^{R b} and ^{R c} are as defined above Included is a hydrocarbyloxysilane compound having a protected second amino group with one.). Specific examples of the hydrocarbyloxysilane compound having a protected second amino group include N, N-methyl (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-ethyl (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-Methyl (trimethylsilyl) aminopropylmethyldiethoxysilane, N, N-ethyl (trimethylsilyl) aminopropylmethyldiethoxysilane, N, N-methyl (trimethylsilyl) aminoethylmethyldimethoxysilane, N, N-ethyl (trimethylsilyl) Aminoethylmethyldimethoxysilane, N, N-methyl (trimethylsilyl) aminoethylmethyldiethoxysilane, N, N-ethyl (trimethylsilyl) aminoethylmethyldiethoxysilane and the like can be preferably mentioned.

Further, as another specific example of the organic silane compound represented by the above general formula (2), for example, N- (1,3-dimethylbutylidene) -3- (methyldiethoxysilyl) -1-propaneamine, N- (1-methylethylidene) -3- (methyldiethoxysilyl) -1-propaneamine, N-ethylidene-3- (methyldiethoxysilyl) -1-propaneamine, N- (1-methylpropanol) -3- (Methyldiethoxysilyl) -1-propaneamine, N- (4-N, N-dimethylaminobenzylidene) -3- (Methyldiethoxysilyl) -1-propaneamine, N- (cyclohexylidene) -3- (Methyldiethoxysilyl) -1-propaneamine and imine residue-containing hydrocarbyloxysilane compounds such as methyldimethoxysilyl compounds, ethyldiethoxysilyl compounds, and ethyldimethoxysilyl compounds corresponding to these methyldiethoxysilyl compounds. Of these, N- (1-methylpropanol) -3- (methyldiethoxysilyl) -1-propaneamine and N- (1,3-dimethylbutylidene)-are particularly preferable. 3- (Methyldiethoxysilyl) -1-propaneamine is suitable.

Further, as another specific example of the organic silane compound represented by the above general formula (2), for example, 3-dimethylaminopropyl (diethoxy) methylsilane, 3-dimethylaminopropyl (dimethoxy) methylsilane, 3-diethylaminopropyl (diethoxy) ) Hydrocarbyloxysilane compounds containing acyclic tertiary amino groups such as methylsilane, 3-diethylaminopropyl (dimethoxy) methylsilane, 2-dimethylaminoethyl (diethoxy) methylsilane, and 2-dimethylaminoethyl (dimethoxy) methylsilane can be preferably mentioned. However, among these, 3-dimethylaminopropyl (dimethoxy) methylsilane and 3-dimethylaminopropyl (diethoxy) methylsilane are particularly preferable.

Further, as another specific example of the organic silane compound represented by the above general formula (2), for example, 3-methylaminopropyl (diethoxy) methylsilane, 3-methylaminopropyl (dimethoxy) methylsilane, 3-ethylaminopropyl ( Preferred examples thereof include acyclic second amino group-containing hydrocarbyloxysilane compounds such as diethoxy) methylsilane, 3-ethylaminopropyl (dimethoxy) methylsilane, 2-methylaminoethyl (diethoxy) methylsilane, and 2-methylaminoethyl (dimethoxy) methylsilane. Of these, 3-methylaminopropyl (diethoxy) methylsilane and 3-methylaminopropyl (dimethoxy) methylsilane are particularly preferable.
As the acyclic primary amino group-containing hydrocarbyloxysilane compound, aminopropyl (diethoxy) methylsilane can be preferably used.

Further, as another specific example of the organic silane compound represented by the above general formula (2), for example, 3- (1-hexamethyleneimino) propyl (methyldiethoxy) silane, 3- (1-hexamethyleneimino) Propyl (methyldimethoxy) silane, (1-hexamethyleneimino) methyl (methyldimethoxy) silane, (1-hexamethyleneimino) methyl (methyldiethoxy) silane, 2- (1-hexamethyleneimino) ethyl (methyldiethoxy) ) Silane, 2- (1-hexamethyleneimino) ethyl (methyldimethoxy) silane, 3- (1-pyrrolidinyl) propyl (methyldiethoxy) silane, 3- (1-pyrrolidinyl) propyl (methyldimethoxy) silane, 3- (1-Heptamethyleneimino) propyl (methyldiethoxy) silane, 3- (1-dodecamethyleneimino) propyl (methyldiethoxy) silane, 3- (1-hexamethyleneimino) propyl (ethyldiethoxy) silane, 3 -[10- (Methyldiethoxysilyl) decyl] -4-oxazoline and other cyclic tertiary amino group-containing hydrocarbyloxysilane compounds can be preferably mentioned, and among these, 3- (1-hexamethyleneimino) More preferably, propyl (methyldiethoxy) silane and (1-hexamethyleneimino) methyl (methyldimethoxy) silane can be mentioned. In particular, 3- (1-hexamethyleneimino) propyl (methyldiethoxy) silane is suitable.

Then, as another specific example of the organic silane compound represented by the above general formula (2), for example, N- (3-methyldimethoxysilylpropyl] -4,5-dihydroimidazole, N- (3-methyldiethoxy). Examples thereof include amidine group-containing hydrocarbyloxysilane compounds such as silylpropyl) -4,5-dihydroimidazole, and among them, N- (3-methyldiethoxysilylpropyl) -4,5-dihydroimidazole is preferable.

Further, as another specific example of the organic silane compound represented by the above general formula (2), for example, (2-glycidoxyethyl) methyldimethoxysilane, (2-glycidoxyethyl) methyldiethoxysilane, ( 2-glycidoxyethyl) ethyldimethoxysilane, (2-glycidoxyethyl) ethyldiethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, (3-glycidoxypropyl) methyldiethoxysilane, ( 3-glycidoxypropyl) ethyldimethoxysilane, (3-glycidoxypropyl) ethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (methyldimethoxy) silane, 2- (3,4-exicyclohexyl) ) Ethyl (methyldiethoxy) silane 2- (3,4-epylcyclohexyl) ethyl (ethyldimethoxy) silane, 2- (3,4-exicyclohexyl) ethyl (ethyldiethoxy) silane and other epoxy group-containing hydrocarbyloxysilanes Compounds can be preferably mentioned, and among these, (3-glycidoxypropyl) methyldimethoxysilane and (3-glycidoxypropyl) methyldiethoxysilane are particularly preferable.
An epithio group-containing hydrocarbyloxysilane compound in which the epoxy group of the epoxy group-containing hydrocarbyloxysilane compound is replaced with an epithio group can also be preferably mentioned.

Further, as another specific example of the organic silane compound represented by the above general formula (2), for example, (3-isocyanatopropyl) methyldimethoxysilane, (3-isocyanatopropyl) methyldiethoxysilane, (3-isocyanatopropyl) methyldiethoxysilane, (3-isocyanatopropyl) methyldiethoxysilane. Contains isocyanate groups such as (isocyanatopropyl) ethyldimethoxysilane, (3-isocyanatopropyl) ethyldiethoxysilane, (3-isocyanatopropyl) methyldiisopropoxysilane, 3- (isocyanatopropyl) ethyldiisopropoxysilane Examples thereof include hydrocarbyloxysilane compounds, of which (3-isocyanatopropyl) methyldiethoxysilane is preferred.

Further, as another specific example of the organic silane compound represented by the above general formula (2), for example, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxy. Examples thereof include hydrocarbyloxysilane compounds containing carboxylic acid hydrocarbyl ester residues such as propylethyldimethoxysilane, 3-methacryloyloxypropylethyldiethoxysilane, and 3-methacryloyloxypropylmethyldiisopropoxysilane, among which 3-methacry is used. Leyloxypropylmethyldimethoxysilane and 3-methacryloyloxypropylmethyldiethoxysilane are preferred.

Further, as another specific example of the organic silane compound represented by the above general formula (2), for example, 3- (methyldiethoxysilyl) propyl succinic anhydride and 3- (methyldimethoxysilyl) propyl succinic anhydride Examples thereof include hydrocarbyloxysilane compounds containing carboxylic acid anhydride residues, and among them, 3- (methyldiethoxysilyl) propylsuccinic anhydride is preferable.
Further, 2- (methyldimethoxysilylethyl) pyridine, 2- (methyldiethoxysilylethyl) pyridine, 2-cyanoethylmethyldiethoxysilane and the like can be mentioned.

Among the various organic silane compounds represented by the above general formula (2), the hydrocarbyloxysilane compound having an amino group or an imine residue is preferable from the viewpoint of improving low heat build-up, and among them, the above-mentioned protected Hydrocarbyloxysilane compounds having a primary amino group are particularly preferred. This is because the low heat build-up of the rubber composition containing the modified conjugated diene (co) polymer is significantly improved by introducing the primary amino group into the molecular chain terminal of the modified conjugated diene (co) polymer.

In the present embodiment, the method for producing a modified conjugated diene (co) polymer is optionally hydrocarbyl at the active site of the conjugated diene (co) polymer prior to the modification reaction step of reacting the organic silane compound. A pre-modification reaction step of reacting the oxysilane compound may be further included.
Here, the hydrocarbyloxysilane compound used in the pre-modification reaction step preferably has a plurality of hydrocarbyloxysilyl groups. Even if one hydrocarbyloxysilyl group is consumed by the reaction of the conjugated diene (co) polymer with the active site, the remaining hydrocarbyloxysilyl group is used to produce the modified conjugated diene (co) polymer according to the present invention. This is because the modification reaction step required for the above can be carried out.

Examples of the conjugated diene monomer used for obtaining a conjugated diene (co) polymer that can be used for producing a modified conjugated diene (co) polymer include 1,3-butadiene, isoprene, and 1,3-pentadiene. , 2,3-Dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1,3-hexadiene and the like. These may be used alone or in combination of two or more. Of these, 1,3-butadiene is particularly preferred.
Examples of the aromatic vinyl monomer used in the conjugated diene (co) polymer include styrene, α-methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, ethylvinylbenzene, divinylbenzene, and 4-cyclo. Examples thereof include hexylstyrene and 2,4,6-trimethylstyrene. These may be used alone or in combination of two or more. Of these, styrene is particularly preferred.
The conjugated diene (co) polymer may be polybutadiene, polyisoprene, butadiene-isoprene copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer or styrene-isoprene-butadiene ternary copolymer. Of these, polybutadiene and styrene-butadiene copolymers are particularly preferred.

The styrene-butadiene copolymer that can be used as a conjugated diene (co) polymer preferably has a weight average molecular weight (Mw) of 100,000 to 800,000 before or after the modification reaction described later. , 150,000 to 700,000, more preferably. By keeping the weight average molecular weight within this range, a decrease in elastic modulus of the vulcanized product and an increase in hysteresis loss are suppressed to obtain excellent fracture resistance, and excellent kneading workability of the rubber composition containing SBR is obtained. can get. The weight average molecular weight is obtained by standard polystyrene conversion based on the GPC method. The styrene-butadiene copolymer may be an emulsion polymerization SBR or a solution polymerization SBR.
The styrene-butadiene copolymer may be referred to as SBR, and the modified styrene-butadiene copolymer may be referred to as modified SBR.

The following methods can be mentioned for producing the modified styrene-butadiene copolymer. That is, in order to react and modify a hydrocarbyloxysilane compound, particularly a hydrocarbyloxysilane compound containing nitrogen and silicon, at the active terminal of the styrene-butadiene copolymer, the styrene-butadiene copolymer is a polymer of at least 10%. It is preferable that the chain has a living property or a pseudo-living property. As the polymerization reaction having such living property, a reaction in which an organic alkali metal compound is used as an initiator and styrene and butadiene are anionic polymerized in an organic solvent is preferable. By anionic polymerization, a conjugated diene portion having a high vinyl bond content can be obtained, and the glass transition temperature Tg can be adjusted to a desired temperature. Heat resistance can be improved by increasing the vinyl bond amount, and fuel efficiency can be improved by increasing the cis-1,4 bond content.

As the organic alkali metal compound used as the above-mentioned anionic polymerization initiator, an organic lithium compound is preferable. The organic lithium compound is not particularly limited, but hydrocarbyl lithium or a lithium amide compound is preferably used. When the former hydrocarbyl lithium is used, it has a hydrocarbyl group at the polymerization initiation terminal and the other terminal has polymerization activity. A styrene-butadiene copolymer, which is a site, is obtained, and the above-mentioned hydrocarbyloxysilane compound is reacted with the active terminal, which is a polymerization active site, to modify it.

When the latter lithium amide compound is used, a styrene-butadiene copolymer having a nitrogen-containing group at the polymerization initiation terminal and the other terminal being a polymerization active site can be obtained. In the case of a lithium amide compound, the modified SBR according to the present invention can be obtained without modification with the above-mentioned hydrocarbyloxysilane compound, but the hydrocarbyloxysilane compound, particularly nitrogen and silicon, is contained at the active terminal which is a polymerization active site. When the hydrocarbyloxysilane compound is reacted and modified, a so-called bi-terminal modified styrene-butadiene copolymer can be obtained, and the dispersibility and reinforcing property of the filler such as carbon black and silica can be further enhanced. preferable.

The hydrocarbyllithium as the polymerization initiator is preferably one having a hydrocarbyl group having 2 to 20 carbon atoms, for example, ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-octyllithium. , N-decyllithium, phenyllithium, 2-naphthyllithium, 2-butylphenyllithium, 4-phenylbutyllithium, cyclohexyllithium, cycloventyllithium, reaction products of diisopropenylbenzene and butyllithium, etc. Of these, n-butyllithium is particularly preferable.

Examples of the lithium amide compound as a polymerization initiator include lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, lithium dodecamethyleneimide, lithium dimethylamide, lithium diethylamide, lithium dibutylamide and lithium. Dipropylamide, Lithiumdiheptylamide, Lithiumdihexylamide, Lithiumdioctylamide, Lithiumdi-2-ethylhexylamide, Lithiumdidecylamide, Lithium-N-methylpiberazide, Lithiumethylpropylamide, Lithiumethylbutylamide, Lithiumethylbenzylamide, Examples thereof include lithium methylphenethylamide. Among these, cyclic lithium amides such as lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, and lithium dodecamethyleneimide are preferable from the viewpoint of the interaction effect with carbon black and the ability to initiate polymerization. In particular, lithium hexamethyleneimide and lithium pyrrolidide are suitable.
Generally, these lithium amide compounds are prepared in advance from the secondary amine and the lithium compound and can be used for polymerization, but they can also be prepared in the polymerization system (in-situ). The amount of the polymerization initiator used is preferably selected in the range of 0.2 to 20 mmol per 100 g of the monomer.

The method for producing a styrene-butadiene copolymer by anionic polymerization using the organolithium compound as a polymerization initiator is not particularly limited, and a conventionally known method can be used.
Specifically, the lithium compound is polymerized with a conjugated diene compound and an aromatic vinyl compound in a reaction-inert organic solvent such as an aliphatic, alicyclic, or aromatic hydrocarbon compound. A styrene-butadiene copolymer having the desired active end is obtained by anionic polymerization as an initiator, optionally in the presence of the randomizer used.

The hydrocarbon solvent is preferably one having 3 to 8 carbon atoms, for example, propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene, trans-2. -Butene, cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene and the like can be mentioned. These may be used alone or in combination of two or more.
The monomer concentration in the solution is preferably 5 to 50% by mass, more preferably 10 to 30% by mass. When copolymerization is carried out using the conjugated diene compound and the aromatic vinyl compound, the content of the aromatic vinyl compound in the charged monomer mixture is preferably 5 to 55% by mass, more preferably 6 to 45% by mass. ..

Further, the randomizer used as desired is a control of the microstructure of the styrene-butadiene copolymer, for example, an increase in 1,2 bonds of the butadiene moiety in the butadiene-styrene copolymer, an increase in 3,4 bonds in the isoprene polymer, and the like. Or, it is a compound having an action of controlling the composition distribution of the monomer unit in the conjugated diene-aromatic vinyl copolymer, for example, randomizing the butadiene unit and the styrene unit in the butadiene-styrene copolymer.
As the randomizer, any known compound commonly used as a conventional randomizer can be appropriately selected and used. Specifically, dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-bis (2-tetrahydrofuryl) -propane, triethylamine, pyridine, N-methylmorpholine, N, N, N', Examples thereof include ethers such as N'-tetramethylethylenediamine and 1,2-dipiperidinoethane, and tertiary amines. Further, potassium salts such as potassium t-amylate and potassium t-butoxide, and sodium salts such as sodium t-amylate can also be used.

These randomizers may be used alone or in combination of two or more. The amount used is preferably selected in the range of 0.01 to 1000 molar equivalents per mol of the lithium compound.
The temperature in this polymerization reaction is preferably selected in the range of 0 to 150 ° C, more preferably 20 to 130 ° C. Although the polymerization reaction can be carried out under the generation pressure, it is usually desirable to operate at a pressure sufficient to keep the monomer in a substantially liquid phase. That is, the pressure depends on the individual substance to be polymerized, the polymerization medium used and the polymerization temperature, but a higher pressure can be used if desired, such a pressure being a reactor with a gas inert to the polymerization reaction. It can be obtained by an appropriate method such as pressurizing.

Next, the polymerization catalyst system of coordination anionic polymerization will be described. As the polymerization catalyst system for coordination anionic polymerization, a catalyst containing a lanthanum series rare earth element compound in an organic solvent is used.
As a catalyst containing a lantern series rare earth element compound,
Component A: Rare earth element-containing compounds with atomic numbers 57 to 71 in the periodic table, or reactants of these compounds with Lewis bases,
Component B: The following general formula (5):
AlR ⁷ R ⁸ R ⁹ ... (5)
(Here, R ⁷ and R ⁸ are the same or different, and are a hydrocarbyl group or a hydrogen atom having 1 to 10 carbon atoms, and R ⁹ is a hydrocarbyl group having 1 to 10 carbon atoms, where R ⁹ is the above R ⁷ or an organoaluminum compound represented by may also) the same or different and R ^8, and C components: consists of at least one organic compound containing a Lewis acid, a metal halide, a complex compound of Lewis base, and an active halogen It is preferable to polymerize the conjugated diene monomer using a catalytic system.

Further, in the present invention, it is preferable to add an organoaluminum oxy compound, so-called aluminoxane, as a component D in addition to the above components A to C to the catalyst system containing the lanthanum series rare earth element compound. Here, it is more preferable that the catalyst system is pre-prepared in the presence of the A component, the B component, the C component, the D component and the conjugated diene monomer.

In the present invention, the A component of the catalyst system containing a lanthanum series rare earth element compound is a compound containing a rare earth element having atomic numbers 57 to 71 in the periodic table, or a reaction product of these compounds and a Lewis base. Here, among the rare earth elements having atomic numbers 57 to 71, neodymium, praseodymium, cerium, lanthanum, gadolinium, samarium and the like, or mixtures thereof are preferable, and neodymium is particularly preferable.

The rare earth element-containing compound is preferably a salt soluble in a hydrocarbon solvent, and specific examples thereof include a carboxylate, an alcoholide, a β-diketone complex, a phosphate and a phosphate of the rare earth element. Among these, carboxylates and phosphates are preferable, and carboxylates are particularly preferable.
Here, examples of the hydrocarbon solvent include saturated aliphatic hydrocarbons having 4 to 10 carbon atoms such as butane, pentane, hexane and heptane, and saturated alicyclic hydrocarbons having 5 to 20 carbon atoms such as cyclopentane and cyclohexane. -Monoolefins such as butane and 2-butane, aromatic hydrocarbons such as benzene, toluene and xylene, methylene chloride, chloroform, trichloroethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, bromobenzene, chlorotoluene and the like. Examples include halogenated hydrocarbons.

The carboxylate of the rare earth element is described in the following general formula (6):
(R ^10- CO ₂ ) ₃ M ¹ ... (6)
(In the formula, R ¹⁰ is a hydrocarbyl group having 1 to 20 carbon atoms, and M ¹ is a rare earth element having atomic numbers 57 to 71 in the periodic table). Here, R ¹⁰ may be saturated or unsaturated, preferably an alkyl group or an alkenyl group, and may be linear, branched or cyclic. Further, the carboxyl group is bonded to a primary, secondary or tertiary carbon atom. Specific examples of the carboxylic acid salt include octanoic acid, 2-ethylhexanoic acid, oleic acid, neodecanoic acid, stearic acid, benzoic acid, naphthenic acid, and versatic acid [trade names manufactured by Shell Chemical Co., Ltd. , Carboxylic acid in which a carboxyl group is bonded to a tertiary carbon atom], and among these, salts of 2-ethylhexanoic acid, neodecanoic acid, naphthenic acid, and versatic acid are preferable.

As the arcoxide of the rare earth element, the following general formula (7):
(R ¹¹ O) ₃ M ² ... (7)
(In the formula, R ¹¹ is a hydrocarbyl group having 1 to 20 carbon atoms, and M ² is a rare earth element having atomic numbers 57 to 71 in the periodic table). Examples of the alkoxy group represented by R ¹¹ O include a 2-ethyl-hexyloxy group, an oleyloxy group, a stearyloxy group, a phenoxy group, a benzyloxy group and the like. Among these, 2-ethyl-hexyloxy group and benzyloxy group are preferable.

Examples of the β-diketone complex of the rare earth element include the acetylacetone complex, the benzoylacetone complex, the propionitrile acetone complex, the valeryl acetone complex, and the ethyl acetylacetone complex of the rare earth element. Among these, an acetylacetone complex and an ethylacetylacetone complex are preferable.

Examples of the rare earth element phosphate and phosphite include the above rare earth element, bis phosphate (2-ethylhexyl), bis phosphate (1-methylheptyl), bis phosphate (p-nonylphenyl), and phosphorus. Bis acid (polyethylene glycol-p-nonylphenyl), phosphoric acid (1-methylheptyl) (2-ethylhexyl), phosphoric acid (2-ethylhexyl) (p-nonylphenyl), 2-ethylhexylphosphonate mono-2-ethylhexyl , 2-Ethylhexylphosphonic acid mono-p-nonylphenyl, bis (2-ethylhexyl) phosphinic acid, bis (1-methylheptyl) phosphinic acid, bis (p-nonylphenyl) phosphinic acid, (1-methylheptyl) (2 Examples thereof include salts with -ethylhexyl) phosphinic acid, (2-ethylhexyl) (p-nonylphenyl) phosphinic acid, etc. Among these, the above rare earth elements, bis phosphate (2-ethylhexyl), bis phosphate (1) -Methylheptyl), 2-ethylhexylphosphonate mono-2-ethylhexyl, salts with bis (2-ethylhexyl) phosphinic acid are preferred.

Among the rare earth element-containing compounds, neodymium phosphate and neodymium carboxylate are more preferable, and neodymium branching such as neodymium 2-ethylhexanoate, neodymium neodecanoate, and neodymium versatic acidate is particularly preferable. The carboxylate is most preferred.

Further, the component A may be a reaction product of the rare earth element-containing compound and a Lewis base. The reaction product has improved solubility of a rare earth element-containing compound in a solvent due to a Lewis base, and can be stably stored for a long period of time. The Lewis base used for easily solubilizing the rare earth element-containing compound in a solvent and for stable storage for a long period of time is 0 to 30 mol, preferably 1 to 10 mol, per mol of the rare earth element. , As a mixture of both, or as a product obtained by reacting both in advance. Here, examples of the Lewis base include acetylacetone, tetrahydrofuran, pyridine, N, N-dimethylformamide, thiophene, diphenyl ether, triethylamine, an organic phosphorus compound, and a monohydric or divalent alcohol.

The rare earth element-containing compound as the component A described above or a reaction product of these compounds and a Lewis base can be used alone or in combination of two or more.

In the present invention, examples of the organic aluminum compound represented by the above general formula (5), which is the B component of the catalytic system used for the polymerization of the terminal active polymer, include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, and triisopropyl. Aluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum; diethylaluminum hydride, di-n-propylaluminum hydride, Di-n-butylaluminum hydride, diisobutylaluminum hydride, dihexyl aluminum hydride, diisohexyl hydride, dioctyl aluminum hydride, diisooctyl aluminum hydride; ethylaluminium dihydride, n-propylaluminum dihydride, Examples thereof include isobutylaluminum dihydride, and among these, triethylaluminum, triisobutylaluminum, hydride diethylaluminum, and hydrogenated diisobutylaluminum are preferable. The organoaluminum compound as the B component described above may be used alone or in combination of two or more.

In the present invention, the C component of the catalyst system used for the polymerization of the terminal active polymer is at least one selected from the group consisting of a Lewis acid, a complex compound of a metal halide and a Lewis base, and an organic compound containing an active halogen. It is a halogen compound.

The Lewis acid has Lewis acidity and is soluble in hydrocarbons. Specifically, methyl aluminum dibromide, methyl aluminum dichloride, ethyl aluminum dibromide, ethyl aluminum dichloride, butyl aluminum dibromide, butyl aluminum dichloride, dimethyl aluminum bromide, dimethyl aluminum chloride, diethyl bromide. Aluminum, diethyl aluminum chloride, dibutyl aluminum bromide, dibutyl aluminum chloride, methyl aluminum sesqui bromide, methyl aluminum sesqui chloride, ethyl aluminum sesqui bromide, ethyl aluminum sesqui chloride, dibutyl tin dichloride, aluminum tribromide, antimony trichloride, Examples thereof include antimony trichloride, phosphorus trichloride, phosphorus pentachloride, tin tetrachloride, and silicon tetrachloride. Among these, diethyl aluminum chloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride, diethyl aluminum bromide, ethyl aluminum sesqui bromide, and ethyl aluminum dibromide are preferable.
It is also possible to use a reaction product of alkylaluminum and halogen such as a reaction product of triethylaluminum and bromine.

Examples of the metal halide constituting the complex compound of the metal halide and the Lewis base include beryllium chloride, beryllium bromide, beryllium iodide, magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, calcium bromide, and iodine. Calcium chloride, barium chloride, barium bromide, barium iodide, zinc chloride, zinc bromide, zinc iodide, cadmium chloride, cadmium bromide, cadmium iodide, mercury chloride, mercury bromide, mercury iodide, manganese chloride, Manganese bromide, manganese iodide, renium chloride, renium bromide, renium iodide, copper chloride, copper iodide, silver chloride, silver bromide, silver iodide, gold chloride, gold iodide, gold bromide, etc. Among these, magnesium chloride, calcium chloride, barium chloride, manganese chloride, zinc chloride and copper chloride are preferable, and magnesium chloride, manganese chloride, zinc chloride and copper chloride are particularly preferable.

Further, as the Lewis base constituting the complex compound of the metal halide and the Lewis base, a phosphorus compound, a carbonyl compound, a nitrogen compound, an ether compound, an alcohol and the like are preferable. Specifically, tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricredil phosphate, triethylphosphine, tributylphosphine, triphenylphosphine, diethylphosphinoetan, diphenylphosphinoetan, acetylacetone, benzoylacetone. , Propionitrile acetone, Valeryl acetone, Ethyl acetyl acetone, Methyl acetoacetate, Ethyl acetoacetate, Phenyl acetoacetate, Diethyl malonate, Diethyl malonate, Diphenyl malonate, Acetic acid, Octanoic acid, 2-Ethyl-hexanoic acid, Olein Acid, stearic acid, benzoic acid, naphthenic acid, versatic acid, triethylamine, N, N-dimethylacetoamide, tetrahydrofuran, diphenyl ether, 2-ethyl-hexyl alcohol, oleyl alcohol, stearyl alcohol, phenol, benzyl alcohol, 1-decanol, lauryl Alcohols and the like can be mentioned, and among these, tri-2-ethylhexyl phosphate, tricresyl phosphate, acetylacetone, 2-ethylhexanoic acid, versatic acid, 2-ethylhexyl alcohol, 1-decanol and lauryl alcohol are preferable.

The Lewis base is reacted at a ratio of usually 0.01 to 30 mol, preferably 0.5 to 10 mol, per 1 mol of the metal halide. The reaction with the Lewis base can be used to reduce the amount of metal remaining in the polymer.
Examples of the organic compound containing an active halogen include benzyl chloride and the like.

Further, examples of the aluminoxane as the D component include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane, chloroaluminoxane and the like. By adding aluminoxane as the D component, the molecular weight distribution becomes sharp and the activity as a catalyst is also improved.

The amount or composition ratio of each component of the catalyst system used in the present invention is appropriately selected according to the purpose or necessity thereof. Of these, the component A is preferably 0.00001 to 1.0 mmol, more preferably 0.0001 to 0.5 mmol, based on 100 g of 1,3-butadiene. By keeping the amount of component A used within the above range, excellent polymerization activity can be obtained, and the need for a decalcification step is eliminated.
The ratio of the A component to the B component is a molar ratio of the A component: B component usually 1: 1 to 1: 700, preferably 1: 3 to 1: 500.
Further, the ratio of halogen in the component A and the component C is usually 1: 0.1 to 1:30, preferably 1: 0.2 to 1:15, more preferably 1: 2.0 to the molar ratio. It is 1: 5.0.
The ratio of aluminum to the A component in the D component is usually 1: 1 to 700: 1, preferably 3: 1 to 500: 1, in terms of molar ratio. It is preferable to keep the amount within the range of these catalyst amounts or component ratios because it acts as a highly active catalyst and eliminates the need for a step of removing the catalyst residue.
Further, in addition to the above components A to C, a polymerization reaction may be carried out in the coexistence of hydrogen gas for the purpose of adjusting the molecular weight of the polymer.

As the catalyst component, in addition to the above-mentioned A component, B component, C component and D component used as necessary, a small amount of conjugated diene monomer such as 1,3-butadiene is added as necessary, specifically, A. It may be used at a ratio of 0 to 1000 mol per 1 mol of the component compound. A conjugated diene monomer such as 1,3-butadiene as a catalyst component is not essential, but when used in combination with this, there is an advantage that the catalytic activity is further improved.

In the production of the catalyst, for example, the components A to C are dissolved in a solvent, and if necessary, a conjugated diene monomer such as 1,3-butadiene is reacted.
At that time, the order of addition of each component is not particularly limited, and aluminoxane may be further added as the D component. From the viewpoint of improving the polymerization activity and shortening the polymerization initiation induction period, it is preferable that each of these components is mixed in advance, reacted, and aged.
Here, the aging temperature is about 0 to 100 ° C, preferably 20 to 80 ° C. If the temperature is lower than 0 ° C, it is difficult to sufficiently mature, and if the temperature exceeds 100 ° C, the catalytic activity may decrease and the molecular weight distribution may expand.
Further, the aging time is not particularly limited, and aging can be performed by contacting in a line before adding to the polymerization reaction tank. Usually, 0.5 minutes or more is sufficient, and it is stable for several days.

In the production of the conjugated diene (co) polymer having the terminal activity, the conjugated diene monomer alone or the conjugated diene monomer is used in an organic solvent using the catalyst system containing the lanthanum series rare earth element-containing compound. It is obtained by solution polymerization of other conjugated diene monomers. Here, as the polymerization solvent, an inert organic solvent is used. Examples of the inert organic solvent include saturated aliphatic hydrocarbons having 4 to 10 carbon atoms such as butane, pentane, hexane and heptane, and saturated alicyclic hydrocarbons having 5 to 20 carbon atoms such as cyclopentane and cyclohexane, 1-. Monoolefins such as butane and 2-butane, aromatic hydrocarbons such as benzene, toluene and xylene, methylene chloride, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, bromobenzene, chloro Examples thereof include halogenated hydrocarbons such as toluene.
Among these, aliphatic hydrocarbons having 5 to 6 carbon atoms and alicyclic hydrocarbons are particularly preferable. These solvents may be used alone or in combination of two or more.
The monomer concentration in the solution used for this coordination anionic polymerization is preferably 5 to 50% by mass, more preferably 10 to 30% by mass.

In the present invention, the temperature in the coordination anionic polymerization reaction is preferably selected in the range of −80 to 150 ° C., more preferably −20 to 120 ° C. Although the polymerization reaction can be carried out under the generation pressure, it is usually desirable to operate at a pressure sufficient to keep the monomer in a substantially liquid phase. That is, the pressure depends on the individual substance to be polymerized, the polymerization medium used and the polymerization temperature, but a higher pressure can be used if desired, such a pressure being a reactor with a gas inert to the polymerization reaction. It can be obtained by an appropriate method such as pressurizing.

When modifying the active end of a conjugated diene (co) polymer having an active end obtained by a coordination anion polymerization reaction, the hydrocarbyloxysilane compound is reacted in advance in the above-mentioned pre-modification reaction step and then hydrolyzed. The organic silane compound and the conjugated diene (co) polymer are bonded and the reaction is carried out by (i) adding or substituting the active site in the vicinity of the characteristic group for producing a silanol group. Later, the reaction of an organic silane compound having a functional group that promotes the reaction between the silanol group and the reinforcing filler or (ii) a functional group that promotes the reaction between the silanol group and the reinforcing filler can be modified. This is preferable from the viewpoint of facilitating the reaction.

In the above-mentioned anionic polymerization and coordination anionic polymerization, reaction inhibitors such as water, oxygen, carbon dioxide, and protonic compounds were removed from all the raw materials involved in the polymerization, such as polymerization initiators, solvents, and monomers. It is desirable to use one.
The polymerization reaction may be carried out by either a batch type or a continuous type.
In this way, a conjugated diene (co) polymer having an active terminal is obtained.

In the modification reaction step of the method for producing a modified conjugated diene (co) polymer in the present invention, the conjugated diene (co) polymer having an active terminal obtained as described above is subjected to the above-mentioned general formula (1) or The organic silane compound represented by the general formula (2) is added to the active terminal of the conjugated diene (co) polymer, preferably in a chemically quantitative amount or in excess thereof, and bonded to the polymer. React with the active terminal.
The modification reaction step and the preliminary modification reaction step in the present invention are usually carried out under the same temperature and pressure conditions as the polymerization reaction.

Next, the hydrolysis step of the method for producing a modified conjugated diene (co) polymer will be described. In the hydrolysis step, after the modification reaction step is completed, the hydrolysis reaction is carried out in the presence of water under acidic, neutral or alkaline conditions. As a result, the hydrolyzable functional group bonded to the modified conjugated diene (co) polymer is efficiently hydrolyzed, and a silanol group is generated at the terminal or side chain of the modified conjugated diene (co) polymer.
The amount of water used in this hydrolysis reaction is preferably an excess molar amount, for example, 2 to 4 times the molar amount of the initiator Li or the like. The hydrolysis time is usually about 10 minutes to several hours.
When the hydrolysis reaction is carried out under alkaline conditions, it is desirable to add an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, preferably sodium hydroxide, as a basic compound, and the hydrolysis reaction is carried out under acidic conditions. It is desirable to add inorganic acids such as hydrochloric acid, sulfuric acid and nitrate, carboxylic acids such as acetic acid and formic acid, silicon tetrachloride and the like as acidic compounds.

In the present invention, a condensation reaction step can be provided between the modification reaction step and the hydrolysis step, or after the hydrolysis step, in which a condensation reaction is further carried out in the presence of a condensation accelerator.

The condensation accelerator used in the condensation reaction is preferably added after the modification reaction and before the start of the condensation reaction. If added before the denaturation reaction, a direct reaction with the active terminal may occur and a hydrocarbyloxy group may not be introduced into the active terminal. Further, when added after the start of the condensation reaction, the condensation accelerator may not be uniformly dispersed and its catalytic performance may deteriorate.
When the condensation reaction step is provided between the modification reaction step and the hydrolysis step, the condensation accelerator is usually added 5 minutes to 5 hours after the start of the modification reaction, preferably 15 minutes to 1 hour after the start of the modification reaction. Later. When the condensation reaction step is provided after the hydrolysis step, it is usually 5 minutes to 5 hours after the start of the hydrolysis reaction, preferably 10 minutes to 2 hours.

The condensation accelerator preferably contains a metal element, and more preferably a compound containing at least one of the metals belonging to groups 2 to 15 of the periodic table.
The condensation accelerator containing the metal element preferably contains at least one selected from Ti, Sn, Bi, Zr and Al, and is an alkoxide, carboxylate or acetylacetonate complex salt of the metal. is there.

As the condensation accelerator containing Ti as a metal component, titanium (Ti) alkoxide, carboxylate and acetylacetonate complex salt are preferably used.
Specifically, tetrakis (2-ethyl-1,3-hexanediorat) titanium, tetrakis (2-methyl-1,3-hexanediorat) titanium, tetrakis (2-propyl-1,3-hexanediorat) ) Titanium, tetrakis (2-butyl-1,3-hexanediorat) titanium, tetrakis (1,3-hexanediorat) titanium, tetrakis (1,3-pentanediorat) titanium, tetrakis (2-methyl-1) , 3-Pentanyolato) Titanium, Tetrax (2-ethyl-1,3-Pentandiorat) Titanium, Tetraquis (2-propyl-1,3-Pentandiorat) Titanium, Tetraquis (2-butyl-1,3) -Pentanyolato) titanium, tetrakis (1,3-heptandiorat) titanium, tetrakis (2-methyl-1,3-heptandiorat) titanium, tetrakis (2-ethyl-1,3-heptandiorat) titanium, tetrakis (2-propyl) -1,3-Heptandiolato) Titanium, Tetrax (2-butyl-1,3-Heptandiolato) Titanium, Tetrakiss (2-ethylhexoxy) Titanium, Tetramethoxytitanium, Tetraethoxytitanium, Tetra-n-propoxytitanium, Tetraisopropoxytitanium , Tetra-n-butoxytitanium, tetra-n-butoxytitanium oligomer, tetraisobutoxytitanium, tetra-sec-butoxytitanium, tetra-tert-butoxytitanium, bis (oleate) bis (2-ethylhexanoate) titanium, Titanium dipropoxybis (triethanolaminate), titanium dibutoxybis (triethanolaminate), titanium tributoxystearate, titanium tripropoxystearate, titanium tripropoxyacetylacetonate, titaniumdipropoxybis (acetylacetonate) , Titanium tripropoxy (ethyl acetoacetate), titanium propoxyacetyl acetonate bis (ethyl acetoacetate), titanium tributoxyacetyl acetonate, titanium dibutoxybis (acetyl acetonate), titanium tributoxyethyl acetoacetate, titanium butoxy acetyl aceto Natebis (ethylacetate acetate), titanium tetrakis (acetylacetonate), titanium diacetylacetonate bis (ethylacetacetate), bis (2-ethylhexanoate) titanium oxide, bis (laurate) titanium oxide, bis (naphthenate) Titanium oxa Id, Bis (Stearate) Titanium Oxide, Bis (Oleate) Titanium Oxide, Bis (Renolate) Titanium Oxide, Tetrakiss (2-ethylhexanoate) Titanium, Tetrakiss (Laurate) Titanium, Tetrakiss (Naftenate) Titanium, Tetrakiss (Stair) Rate) Titanium, Tetrakiss (Oleate) Titanium, Tetrakiss (Rinolate) Titanium, Titanium di-n-butoxide (bis-2,4-pentandionate), Titanium oxide bis (steerate), Titanium oxide bis (tetramethylheptangeonate) ), Titanium oxide bis (pentangionate), titanium tetra (lactate) and the like.
Of these, tetrakis (2-ethyl-1,3-hexanediorat) titanium, tetrakis (2-ethylhexoxy) titanium, and titaniumdi-n-butoxide (bis-2,4-pentanionate) are preferable.

Examples of the condensation accelerator containing Sn as a metal component include a tin compound having an oxidation number of 2 represented by Sn (OCOR ³¹ ) ₂ (in the formula, R ³¹ is an alkyl group having 2 to 19 carbon atoms) and R ³² _x. A tin compound having an oxidation number of 4 represented by SnA ⁵ _y B ¹ _4-y-x (in the formula, R ³² is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, x is an integer of 1 to 3 and y is 1. or 2, ^{a 5} represents a carboxyl group having 2 to 30 carbon atoms, beta-dicarbonyl group having 5 to 20 carbon atoms, a hydrocarbyloxy group having 3 to 20 carbon atoms, and hydrocarbyl group having 1 to 20 carbon atoms and / or carbon A group selected from a siloxy group trisubstituted with a number 1 to 20 of a hydrocarbyloxy group, B ¹ is a hydroxyl group or a halogen) is preferable.

More specifically, the tin carboxylate includes divalent tin dicarboxylic acid salt, tetravalent dihydrocarbyltin dicarboxylic acid salt (including bis (hydrocarbyldicarboxylic acid) salt), and bis (β). -Diketonate), alkoxyhalide, monocarboxylic acid hydroxide, alkoxy (trihydrocarbyl syroxide), alkoxy (dihydrocarbyl alkoxysiloxide), bis (trihydrocarbyl syroxide), bis (dihydrocarbyl oxysiloxide), etc. It can be preferably used. The hydrocarbyl group bonded to tin preferably has 4 or more carbon atoms, and particularly preferably has 4 to 8 carbon atoms.

Examples of the condensation accelerator containing Zr, Bi, or Al as a metal component (for example, alkoxide, carboxylic acid, or acetylacetonate complex salt of these metals) include the following (a) to (e).

(A) Bismus Carboxylate (b) Zirconium Alkoxide (c) Zirconium Carboxylate (d) Aluminum Alkoxide (e) Aluminum Carboxylate

Specifically, tris (2-ethylhexanoate) bismuth, tris (laurate) bismus, tris (naphthenate) bismus, tris (steerate) bismus, tris (oleate) bismus, tris (linolate) bismus, tetraethoxyzirconium. , Tetra n-propoxyzirconium, tetraisopropoxyzirconium, tetra n-butoxyzirconium, tetrasec-butoxyzirconium, tetratert-butoxyzirconium, tetra (2-ethylhexoxy) zirconium, zirconium tributoxystearate, zirconium tributoxyacetylacetonate , Zirconium butoxybis (acetylacetonate), zirconium tributoxyethylacetate, zirconium butoxyacetylacetonate bis (ethylacetacetate), zirconium tetrakis (acetylacetate), zirconium diacetylacetonate bis (ethylacetacetate), bis ( 2-Ethylhexanoate) zirconium oxide, bis (laurate) zirconium oxide, bis (naphthenate) zirconium oxide, bis (steerate) zirconium oxide, bis (oleate) zirconium oxide, bis (linolate) zirconium oxide, tetrakis (2- Ethylhexanoate) zirconium, tetrakis (laurate) zirconium, tetrakis (naphthenate) zirconium, tetrakis (steerate) zirconium, tetrakis (oleate) zirconium, tetrakis (linolate) zirconium, triethoxyaluminum, trin-propoxyaluminum, triiso Propoxyaluminum, tri-n-butoxyaluminum, trisec-butoxyaluminum, tritert-butoxyaluminum, tri (2-ethylhexoxy) aluminum, aluminum dibutoxystearate, aluminum dibutoxyacetylacetonate, aluminum butoxybis (acetylacetonate) , Aluminum dibutoxyethyl acetoacetate, aluminum tris (acetylacetonate), aluminum tris (ethylacetacetate), tris (2-ethylhexanoate) aluminum, tris (laurate) aluminum, tris (naphthenate) aluminum, tris (steer) Rate) Aluminum, Tris (Rate) Examples thereof include oleate) aluminum and tris (linolate) aluminum.

Among these, tris (2-ethylhexanoate) bismuth, tetra n-propoxyzirconium, tetra n-butoxyzirconium, bis (2-ethylhexanoate) zirconium oxide, bis (oleate) zirconium oxide, triisopropoxy Aluminum, trisec-butoxyaluminum, tris (2-ethylhexanoate) aluminum, tris (steerate) aluminum, zirconium tetrakis (acetylacetonate), aluminum tris (acetylacetonate) are preferable.

The blending amount (usage amount) of the condensation accelerator is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the rubber component in the rubber composition described later, and is 0.5 to 5 parts by mass. More preferred. By setting the amount of the condensation accelerator used in the above range, the condensation reaction proceeds efficiently.

The condensation reaction is preferably carried out in an aqueous solution, and the temperature at the time of the condensation reaction is preferably 85 to 180 ° C., more preferably 100 to 170 ° C., and particularly preferably 110 to 150 ° C. By setting the temperature during the condensation reaction within the above range, the condensation reaction can be efficiently progressed and completed, and deterioration of quality due to aging reaction of the polymer due to aging of the obtained modified conjugated diene polymer can be suppressed. Can be done.

The condensation reaction time is preferably about 5 minutes to 10 hours, more preferably about 15 minutes to 5 hours. By setting the condensation reaction time within the above range, the condensation reaction can be completed smoothly.
The pressure of the reaction system during the condensation reaction is preferably 0.01 to 20 MPa, more preferably 0.05 to 10 MPa.
The type of the condensation reaction is not particularly limited, and a batch reactor or a continuous reactor such as a multi-stage continuous reactor may be used. Further, this condensation reaction and desolvation may be carried out at the same time.

After the above-mentioned hydrolysis step or hydrolysis step and condensation reaction step are completed, an isopropanol solution of 2,6-di-t-butyl-p-cresol (BHT) or the like is added to the polymerization reaction system to stop the polymerization reaction. To do.
Then, the modified conjugated diene (co) polymer of the present invention is obtained through a desolvation treatment such as steam stripping in which steam is blown to reduce the partial pressure of the solvent and a vacuum drying treatment.
Here, when a hydrocarbyloxysilane compound having a protected primary amino group is used as the organic silane compound represented by the general formula (2) in the modification reaction step, the above-mentioned hydrolysis step, steam stripping, etc. In the desolvation treatment step using water vapor, a deprotection treatment for removing the protecting group of the protected nitrogen atom to generate a primary amino group is performed at the same time, but in addition to this, the desolvation treatment is performed after the modification reaction step is completed. From the hydrocarbyloxysilane compound, it is converted to a liberated primary amino group by hydrolyzing the protecting group on the primary amino group by various methods as necessary at any stage until it becomes a dry polymer. The protected primary amino group can be deprotected.

Next, the modified conjugated diene (co) polymer obtained by the above-mentioned production method (hereinafter, referred to as modified conjugated diene (co) polymer I) will be described.
[Modified conjugated diene (co) polymer I]
The modified conjugated diene (co) polymer I in the present invention contains a silanol group and a functional group in the vicinity of the silanol group, which promotes the reaction between the silanol group and the reinforcing filler. It has at the end of the chain.
Further, the modified conjugated diene (co) polymer I in the present invention is more specifically a modified conjugated diene (co) polymer represented by the following general formula (3) or the following general formula (4).

ここで、Ｒ^１は単結合又は炭素数１〜２０の二価の炭化水素基；Ｒ^２及びＲ^３はそれぞれ独立に水素又は炭素数１〜２０の一価の炭化水素基；Ａ^３はシラノール基と補強性充填材との反応を促進する官能基であり、ｍは１〜１０の整数である。

Here, R ¹ is a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms; R ² and R ³ are independently hydrogen or a monovalent hydrocarbon group having 1 to 20 carbon atoms; A ³ is silanol. It is a functional group that promotes the reaction between the group and the reinforcing filler, and m is an integer of 1 to 10.

ここで、Ｒ^４は単結合又は炭素数１〜２０の炭化水素基；Ｒ^５及びＲ^６はそれぞれ独立に単結合、水素又は炭素数１〜２０の炭化水素基；Ａ^４は単結合、炭素数１〜２０の炭化水素基又はシラノール基と補強性充填材との反応を促進する官能基；Ｂ及びＤはそれぞれ独立にシラノール基と補強性充填材との反応を促進する官能基を少なくとも一つ含む基；ｐ及びｑはそれぞれ独立に０〜５の整数であり、（ｐ＋ｑ）が１以上である。ｎは１〜１０の整数であり、好ましくは１〜６の整数である。
なお、（Polymer）− は変性共役ジエン（共）重合体のポリマー鎖である。

Here, R ⁴ is a single bond or a hydrocarbon group having 1 to 20 carbon atoms; R ⁵ and R ⁶ are independently single bonds, hydrogen or a hydrocarbon group having 1 to 20 carbon atoms; A ⁴ is a single bond or carbon. Numbers 1 to 20 hydrocarbon groups or functional groups that promote the reaction between the silanol group and the reinforcing filler; B and D each independently have at least one functional group that promotes the reaction between the silanol group and the reinforcing filler. Groups containing one; p and q are independently integers from 0 to 5, and (p + q) is 1 or more. n is an integer of 1 to 10, preferably an integer of 1 to 6.
In addition, (Polymer)-is a polymer chain of a modified conjugated diene (co) polymer.

In the general formula (3) and the above general formula (4), R ⁵ when R ¹ , R ⁴ , p is 1, or R ⁶ when q is 1, divalent of 1 to 20 carbon atoms. As specific examples of the hydrocarbon group of, R ¹ , R ⁴ in the general formula (1) and the general formula (2), R ⁵ when p is 1, or R ⁶ when q is 1. The same specific example can be given.
Further, in the above general formula (3) and the above general formula (4), R ⁵ when R ² , R ³ , p is 0 or R ⁶ when q is 0 has 1 to 20 carbon atoms. specific examples of the monovalent hydrocarbon group, when R ⁵ or q where R ^2, R 3 wherein in the general formula (1) and the general formula (2), ^p is 0 is 0 R ^The same specific example as the monovalent hydrocarbon group having 1 to 20 carbon atoms, which is ⁶ , can be mentioned.

In the general formula (3) and the general formula (4), the functional group A ³ and A ⁴ to promote the reaction between the silanol group and the reinforcing filler, each independently, for example, (thio) ether bond, (Thio) A divalent functional group having at least one bond selected from a urethane bond, an imino bond and an amide bond, and a nitrile group (cyano group), a pyridyl group, an N-alkylpyrrolidonic group, and an N-alkyl group. Imidazolyl group, N-alkylpyrazolyl group, (thio) ketone group, (thio) aldehyde group, isocyanuric acid triester residue, (thio) carboxylic acid hydrocarbyl ester residue having 1 to 20 carbon atoms, carbon number 1 to 20 (Thio) A functional group selected from a carboxylic acid metal salt residue, a carboxylic acid anhydride residue having 1 to 20 carbon atoms, a carboxylic acid halide residue having 1 to 20 carbon atoms, and a dihydrocarbyl carbonate residue. It is at least one divalent functional group selected from the group consisting of the derived divalent functional groups.
Here, the divalent functional group having at least one bond selected from (thio) ether bond, (thio) urethane bond, imino bond and amide bond is (thio) ether bond, (thio) urethane bond, It may be an imino bond or an amide bond, or it may be a divalent hydrocarbon group having 1 to 20 carbon atoms having a (thio) ether bond, a (thio) urethane bond, an imino bond and / or an amide bond. .. As the divalent hydrocarbon group having 1 to 20 carbon atoms, R ^5, or q in the case where R ¹ , R ⁴ , and p in the general formula (1) and the general formula (2) are 1 is 1. The same specific example as R ^{6 in a} certain case can be mentioned.

The general formula (3), and ^{A 3} and ^{A 4} in the general formula (4), each of ^{A 2} of ^{A 1} and of the general formula (1) (2), the modified conjugated diene (co) polymer activity It shows a functional group bonded to the site and has an action of promoting the reaction between the silanol group formed in the hydrolysis reaction step and the reinforcing filler.

In the above general formula (4), the groups B and D containing at least one functional group that promotes the reaction between the silanol group and the reinforcing filler are independently protected as a primary amino group and a secondary amino group, respectively. Primary or secondary amino group, tertiary amino group, cyclic amino group, oxazolyl group, imidazolyl group, aziridinyl group, (thio) ketone group, (thio) aldehyde group and amide group, (thio) epoxy group, glycidoxy group , (Thio) isocyanate group, nitrile group (cyano group), pyridyl group, N-alkylpyrrolidnyl group, N-alkylimidazolyl group, N-alkylpyrazolyl group, imino group, amide group, ketimine group, imine residue, Isocyanuric acid triester residue, (thio) carboxylic acid hydrocarbyl ester residue having 1 to 20 carbon atoms, residue of (thio) carboxylic acid metal salt having 1 to 20 carbon atoms, carboxylic acid anhydride having 1 to 20 carbon atoms. Included are at least one functional group selected from residues, carboxylic acid halide residues having 1 to 20 carbon atoms, dihydrocarbyl carbonate residues and functional groups represented by the general formula -EFG.
Here, E is an imino group, a divalent imine residue, a divalent pyridine residue or a divalent amide residue, and F is an alkylene group having 1 to 20 carbon atoms, a phenylene group or an aralkylene having 8 to 20 carbon atoms. Group, G is a primary amino group, a secondary amino group, a protected primary or secondary amino group, a tertiary amino group, a cyclic amino group, an oxazolyl group, an imidazolyl group, an aziridinyl group, a ketimine group, a nitrile group (cyano). Group), amide group, pyridine group or (thio) isocyanate group.
Specific examples of the functional group represented by the general formula -E-F-G are as described above.
The desorbable functional group of the protected primary or secondary amino group may remain in the modified conjugated diene (co) polymer of the present invention without being deprotected.

As shown in the general formula (3) or the general formula (4), the modified conjugated diene (co) polymer of the present invention preferably has only one silanol group present in the molecular chain. This is because if two or more silanol groups are present in the molecular chain, the silanol groups may condense with each other, increasing the viscosity of the modified conjugated diene (co) polymer and making the kneading operation difficult.

Further, in the present embodiment, the modified conjugated diene (co) polymer has both a silanol group and a functional group that promotes the reaction between the silanol group and the reinforcing filler in the vicinity of the silanol group, and thus the silanol group. Only modified conjugated diene (co) polymers that have only a silanol group and no functional group that promotes the reaction between the silanol group and the reinforcing filler, and functional groups that promote the reaction between the silanol group and the reinforcing filler. Compared with the modified conjugated diene (co) polymer having and not having a silanol group, the low calorific value is improved in both the silica-blended rubber composition and the carbon black-blended rubber composition.

In the present embodiment, the modified conjugated diene (co) polymer does not limit the vinyl bond content of the conjugated diene portion, but is preferably 70% or less. If it is 70% or less, it is preferable when it is used for a tire tread because the fracture characteristics and wear characteristics are improved. Further, the styrene content is preferably 0 to 50% by mass. This is because if it is 50% by mass or less, the balance between low heat generation and wet skid performance is improved.
The vinyl bond content is obtained by the infrared method (Molero method), and the styrene content is obtained by calculating the integral ratio of the spectrum by ¹ H-NMR.

[Rubber component B]
The rubber component B applicable to the rubber composition according to the present embodiment has a glass transition temperature of −35 ° C. or higher. Further, the glass transition point of the rubber component B is preferably higher than the glass transition point of the rubber component A.
If the glass transition temperature of the rubber component B is less than −35 ° C., sufficient wet grip performance cannot be obtained. From this point of view, the glass transition temperature of the rubber component B is more preferably −30 ° C. or higher, and even more preferably −25 ° C. or higher.
The amount of styrene + 1/2 vinyl of the rubber component B is preferably 45% by mass or more, and more preferably 50% by mass or more. If the rubber component B has the above properties, sufficient wet grip performance can be obtained.
Examples of the diene rubber that can be used as the rubber component B include natural rubber, polybutadiene rubber, synthetic polyisoprene rubber, styrene-isoprene rubber, ethylene-butadiene copolymer rubber, propylene-butadiene copolymer rubber, and ethylene-propylene-. Examples thereof include butadiene copolymer rubber, ethylene-α-olefin-diene copolymer rubber, butyl rubber, butyl halide rubber, copolymer of styrene having a methyl halide group and isobutylene, and chloroprene rubber.

[Reinforcing filler]
The rubber composition according to the present embodiment preferably contains 30 to 150 parts by mass of the reinforcing filler with respect to a total of 100 parts by mass of the rubber component A and the rubber component B, and contains 40 to 120 parts by mass. It is more preferable to contain it. If it is 30 parts by mass or more, the wear resistance is improved, and if it is 150 parts by mass or less, the fuel efficiency is improved.
The reinforcing filler is preferably silica and / or carbon black. In particular, the filler is preferably silica alone or silica and carbon black, and the content ratio of silica to carbon black (silica: carbon black) is (100: 0) to (30:70) by mass ratio. It is preferably (100: 0) to (50:50), and more preferably. The blending amount of silica is preferably 10 to 100 parts by mass, and more preferably 30 to 80 parts by mass with respect to 100 parts by mass of the rubber component. Within this range, fuel efficiency and wear resistance can be further improved.

Examples of silica include wet silica (hydrous silicic acid), dry silica (silicic anhydride), calcium silicate, aluminum silicate, etc. Among them, the wet type, which has the most remarkable effect of achieving both wet performance and wear resistance. Silica is preferred.
The BET specific surface area of silica (measured according to ISO 5794/1) is preferably 80 m ² / g or more, more preferably 120 m ² / g or more, and particularly preferably 150 m ² / g or more. The upper limit of the BET specific surface area is not particularly limited, but is usually about 450 m ² / g. Examples of such silica include Tosoh Silica Co., Ltd., trade name "Nip Seal AQ" (BET specific surface area = 205 m ² / g), "Nip Seal KQ", Degussa Co., Ltd., product name "Ultra Jill VN3" (BET specific surface area). = 175 m ² / g) and other commercially available products can be used.

The carbon black is not particularly limited, and for example, HAF, N339, IISAF, 1SAF, SAF and the like are used. The specific surface area of carbon black by the nitrogen adsorption method (measured according to N ₂ SA, JIS K 6217-2: 2001) is preferably 70 to 180 m ² / g, and more preferably 80 to 180 m ² / g. Further, DBP oil absorption amount (JIS K 6217-4: measured according to 2008) is preferably 70~160cm ³ / 100g, more preferably 90~160cm ³ / 100g. By using carbon black, the effect of improving the fracture resistance, wear resistance, etc. is increased. N339, IISAF, ISAF, and SAF, which have excellent wear resistance, are particularly preferable.
One type of silica and / or carbon black may be used, or two or more types may be used in combination.

[Silane coupling agent]
In the rubber composition according to the present embodiment, if silica is used as one of the reinforcing fillers, if desired, a silane cup rigging agent is used for the purpose of further improving the reinforcing property and fuel efficiency of the rubber composition. It is preferable to mix.
Examples of the silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, and bis (2-triethoxysilyl). Ethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltri Methoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-triethoxysilyl Ethyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-trimethoxysilylpropylbenzothiazolyltetrasulfide, 3-triethoxysilylpropylbenzolyltetrasulfide, 3-triethoxysilylpropylmethacrylate monosulfide, 3-trimethoxy Cyrilpropyl methacrylate monosulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyl dimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, dimethoxymethylsilylpropylbenzothiazolyl Examples thereof include tetrasulfide and 3-octanoylthiopropyltriethoxysilane. Among these, bis (3-triethoxysilylpropyl) polysulfide and 3-octanoylthiopropyltriethoxy are used from the viewpoint of improving the reinforcing property. Silane and 3-trimethoxysilylpropylbenzothiadyltetrasulfide are suitable.
One of these silane coupling agents may be used alone, or two or more thereof may be used in combination.

From the viewpoint of the effect as a coupling agent and the prevention of gelation, a preferable blending amount of this silane coupling agent is a mass ratio (silane coupling agent / silica) of (1/100) to (20/100). Is preferable. If it is (1/100) or more, the effect of improving the low heat generation of the rubber composition is more preferably exhibited, and if it is (20/100) or less, the cost of the rubber composition is reduced and it is economical. Is improved. Further, the mass ratio is more preferably (3/100) to (20/100), and the mass ratio is particularly preferably (4/100) to (10/100).

[Other additives]
The rubber composition according to the present embodiment contains various chemicals usually used in the rubber industry, for example, vulcanizing agents, vulcanization accelerators, process oils, and aging, as long as the effects of the present invention are not impaired. It can contain an inhibitor, a scorch inhibitor, zinc oxide, stearic acid and the like.
Examples of the vulcanizing agent include sulfur and the like. The amount of the vulcanizing agent used is preferably 0.1 to 10.0 parts by mass, more preferably 1.0 to 5.0 parts by mass, as the sulfur content with respect to 100 parts by mass of the rubber component. If it is less than 0.1 part by mass, the breaking strength, wear resistance and fuel efficiency of the vulcanized rubber may be lowered, and if it exceeds 10.0 parts by mass, the rubber elasticity may be lost.

Examples of the vulcanization accelerator that can be used in the rubber composition according to the present embodiment include M (2-mercaptobenzothiazole), DM (dibenzothiazil disulfide), and CZ (N-cyclohexyl-2-benzothiazylsulfenamide). ) And other thiazole-based, DPG (diphenylguanidine) and other guanidine-based, and TOT (tetrakis (2-ethylhexyl) thiuram disulfide) and other thiuram-based vulcanization accelerators. , 0.1 to 5.0 parts by mass is preferable, and more preferably 0.2 to 3.0 parts by mass with respect to 100 parts by mass of the rubber component.

Further, as the process oil used as a softener that can be used in the rubber composition according to the present embodiment, an aromatic oil is used from the viewpoint of compatibility with SBR. Further, from the viewpoint of emphasizing low temperature characteristics, naphthenic oil or paraffin oil is used. The amount used is preferably 0 to 100 parts by mass with respect to 100 parts by mass of the rubber component, and if it is 100 parts by mass or less, the tensile strength and fuel efficiency (low heat generation) of the vulcanized rubber are suppressed from deteriorating. can do.

Examples of the antioxidant that can be used in the rubber composition according to the present embodiment include 3C (N-isopropyl-N'-phenyl-p-phenylenediamine, 6C [N- (1,3-dimethylbutyl) -N'-. Phenyl-p-phenylenediamine], AW (6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline), high-temperature condensate of diphenylamine and acetone, etc. The amount used is rubber. It is preferably 0.1 to 5.0 parts by mass, more preferably 0.3 to 3.0 parts by mass with respect to 100 parts by mass of the component.

[Preparation of rubber composition, production of pneumatic tires]
The rubber composition according to the present embodiment is obtained by kneading the above-mentioned various components and additives using a kneader such as a Banbury mixer, a roll, or an internal mixer.
That is, in the rubber composition according to the present embodiment, the rubber component A, the rubber component B, and the reinforcing filler are kneaded in the first stage of kneading, and then the vulcanizing agent and vulcanization promotion are carried out in the final stage of kneading. It can be prepared by mixing the agents.
Since the rubber component A contains a modified conjugated diene (co) polymer having a high affinity with a reinforcing filler such as silica, the rubber of the rubber component A and the rubber component B can be obtained by the above kneading. The reinforcing filler can be satisfactorily dispersed in the component A.
The obtained rubber composition can be further molded and then vulcanized to produce a tread of a pneumatic tire, particularly a tread ground contact portion.
Further, the rubber composition according to the present embodiment is used for the tread, and the tire is manufactured by a normal tire manufacturing method. That is, the rubber composition containing the above-mentioned various chemicals is processed into each member at the stage of unvulcanization, and is pasted and molded on a tire molding machine by a usual method to form a raw tire. The raw tire is heated and pressurized in a vulcanizer to obtain a tire. In this way, a tire having low heat generation and good wear resistance, particularly a pneumatic tire can be obtained.

Hereinafter, the present invention will be described in detail with reference to examples. The present invention is not limited to the examples.
[Measuring method]
Each characteristic was evaluated according to the following method.
<Tire performance>
A vulcanized rubber sample was cut out from the tread of the tire and evaluated as follows.
(Wet grip performance)
Using a viscoelastic spectrometer (manufactured by Toyo Seiki Co., Ltd.), tan δ was measured at a frequency of 52 Hz, an initial strain of 10%, a measurement temperature of 0 ° C., and a dynamic strain of 1%, and the tan δ value of Comparative Example 1 was set to 100 by the following formula. Displayed as an index. The larger the value of this index, the better the wet grip performance.
Wet figure of merit = {(tan δ value of test tire) / (tan δ value of Comparative Example 1)} × 100

(Low heat generation)
Using a viscoelastic spectrometer (manufactured by Toyo Seiki Co., Ltd.), tan δ was measured at a frequency of 52 Hz, an initial strain of 10%, a measurement temperature of 60 ° C., and a kinetic strain of 1%. Expressed as an exponent by the formula. The larger the value of this index, the better the low heat generation.
Low heat generation index = {(tan δ value of Comparative Example 1) / (tan δ value of test tire)} × 100

(Abrasion resistance)
A vulcanized rubber sample was cut out from the tire tread, and the amount of wear with a slip ratio of 60% at room temperature was measured using a Ramborn type wear tester according to JIS K6264. Expressed as an exponent by the formula. The larger the value of this index, the better the wear resistance.
Wear resistance index = {(wear amount of Comparative Example 1) / (wear amount of test tire)} x 100

[Manufacturing example]
-Production Example 1: Production of Modified SBR1 Modified SBR1 described later was produced as follows. That is, 2750 g of cyclohexane, 29.5 g of tetrahydrofuran, 50 g of styrene, and 450 g of 1,3-butadiene were charged into an autoclave reactor having an internal volume of 5 liters substituted with nitrogen. After adjusting the temperature of the contents of the reactor to 10 ° C., 215 mg of n-butyllithium was added to initiate polymerization. The polymerization was carried out under adiabatic conditions and the maximum temperature reached 85 ° C.
When the polymerization conversion rate reached 99%, 10 g of butadiene was added, and the mixture was further polymerized for 5 minutes. From the reactor, a small amount of the polymer solution was sampled in 30 g of a cyclohexane solution to which 1 g of methanol was added, and then 1129 mg of aminopropylmethyldiethoxysilane was added, and a modification reaction was carried out for 15 minutes to obtain modified SBR1.
The amount of styrene of the obtained modified SBR1 was 10%, the amount of vinyl in the diene compound portion was 40%, and the Tg was about −70 ° C.

Production Example 2: Production of Modified SBR2 2500 g of cyclohexane, 25 g of tetrahydrofuran, 100 g of styrene, and 390 g of 1,3-butadiene were charged into a dry, nitrogen-substituted 5 liter autoclave reactor. After adjusting the temperature of the reactor contents to 10 ° C., 375 mg of n-butyllithium (BuLi) was added to initiate polymerization. The polymerization was carried out under adiabatic conditions and the maximum temperature reached 85 ° C. When the polymerization conversion rate reaches 99%, 10 g of butadiene is added, and after further polymerization for 5 minutes, 100 mg of silicon tetrachloride is added and the reaction is carried out for 5 minutes, followed by N, N-bis (trimethylsilyl) amino. 1020 mg of propylmethyldiethoxysilane was added and the reaction was carried out for 15 minutes. 2,6-di-t-butyl-p-cresol (BHT) was added to the polymer solution after the reaction to stop the reaction. Then, the solvent was removed by steam stripping and dried by a heat roll adjusted to 110 ° C. to obtain modified SBR2.
The amount of styrene of the obtained modified SBR2 was 25%, the amount of vinyl in the diene compound portion was 55%, and the Tg was about −15 ° C.

-Production example 3: Production of modified BR A glass bottle with a rubber stopper having a volume of about 1 liter was dried and replaced with nitrogen, and a cyclohexane solution of butadiene and dried cyclohexane were added thereto to add 15.0% by mass of butadiene. 330 g of cyclohexane solution was added. To this, 0.513 mmol of hexamethyleneimine (HMI) was added. Next, 0.36 mL of tert-butyllithium (1.57M) and 0.057 mL of 2,2-di (2-tetrahydrofuryl) propane (0.2N) were added, and the mixture was added in a water bath at 50 ° C. for 4.5 hours. Polymerization was performed. Then, 0.10 mmol of tin tetrachloride (SnCl ₄ ) was added at 50 ° C., and the mixture was reacted for 1 hour. After reprecipitation in isopropanol containing a trace amount of NS-5, it was dried in a drum to obtain a modified BR in a yield of almost 100%.

[Examples and Comparative Examples]
Table 1 shows the properties of the rubber components used in the production of the rubber composition of the specimen. Rubber compositions having the compounding compositions shown in Table 2 were prepared, and these rubber compositions were used in the tread portion to produce pneumatic radial tires for passenger cars (tire size 195 / 60R15) according to a conventional method. The performance of each of the obtained specimen tires was evaluated by the method described above.

[note]
* 1 NR: Natural rubber * 2 SBR1: Emulsion polymerization SBR "E-SBR" manufactured by JSR Corporation (styrene content 40%, diene compound portion vinyl content 19%, glass transition temperature -31 ° C)
* 3 SBR2: Emulsion polymerization SBR "E-SBR" manufactured by JSR Corporation (styrene content 45%, diene compound portion vinyl content 19%, glass transition temperature -24 ° C)
* 4 SBR3: Emulsion polymerization SBR "E-SBR" manufactured by JSR Corporation (styrene content 37%, diene compound portion vinyl content 19%, glass transition temperature -38 ° C)
* 5 SBR4: Emulsion polymerization SBR "E-SBR" manufactured by JSR Corporation (styrene content 24%, diene compound portion vinyl content 19%, glass transition temperature -55 ° C)
* 6 SBR5: Solution-polymerized SBR "S-SBR" manufactured by JSR Corporation (39% styrene content, 40% vinyl content in the diene compound portion, glass transition temperature -15 ° C)
* 7 Modified SBR1: The one obtained in Production Example 1 was used.
* 8 Unmodified BR: "Diene NF35R" manufactured by Asahi Kasei Corporation
* 9 Modified SBR2: The one obtained in Production Example 2 was used.
* 10 Modified BR: The one obtained in Production Example 3 was used.
* 11 Made by Toso Silica Co., Ltd., Product name "Nip Seal AQ" (BET specific surface area = 205 m ² / g)
* 12 Carbon black: "Asahi # 70 (N330)" manufactured by Asahi Carbon Co., Ltd.
* 13 Silane coupling agent: Bis (3-trietoxysilylpropyl) disulfide (average sulfur chain length: 2.35), manufactured by Evonik, trade name "Si75"
* 14 Process oil: Aromatic oil, "Aromax # 3" manufactured by Fujikosan Co., Ltd.
* 15 Anti-aging agent 6C: N- (1,3-dimethyl) -N'-phenyl-p-phenylenediamine, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., "Nocrack 6C"
* 16 Vulcanization accelerator DM: Dibenzothiazil sulfide, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., "Noxeller DM-P"

[Evaluation results]
According to the results shown in Tables 1 and 2, by using a rubber component having a glass transition point of −35 ° C. or higher and a rubber component having a glass transition point lower than this, and using those that are incompatible with each other. , Wet grip performance is improved. Further, by using the modified SBR having a relatively low glass transition point, the dispersibility of silica, which is a reinforcing filler, can be improved. This improves low heat generation.

Claims (4)

Butadiene copolymer including a rubber component A, - natural rubber and the glass transition temperature of -50 ° C. or less of the modified styrene
A rubber component B made of a styrene-butadiene copolymer having a glass transition temperature of −35 ° C. or higher and a reinforcing filler are blended.
The modified styrene-butadiene copolymer is contained in an amount of 10 to 40% by mass based on the total amount of the rubber component.
The modified styrene-butadiene copolymer is present at the molecular terminal of the styrene-butadiene copolymer in a silanol group and in the range of 1 to 20 carbon atoms (may be via a silicon atom) from the silanol group. It is a functional group and has a functional group that promotes the reaction between the silanol group and the reinforcing filler.
A rubber composition characterized in that two peaks based on each of the rubber component A and the rubber component B are observed in the temperature dispersion curve of tan δ by a dynamic viscoelasticity test. The rubber composition according to claim 1, wherein the rubber component A is contained in an amount of 50% by mass or more based on the total mass of the rubber component A and the rubber component B. The rubber composition according to claim 1 or 2, wherein the ratio of the natural rubber to the rubber component A is 10% by mass or more and 80% by mass or less based on the total mass of the rubber component A. A tire using the rubber composition according to any one of claims 1 to 3.