JP2011068828A - Modified conjugated diene-based copolymer, modified conjugated diene-based copolymer composition, rubber composition, and method for producing modified conjugated diene-based copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a modified conjugated diene-based copolymer and a rubber composition using the modified conjugated diene-based copolymer suitable for footwear having excellent balance among strength, abrasion-resistant performance, foot comfort, and flexibility. <P>SOLUTION: The modified conjugated diene-based copolymer is provided, which has a silyl group substituted by two or more alkoxy groups and one or more nitrogen atoms at the end of a conjugated diene-based copolymer obtained by copolymerizing a conjugated diene compound and an aromatic vinyl compound using a polyfunctional anionic initiator prepared using a polyvinyl aromatic compound and lithium, and further, which satisfies the following (I) to (III). (I) The bonding amount of the aromatic vinyl compound is 25-75 mass%. (II) The block bonding amount of the aromatic vinyl compound is 3-50 mass%. And (III) the modification ratio determined by the amount of adsorption to a column of gel permeation chromatography measurement using a silica particle-packed column is 78 mass% or more. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a modified conjugated diene copolymer, a modified conjugated diene copolymer composition, a rubber composition, and a method for producing a modified conjugated diene copolymer.

Conventionally, rubber materials have been widely used as footwear materials.
In these processed products, the rubber material is the main component, and various fillers and additives are used to give the rubber material the original properties and to give or improve various properties required according to the application. A rubber composition containing a coloring agent, a reinforcing agent and the like is used as a raw material.
Specifically, carbon black is blended as a filler in order to impart reinforcement.

On the other hand, when the required rubber product is other than black, compounding of silica or the like is performed instead of carbon black.
However, a rubber composition using silica as a reinforcing filler has the following problems.
For example, silica has a low affinity with rubber compared to carbon black, so dispersibility in rubber is not necessarily good, and it tends to lead to insufficient wear resistance and strength properties due to poor dispersibility. .

  In order to improve the dispersibility of silica, conventionally, a composition for footwear containing a modified polymer obtained by reacting a polyfunctional compound having an epoxy group in a molecule has been disclosed (for example, patents). Reference 1).

In addition, a rubber composition in which a specific rubber-like polymer and an inorganic filler are mixed, the inorganic filler is finely dispersed, is transparent and has improved wear resistance, and a method for producing the same has also been proposed (for example, a patent) Reference 2).
Also disclosed is a manufacturing method in which a modified polymer and a predetermined amount of an inorganic filler are mixed in advance and then mixed with the remaining inorganic filler to obtain a composition (for example, Patent Documents). 3).

In addition, for the purpose of obtaining a rubber composition having a strong interaction with inorganic fillers such as silica, proposals for various structures of styrene-butadiene (co) polymers modified with amino groups and alkoxysilyl groups are proposed. Has been made.
For example, a diene rubber in which a tertiary amino group and an alkoxysilyl group are introduced (see, for example, Patent Documents 4 and 5), a modified polymer having a primary amino group and an alkoxysilyl group (for example, Patent Document 6). See).
Since these modified polymers have a strong interaction with silica, silica is finely dispersed in the rubber, and excellent performance is expressed by direct chemical bonding with the rubber. When used for a tread member, the brake performance, rolling resistance performance and the like are effectively improved.

JP 2002-284931 A International Publication No. 2003/091327 Pamphlet International Publication No. 2003/085010 Pamphlet JP 7-233217 A International Publication No. 2003/087171 Pamphlet Japanese Patent Laid-Open No. 2004-18795

However, although the composition disclosed in Patent Document 1 is improved in wear resistance and anti-slip performance as compared with a composition composed of a conventional modified polymer, physical strength is insufficient. .
Also, the rubber composition disclosed in Patent Document 2 is still insufficient in physical strength.
Furthermore, the composition disclosed in Patent Document 3 does not have an effect of improving physical strength and wear resistance.
Furthermore, since the modified polymers disclosed in Patent Documents 4 to 6 have a strong interaction with silica, the dispersed particle diameter of silica becomes fine, and a sufficient strength cannot be obtained in the composition. .

On the other hand, in recent years, materials for weight reduction have been made thinner and foamed in shoes, particularly sports shoes, etc., and the materials used are required to have higher strength and wear resistance. ing.
Therefore, in the present invention, a rubber composition having an excellent balance between strength, wear resistance, comfort and flexibility is obtained without increasing the amount of inorganic filler while improving the dispersibility of the inorganic filler such as silica. For this purpose, a modified conjugated diene copolymer, the modified conjugated diene copolymer composition, and a rubber composition using the same are provided.

As a result of diligent research to solve the above-described problems of the prior art, the present inventors have polymerized using a specific polyfunctional anionic polymerization initiator, and modified the polymerization active terminal with a compound having a specific functional group. When the modified conjugated diene copolymer obtained by adding an inorganic filler, especially a silica-based inorganic filler, and further forming a vulcanized product, the balance between strength, wear resistance, comfort and flexibility is obtained. The present inventors have found that a rubber composition having excellent resistance can be obtained, and have completed the present invention.
That is, the present invention is as follows.

[1]
In the terminal part of the conjugated diene copolymer obtained by copolymerizing a conjugated diene compound and an aromatic vinyl compound using a polyfunctional anionic initiator prepared using a polyvinyl aromatic compound and lithium, 2 A modified conjugated diene copolymer having a silyl group substituted with one or more alkoxy groups and one or more nitrogen atoms, and further a modified conjugated diene copolymer satisfying the following conditions (I) to (III) I will provide a.
(I) The binding amount of the aromatic vinyl compound is 25 to 75% by mass.
(II) The amount of block bonds of the aromatic vinyl compound is 3 to 50% by mass.
(III) The modification rate determined by the amount of adsorption to the column of gel permeation chromatography measurement using a silica particle packed column is 78% by mass or more.

[2]
The compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms is represented by the following formula (1):

(Wherein ^{(1), R 1, R} 2 are each independently an alkyl group or an aryl group having 1 to 20 carbon atoms.
R ³ is an alkylene group having 1 to 20 carbon atoms.
R ⁴ and R ⁵ are hydrocarbon groups having 1 to 6 carbon atoms, which may be the same or different, and form a ring structure of 5 or more members with two adjacent Ns.
R ⁶ is any one selected from the group consisting of a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms substituted with a heteroatom having no active hydrogen, and an organically substituted silyl group. is there.
m is an integer of 2 or 3. )

Or the following formula (2)

(Wherein ^{(2), R 1, R} 2 are each independently an alkyl group or an aryl group having 1 to 20 carbon atoms.
R ³ is an alkylene group having 1 to 20 carbon atoms.
R ⁴ and R ⁵ are hydrocarbon groups having 1 to 6 carbon atoms, which may be the same or different, and form a ring structure of 5 or more members with two adjacent Ns.
R ⁶ is any one selected from the group consisting of a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms substituted with a heteroatom having no active hydrogen, and an organically substituted silyl group. is there.
m is an integer of 2 or 3.
R ⁷ is any one selected from the group consisting of a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a heteroatom having no active hydrogen, and an organically substituted silyl group. It is. )

The modified conjugated diene copolymer according to the above [1] represented by:

[3]
In the modified conjugated diene copolymer, a conjugated diene compound is bonded to a block bond of an aromatic vinyl compound as a terminal of the conjugated diene copolymer, and the terminal is substituted with two or more alkoxy groups. The modified conjugated diene copolymer according to the above [1] or [2], which is modified with a compound having a silyl group and at least one nitrogen atom.

[4]
The modified conjugated diene polymer according to any one of [1] to [3], wherein a molar ratio of the polyvinyl aromatic compound to the lithium (polyvinyl aromatic compound / lithium) is 0.05 to 1.0. I will provide a.

[5]
100 parts by mass of a polymer composition containing 10% by mass or more of the modified conjugated diene copolymer according to any one of [1] to [4], 1-150 parts by mass of a silica-based inorganic filler, A modified conjugated diene copolymer composition is provided.

[6]
A rubber composition for footwear containing the modified conjugated diene copolymer composition described in [5] above and vulcanized is provided.

[7]
A method for producing a modified conjugated diene copolymer according to the above [1] to [4],
(A) a step of adjusting a polyfunctional anionic polymerization initiator using a polyvinyl aromatic compound and lithium;
(B) using the polyfunctional anionic polymerization initiator, copolymerizing a conjugated diene compound and an aromatic vinyl compound to obtain a conjugated diene copolymer;
(C) a step of reacting a compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms at the polymerization active terminal of the conjugated diene copolymer;
A method for producing a modified conjugated diene-based copolymer is provided.

According to the present invention, when combined with various inorganic fillers, particularly silica, a modified conjugated diene copolymer, a modified conjugated diene copolymer that exhibits an excellent balance of strength, wear resistance, and flexibility. A coalescence composition is obtained.
According to the present invention, it is possible to obtain a rubber composition capable of exhibiting a balance of strength, wear resistance, comfort and flexibility, particularly for footwear applications.

  Hereinafter, although the form for implementing this invention (henceforth "this embodiment") is demonstrated, this invention is not limited to the form shown below.

[Modified Conjugated Diene Copolymer]
The modified conjugated diene copolymer of this embodiment is obtained by copolymerizing a conjugated diene compound and an aromatic vinyl compound using a polyfunctional anion initiator prepared using a polyvinyl aromatic compound and lithium. The conjugated diene copolymer is a modified conjugated diene copolymer having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms at the terminal portion, and the following (I) to (I A modified conjugated diene copolymer satisfying the condition (III).
(I) The binding amount of the aromatic vinyl compound is 25 to 75% by mass.
(II) The amount of block bonds of the aromatic vinyl compound is 3 to 50% by mass.
(III) The modification rate determined by the amount of adsorption to the column of gel permeation chromatography measurement using a silica particle packed column is 78% by mass or more.

The modified conjugated diene copolymer of this embodiment will be described together with its production method.
The modified conjugated diene copolymer of the present embodiment includes (A) a step of adjusting a polyfunctional anionic polymerization initiator using a polyvinyl aromatic compound and lithium, and (B) using the polyfunctional anionic polymerization initiator. A step of copolymerizing a conjugated diene compound and an aromatic vinyl compound to obtain a conjugated diene copolymer, and (C) two or more alkoxy groups at the polymerization active terminal of the conjugated diene copolymer. And a step of reacting a compound having a substituted silyl group and one or more nitrogen atoms.
That is, by reacting a compound (modifier) having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms at the polymerization active terminal of the conjugated diene copolymer, the following formula: As shown in (3), a modified conjugated diene copolymer is obtained in a form in which one or more alkoxy groups are reduced from the structure of the original modifier.
In the step (A), a polyvinyl aromatic compound and an organolithium compound are reacted to start polyfunctional anionic polymerization in which the molar ratio of polyvinyl aromatic compound / lithium is in the range of 0.05 to 1.0. It is preferable to prepare an agent.

In Formula (3), Polym is a conjugated diene polymer chain, and R ¹ and R ² each independently represents an alkyl group or an aryl group.
A is an organic group containing a nitrogen atom,
m is an integer of 2 or 3.

Here, the reaction rate constant when the first polymer chain reacts with the alkoxy group bonded to one silyl group is k ₁ , the reaction rate constant when the second polymer chain reacts with k ₂ ,. If this is the case, k ₁ > k ₂ >... From the three-dimensional effect around the modifier, etc., and the difference in reaction rate further increases depending on the type of A and R ² . Therefore, in reality, it is difficult for all alkoxy groups in the same modifier to react with the active terminal.
Therefore, a modified conjugated diene having a silyl group substituted with one or more alkoxy groups at the polymer end by adding a modifier so that the alkoxy group has a sufficient number of moles relative to the number of moles of the active end. A system copolymer is obtained.

(Polyfunctional anionic polymerization initiator)
A polyfunctional anionic polymerization initiator for obtaining a conjugated diene copolymer before modification will be described.
The polyfunctional anionic polymerization initiator can be prepared by reacting a polyvinyl aromatic compound and an organolithium compound as described above.
For example, a method of reacting an organolithium compound and a polyvinyl aromatic compound in a predetermined hydrocarbon solvent; a method of reacting an organolithium compound and a conjugated diene compound and then reacting a polyvinyl aromatic compound; and an organolithium compound A method of reacting a polyvinyl aromatic compound after reacting with a monovinyl aromatic compound; reacting an organolithium compound in the presence of two or three of a conjugated diene compound and / or a monovinyl aromatic compound and a polyvinyl aromatic compound Methods and the like.
The polyfunctional anionic polymerization initiator prepared as described above is used for polymerization of a conjugated diene copolymer composed of a conjugated diene compound-aromatic vinyl compound.
In particular, a method of reacting an organolithium compound and a polyvinyl aromatic compound in a hydrocarbon solvent; a method of reacting an organolithium compound and a conjugated diene compound and then reacting the polyvinyl aromatic compound; a conjugated diene compound and polyvinyl aroma A polyfunctional anion initiator prepared by a method of reacting a monoorganolithium compound in the presence of a group compound is preferred.
In addition, in order to promote and stabilize the formation of the polyfunctional anionic polymerization initiator, it is preferable to add a Lewis base into the system during the preparation.

<Polyvinyl aromatic compound>
Examples of the polyvinyl aromatic compound used for the preparation of the polyfunctional anionic polymerization initiator include o, m and p-divinylbenzene, o, m and p-diisopropenylbenzene, 1,2,4-trivinylbenzene, 1 , 2-vinyl-3,4-dimethylbenzene, 1,3-divinylnaphthalene, 1,3,5-trivinylnaphthalene, 2,4-divinylbiphenyl, 3,5,4'-trivinylbiphenyl, 1,2 -Divinyl-3,4-dimethylbenzene, 1,5,6-trivinyl-3,7-diethylnaphthalene and the like. These may be used alone or in combination of two or more.
In particular, divinyl benzene and diisopropenyl benzene are preferable, and a mixture of these o-, m-, and p-isomers may be used. For industrial use, it is economically advantageous to use a mixture of these isomers.

<Conjugated diene compounds and monovinyl aromatic compounds>
For the preparation of the polyfunctional anionic polymerization initiator, a conjugated diene compound and / or a monoaromatic vinyl compound can be used together with the above-described polyvinyl aromatic compound.
Examples of the conjugated diene compound used for the preparation of the polyfunctional anionic polymerization initiator include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1, Examples include 3-pentadiene, 1,3-heptadiene, 1,3-hexadiene, and the like. In particular, 1,3-butadiene and isoprene are preferable.
Examples of the monovinyl aromatic compound used for the preparation of the polyfunctional anionic polymerization initiator include styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene and the like. In particular, styrene is preferable.
The conjugated diene compound and / or monoaromatic vinyl compound is preferably added so that the polyfunctional anionic polymerization initiator measured by GPC has a polystyrene-equivalent weight average molecular weight in the range of 500 to 20,000. More preferably, it is added so as to be 10,000 to 10,000.

<Organic lithium compounds>
Examples of the organolithium compound used for the preparation of the polyfunctional anionic polymerization initiator include monoorganolithium such as n-butyllithium, sec-butyllithium, tert-butyllithium, n-propyllithium, iso-propyllithium, and benzyllithium. Compound; 1,4-dilithiobutane, 1,5-dilithiopentane, 1,6-dilithiohexane, 1,10-dilithiodecane, 1,1-dilithiodiphenylene, dilithiopolybutadiene, dilithiopolyisoprene, 1,4- Dilithiobenzene, 1,2-dilithio-1,2-diphenylethane, 1,4-dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, 1,3,5-trilithio-2,4 Polyfunctional organolithium compounds such as 6-triethylbenzene can be mentioned. In particular, a monoorganolithium compound of n-butyllithium, sec-butyllithium, or tert-butyllithium is preferable.

<Hydrocarbon solvent>
Examples of the hydrocarbon solvent used for the preparation of the polyfunctional anionic polymerization initiator include aliphatic hydrocarbons such as butane, pentane, hexane and heptane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, benzene, toluene, xylene and the like. And aromatic hydrocarbons.

<Lewis base>
In preparing the polyfunctional anionic polymerization initiator, it is effective to add a Lewis base in the system in order to promote or stabilize the formation of the polyfunctional anionic polymerization initiator.
Examples of the Lewis base include tertiary monoamine, tertiary diamine, chain or cyclic ether.
Examples of the tertiary monoamine include trimethylamine, triethylamine, methyldiethylamine, 1,1-dimethoxytrimethylamine, 1,1-diethoxytrimethylamine, 1,1-diethoxytriethylamine, N, N-dimethylformamide diisopropyl acetal, N, N -Compounds such as dimethylformamide dicyclohexyl acetal.
As the tertiary diamine, for example, N, N, N ′, N′-tetramethyldiaminomethane, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylpropane Diamine, N, N, N ′, N′-tetramethyldiaminobutane, N, N, N ′, N′-tetramethyldiaminopentane, N, N, N ′, N′-tetramethylhexanediamine, dipiperidi And compounds such as nopentane and dipiperidinoethane.
Examples of the chain ether include dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene dimethyl ether.
Examples of the cyclic ether include tetrahydrofuran, bis (2-oxolanyl) ethane, 2,2-bis (2-oxolanyl) propane, 1,1-bis (2-oxolanyl) ethane, and 2,2-bis (2-oxolanyl). ) Butane, 2,2-bis (5-methyl-2-oxolanyl) propane, 2,2-bis (3,4,5-trimethyl-2-oxolanyl) propane, and the like.
Among the Lewis bases described above, tertiary monoamine trimethylamine, triethylamine, tertiary diamine N, N, N ′, N′-tetramethylethylenediamine, and cyclic ether tetrahydrofuran are preferred.
The said Lewis base may be used independently and may be used in combination of 2 or more type.

<Use amount of polyvinyl aromatic compound>
The amount of the above-mentioned polyvinyl aromatic compound used in the preparation of the polyfunctional anionic polymerization initiator is in the range of 0.05 to 1.0 mol with respect to 1 mol of the above-described organic lithium compound, and A range of 1 to 0.5 mol is preferred.
Thereby, a polyfunctional anionic polymerization initiator having a polyvinyl aromatic compound / lithium molar ratio in the range of 0.05 to 1.0 can be prepared.
The greater the amount of polyvinyl aromatic compound used, the greater the proportion of molecular chain ends to which functional groups are imparted by the modification reaction described later, and the affinity and reactivity with the silica-based particles described later are improved. Although the balance of strength, wear resistance, comfort, and flexibility in the conjugated diene copolymer composition can be improved, 1 mol of the organic lithium compound is used from the viewpoint of improving the workability at the time of kneading the composition. It is preferable that it is 1.0 mol or less with respect to.

<Addition amount of Lewis base>
Moreover, when preparing a polyfunctional anionic polymerization initiator, when adding a Lewis base as mentioned above, with respect to the said hydrocarbon solvent used when preparing a polyfunctional anionic polymerization initiator, 30-50, It is preferable to add within the range of 000 ppm, and it is preferable to add within the range of 200 to 20,000 ppm.
Addition of 30 ppm or more is preferable in order to fully express the effect of promoting and stabilizing the reaction, ensuring the degree of freedom of microstructure adjustment in the subsequent polymerization step, and recovering and purifying the solvent after polymerization In consideration of separation from the polymerization solvent in, it is preferably added at 50,000 ppm or less.

<Preparation temperature and reaction time of polyfunctional anionic polymerization initiator>
The temperature for preparing the polyfunctional anionic polymerization initiator is preferably in the range of 10 ° C to 140 ° C, and more preferably in the range of 35 ° C to 110 ° C. From the viewpoint of productivity, it is preferably 10 ° C or higher, and preferably 140 ° C or lower in order to suppress side reactions due to high temperatures.
The reaction time for preparing the polyfunctional anionic polymerization initiator depends on the reaction temperature described above, but is in the range of 5 minutes to 24 hours.

(Conjugated diene copolymer)
Next, the conjugated diene copolymer before modification for obtaining the modified conjugated diene copolymer of the present embodiment will be described.
The conjugated diene copolymer before modification is obtained by copolymerizing a conjugated diene compound and an aromatic vinyl compound using the above-described polyfunctional anionic polymerization initiator.
In the copolymerization step, a polyfunctional anionic polymerization initiator is prepared in advance in a predetermined reactor and supplied to the reactor for copolymerization of the conjugated diene compound and the aromatic vinyl compound to conduct the polymerization reaction. Alternatively, a polyfunctional anionic polymerization initiator may be prepared in a reactor for performing copolymerization, and a predetermined monomer may be supplied to the reactor to perform a polymerization reaction.
From the viewpoint of productivity and quality stability at the time of mass production of a polymer, a polyfunctional anionic polymerization initiator is prepared in advance in a predetermined reactor, and this is used as a reactor for polymerization as required. It is preferable to carry out the copolymerization of the conjugated diene compound and the aromatic vinyl compound.
The polymerization of the conjugated diene copolymer is preferably carried out by a polymerization system such as a batch system or a continuous system in one reactor or two or more connected reactors.

<Polar compound>
When producing a conjugated diene copolymer before modification, for the purpose of randomly copolymerizing an aromatic vinyl compound with a conjugated diene compound, or as a vinylating agent for controlling the microstructure of the conjugated diene part, For the purpose of improving the polymerization rate, a small amount of the following polar compound may be added.
Examples of the polar compound include ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2,2-bis (2-oxolanyl) propane; Tertiary amine compounds such as methylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclidine; alkali metal alkoxides such as potassium tert-amylate, potassium tert-butylate, sodium tert-butylate, sodium amylate Compound: Examples include phosphine compounds such as triphenylphosphine.
These polar compounds may be used alone or in combination of two or more.
Although the usage-amount of the polar compound mentioned above is selected according to the objective and the grade of an effect, it is 0.01-100 mol normally with respect to 1 mol of lithium in a polyfunctional anion polymerization initiator.

<Conjugated diene compound>
Examples of the conjugated diene compound used for the synthesis of the conjugated diene copolymer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 3-methyl-1. , 3-pentadiene, 1,3-heptadiene, 1,3-hexadiene and the like. These may be used alone or in combination of two or more. Among these, 1,3-butadiene and isoprene are particularly preferable.
When allenes and acetylenes are contained as impurities, the denaturation reaction described later is inhibited. Therefore, the total of these concentrations is preferably 200 ppm or less, more preferably 100 ppm or less, and 50 ppm or less. More preferably it is.

<Aromatic vinyl compound>
Examples of the aromatic vinyl compound used for the synthesis of the conjugated diene copolymer include styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and diphenylethylene. These may be used alone or in combination of two or more. Of these, styrene is particularly preferred.

<Polymerization solvent>
The conjugated diene copolymer is polymerized in a predetermined solvent.
As the polymerization solvent, for example, hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons are used.
Specifically, aliphatic hydrocarbons such as butane, pentane, hexane and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; There may be mentioned hydrocarbons composed of mixtures thereof.

<Polymerization temperature>
The polymerization temperature of the conjugated diene copolymer is not particularly limited as long as the living anionic polymerization proceeds. However, it is preferably 0 ° C. or higher from the viewpoint of productivity, and the modification reaction to the active terminal after the polymerization is completed. It is preferable to carry out at 120 degrees C or less from a viewpoint of fully ensuring the quantity, More preferably, it is the range of 20-100 degreeC, More preferably, it is the range of 30-85 degreeC.
The polymerization temperature can be controlled by taking into consideration that the polymerization is an exothermic reaction, further adjusting the monomer and solvent feed temperatures, controlling the monomer concentration, and cooling and heating from the outside of the reactor.

<Impurity treatment>
The conjugated diene compound, aromatic vinyl compound, and polymerization solvent described above are each used alone or before a mixture of these is subjected to a polymerization reaction in advance, using impurities such as allenes and acetylenes as organometallic compounds. In this way, a polymer having a high concentration of active ends can be obtained, and a high modification rate can be achieved.

The modified conjugated diene copolymer of the present embodiment is obtained by modifying the polymerization active terminal of the conjugated diene copolymer with a predetermined modifier described later.
Specifically, as described above, a conjugated diene compound and an aromatic vinyl compound are copolymerized using a polyfunctional anionic initiator to obtain a conjugated diene copolymer, and a modifier is added to the polymerization active terminal. A modified conjugated diene copolymer obtained by reacting is obtained.

<Modifier>
As the modifier, a compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms is used.
As a compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms used in the modification reaction, the following formula (1),

(In the formula ^{(1), R 1, R} 2 are independently an alkyl group having 1 to 20 carbon atoms, or an aryl group, R ³ is an alkylene group having 1 to 20 carbon atoms, R ^4, R ⁵ is a hydrocarbon group having 1 to 6 carbon atoms which may be the same or different, and forms a ring structure of 5 or more members with two adjacent Ns, and R ⁶ has 1 to 20 carbon atoms One selected from the group consisting of a hydrocarbon group, a hydrocarbon group having 1 to 20 carbon atoms substituted with a heteroatom having no active hydrogen, and an organically substituted silyl group, and m is an integer of 2 or 3 .)

  Or the following formula (2)

(In Formula (2), the definition of R < ¹ > -R < ⁶ >, m is the same as that of the said Formula (1).
R7 is any selected from the group consisting of a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms that may be substituted with a heteroatom having no active hydrogen, and an organically substituted silyl group. It is. )

And hydrocarbyloxysilane having a cyclic amino group containing two or more nitrogen atoms, hydrocarbyloxysilane having a functional group such as other cyclic amine, acyclic amine, imine, isocyanate, and cyclic azasilane. It is done.

Specific examples of the hydrocarbyloxysilane having a cyclic amino group represented by the formula (1) are shown below.
For example, 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine, 1- [3- (diethoxyethylsilyl) propyl] -4-methylpiperazine, 1- [3- (trimethoxysilyl) propyl ] -3-methylimidazolidine, 1- [3- (diethoxyethylsilyl) propyl] -3-ethylimidazolidine, 1- [3- (triethoxysilyl) propyl] -3-methylhexahydropyrimidine, 1- [3- (dimethoxymethylsilyl) propyl] -3-methylhexahydropyrimidine, 3- [3- (tributoxysilyl) propyl] -1-methyl-1,2,3,4-tetrahydropyrimidine, 3- [3 -(Dimethoxymethylsilyl) propyl] -1-ethyl-1,2,3,4-tetrahydropyrimidine, 1- (2-ethoxyethyl) ) -3- [3- (trimethoxysilyl) propyl] imidazolidine, (2- {3- [3- (trimethoxysilyl) propyl] tetrahydropyrimidin-1-yl} ethyl) dimethylamine, 1- [3- (Triethoxysilyl) propyl] -4- (trimethylsilyl) piperazine, 1- [3- (dimethoxymethylsilyl) propyl] -4- (trimethylsilyl) piperazine, 1- [3- (tributoxysilyl) propyl] -4- (Trimethylsilyl) piperazine, 1- [3- (diethoxyethylsilyl) propyl] -3- (triethylsilyl) imidazolidine, 1- [3- (triethoxysilyl) propyl] -3- (trimethylsilyl) imidazolidine, 1 -[3- (Dimethoxymethylsilyl) propyl] -3- (trimethylsilyl) hexa Mud pyrimidine, 1- [3- (triethoxysilyl) propyl] -3- (trimethylsilyl) hexahydropyrimidine, 1- [4- (triethoxysilyl) butyl] -4- (trimethylsilyl) piperazine.
Among these, 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine, 1- [3- (trimethoxysilyl) propyl] -3-methylimidazolidine, 1- [3- (triethoxysilyl) ) Propyl] -3-methylhexahydropyrimidine, 1- [3- (triethoxysilyl) propyl] -4- (trimethylsilyl) piperazine, 1- [3- (triethoxysilyl) propyl] -3- (trimethylsilyl) imidazo Lysine, 1- [3- (triethoxysilyl) propyl] -3- (trimethylsilyl) hexahydropyrimidine is preferably used, and 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine, 1- [3 -(Triethoxysilyl) propyl] -4- (trimethylsilyl) piperazine is preferred.

Specific examples of the hydrocarbyloxysilane having a cyclic amino group represented by the formula (2) are shown below.
For example, 2- [3- (trimethoxysilyl) propyl] -1,3-dimethylimidazolidine, 2- (diethoxyethylsilyl) -1,3-diethylimidazolidine, 2- (triethoxysilyl) -1, 4-diethylpiperazine, 2- (dimethoxymethylsilyl) -1,4-dimethylpiperazine, 5- (triethoxysilyl) -1,3-dipropylhexahydropyrimidine, 5- (diethoxyethylsilyl) -1,3 -Diethylhexahydropyrimidine, {2- [3- (2-dimethylaminoethyl) -2- (ethyldimethoxysilyl) -imidazolidin-1-yl] -ethyl} -dimethylamine, 5- (trimethoxysilyl)- 1,3-bis- (2-methoxyethyl) -hexahydropyrimidine, 5- (ethyldimethoxysilyl) -1,3-bi -(2-trimethylsilylethyl) -hexahydropyrimidine) -1,3-dimethylimidazolidine, 2- (3-diethoxyethylsilyl-propyl) -1,3-diethylimidazolidine, 2- (3-triethoxy Silyl-propyl) -1,4-diethylpiperazine, 2- (3-dimethoxymethylsilyl-propyl) -1,4-dimethylpiperazine, 5- (3-triethoxysilyl-propyl) -1,3-dipropylhexa Hydropyrimidine, 5- (3-diethoxyethylsilyl-propyl) -1,3-diethylhexahydropyrimidine, {2- [3- (2-dimethylaminoethyl) -2- (3-ethyldimethoxysilyl-propyl) -Imidazolidin-1-yl] -ethyl} -dimethylamine, 5- (3-trimethoxysilyl-propi ) -1,3-bis- (2-methoxyethyl) -hexahydropyrimidine, 5- (3-ethyldimethoxysilyl-propyl) -1,3-bis- (2-trimethylsilylethyl) -hexahydropyrimidine, 2- [3- (Trimethoxysilyl) propyl] -1,3-bis (trimethylsilyl) imidazolidine, 2- (diethoxyethylsilyl) -1,3-bis (triethylsilyl) imidazolidine, 2- (triethoxysilyl) -1,4-bis (trimethylsilyl) piperazine, 2- (dimethoxymethylsilyl) -1,4-bis (trimethylsilyl) piperazine, 5- (triethoxysilyl) -1,3-bis (tripropylsilyl) hexahydropyrimidine Etc.
Among these, 2- [3- (trimethoxysilyl) propyl] -1,3-dimethylimidazolidine and 2- [3- (trimethoxysilyl) propyl] -1,3- (bistrimethylsilyl) imidazolidine are preferable. .

A compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms used as a modifier, other than the compounds represented by the formulas (1) and (2), Specific examples of hydrocarbyloxysilane having a cyclic amino group are shown below.
For example, [3- (1-hexamethyleneimino) propyl] triethoxysilane, [3- (1-hexamethyleneimino) propyl] trimethoxysilane, [2- (1-hexamethyleneimino) ethyl] triethoxysilane, [2- (1-Hexamethyleneimino) ethyl] trimethoxysilane, [3- (1-pyrrolidinyl) propyl] triethoxysilane, [3- (1-pyrrolidinyl) propyl] trimethoxysilane, [3- (1- Heptamethyleneimino) propyl] triethoxysilane, [3- (1-dodecamethyleneimino) propyl] triethoxysilane, [3- (1-hexamethyleneimino) propyl] diethoxymethylsilane, [3- (1-hexa Methyleneimino) propyl] diethoxyethylsilane and the like.

Specific examples of hydrocarbyloxysilane having a non-cyclic amino group, which is a compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms, used as a modifier, are shown below.
For example, [3- (dimethylamino) propyl] triethoxysilane, [3- (dimethylamino) propyl] trimethoxysilane, [3- (diethylamino) propyl] triethoxysilane, [3- (diethylamino) propyl] trimethoxy Silane, [2- (dimethylamino) ethyl] triethoxysilane, [2- (dimethylamino) ethyl] trimethoxysilane, [3- (dimethylamino) propyl] diethoxymethylsilane, [3-dibutylaminopropyl] tri Ethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-bis (trimethylsilyl) aminopropyltrimethoxysilane, N, N-bis (trimethylsilyl) aminopropyltriethoxysilane, N, N-bis (Trimethylsil ) Aminopropylmethyldiethoxysilane, N, N-bis (trimethylsilyl) aminoethyltrimethoxysilane, N, N-bis (trimethylsilyl) aminoethyltriethoxysilane, N, N-bis (trimethylsilyl) aminoethylmethyldimethoxysilane and N, N-bis (trimethylsilyl) aminoethylmethyldiethoxysilane and the like can be mentioned.

Specific examples of hydrocarbyloxysilanes containing imino groups, which are compounds having silyl groups substituted with two or more alkoxy groups and one or more nitrogen atoms, used as modifiers are shown below.
For example, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine, N- (1-methylethylidene) -3- (triethoxysilyl) -1-propanamine, N -Ethylidene-3- (triethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -3- (triethoxysilyl) -1-propanamine, N- (4-N, N-dimethylamino) Benzylidene) -3- (triethoxysilyl) -1-propanamine, N- (cyclohexylidene) -3- (triethoxysilyl) -1-propanamine, 1- [3- (triethoxysilyl) propyl]- 4,5-dihydroimidazole, 1- [3- (trimethoxysilyl) propyl] -4,5-dihydroimidazole, N- (3-triethoxysilylpro ) -4,5-dihydroimidazole, N- (3-isopropoxysilylpropyl) -4,5-dihydroimidazole, N- (3-methyldiethoxysilylpropyl) -4,5-dihydroimidazole and the like. .

Specific examples of a hydrocarbyloxysilane having an isocyanate group, which is a compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms, used as a modifier, are shown below.
For example, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropylmethyldiethoxysilane, 3-isocyanatopropyltriisopropoxysilane, tris (3-trimethoxysilylpropyl) isocyanate Examples include nurate.

Specific examples of the cyclic azasilane compound, which is a compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms used as a modifier, are shown below.
For example, Nn-butyl-aza-2,2-dimethoxysilacyclopentane, N-ethyl-aza-2,2-diethoxy-4-methylsilacyclopentane, N-allyl-aza-2,2-dimethoxysila Examples include cyclopentane and 1-trimethylsilyl-2,2-dimethoxy-1-aza-2-silacyclopentane.

Among the modifiers described above, the compound represented by the above formula (1) or (2) is preferable, and the compound represented by the above formula (1) is particularly preferable.
These modifiers may be used alone or in combination of two or more.

<Modification reaction temperature and reaction time>
The reaction temperature, reaction time, etc. when the above modifier is reacted with the polymerization active terminal of the conjugated diene copolymer are not particularly limited, but the reaction is performed at 0 ° C. or higher and 120 ° C. or lower for 30 seconds or longer. It is preferable to make it.

<Addition amount of modifier>
The modifier is added so that the total number of moles of alkoxy groups bonded to the silyl group in the added modifier is in the range of 1 to 5 times the total number of moles of lithium contained in the polymerization initiator described above. Preferably, it is added in a range of 1.5 to 3 times, and more preferably in a range of 1.5 to 2.5 times.
From the viewpoint of obtaining a predetermined modification rate, which will be described later, and leaving one or more alkoxy groups at the end of the modified conjugated diene-based molecular chain, it is preferably 1 or more times, from a cost viewpoint. It is preferable to make it 5 times or less.

<Reaction terminator, other treatment>
After performing the modification reaction of the conjugated diene copolymer with the above-described modifier, a reaction terminator may be added to the polymer solution as necessary.
As the reaction terminator, usually, alcohols such as methanol, ethanol and propanol; organic acids such as stearic acid, lauric acid and octanoic acid: water and the like can be used.
In addition, after the modification reaction of the conjugated diene polymer, the metals contained in the polymer may be decalcified as necessary. As the deashing method, for example, a method is used in which an oxidant such as water, an organic acid, an inorganic acid, or hydrogen peroxide is brought into contact with the polymer solution to extract metals, and then the aqueous layer is separated.
In addition, after the modification reaction of the conjugated diene copolymer, an antioxidant may be added to the polymer solution. Examples of the antioxidant include phenol-based stabilizers, phosphorus-based stabilizers, sulfur-based stabilizers and the like.

<Method for Obtaining Modified Conjugated Diene Copolymer>
As a method for obtaining the modified conjugated diene copolymer from the polymer solution, a conventionally known method can be applied.
For example, after separating the solvent by steam stripping or the like, the polymer is separated by filtration, further dehydrated and dried to obtain the polymer, concentrated in a flushing tank, and further devolatilized by a vent extruder or the like. A method, a method of directly devolatilizing with a drum dryer or the like can be applied.

<Modification rate>
The modification rate, that is, the content of the polymer having a functional group component in the modified conjugated diene copolymer is preferably 78% by mass or more, more preferably 86% by mass or more, and 90% by mass or more. More preferably.
Thereby, when a composition using a modified conjugated diene polymer described later is used as a vulcanized product, the balance of strength, wear resistance, comfort, and flexibility becomes good, practically sufficient strength, A balance of wear resistance, comfort and flexibility.
The modification rate can be adjusted to 78% by mass or more as described above by controlling the concentration of allenes and acetylenes which are impurities in the conjugated diene compound described above, the treatment method thereof, and the polymerization temperature.
As a method for measuring the content of the polymer having a functional group component, that is, the modification rate, measurement by chromatography capable of separating the functional group-containing modified component and the non-modified component is preferable.
As a measurement method by this chromatography, a gel permeation chromatography (GPC) column using a polar substance such as silica adsorbing a functional group component as a filler is used, and the internal standard of the non-adsorbed component is quantified by comparison. The method is preferred.

<Weight average molecular weight of modified conjugated diene copolymer>
The weight average molecular weight (polystyrene conversion) of the modified conjugated diene copolymer in the present embodiment is preferably 100,000 to 2,000,000, more preferably 200,000 to 1,000,000, more preferably 250,000 to 50, considering workability and physical properties. Ten thousand is more preferable.
In addition, when the conjugated diene copolymer before modification described above is polymerized by a batch process, a plurality of peaks are observed in the modified conjugated diene copolymer in the molecular weight distribution by GPC. The peak on the lowest molecular weight side is considered to be a component generated by polymerization initiated by a monofunctional component in the polyfunctional polymerization initiator mixture.
The more the polyfunctional component is used as a polymerization initiator, the more the composition using the modified conjugated diene copolymer will have better strength, wear resistance, comfort and flexibility, but on the other hand, the processability will deteriorate. From this viewpoint, it is preferable that the peak area on the lowest molecular weight side is 20 to 50%.

<Binding amount of aromatic vinyl compound in modified conjugated diene copolymer>
The binding amount of the aromatic vinyl compound in the copolymer of the modified conjugated diene copolymer of the present embodiment is 25 to 75% by mass, preferably 30 to 65% by mass, more preferably 35 to 55% by mass. % Range.
When the bond amount of the aromatic vinyl compound is less than 25% by mass, the strength and the wear resistance are inferior, and when it exceeds 75% by mass, the hardness of the modified conjugated diene copolymer composition described later increases, and the flexibility is sufficient. In particular, when the rubber composition described later is used as footwear, the comfort is deteriorated.
The binding amount of the aromatic vinyl compound can be measured by the method described in Examples described later.

<Block bond amount of aromatic vinyl compound in modified conjugated diene copolymer>
The amount of block binding of the aromatic vinyl compound in the modified conjugated diene copolymer was determined by dissolving a predetermined sample in chloroform, adding t-butyl hydroperoxide and osmium tetraoxide, stirring, and adding methanol to the resulting decomposition solution. The resulting precipitate is filtered, dissolved and diluted with chloroform, the absorbance is measured using a UV meter, and the coefficient (F) obtained from a predetermined calibration curve can be used for calculation.
Block bond amount (% by mass) = (F) × (absorbance) × 100 / sample weight The block bond amount of the aromatic vinyl compound in the modified conjugated diene copolymer of the present embodiment is 3 to 50% by mass, Preferably it is 5-35 mass%.
When the amount of block binding of the aromatic vinyl compound is less than 3% by mass, the strength is inferior, and when it exceeds 50% by mass, the wear resistance is remarkably inferior.
When the modified conjugated diene copolymer composition is used for a tread portion of a tire or the like, the aromatic vinyl in the modified conjugated diene copolymer, which has been considered unpreferable for improving wear resistance, is used. When the block structure of the compound is used as a rubber composition for footwear, it is important for achieving a balance between strength and wear resistance.
On the other hand, in rubber for tire tread materials, the block structure of the aromatic vinyl compound has been a cause of deterioration in heat generation, reduction in fuel efficiency, and reduction in wear resistance.
The amount of block bonds of the aromatic vinyl compound can be measured by the method described in Examples described later.

The modified conjugated diene copolymer of the present embodiment is obtained by polymerizing a conjugated diene compound and an aromatic vinyl compound, the terminal thereof, a modifier (a silyl group substituted with two or more alkoxy groups, and one or more nitrogen atoms). Before or after reacting the compound having an atom), a polyfunctional modifier generally referred to as a coupling agent may be reacted.
In this case, as the polyfunctional modifier, those having a functional group having a high affinity with silica are preferable, a glycidyl compound containing an amino group in the molecule, or two diglycidylamino groups in one molecule or It is a compound having three.
For example, tetraglycidyl metaxylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane and the like can be mentioned. These polyfunctional modifiers may be used alone or in combination of two or more.

<Vinyl bond amount of modified conjugated diene copolymer>
The vinyl bond content of the modified conjugated diene copolymer of the present embodiment is preferably 60% or less, and more preferably 45% or less. When the amount of vinyl bonds exceeds 60%, wear resistance is lowered, which is not preferable.
The amount of vinyl bonds in the modified conjugated diene copolymer can be measured by the method described in Examples described later.

<Modified state of modified conjugated diene copolymer>
In the modified conjugated diene copolymer of the present embodiment, the conjugated diene compound is bonded to the block bond of the aromatic vinyl compound as a terminal of the conjugated diene copolymer, and the terminal is substituted with two or more alkoxy groups. It is modified with a compound having a modified silyl group and one or more nitrogen atoms.
That is, before modification with a compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms, a conjugated diene compound is added to the block bond portion of the aromatic vinyl compound of the conjugated diene copolymer. Is added.
The addition amount of the conjugated diene compound is preferably in the range of 0.5 to 10% by mass and more preferably 1 to 6% by mass with respect to the weight of the modified conjugated diene copolymer. If it is less than 0.5% by mass, the modification rate of the modifier (a compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms) is low, and the wear resistance is poor. If it exceeds 10% by mass, the flexibility of the random structure of the copolymer is lowered and the shoe sole becomes hard, which is not preferable.

<Modification rate of modified conjugated diene copolymer>
The modification rate of the modified conjugated diene copolymer of the present embodiment is 78% by mass or more.
The modification rate is determined by the amount of adsorption onto the column in gel permeation chromatography measurement using a silica particle packed column.

<Mooney viscosity of modified conjugated diene copolymer>
The Mooney viscosity (ML1 + 4 (100 ° C.)) measured at 100 ° C. of the modified conjugated diene copolymer of the present embodiment is preferably in the range of 30 to 100, more preferably in the range of 40 to 80. .
When the Mooney viscosity is less than 30, the strength and wear resistance of the rubber composition using the modified conjugated diene copolymer of the present embodiment are reduced, and when it exceeds 100, the processing performance is extremely reduced. It becomes difficult to obtain a practically good rubber composition.

[Modified Conjugated Diene Copolymer Composition]
In the modified conjugated diene copolymer composition of the present embodiment, the silica-based inorganic filler described later is 1 with respect to 100 parts by mass of the polymer composition containing 10% by mass or more of the modified conjugated diene copolymer described above. It shall be contained in 150 parts by mass.
Content of a silica type inorganic filler becomes like this. Preferably it is 10-100 mass parts, More preferably, it is 20-80 mass parts.
When the blending ratio of the silica-based inorganic filler is less than 1 part by mass, the blending effect cannot be obtained, and when it exceeds 150 parts by mass, the workability is lowered and the wear resistance is deteriorated.
The polymer composition is composed of the above-described modified conjugated diene copolymer and a rubber component to be described later other than the modified conjugated diene copolymer.

(Silica-based inorganic filler)
As the silica-based inorganic filler, solid particles having SiO ₂ or Si ₃ Al as the main component of the structural unit can be used.
Examples thereof include inorganic fibrous substances such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, glass fiber, and the like.
Further, a silica-based inorganic filler having a hydrophobic surface or a mixture of a silica-based inorganic filler and a non-silica inorganic filler can also be used. Among these, silica and glass fiber are preferable, and silica is more preferable.
As the silica, any of dry silica, wet silica, synthetic silicate silica, and the like can be used. In particular, wet silica is particularly preferable because it provides remarkable effects of improving the fracture characteristics and anti-slip properties.

In the modified conjugated diene copolymer composition, from the viewpoint of obtaining practically good wear resistance and fracture characteristics, the nitrogen adsorption specific surface area required by the BET adsorption method of the silica-based inorganic filler is 170 to 300 mm ² / g. It is preferable that it is 200-300 mm < ² > / g.

(Inorganic fillers other than silica)
In addition to the silica-based inorganic filler described above, other inorganic fillers may be added to the modified conjugated diene-based copolymer composition in order to improve reinforcing properties.
Examples of inorganic fillers other than silica include carbon black.
As carbon black, carbon black of each class such as SRF, FEF, HAF, ISAF, SAF can be used, nitrogen adsorption specific surface area is 50 mg / g or more, dibutyl phthalate (DBP according to ASTM-D2414-79 standard) oil absorption 80 ml / 100 g of carbon black is preferred.

In addition to the silica-based inorganic filler and carbon black described above, a metal oxide or a metal hydroxide may be added to the modified conjugated diene copolymer composition.
The metal oxide refers to solid particles having the chemical formula MxOy (M is a metal atom, x and y are each an integer of 1 to 6) as a main component, such as alumina, titanium oxide, magnesium oxide, and oxidation. Zinc etc. are mentioned.
Examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, zirconium hydroxide and the like.
Furthermore, a mixture of inorganic fillers other than metal oxides and metal oxides can be used in the modified conjugated diene copolymer composition.

(Silane coupling agent)
The modified conjugated diene copolymer composition may contain a silane coupling agent.
The silane coupling agent has a function of tightly interacting the modified conjugated diene copolymer and other rubber components with the silica-based inorganic filler, and the modified conjugated diene copolymer and other It has an affinity or binding group for each of the rubber component and the silica-based inorganic filler.
Examples of the silane coupling agent include bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl] -disulfide, and bis- [2- (triethoxy Silyl) -ethyl] -tetrasulfide and the like.
0.1-30 mass parts is preferable with respect to 100 mass parts of silica-type inorganic fillers mentioned above, as for the compounding quantity of a silane coupling agent, 0.5-20 mass parts is more preferable, and 1-15 mass parts is. Further preferred.
The amount of silane coupling agent. When the amount is less than 0.1 parts by mass with respect to 100 parts by mass of the silica-based inorganic filler described above, an effective blending effect cannot be obtained. Is not necessary.

(Method for producing modified conjugated diene copolymer composition)
Regarding the method for producing the modified conjugated diene copolymer composition by mixing the above-mentioned modified conjugated diene copolymer, silica inorganic filler, carbon black, other fillers, and silane coupling agent, It is not limited and a conventionally well-known method is applicable.
For example, a melt kneading method using a general blender such as an open roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, a multi-screw extruder, etc. The method of removing by heating etc. are mentioned.
Of these, a melt kneading method using a roll, a Banbury mixer, a kneader, or an extruder is preferred from the viewpoint of productivity and good kneading properties.
In addition, the modified conjugated diene copolymer and various compounding agents may be kneaded in a single step, mixed in multiple times, and kneaded.

The modified conjugated diene copolymer composition in the present embodiment may be vulcanized with a vulcanizing agent.
(Vulcanizing agent)
As the vulcanizing agent, for example, radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur and sulfur compounds can be used.
Sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, polymeric polysulfur compounds, and the like.
The amount of the vulcanizing agent used is usually 0.01 to 20 parts by weight, preferably 0.1 to 15 parts by weight, based on 100 parts by weight of the modified conjugated diene copolymer and other rubber components. .
As the vulcanization method, a conventionally known method can be applied. The vulcanization temperature can be 120 to 200 ° C, and the range of 140 to 180 ° C is preferable.

(Vulcanization accelerator, vulcanization aid)
Further, when vulcanizing the modified conjugated diene polymer composition, a vulcanization accelerator may be used as necessary.
A conventionally well-known material can be used as a vulcanization accelerator. Examples thereof include vulcanization accelerators such as sulfenamide, guanidine, thiuram, aldehyde-amine, aldehyde-ammonia, thiazole, thiourea, and dithiocarbamate.
Examples of the vulcanization aid include zinc white and stearic acid.
The amount of the vulcanization accelerator used is usually 0.01 to 20 parts by weight, preferably 0.1 to 15 parts by weight, based on 100 parts by weight of the modified conjugated diene copolymer and other rubber components. .
In general, the vulcanization aid is preferably used in an amount of 0.5 to 2.0 phr for the primary accelerator and 0.2 to 0.5 phr for the secondary accelerator.

(Rubber softener)
The modified conjugated diene copolymer composition in the present embodiment may contain a rubber softener in order to improve processability.
As the rubber softener, mineral oil or a liquid or low molecular weight synthetic softener is suitable.
The mineral oil rubber softener called process oil or extender oil used for softening, increasing volume and improving processability of rubber is a mixture of aromatic ring, naphthene ring and paraffin chain. A paraffin chain having 50% or more carbon atoms in the total carbon is called paraffinic, a naphthene ring having 30 to 45% carbon is naphthenic, and an aromatic carbon having more than 30% aromatic is aromatic. It is called a system.
The rubber softener is preferably a naphthenic and / or paraffinic one.
The blending amount of the rubber softener is preferably 0 to 100 parts by weight, more preferably 10 to 90 parts by weight, and 30 to 90 parts by weight with respect to 100 parts by weight of the modified conjugated diene copolymer and other rubber components. Further preferred.
If the blending amount of the rubber softener exceeds 100 parts by mass with respect to 100 parts by mass of the modified conjugated diene copolymer and other rubber components, bleeding out tends to occur and the surface of the composition may become sticky. It is not preferable.

(Other rubber components other than modified conjugated diene copolymers)
In the modified conjugated diene copolymer composition of the present embodiment, a rubbery polymer as a rubber component other than the above-described modified conjugated diene copolymer can be used in combination with the modified conjugated diene copolymer.
For example, a conjugated diene polymer or a hydrogenated product thereof, a random copolymer of a conjugated diene compound and a vinyl aromatic compound or a hydrogenated product thereof, a block copolymer of a conjugated diene compound and a vinyl aromatic compound, or a method thereof Examples thereof include hydrogenated products, non-diene polymers, and natural rubber.
Specifically, butadiene rubber or hydrogenated product thereof, isoprene rubber or hydrogenated product thereof, styrene-butadiene rubber or hydrogenated product thereof, styrene-butadiene block copolymer or hydrogenated product thereof, styrene-isoprene block copolymerized Examples thereof include styrene-based elastomers such as coalescence or hydrogenated products thereof, acrylonitrile-butadiene rubber, or hydrogenated products thereof.
Non-diene polymers include ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, ethylene-octene rubber, and other olefinic elastomers, butyl rubber, brominated butyl rubber. Acrylic rubber, fluorine rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β-unsaturated nitrile-acrylate ester-conjugated diene copolymer rubber, urethane rubber, polysulfide rubber and the like.
The rubbery polymer as the various rubber components described above may be a modified rubber provided with a functional group.
These may be used alone or in combination of two or more.
In addition, when mixing 2 or more types, it is preferable that the mixing amount of the modified | denatured conjugated diene type copolymer mentioned above is 10 mass% or more of a polymer composition, and it is more preferable that it is 20 mass% or more.
If the amount of the modified conjugated diene copolymer described above is less than 10% by mass of the polymer composition, the effect of addition is not sufficiently exhibited.

(Other additives)
The modified conjugated diene copolymer composition of the present embodiment includes a predetermined softening agent and filler other than those described above, as well as heat resistance stabilizer, antistatic agent, and weather resistance stabilizer, as long as the characteristics are not impaired. Various additives such as anti-aging agent, coloring agent, lubricant and the like may be contained.
Examples of the filler include calcium carbonate, magnesium carbonate, aluminum sulfate, barium sulfate and the like.
The softener has a function of adjusting the hardness and fluidity of the target product, and examples thereof include liquid paraffin, castor oil, and linseed oil.
Known materials can be applied as the heat resistance stabilizer, antistatic agent, weather resistance stabilizer, anti-aging agent, colorant, and lubricant.

(Rubber composition)
The rubber composition of the present embodiment includes a polymer composition containing 10% by mass or more of the modified conjugated diene copolymer described above, a silica-based inorganic filler, and a silane coupling agent that is blended as necessary. Add additives and knead each component uniformly using a known kneading method such as a Banbury mixer, heating roll, various kneaders, single-screw extruder, twin-screw extruder, etc., and further vulcanize It is obtained by applying. You may perform a crosslinking process as needed.
The rubber composition of the present embodiment includes sports shoes such as jogging shoes, tennis shoes, basketball shoes, and volleyball shoes, trekking shoes used in rocky places, fishing boots, diving shoes, motorcycle shoes, and bath shoes. It is suitable for footwear applications such as outsole of shoes such as rain shoes and beach sandals. However, it is not limited to these.

Examples of the present invention and comparative examples will be specifically described below.
The physical property measurement method and evaluation method applied to the examples and comparative examples are shown below.

[(1) Bonded styrene content]
The sample for measurement was made into a chloroform solution, and the amount of bound styrene (% by mass) was measured by UV254 nm absorption by styrene phenyl group using Shimadzu Corporation UV-2450.

[(2) Bond amount of styrene block]
A weighed sample for measurement was dissolved in chloroform, tertiary butyl hydroperoxide and osmium tetraoxide were added, and the mixture was decomposed in an 80 ° C. water bath for 15 minutes with stirring, and then 10-fold volume of methanol was added to the decomposition solution. Was added and the resulting precipitate was filtered off.
The resulting precipitate was dissolved and diluted with chloroform, the absorbance was measured using a UV meter, and the amount of styrene block bound was determined from the following formula.
Styrene block bond amount (% by mass) = (F) × (absorbance) × 100 / weight of sample for measurement ((F) is a coefficient obtained from a calibration curve.)

[(3) Amount of butadiene 1,2 bond]
The measurement sample is a carbon disulfide solution, the infrared spectrum is measured in the range of 600 to 1000 cm ⁻¹ using a solution cell, and the microstructure of the butadiene portion is determined from the predetermined absorbance according to the calculation formula of the Hampton method. The amount of butadiene 1,2 bond was determined.
As the IR spectrum analyzer, “JASCO Corporation FT-IR230” was used.

[(4) Mooney viscosity]
According to JIS K 6300, a Mooney viscometer was used, and according to JIS K 6300, the viscosity was measured at 100 ° C. for 1 minute of preheating and 2 minutes after 4 rotations.

[(5) Denaturation rate]
Applying the property that the denatured component adsorbs to the GPC column using silica gel as a filler, the sample solution containing the sample and the low molecular weight internal standard polystyrene is GPC (Tosoh) of polystyrene gel (Showa Denko: Shodex). (Manufactured by: HLC-8020) and silica column (manufactured by DuPont: Zorbax) GPC (manufactured by Tosoh: column oven; CO-8020, detector: RI-8021). The amount of adsorption onto the column was measured to determine the denaturation rate.

(Preparation of polyfunctional anionic polymerization initiator)
The preparation method of the polyfunctional anionic polymerization initiator used when superposing | polymerizing the modified conjugated diene type copolymer used by the Example mentioned later and a comparative example is demonstrated.
The autoclave equipped with a stirring device and a jacket with an internal volume of 10 L was washed and dried, and then purged with nitrogen.
Thereafter, 1000 g of 1,3-butadiene subjected to a drying treatment, 4800 g of cyclohexane, 500 ppm of tetrahydrofuran, and 42 g of divinylbenzene were added.
Next, 104 g of n-butyllithium was added and reacted at 75 ° C. for 1 hour to prepare.
For the preparation of the polyfunctional anionic polymerization initiator, a divinylbenzene mixture (manufactured by Nippon Steel Chemical Co., Ltd.) containing m-divinylbenzene, p-divinylbenzene, ethylvinylbenzene, etc. and having a divinylbenzene concentration of 57% by mass is used. It was.

[Production of modified conjugated diene copolymer used in Examples 1 to 3 described later]
(Method for producing sample A)
An autoclave with an internal volume of 10 liters and a temperature-controllable autoclave with a jacket was used as the reactor.
575 g of butadiene from which impurities were removed, 510 g of styrene, 4800 g of cyclohexane, and 0.19 g of 2,2-bis (2-oxolanyl) propane were added to the reactor, and the reactor internal temperature was maintained at 50 ° C.
Thereafter, the polyfunctional polymerization initiator prepared as described above was supplied to the reactor so that the amount of lithium added was 10.5 mmol.
After the start of the reaction, the temperature in the reactor reached 75 ° C. due to heat generated by polymerization, and then 40 g of butadiene was fed in 30 seconds (addition).
After completion of the polymerization reaction, 0.38 mmol of tetraglycidyl-1,3-bisaminomethylcyclohexane was added to the reactor and stirred for 30 seconds to carry out the reaction.
Thereafter, 5.25 mmol of 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine was added as a modifier, and the modification reaction was performed by stirring for 5 minutes.
After adding 1.8 g of an antioxidant (BHT) to the polymer solution obtained by the reaction described above, the solvent was removed to obtain a styrene-butadiene copolymer (sample A) having a modifying component.
As a result of analyzing (Sample A), the amount of bound styrene was 45% by mass, the amount of styrene block bound was 16% by mass, and the Mooney viscosity of the polymer was 60.
The 1,2-bond amount of the microstructure of the butadiene portion determined by calculation according to the Hampton method from the measurement result using an infrared spectrophotometer is 27%, and the modification obtained from GPC using a silica-based adsorption column The rate was 85%.

(Method for producing Sample B)
N, N-bis (trimethylsilyl) aminopropyltrimethoxysilane was used as a modifier.
The other conditions were the same as in Sample A described above to obtain a modified conjugated diene copolymer (Sample B).
As a result of analyzing (Sample B), the amount of bound styrene was 45% by mass, the amount of styrene block bound was 16% by mass, and the Mooney viscosity of the polymer was 60.
The 1,2-bond amount of the microstructure of the butadiene portion determined by calculation according to the Hampton method from the measurement result using an infrared spectrophotometer is 27%, and the modification obtained from GPC using a silica-based adsorption column The rate was 83%.

(Method for producing Sample C)
An autoclave with an internal volume of 10 liters and a temperature-controllable autoclave with a jacket was used as the reactor.
115 g of styrene from which impurities were removed, 4800 g of n-hexane, and 0.19 g of 2,2-bis (2-oxolanyl) propane were charged into the reactor, and the reactor internal temperature was maintained at 50 ° C.
Thereafter, the polyfunctional polymerization initiator prepared as described above was supplied to the reactor so that the amount of lithium added was 10.5 mmol.
After the start of the reaction, after the temperature in the reactor disappeared due to the exothermic reaction of polymerization (peaking), 720 g of butadiene and 280 g of styrene were supplied, and after the temperature in the reactor reached 75 ° C., 10 g of butadiene was added for 30 seconds. Supplied with.
After the completion of the polymerization reaction, 0.38 mmol of tetraglycidyl-1,3-bisaminomethylcyclohexane was added to the reactor and stirred for 30 seconds to carry out the reaction, and then 1- [3- (triethoxysilyl) ) Propyl] -4-methylpiperazine was added in an amount of 5.25 mmol and stirred for 5 minutes to carry out a denaturing reaction.
After adding 1.8 g of antioxidant (BHT) to the polymer solution obtained by the reaction described above, the solvent was removed to obtain a styrene-butadiene copolymer (sample C) having a modifying component.
As a result of analyzing (Sample C), the amount of bound styrene was 35% by mass, the amount of styrene block bound was 5% by mass, and the Mooney viscosity of the polymer was 59.
The 1,2-bond content of the microstructure of the butadiene portion determined by calculation according to the Hampton method from the measurement results using an infrared spectrophotometer is 32%, and the modification determined by GPC using a silica-based adsorption column The rate was 87%.

[Production of Modified Conjugated Diene Copolymer Used in Comparative Examples 1 and 2 to be described later]
(Method for producing sample D)
The polymerization reaction was carried out in the same manner as (Sample A) except that 430 g of butadiene, 510 g of styrene, 185 g of butadiene to be added, and 10.2 mmol of n-butyllithium as a polymerization initiator were changed, and (Sample D) The modified conjugated diene copolymer was obtained.
As a result of analyzing (Sample D), the amount of bound styrene was 45% by mass, the amount of styrene block bound was 0% by mass, and the Mooney viscosity of the polymer was 59.
The 1,2-bond content of the microstructure of the butadiene portion determined by calculation according to the Hampton method from the measurement results using an infrared spectrophotometer is 32%, and the modification determined by GPC using a silica-based adsorption column The rate was 80%.

(Method for producing sample E)
The polymerization initiator was changed to 10.2 mmol of n-butyllithium.
Other conditions were the same as in (Sample A) described above to obtain a modified conjugated diene copolymer of (Sample E).
As a result of analyzing (Sample E), the amount of bound styrene was 45% by mass, the amount of styrene block bound was 16% by mass, and the Mooney viscosity of the polymer was 60.
The 1,2-bond amount of the microstructure of the butadiene portion determined by calculation according to the Hampton method from the measurement result using an infrared spectrophotometer is 27%, and the modification obtained from GPC using a silica-based adsorption column The rate was 79%.

[Examples 1 to 3], [Comparative Examples 1 and 2]
Using the modified conjugated diene copolymers of (Sample A) to (Sample E) produced as described above as raw rubber, rubber compositions were obtained according to the formulation shown in Table 1 below.
The kneading was performed by the following method.
Using a closed kneader (with an internal volume of 0.3 liters) attached with a temperature control device, as the first stage kneading, under the conditions of a filling rate of 65% and a rotor rotational speed of 50/57 rpm, the raw rubber (sample A) to (Sample E), filler (silica), and organosilane coupling agent were kneaded. At this time, the temperature of the closed kneader was controlled, and a rubber composition was obtained at a discharge temperature (compound) of 155 to 160 ° C.
Next, as a second stage kneading, zinc white, stearic acid, and an antioxidant were kneaded. Also in this case, the temperature of the closed kneader was controlled, and a rubber composition was obtained at a discharge temperature (compound) of 155 to 160 ° C.
After cooling, as a third stage kneading, sulfur and a vulcanization accelerator were kneaded with an open roll set at 70 ° C.
The obtained kneaded product was vulcanized with a vulcanization press at 160 ° C. for 20 minutes to prepare a rubber composition test piece.
Using this test piece, the following physical property test was conducted.

(1) Hardness Using a JIS-A hardness tester, the hardness was measured according to JIS-K-6301.

(2) Comfort (rebound resilience)
The specimen was heated to 50 ° C. by the Rupke method according to JIS-K-6301, and the impact resilience was measured and indexed.
The larger the value, the better the comfort.

(3) Flexibility Viscoelastic parameters were measured in a torsion mode using a viscoelasticity tester (ARES) manufactured by Rheometrics Scientific.
The storage elastic modulus (G ′) measured at 50 ° C. with a frequency of 10 Hz and a strain of 3% was measured and indexed.
Larger values indicate better flexibility.

(4) Abrasion resistance Using an Akron abrasion tester, the amount of wear at a load of 6 pounds and 1000 revolutions was measured and indexed. A larger index indicates better wear resistance.

(5) Tensile strength Measured according to the tensile test method of JIS K 6251 and indexed.
The larger the index, the better the tensile strength.
The evaluation results are shown in Table 1 below.

As shown in Table 1, the rubber compositions using the conjugated diene copolymers of Examples 1 to 3 all have hardness, tensile strength, impact resilience (comfort), flexibility, and wear resistance. I found it excellent.
Since Comparative Example 1 uses a modified conjugated diene copolymer that does not satisfy the requirements defined in the present invention in the amount of block bond of the aromatic vinyl compound, all of the above characteristics are compared with Examples 1 to 3. It was inferior.
In Comparative Example 2, since the polymerization initiator used in the polymerization step of the conjugated diene copolymer was not polyfunctional anionic polymerization initiator but n-butyl lithium, Examples 1 to 3 were used in the balance of the above characteristics. It was inferior to that.

  The modified conjugated diene copolymer, modified conjugated diene copolymer composition, and rubber composition of the present invention are industrially applicable as footwear materials, various automobile parts, industrial articles, asphalt compositions, etc. There is.

Claims (7)

In the terminal part of the conjugated diene copolymer obtained by copolymerizing a conjugated diene compound and an aromatic vinyl compound using a polyfunctional anionic initiator prepared using a polyvinyl aromatic compound and lithium, 2 A modified conjugated diene copolymer having a silyl group substituted with one or more alkoxy groups and one or more nitrogen atoms,
Furthermore, a modified conjugated diene copolymer satisfying the following conditions (I) to (III).
(I) The binding amount of the aromatic vinyl compound is 25 to 75% by mass.
(II) The amount of block bonds of the aromatic vinyl compound is 3 to 50% by mass.
(III) The modification rate determined by the amount of adsorption to the column of gel permeation chromatography measurement using a silica particle packed column is 78% by mass or more. A compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms,
Following formula (1)

(Wherein ^{(1), R 1, R} 2 are each independently an alkyl group or an aryl group having 1 to 20 carbon atoms.
R ³ is an alkylene group having 1 to 20 carbon atoms.
R ⁴ and R ⁵ are hydrocarbon groups having 1 to 6 carbon atoms, which may be the same or different, and form a ring structure of 5 or more members with two adjacent Ns.
R ⁶ is any one selected from the group consisting of a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms substituted with a heteroatom having no active hydrogen, and an organically substituted silyl group. is there.
m is an integer of 2 or 3. )
Or
Following formula (2)

(Wherein ^{(2), R 1, R} 2 are each independently an alkyl group or an aryl group having 1 to 20 carbon atoms.
R ³ is an alkylene group having 1 to 20 carbon atoms.
R ⁴ and R ⁵ are hydrocarbon groups having 1 to 6 carbon atoms, which may be the same or different, and form a ring structure of 5 or more members with two adjacent Ns.
R ⁶ is any one selected from the group consisting of a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms substituted with a heteroatom having no active hydrogen, and an organically substituted silyl group. is there.
m is an integer of 2 or 3.
R ⁷ is any one selected from the group consisting of a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a heteroatom having no active hydrogen, and an organically substituted silyl group. It is. )
The modified conjugated diene copolymer according to claim 1 represented by:   In the modified conjugated diene copolymer, a conjugated diene compound is bonded to a block bond of an aromatic vinyl compound as a terminal of the conjugated diene copolymer, and the terminal is substituted with two or more alkoxy groups. The modified conjugated diene copolymer according to claim 1 or 2, which has been modified with a compound having a silyl group and one or more nitrogen atoms.   The modified conjugated diene polymer according to any one of claims 1 to 3, wherein a molar ratio of the polyvinyl aromatic compound to the lithium (polyvinyl aromatic compound / lithium) is 0.05 to 1.0. 100 parts by mass of a polymer composition containing 10% by mass or more of the modified conjugated diene copolymer according to any one of claims 1 to 4,
1 to 150 parts by mass of a silica-based inorganic filler,
A modified conjugated diene copolymer composition.   A rubber composition for footwear containing the modified conjugated diene copolymer composition according to claim 5 and vulcanized. A method for producing the modified conjugated diene copolymer according to any one of claims 1 to 4,
(A) a step of adjusting a polyfunctional anionic polymerization initiator using a polyvinyl aromatic compound and lithium;
(B) using the polyfunctional anionic polymerization initiator, copolymerizing a conjugated diene compound and an aromatic vinyl compound to obtain a conjugated diene copolymer;
(C) a step of reacting a compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms at the polymerization active terminal of the conjugated diene copolymer;
A process for producing a modified conjugated diene copolymer.