KR102536506B1 - Conjugated diene polymer, method for producing conjugated diene polymer, conjugated diene polymer composition, and rubber composition - Google Patents

Abstract

A conjugated diene polymer excellent in tensile strength, abrasion resistance and low hysteresis loss when used as a vulcanizate is obtained.
A conjugated diene-based polymer having a branching degree (Bn) of 7 or more and a weight average molecular weight of 45×10 ⁴ or more and 500×10 ⁴ or less as measured by GPC-light scattering method with a viscosity detector, wherein the aromatic vinyl monomer unit in the conjugated diene-based polymer The content of is 30 to 45% by mass, and the value of the content (% by mass) of the aromatic vinyl monomer unit is larger than the value of the amount of vinyl bonds (mol%) in the conjugated diene monomeric unit.

Description

Conjugated diene polymer, method for producing conjugated diene polymer, conjugated diene polymer composition, and rubber composition

The present invention relates to a conjugated diene-based polymer, a method for producing the conjugated diene-based polymer, a conjugated diene-based polymer composition, and a rubber composition.

BACKGROUND OF THE INVENTION Conventionally, there has been an increasing demand for low fuel consumption for automobiles, and improvement of rubber materials used for automobile tires, particularly tire treads in contact with road surfaces, has been demanded.

[0002] In recent years, with the growing demand for fuel economy regulations for automobiles, automobiles tend to be lightweight due to resinization of members and the like, and also for tires, there is an increasing demand for thinning tire members from the viewpoint of weight reduction.

In order to reduce the weight of a tire, it is necessary to reduce the thickness of a tread part in contact with a road surface with a high proportion of rubber material, and a rubber material having a higher tensile strength than before is required for the tread part.

In addition, in order to reduce energy loss due to tires during driving, rubber materials used in tire treads are required to have low rolling resistance, that is, low hysteresis loss.

On the other hand, from the viewpoint of safety, it is required to have sufficient abrasion resistance for practical use.

As a rubber material that meets the above-described requirements, a rubber composition containing, for example, a rubber-like polymer having a predetermined structure and a reinforcing filler such as carbon black or silica is exemplified.

That is, by introducing a functional group having affinity or reactivity with silica into the molecular terminal portion of the highly mobile rubber-like polymer, the dispersibility of silica in the rubber composition is improved, and furthermore, the rubbery phase is formed by bonding with silica particles. Mobility of the molecular terminal portion of the polymer is reduced, reducing hysteresis loss, improving abrasion resistance and breaking strength.

For example, Patent Documents 1 to 3 propose a rubber composition of a modified conjugated diene polymer obtained by reacting an amino group-containing alkoxysilane with an active end of a conjugated diene polymer and silica.

Japanese Unexamined Patent Publication No. 2005-290355 Japanese Unexamined Patent Publication No. 11-189616 Japanese Unexamined Patent Publication No. 2003-171418

However, in conventionally proposed rubber compositions, since silica has a hydrophilic surface to carbon black, which has a hydrophobic surface, it is less compatible with conjugated diene-based polymers than in rubber compositions with carbon black. It has a problem of poor dispersibility in the medium. Therefore, the rubber composition containing silica needs to contain a silane modifier or the like separately in order to provide a bond between the silica and the conjugated diene-based polymer and improve the dispersibility in the rubber composition.

In addition, when a functional group with high reactivity with silica is introduced into the molecular terminal of the conjugated diene polymer, the reaction with the silica particles proceeds during the kneading step, resulting in an increase in the viscosity of the rubber composition, making it difficult to break, Or, when forming a sheet after kneading, it has a problem that workability tends to be deteriorated, such as surface roughness or sheet fall-off.

In addition, the rubber composition containing silica conventionally proposed as described above has a problem that the balance between tensile strength, wear resistance and low hysteresis loss is not sufficient when the rubber composition is used as a vulcanizate.

Therefore, in the present invention, an object of the present invention is to provide a conjugated diene-based polymer from which a rubber composition excellent in tensile strength, abrasion resistance, and low hysteresis loss property when used as a vulcanizate is obtained.

As a result of intensive research and study to solve the problems of the prior art, the present inventors have found that the branching degree (Bn) is a specific numerical value or more, the weight average molecular weight is a specific numerical range, and the content of the aromatic vinyl monomer unit is a specific numerical range. Tensile strength when the conjugated diene-based copolymer specifying the relationship between the value of the content (% by mass) of the aromatic vinyl monomer unit and the value of the amount of vinyl bonds (mol%) in the conjugated diene monomer unit is made into a vulcanizate , wear resistance, and low hysteresis loss properties were found to be excellent, and the present invention was completed.

That is, this invention is as follows.

〔One〕

The branching degree (Bn) by the GPC-light scattering method with a viscosity detector is 7 or more,

A conjugated diene-based polymer having a weight average molecular weight of 45 × 10 ⁴ or more and 500 × 10 ⁴ or less,

The content of the aromatic vinyl monomer unit in the conjugated diene polymer is 30 to 45% by mass,

A conjugated diene-based polymer in which the value of the content (% by mass) of the aromatic vinyl monomeric unit is greater than the value of the amount of vinyl bonds (mol%) in the conjugated diene monomeric unit.

〔2〕

The conjugated diene polymer according to [1] above, wherein the conjugated diene polymer has a modification ratio of 60% by mass or more as measured by the column adsorption GPC method.

[3]

The conjugated diene polymer according to [1] or [2] above, containing a nitrogen atom and a silicon atom.

〔4〕

The conjugated diene-based polymer has a star-shaped polymer structure with three or more branches,

At least one star-shaped branched chain has a portion derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group, and in the portion derived from the vinyl-based monomer containing the alkoxysilyl group or halosilyl group, further having a main chain branched structure of

The conjugated diene polymer according to any one of [1] to [3].

[5]

The conjugated diene polymer according to [4] above, wherein the vinyl monomer containing the alkoxysilyl group or halosilyl group is a compound represented by the following formula (1) or (2).

(In Formula (1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.

R ² to R ³ each independently represent an alkyl group of 1 to 20 carbon atoms or an aryl group of 6 to 20 carbon atoms, and may have a branched structure at a part thereof.

R ¹ to R ³ in the case of a plurality of presence are independent of each other.

X ¹ represents an independent halogen atom.

m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.)

(In formula (2), each of R ² to R ⁵ independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof. R in the case of multiple presence ² to R ⁵ are each independent.

X ² to X ³ represent independent halogen atoms.

m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.

a represents an integer of 0 to 2, b represents an integer of 0 to 3, and c represents an integer of 0 to 3. (a+b+c) represents 3.)

[6]

The conjugated diene-based polymer according to [5] above, which has a monomer unit based on the compound represented by the formula (1), wherein R ¹ is a hydrogen atom in the formula (1) and m=0.

[7]

The conjugated diene polymer according to [5] above, which has a monomer unit based on the compound represented by the formula (2), in which m = 0 and b = 0 in the formula (2).

〔8〕

In the above [5] having a monomer unit based on the compound represented by the above formula (1), wherein R ¹ is a hydrogen atom in the above formula (1), m = 0, l = 0, and n = 3; Conjugated diene-based polymers described.

[9]

A monomer based on the compound represented by the above formula (2), wherein m = 0, l = 0, n = 3, a = 0, b = 0, and c = 3 in the above formula (2) The conjugated diene polymer according to [5] above having units.

[10]

As a method for producing the conjugated diene polymer according to any one of [1] to [9] above,

Using an organolithium compound as a polymerization initiator, adding a branching agent while polymerizing at least a conjugated diene compound and an aromatic vinyl compound in a solvent containing a polar compound to obtain a conjugated diene polymer having a main chain branched structure; A method for producing a conjugated diene-based polymer.

[11]

The method for producing the conjugated diene-based polymer according to [10] above, which further includes a step of reacting a coupling agent with the conjugated diene-based polymer having the main chain branched structure.

[12]

100 parts by mass of the conjugated diene polymer according to any one of [1] to [9] above;

1 to 60 parts by mass of softener for rubber

A conjugated diene-based polymer composition containing a.

[13]

A rubber composition comprising a rubber component and 5.0 parts by mass or more and 150 parts by mass or less of a filler with respect to 100 parts by mass of the rubber component,

A rubber composition in which the rubber component contains 10 parts by mass or more of the conjugated diene polymer according to any one of [1] to [9] above with respect to 100 parts by mass of the total amount of the rubber component.

ADVANTAGE OF THE INVENTION According to this invention, the conjugated diene type polymer excellent in tensile strength, abrasion resistance, and low hysteresis loss property when used as a vulcanizate can be obtained.

Hereinafter, the mode for implementing the present invention (hereinafter, referred to as "the present embodiment") will be described in detail.

In addition, the present embodiment below is an example for explaining the present invention, and the present invention is not limited to the following embodiment. This invention can be implemented with appropriate modifications within the scope of the gist.

[Conjugated diene polymer]

The conjugated diene-based polymer of the present embodiment,

The branching degree (Bn) by the GPC-light scattering method with a viscosity detector is 7 or more,

A conjugated diene-based polymer having a weight average molecular weight of 45 × 10 ⁴ or more and 500 × 10 ⁴ or less, wherein the content of the aromatic vinyl monomer unit in the conjugated diene-based polymer is 30 to 45% by mass, and the content of the aromatic vinyl monomer unit (% by mass) ) It is a conjugated diene type polymer whose value is larger than the value of the amount of vinyl bonds (mol%) in a conjugated diene monomeric unit.

As described above, the degree of branching (Bn), the weight average molecular weight, the content of aromatic vinyl monomer units, and the "value of the content of aromatic vinyl monomer units" and "the value of the amount of vinyl bonds in the conjugated diene monomer units" specify a magnitude relationship. Thereby, a conjugated diene polymer excellent in processability when used as a vulcanizate and excellent in tensile strength and abrasion resistance when used as a vulcanized product is obtained.

(Branching map (Bn))

From the viewpoint of workability, abrasion resistance, and breaking strength, the conjugated diene-based polymer of the present embodiment has a branching degree (Bn) by a GPC-light scattering method measurement method with a viscosity detector (hereinafter, it may be simply described as a branching degree (Bn)). .) is 7 or more.

The degree of branching (Bn) of 7 or more means that the conjugated diene-based polymer of the present embodiment has 7 or more side chain polymer chains with respect to the substantially longest polymer main chain.

The branching degree (Bn) of the conjugated diene-based polymer is determined by using the shrinkage factor (g') measured by GPC-light scattering method with a viscosity detector, g'=6Bn/{(Bn+1)(Bn+2)} is defined as

In general, a branched polymer tends to have a smaller molecular size when compared with a straight-chain polymer of the same absolute molecular weight.

The shrinkage factor (g') is an index of the ratio of the size occupied by a molecule to a linear polymer of supposedly the same absolute molecular weight. That is, as the branching degree of the polymer increases, the shrinkage factor (g') tends to decrease.

Regarding this shrinkage factor, in the conjugated diene-based polymer of the present embodiment, when intrinsic viscosity is used as an index of molecular size, the linear polymer follows the relational expression of intrinsic viscosity [η] = -3.883M ^0.771 do. In the above formula, M is an absolute molecular weight.

However, the shrinkage factor indicates the size reduction rate of the molecule and does not accurately indicate the branched structure of the polymer.

Therefore, the degree of branching (Bn) of the conjugated diene polymer is calculated using the value of the shrinkage factor (g') at each absolute molecular weight of the conjugated diene polymer. The calculated "branching degree (Bn)" accurately indicates the number of polymers directly or indirectly bonded to each other with respect to the longest main chain structure.

The calculated branching degree (Bn) becomes an index indicating the branching structure of the conjugated diene-based polymer. For example, in the case of a general four-branched star-shaped polymer (four polymer chains are connected at the center), two arms of the polymer chain are bonded to the longest highly branched main chain structure, and the branching degree (Bn) is 2. It is evaluated.

In the case of the 8-branched star polymer, 6 arms of the polymer chain are bonded to the longest highly branched main chain structure, and the branching degree (Bn) is evaluated as 6.

The conjugated diene-based polymer of the present embodiment has a branching degree (Bn) of 7 or more. In this case, 7 arms of the polymer chain are bonded to the longest highly branched main chain structure, which is similar to a 9-branched star polymer structure. It means that it is a conjugated diene-type polymer having a branch.

Here, "branching" is formed by direct or indirect bonding of another polymer to one polymer. In addition, "branching degree (Bn)" is the number of polymers directly or indirectly bonded to each other with respect to the longest main chain structure.

Since the branching degree (Bn) is 7 or more, the conjugated diene polymer of the present embodiment is very excellent in processability when used as a vulcanizate, and excellent in abrasion resistance and breaking strength when used as a vulcanized product.

In general, when the absolute molecular weight of the conjugated diene polymer increases, processability tends to deteriorate, and when the absolute molecular weight of the conjugated diene polymer having a linear polymer structure is increased, the viscosity when used as a vulcanizate increases significantly. As a result, workability deteriorates significantly.

Therefore, even if a large number of functional groups are introduced into the conjugated diene polymer to improve the affinity and/or reactivity with the silica blended as the filler, the silica cannot be sufficiently dispersed in the conjugated diene polymer in the kneading step. . As a result, the function of the introduced functional group is not exhibited, and the originally expected effect of improving the low hysteresis loss property by introducing the functional group tends not to be exhibited.

On the other hand, by specifying the branching degree (Bn) of 7 or more in the conjugated diene polymer of the present embodiment, the increase in viscosity when used as a vulcanizate accompanying the increase in absolute molecular weight is significantly suppressed. For example, in the kneading step, it is sufficiently mixed with silica or the like, and it becomes possible to disperse the silica around the conjugated diene polymer. As a result, for example, in a conjugated diene-based polymer, it is possible to improve abrasion resistance and tensile strength by setting the molecular weight high, and further, by dispersing silica around the polymer by sufficient kneading, the functional group acts and/or reacts. This makes it possible to obtain a rubber composition having a practically sufficient low hysteresis loss property.

The absolute molecular weight of the conjugated diene polymer can be measured by the method described in Examples described later.

The branching degree (Bn) of the conjugated diene polymer of the present embodiment is 7 or more, preferably 8 or more, more preferably 9 or more. A conjugated diene polymer having a branching degree (Bn) within this range tends to have excellent processability when used as a vulcanizate.

The upper limit of the degree of branching (Bn) of the conjugated diene polymer is not particularly limited and may be equal to or greater than the detection limit, but is preferably 84 or less, more preferably 80 or less, still more preferably 64 or less, and still more More preferably, it is 57 or less.

The conjugated diene-based polymer of the present embodiment tends to have excellent wear resistance when used as a vulcanizate due to a branching degree (Bn) of 84 or less.

The degree of branching of the conjugated diene-based polymer of the present embodiment can be controlled by adjusting the addition amount of the branching agent, and also by adjusting the combination of the addition amount of the branching agent and the addition amount of the terminal coupling agent, or a modifier having a nitrogen atom-containing group. , can be controlled by 7 or more.

Specifically, the control of the degree of branching is the number of functional groups of the branching agent, the amount of the branching agent added, the timing of the addition of the branching agent, and the number of functional groups of the coupling agent or nitrogen atom-containing modifier, coupling agent or nitrogen atom-containing modifier It can be controlled by adjusting the addition amount. More specifically, it describes in the manufacturing method of the conjugated diene type polymer described later.

(monomer)

The conjugated diene polymer of this embodiment contains a conjugated diene compound and an aromatic vinyl compound as a compound forming a monomer unit.

Examples of the conjugated diene compound include, but are not limited to, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3- pentadiene, 1,3-hexadiene, and 1,3-heptadiene.

Among these, from the viewpoint of industrial availability, 1,3-butadiene and isoprene are preferable.

These may be used individually by 1 type, and may use 2 or more types together.

Examples of the aromatic vinyl compound include, but are not limited to, styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and diphenylethylene.

Among these, styrene is preferable from the viewpoint of industrial availability.

These may be used individually by 1 type, and may use 2 or more types together.

(coupling agent)

The conjugated diene-based polymer of the present embodiment may be one obtained by performing a coupling reaction using a reactive compound (hereinafter, also referred to as a coupling agent) with respect to the active end of the conjugated diene-based polymer obtained in the polymerization step.

The coupling agent used in the coupling reaction step may have any structure as long as it is a bifunctional or higher functional reactive compound, but a bifunctional or higher functional reactive compound having a silicon atom is preferred.

More specifically, it describes in the manufacturing method of the conjugated diene type polymer described later.

By using a reactive compound having a silicon atom for the coupling agent, the conjugated diene polymer of the present embodiment has a silicon atom.

It is preferable that the conjugated diene type polymer of this embodiment contains a nitrogen atom.

The conjugated diene polymer containing a nitrogen atom is, for example, a coupling reaction using a modifier having a nitrogen atom-containing group described below, and an organic monolithium compound having a substituted amino group as a polymerization initiator. It is obtained by methods such as

(content of nitrogen atoms)

It is preferable that content of nitrogen atoms of the conjugated diene type polymer of this embodiment is 5 mass ppm or more with respect to the total amount of the said conjugated diene type polymer. The content of nitrogen atoms (hereinafter sometimes referred to as “nitrogen content”) is the nitrogen-containing functional group of the conjugated diene polymer, for example, the nitrogen-containing functional group at the initiation end, in the main chain, and at the terminal end. is the total amount of nitrogen atoms in

The nitrogen content of the conjugated diene polymer is more preferably 8 ppm by mass or more, more preferably 10 ppm by mass or more, and still more preferably 13 ppm by mass or more with respect to the total amount of the conjugated diene polymer.

By setting it as the above-mentioned content, when the conjugated diene type polymer of this embodiment is used as a vulcanizate, the balance of low hysteresis loss and wet skid resistance tends to be excellent.

Further, in the polymerization step of the conjugated diene polymer of the present embodiment, when an organic monolithium compound having a substituted amino group is used as the polymerization initiator, from the viewpoint of suppressing the chain transfer reaction during polymerization, the conjugated diene polymer The nitrogen content is preferably 150 ppm by mass or less, more preferably 100 ppm by mass or less, and still more preferably 80 ppm by mass or less.

The nitrogen content can be measured by an oxidative combustion-chemiluminescence method (JIS-2609: crude oil and crude oil products-nitrogen content test method). More specifically, it can be measured by the method described in the Examples described later.

(Modifying agent having a nitrogen atom-containing group)

The conjugated diene-based polymer of the present embodiment is a reactive compound having a nitrogen atom-containing group at the active end of the conjugated diene-based polymer obtained through a polymerization step or further a branching step (hereinafter referred to as "modifier having a nitrogen atom-containing group"). It is preferable that it is a conjugated diene type polymer obtained by performing a coupling reaction by ().

In particular, it is more preferable to have a nitrogen atom-containing group and to react a coupling agent having a bifunctional or higher functional group at the end of polymerization.

When a conjugated diene-based polymer coupled using a modifier having a nitrogen atom-containing group is used as a rubber composition in which a filler such as silica is blended, the dispersibility of silica is good, the processability is good, and it is also used as a vulcanizate. When this is done, the balance between low hysteresis loss and wet skid resistance tends to be dramatically improved.

More specifically, it describes in the manufacturing method of the conjugated diene type polymer described later.

Examples of the modifier having a nitrogen atom-containing group include, but are not limited to, isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, carbonyl compounds containing nitrogen groups, vinyl compounds containing nitrogen groups, and nitrogen group-containing compounds. An epoxy compound etc. are mentioned.

The modifier having a nitrogen atom-containing group preferably has a nitrogen atom-containing functional group, and the nitrogen atom-containing functional group is preferably an amine compound having no active hydrogen. For example, a tertiary amine compound, the active hydrogen A protected amine compound substituted with a protecting group, an imine compound represented by the general formula -N=C, and an alkoxysilane compound bonded to the above nitrogen atom-containing group are exemplified.

More specifically, it describes in the manufacturing method of the conjugated diene type polymer described later.

(Modification rate of conjugated diene polymer)

It is preferable that the denaturation rate of the conjugated diene type polymer of this embodiment measured by the column adsorption GPC method is 60 mass % or more.

In this specification, "denaturation rate" shows the mass ratio of the conjugated diene type polymer which has a nitrogen atom containing functional group with respect to the total amount of a conjugated diene type polymer.

For example, when a modifier having a nitrogen atom-containing group is reacted at the end of the polymer, the total amount of the conjugated diene-based polymer having a nitrogen-atom-containing functional group by the modifier having a nitrogen-atom-containing group The mass ratio is expressed as the denaturation rate.

On the other hand, even when the polymer is branched by a branching agent containing a nitrogen atom, since the resulting conjugated diene polymer has a nitrogen atom-containing functional group, this branched polymer is also counted when calculating the modification rate.

That is, in this specification, the mass ratio of the sum of the polymer subjected to the coupling reaction with the modifier having a nitrogen atom-containing functional group and/or the polymer branched with the branching agent having a nitrogen atom-containing functional group is the "modification rate".

At least one end of the conjugated diene-based polymer of the present embodiment is modified with a modifier having a nitrogen atom-containing group, thereby improving processability when used as a rubber composition blended with a filler or the like, and converting the rubber composition into a vulcanizate. The effect of drastically improving the low hysteresis loss tends to be obtained while maintaining the abrasion resistance and breaking strength.

The conjugated diene-based polymer of the present embodiment has a denaturation rate (hereinafter , Also simply described as "denaturation rate") is preferably 60% by mass or more.

The modification rate is preferably 70% by mass or more, more preferably 75% by mass or more, and still more preferably 80% by mass or more.

Although the upper limit of the said modification|denaturation rate is not specifically limited, For example, it is 98 mass %. When the modification rate is within the above range, the dispersibility of silica when used as a vulcanizate is improved, and the hysteresis loss property is excellent.

The denaturation rate can be measured by chromatography capable of separating functional group-containing denatured components and non-denatured components.

As a method using this chromatography, a method using a column for gel permeation chromatography using a polar substance such as silica that adsorbs a specific functional group as a filler, and using an internal standard for comparison to quantify non-adsorbed components (column adsorption) GPC method).

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

More specifically, the denaturation rate can be measured by the method described in Examples.

In the conjugated diene polymer of the present embodiment, the modification rate can be controlled by adjusting the addition amount and reaction method of the modifier and the addition amount and reaction method of the branching agent, thereby controlling to 60% by mass or more. .

For example, a polymerization method using an organolithium compound having at least one nitrogen atom in a molecule as a polymerization initiator, a method of copolymerizing a monomer having at least one nitrogen atom in a molecule, and at least one nitrogen atom in a molecule. The modification rate can be controlled by appropriately combining a method using a branching agent having atoms and a method using a modifier having a structural formula described below, and adjusting polymerization conditions and reaction conditions.

(Branched structure of conjugated diene polymer)

The conjugated diene-based polymer of the present embodiment is a conjugated diene-based polymer having a star-shaped polymer structure with three or more branches, from the viewpoint of balance between workability and wear resistance, and an alkoxysilyl group or halosilyl group is added to at least one branched chain of the star-shaped structure. It is preferable that it is a conjugated diene polymer which has a part derived from the containing vinylic monomer, and has a further main chain branch structure in the part derived from the vinylic monomer containing the alkoxysilyl group or halosilyl group.

The portion derived from the vinyl-based monomer containing the alkoxysilyl group or halosilyl group is a portion containing silylbenzene in the conjugated diene-based polymer. When the branching agent, the vinyl monomer, reacts with the polymer chain, OH of the alkoxysilyl group or halogen of the halosilyl group, which is included in the branching agent, becomes a leaving group, and the active end of the polymer is substituted and bonded. Further, a branched structure is generated by polymerization of the vinyl structure of the vinyl-based monomer as a conjugated diene. As a result, a structure in which a polymer chain is bonded to silicon of silylbenzene is formed, and this structure is referred to as a portion derived from a vinyl monomer. When a vinyl monomer has a plurality of leaving groups, a plurality of polymer chains can bond to silicon of silylbenzene, but the silylbenzene to which a plurality of polymer chains bond is naturally a portion derived from the vinyl monomer.

The "star-shaped polymer structure" as used herein refers to a structure in which a plurality of polymer chains (arms) are bonded from one central branch point.

In addition, one central branch point here has a substituent containing an atom derived from a coupling agent or a nitrogen atom derived from a modifier.

The "main chain branching structure" as used herein refers to a structure in which a branch point is formed at a portion derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group in the polymer chain, and the polymer chain (arm) extends from the branch point. says

In particular, in the main chain branched structure comprising a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group, when a signal is detected by ²⁹ Si-NMR, it is in the range of -45 ppm to -65 ppm, and more specifically, -50 ppm to -60 ppm. Peaks derived from the main chain branching structure are detected in the range of .

In the conjugated diene-based polymer of the present embodiment, from the viewpoint of improving the branching degree (Bn), it is preferable that the main chain branch point constituted by a moiety derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group is two or more branch points, , The branch structure derived from the star-shaped polymer structure formed by the coupling agent in the reaction step performed after the polymerization and branching step is preferably 3 or more branches, more preferably 4 or more branches, and still more preferably 8 or more branches. As described above, the portion derived from the vinyl monomer refers to a structure containing silylbenzene.

In addition, the degree of branching (Bn) increases both in the case of modification with a coupling agent that forms a star structure and in the case of introducing a branching agent into the polymer, but branching the entire polymer chain by the coupling agent increases the degree of branching. The contribution to (Bn) is large.

In the design of the polymer, the branching degree (Bn) can be controlled by the selection of a coupling agent, the selection of the type of branching agent or the setting of the addition amount, but the control of the branching degree (Bn) is easy by considering the contribution rate.

(main chain branch structure)

In the conjugated diene polymer of the present embodiment, the main chain branching structure is preferably at least two branch points, and more preferably at least three branch points at the branching point in the portion derived from the vinyl monomer containing an alkoxysilyl group or halosilyl group. And, it is more preferable that it is more than the 4 branch point.

In addition, the branch point forming the main chain branching structure preferably has at least two or more polymer chains, more preferably has three or more non-main chain polymer chains, and still more preferably has four non-main chain polymer chains. have more than one

(star-shaped polymer structure)

The conjugated diene-based polymer of the present embodiment preferably has a star-shaped polymer structure, preferably has three or more branches derived from the star-shaped polymer structure, more preferably four or more branches, still more preferably six or more branches, It is even more preferable that it is 8 or more branches.

The conjugated diene-based polymer of the present embodiment is a conjugated diene-based polymer having a star-shaped polymer structure with three or more branches, and a portion derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group in at least one star-shaped branch chain. and a conjugated diene polymer having a further main chain branched structure in a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group. Regarding the method for obtaining a conjugated diene-based polymer having such a structure, the "star-shaped polymer structure" can be formed by adjusting the number of functional groups in the coupling agent and the addition amount of the coupling agent, and the "main chain branching structure" is the branching agent It can be controlled by adjusting the number of functional groups, the addition amount of the branching agent, and the timing of addition of the branching agent.

As a specific production method, polymerization is performed using an organolithium-based compound as a polymerization initiator, a branching agent for imparting a specific branching point is added during or after polymerization, and after polymerization is continued, a modifier for imparting a specific branching ratio is added. A method of denaturation using .

Means for controlling such polymerization conditions are described in the manufacturing methods in Examples described later.

(Detailed structure of main chain branching structure)

In the conjugated diene polymer of the present embodiment, the portion derived from the vinyl monomer containing the alkoxysilyl group or halosilyl group described above is a monomer unit based on a compound represented by the following formula (1) or (2), It is preferable to have a branch point of a polymer chain by a monomeric unit based on a compound represented by the following formula (1) or (2). The conjugated diene polymer of the present embodiment is more preferably a conjugated diene polymer obtained using a coupling agent, and at least one end of the conjugated diene polymer is a modified conjugated diene polymer modified with a nitrogen atom-containing group. desirable.

(In Formula (1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.

R ² to R ³ each independently represent an alkyl group of 1 to 20 carbon atoms or an aryl group of 6 to 20 carbon atoms, and may have a branched structure at a part thereof.

R ¹ to R ³ in the case of a plurality of presence are independent of each other.

X ¹ represents an independent halogen atom.

m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.)

(In formula (2), each of R ² to R ⁵ independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.

R ² to R ⁵ in the case of a plurality of presence are independent of each other.

X ² to X ³ represent independent halogen atoms.

m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3.

(m+n+l) represents 3.

a represents an integer of 0 to 2, b represents an integer of 0 to 3, and c represents an integer of 0 to 3. (a+b+c) represents 3.)

The conjugated diene-based polymer of the present embodiment has a monomer unit based on the compound represented by the formula (1) in which R ¹ is a hydrogen atom and m=0 in the formula (1) described above. It is desirable to be Thereby, the branching number is improved, and the effect of improving wear resistance and workability is obtained.

Further, the conjugated diene polymer of the present embodiment is a conjugated diene polymer having a monomer unit based on the compound represented by the formula (2) in which m = 0 and b = 0 in the formula (2). it is desirable Thereby, the effect of improving wear resistance and workability is obtained.

In addition, the conjugated diene polymer of this embodiment is m = 0, l = 0, n = 3, a = 0, b = 0, and c = 3 in the formula (2), the formula (2 ) is preferably a conjugated diene-based polymer having a monomer unit based on a compound represented by Thereby, the effect of improving wear resistance and workability is obtained.

In the conjugated diene polymer of the present embodiment, in the formula (1), R ¹ is a hydrogen atom, m = 0, l = 0, and n = 3, the compound represented by the formula (1) It is more preferable that it is a conjugated diene type polymer which has a monomer unit based on. As a result, the modification rate and the degree of branching are improved, and the effects of improving fuel economy performance, wear resistance and workability are obtained.

(branching agent)

In the conjugated diene polymer of the present embodiment, it is preferable to use a branching agent represented by the following formula (1) or formula (2) as the branching agent when constructing the main chain branching structure.

The portion derived from the vinyl monomer containing the alkoxysilyl group or halosilyl group is a monomer unit based on a compound represented by the following formula (1) or (2), and the conjugated diene polymer of the present embodiment is It is preferable that it is a structure which has a branch point of the polymer chain by the monomeric unit based on the compound represented by Formula (1) or (2).

(In Formula (1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.

R ² to R ³ each independently represent an alkyl group of 1 to 20 carbon atoms or an aryl group of 6 to 20 carbon atoms, and may have a branched structure at a part thereof.

R ¹ to R ³ in the case of a plurality of presence are independent of each other.

X ¹ represents an independent halogen atom.

m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.)

(In formula (2), each of R ² to R ⁵ independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.

R ² to R ⁵ in the case of a plurality of presence are independent of each other.

X ² to X ³ represent independent halogen atoms.

m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3.

(m+n+l) represents 3.

a represents an integer of 0 to 2, b represents an integer of 0 to 3, and c represents an integer of 0 to 3. (a+b+c) represents 3.)

In the present embodiment, the branching agent used when constructing the main chain branching structure of the conjugated diene-based polymer is, from the viewpoint of the continuity of polymerization and the improvement of the degree of branching, Preferably R ¹ of formula (1) is a hydrogen atom , it is preferably a compound of m = 0.

Further, in the present embodiment, the branching agent used when constructing the main chain branching structure of the conjugated diene-based polymer is a compound of m=0 and b=0 in formula (2) from the viewpoint of improving the degree of branching. It is desirable to be

Further, in the present embodiment, the branching agent used when constructing the main chain branching structure of the conjugated diene-based polymer has R ¹ It is a hydrogen atom, m=0, l=0, and it is more preferable that it is a compound with n=3.

Further, in the present embodiment, the branching agent used when constructing the main chain branching structure of the conjugated diene-based polymer is, from the viewpoint of improving the modification rate and branching degree, in the above formula (2), m = 0, l = A compound in which 0, n = 3, a = 0, b = 0, and c = 3 is preferred.

Examples of the branching agent represented by the formula (1) include, but are not limited to, trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, and trippropoxy(4-vinylphenyl)silane. -vinylphenyl)silane, tributoxy(4-vinylphenyl)silane, triisopropoxy(4-vinylphenyl)silane, trimethoxy(3-vinylphenyl)silane, triethoxy(3-vinylphenyl)silane , tripropoxy (3-vinylphenyl) silane, tributoxy (3-vinylphenyl) silane, triisopropoxy (3-vinylphenyl) silane, trimethoxy (2-vinylphenyl) silane, triethoxy ( 2-vinylphenyl)silane, tripropoxy(2-vinylphenyl)silane, tributoxy(2-vinylphenyl)silane, triisopropoxy(2-vinylphenyl)silane, dimethoxymethyl(4-vinylphenyl) Silane, diethoxymethyl (4-vinylphenyl) silane, dipropoxymethyl (4-vinylphenyl) silane, dibutoxymethyl (4-vinylphenyl) silane, diisopropoxymethyl (4-vinylphenyl) silane, dimethicone Toxymethyl (3-vinylphenyl) silane, diethoxymethyl (3-vinylphenyl) silane, dipropoxymethyl (3-vinylphenyl) silane, dibutoxymethyl (3-vinylphenyl) silane, diisopropoxymethyl ( 3-vinylphenyl)silane, dimethoxymethyl(2-vinylphenyl)silane, diethoxymethyl(2-vinylphenyl)silane, dipropoxymethyl(2-vinylphenyl)silane, dibutoxymethyl(2-vinylphenyl) Silane and diisopropoxymethyl (2-vinylphenyl) silane are mentioned.

Moreover, as a branching agent represented by the said Formula (1), dimethyl methoxy (4-vinylphenyl) silane, dimethyl ethoxy (4-vinylphenyl) silane, dimethyl propoxy (4-vinylphenyl) silane, for example , dimethylbutoxy (4-vinylphenyl) silane, dimethylisopropoxy (4-vinylphenyl) silane, dimethylmethoxy (3-vinylphenyl) silane, dimethylethoxy (3-vinylphenyl) silane, dimethylpropoxy ( 3-vinylphenyl)silane, dimethylbutoxy(3-vinylphenyl)silane, dimethylisopropoxy(3-vinylphenyl)silane, dimethylmethoxy(2-vinylphenyl)silane, dimethylethoxy(2-vinylphenyl) Silane, dimethylpropoxy(2-vinylphenyl)silane, dimethylbutoxy(2-vinylphenyl)silane, dimethylisopropoxy(2-vinylphenyl)silane, trimethoxy(4-isopropenylphenyl)silane, tri Ethoxy(4-isopropenylphenyl)silane, tripropoxy(4-isopropenylphenyl)silane, tributoxy(4-isopropenylphenyl)silane, triisopropoxy(4-isopropenylphenyl) Silane, trimethoxy(3-isopropenylphenyl)silane, triethoxy(3-isopropenylphenyl)silane, tripropoxy(3-isopropenylphenyl)silane, tributoxy(3-isopropenylphenyl)silane Phenyl) silane, triisopropoxy (3-isopropenylphenyl) silane, trimethoxy (2-isopropenylphenyl) silane, triethoxy (2-isopropenylphenyl) silane, tripropoxy (2- isopropenylphenyl)silane, tributoxy(2-isopropenylphenyl)silane, triisopropoxy(2-isopropenylphenyl)silane, dimethoxymethyl(4-isopropenylphenyl)silane, diethoxymethyl (4-isopropenylphenyl) silane, dipropoxymethyl (4-isopropenylphenyl) silane, dibutoxymethyl (4-isopropenylphenyl) silane, diisopropoxymethyl (4-isopropenylphenyl) Silane, dimethoxymethyl (3-isopropenylphenyl) silane, diethoxymethyl (3-isopropenylphenyl) silane, dipropoxymethyl (3-isopropenylphenyl) silane, dibutoxymethyl (3-isopropenylphenyl) silane Phenylphenyl) silane, diisopropoxymethyl (3-isopropenylphenyl) silane, dimethoxymethyl (2-isopropenylphenyl) silane, diethoxymethyl (2-isopropenylphenyl) silane, dipropoxymethyl (2-isopropenylphenyl)silane, dibutoxymethyl(2-isopropenylphenyl)silane, diisopropoxymethyl(2-isopropenylphenyl)silane, dimethylmethoxy(4-isopropenylphenyl)silane , dimethylethoxy (4-isopropenylphenyl) silane, dimethylpropoxy (4-isopropenylphenyl) silane, dimethylbutoxy (4-isopropenylphenyl) silane, dimethylisopropoxy (4-isopropenylphenyl) Phenyl) silane, dimethylmethoxy (3-isopropenylphenyl) silane, dimethylethoxy (3-isopropenylphenyl) silane, dimethylpropoxy (3-isopropenylphenyl) silane, dimethylbutoxy (3-isopropenylphenyl) silane Propenylphenyl) silane, dimethylisopropoxy (3-isopropenylphenyl) silane, dimethylmethoxy (2-isopropenylphenyl) silane, dimethylethoxy (2-isopropenylphenyl) silane, dimethylpropoxy ( 2-isopropenylphenyl) silane, dimethylbutoxy (2-isopropenylphenyl) silane, dimethylisopropoxy (2-isopropenylphenyl) silane, trichloro (4-vinylphenyl) silane, trichloro (3 -vinylphenyl)silane, trichloro(2-vinylphenyl)silane, tribromo(4-vinylphenyl)silane, tribromo(3-vinylphenyl)silane, tribromo(2-vinylphenyl)silane, dichloro Methyl (4-vinylphenyl) silane, dichloromethyl (3-vinylphenyl) silane, dichloromethyl (2-vinylphenyl) silane, dibromomethyl (4-vinylphenyl) silane, dibromomethyl (3-vinylphenyl) ) Silane, dibromomethyl (2-vinylphenyl) silane, dimethylchloro (4-vinylphenyl) silane, dimethylchloro (3-vinylphenyl) silane, dimethylchloro (2-vinylphenyl) silane, dimethylbromo (4 -Vinylphenyl)silane, dimethylbromo(3-vinylphenyl)silane, and dimethylbromo(2-vinylphenyl)silane are mentioned.

Among these, trimethoxy (4-vinylphenyl) silane, triethoxy (4-vinylphenyl) silane, tripropoxy (4-vinylphenyl) silane, tributoxy (4-vinylphenyl) silane, triiso Propoxy(4-vinylphenyl)silane, trimethoxy(3-vinylphenyl)silane, triethoxy(3-vinylphenyl)silane, tripropoxy(3-vinylphenyl)silane, tributoxy(3-vinyl Phenyl)silane, triisopropoxy(3-vinylphenyl)silane, trichloro(4-vinylphenyl)silane are preferred, trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane , Tripropoxy(4-vinylphenyl)silane, tributoxy(4-vinylphenyl)silane, and triisopropoxy(4-vinylphenyl)silane are more preferable.

Although it is not limited to the following as a branching agent represented by said formula (2), For example, 1, 1-bis (4-trimethoxysilylphenyl) ethylene, 1, 1-bis (4-triethoxy Silylphenyl) ethylene, 1,1-bis (4-tripropoxysilylphenyl) ethylene, 1,1-bis (4-tripentoxysilylphenyl) ethylene, 1,1-bis (4-triisopropoxysilyl Phenyl) ethylene, 1,1-bis (3-trimethoxysilylphenyl) ethylene, 1,1-bis (3-triethoxysilylphenyl) ethylene, 1,1-bis (3-tripropoxysilylphenyl) Ethylene, 1,1-bis(3-tripentoxysilylphenyl)ethylene, 1,1-bis(3-triisopropoxysilylphenyl)ethylene, 1,1-bis(2-trimethoxysilylphenyl)ethylene , 1,1-bis (2-triethoxysilylphenyl) ethylene, 1,1-bis (3-tripropoxysilylphenyl) ethylene, 1,1-bis (2-tripentoxysilylphenyl) ethylene, 1 , 1-bis (2-triisopropoxysilylphenyl) ethylene, 1,1-bis (4- (dimethylmethoxysilyl) phenyl) ethylene, 1,1-bis (4- (diethylmethoxysilyl) phenyl ) ethylene, 1,1-bis (4- (dipropylmethoxysilyl) phenyl) ethylene, 1,1-bis (4- (dimethylethoxysilyl) phenyl) ethylene, 1,1-bis (4- (di ethylethoxysilyl)phenyl)ethylene and 1,1-bis(4-(dipropylethoxysilyl)phenyl)ethylene.

Among these, 1,1-bis(4-trimethoxysilylphenyl)ethylene, 1,1-bis(4-triethoxysilylphenyl)ethylene, 1,1-bis(4-tripropoxysilylphenyl) Ethylene, 1,1-bis(4-tripentoxysilylphenyl)ethylene, 1,1-bis(4-triisopropoxysilylphenyl)ethylene are preferred, and 1,1-bis(4-trimethoxysilyl Phenyl)ethylene is more preferred.

(weight average molecular weight)

The weight average molecular weight of the conjugated diene copolymer of the present embodiment is 45×10 ⁴ or more and 500×10 ⁴ or less, preferably 50×10 ⁴ or more, and more preferably 60×10 ⁴ or more. The weight average molecular weight is preferably 450×10 ⁴ or less, more preferably 400×10 ⁴ or less, and even more preferably 350×10 ⁴ or less.

When the weight average molecular weight is 45 × 10 ⁴ or more, it is excellent in wear resistance when used as a vulcanized product. In addition, when the weight average molecular weight is 500×10 ⁴ or less, workability when used as a vulcanizate and filler dispersibility are excellent, and fracture properties sufficient for practical use are obtained.

The weight average molecular weight of the conjugated diene polymer can be measured by the method described in Examples described later.

The weight average molecular weight of the conjugated diene-based polymer of the present embodiment can be controlled within the above numerical range by adjusting the addition amount of the polymerization monomer, polymerization temperature, polymerization time, and the like.

(absolute molecular weight)

Absolute molecular weight is measured by a GPC-light scattering method with a viscosity detector.

In general, a polymer having a branched structure tends to have a smaller molecular size when compared with a linear polymer having the same molecular weight. Therefore, the molecular weight of the polymer having a branched structure is sieved according to the molecular size of the polymer, and the molecular weight in terms of polystyrene obtained by gel permeation chromatography (hereinafter also referred to as “GPC”) measurement, a relative comparison method with a standard polystyrene sample, is too low. tend to be evaluated.

On the other hand, according to the light scattering method, since the molecular weight (absolute molecular weight) is measured by directly observing the size of the molecule, it is not affected by the structure of the polymer or the interaction with the column filler, and the branched structure of the conjugated diene polymer There is a tendency that the molecular weight can be accurately measured without being affected by the polymer structure.

The absolute molecular weight of the conjugated diene-based polymer of the present embodiment is preferably 70 × 10 ⁴ to 100 × 10 ⁵ , and more preferably 80 × 10 ⁴ to 500 × 10 ⁴ from the viewpoints of tensile strength and abrasion resistance, More preferably, it is 90×10 ⁴ to 350×10 ⁴ .

The absolute molecular weight of the conjugated diene-based polymer can be controlled within the above numerical range by adjusting the addition amount of the polymerization initiator, polymerization temperature, polymerization time, addition amount of the branching agent, and the like.

(Content of aromatic vinyl monomer unit)

The conjugated diene polymer of the present embodiment may be a polymer of a conjugated diene compound, an aromatic vinyl compound, and a branching agent, or may be a copolymer of monomers other than these.

For example, when the conjugated diene monomer is butadiene or isoprene, and a branching agent containing this and a vinyl aromatic moiety is polymerized, the polymer chain is so-called polybutadiene or polyisoprene, and the branching moiety contains a structure derived from vinyl aromatics. become a polymer. By having such a structure, the linearity per polymer chain is improved, and the crosslinking density after vulcanization can be improved, and the effect of improving abrasion resistance is exhibited. Therefore, the conjugated diene-based polymer of the present embodiment is suitable for applications such as tires, resin modification, automobile interior and exterior products, anti-vibration rubber, and shoes.

When the conjugated diene-based polymer is used for tire tread applications, a copolymer of a conjugated diene compound, an aromatic vinyl compound, and a branching agent is suitable. From this point of view, in the conjugated diene polymer of the present embodiment, the content of the aromatic vinyl monomer unit is 30 to 45% by mass, and from the viewpoint of abrasion resistance and tensile strength, 32% by mass or more is preferable, and 34% by mass It is more preferable that it is above, and it is more preferable that it is 36 mass % or more.

Moreover, from a fuel economy viewpoint, it is preferable that it is 43 mass % or less, and it is more preferable that it is 41 mass % or less.

Content of the aromatic vinyl monomer unit in the conjugated diene polymer can be controlled within the above numerical range by adjusting the addition amount of the aromatic vinyl monomer in the polymerization step.

In the conjugated diene polymer of the present embodiment, the value of the content (% by mass) of the aromatic vinyl monomer unit in the conjugated diene polymer is greater than the value of the amount of vinyl bonds (mol%) in the conjugated diene monomer unit. .

From this point of view, the value of the amount of vinyl bonds is preferably small. As a method for reducing the value of the amount of vinyl bonds (mol%), it is effective to add a branching agent during polymerization of the conjugated diene-based polymer and perform the polymerization step while maintaining randomization performance. Thereby, the value of the content (% by mass) of the aromatic vinyl monomeric unit can be controlled to be larger than the amount of vinyl bonds (mol%) in the conjugated diene monomeric unit.

By reducing the value of the amount of vinyl bonds in the conjugated diene monomer unit, the molecular chain length of the conjugated diene compound can be increased, and when used as a vulcanized product, the tensile strength tends to be excellent.

The amount of vinyl bonds in the conjugated diene monomer unit is preferably 45 mol% or less, more preferably 40 mol% or less, still more preferably 35 mol% or less, and still more preferably 30 mol% or less.

Here, the content (mass%) of the aromatic vinyl monomer unit in the conjugated diene polymer of the present embodiment can be measured by ultraviolet absorption of a phenyl group, and the content (mass%) of the conjugated diene monomeric unit can also be obtained from this. Specifically, it is measured according to the method described in the Examples described later.

When the value of the content (% by mass) of the aromatic vinyl monomer unit is greater than the value of the amount of vinyl bonds (mol%) in the conjugated diene monomer unit, the tensile strength and abrasion resistance when used as a vulcanized product tend to be excellent.

Here, when the modified diene-based polymer is a copolymer of butadiene and styrene, the amount of vinyl bonds in the butadiene bonding unit (1,2-bonded quantity) can be obtained. Specifically, it can be measured by the method described in the Examples described later.

When the conjugated diene polymer of this embodiment is a conjugated diene-aromatic vinyl copolymer, it is preferable that the number of blocks in which 30 or more aromatic vinyl units are chained is small or absent. More specifically, when the copolymer is a butadiene-styrene copolymer, the copolymer is decomposed by the method of Kolthoff (the method described in I.M.KOLTHOFF, et al., J.Polym.Sci.1, 429 (1946)), In a known method for analyzing the amount of polystyrene insoluble in methanol, the number of blocks in which 30 or more aromatic vinyl units are chained is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, based on the total amount of the copolymer. .

When the conjugated diene-based polymer of the present embodiment is a conjugated diene-aromatic vinyl copolymer, from the viewpoint of improving fuel economy performance, it is preferable that the proportion of aromatic vinyl units alone is higher.

Specifically, when the copolymer is a butadiene-styrene copolymer, the copolymer is decomposed by an ozone decomposition method known as the method of Tanaka et al. (Polymer, 22, 1721 (1981)), and the styrene chain by GPC When the distribution is analyzed, it is preferable that the amount of isolated styrene is 40 mass% or more relative to the total amount of bound styrene, and the chain styrene structure of 8 or more styrene chains is 5.0 mass% or less.

In this case, the resulting vulcanized rubber has excellent performance, particularly low hysteresis loss.

[Method for Producing Conjugated Diene Polymer]

The manufacturing method of the conjugated diene type polymer of this embodiment is the above-mentioned weight average molecular weight, branching degree (Bn) is 7 or more, content of an aromatic vinyl monomer unit is 30-45 mass %, content of an aromatic vinyl monomer unit A production method for obtaining a conjugated diene-based polymer having a value of (mass %) greater than the value of the amount of vinyl bonds (mol%) in the conjugated diene monomer unit, using an organolithium compound as a polymerization initiator and containing a polar compound There is a step of adding a branching agent while polymerizing at least a conjugated diene compound and an aromatic vinyl compound in a solvent to obtain a conjugated diene polymer having a main chain branched structure.

The method for producing the conjugated diene-based polymer of the present embodiment uses an organolithium compound as a polymerization initiator, polymerizes at least a conjugated diene compound and an aromatic vinyl compound, and uses at least any one of the various branching agents described above to form a main chain branching structure. It is preferable to have a polymerization and branching step of obtaining a conjugated diene polymer having a main chain branched structure, and a coupling step of reacting a coupling agent or a modifier having a nitrogen atom-containing group with the conjugated diene polymer having the main chain branched structure, and coupling them. .

(polymerization and branching process)

The polymerization and branching step in the method for producing the conjugated diene polymer of the present embodiment is, for example, by polymerizing at least a conjugated diene compound and an aromatic vinyl compound using an organolithium compound as a polymerization initiator and adding a branching agent. , It is a process of obtaining a conjugated diene-based polymer having a main chain branched structure.

In the polymerization step, it is preferable to perform polymerization by a growth reaction by a living anionic polymerization reaction, whereby a conjugated diene-based polymer having an active end can be obtained. Then, also in the branching process using a branching agent, main chain branching can be appropriately controlled, and a conjugated diene-based polymer with a high modification rate tends to be obtained by performing a coupling process.

<Polymerization initiator>

As a polymerization initiator, it is preferable to use an organolithium compound, and to use at least an organic monolithium compound.

Examples of the organic monolithium compound include, but are not limited to, low molecular weight compounds and solubilized oligomer organic monolithium compounds.

Further, examples of the organic monolithium compound include a compound having a carbon-lithium bond, a compound having a nitrogen-lithium bond, and a compound having a tin-lithium bond in the bonding mode between the organic group and the lithium. there is.

The usage amount of the organic monolithium compound as a polymerization initiator is preferably determined by the target conjugated diene polymer.

The usage amount of monomers such as a conjugated diene compound relative to the usage amount of the polymerization initiator is related to the degree of polymerization of the target conjugated diene polymer. That is, it tends to relate to number average molecular weight and/or weight average molecular weight.

Therefore, in order to increase the molecular weight of the conjugated diene polymer, the amount of the polymerization initiator may be adjusted in the direction of reducing the amount used, and in order to decrease the molecular weight, the amount of the polymerization initiator may be adjusted in the direction of increasing.

The organic monolithium compound is preferably an organic monolithium compound having a substituted amino group, for example, an alkyllithium compound having a substituted amino group, from the viewpoint of being used as one method of introducing a nitrogen atom into a conjugated diene polymer. , or dialkylaminolithium.

In this case, a conjugated diene-based polymer having a nitrogen atom containing an amino group at the polymerization initiating terminal is obtained. When the conjugated diene polymer obtained in the polymerization step has a nitrogen atom containing an amino group at the polymerization initiating terminal, a chain transfer reaction tends to occur when anionic polymerization proceeds, and it is used as a coupling agent or modifier for the active terminal after polymerization. Therefore, it is difficult to obtain a sufficient amount of reaction, and the absolute molecular weight tends to be small. Therefore, from the viewpoint of tensile strength and abrasion resistance when the conjugated diene-based copolymer of the present embodiment is used as a vulcanizate, it is preferable to select a polymerization temperature capable of controlling the chain transfer reaction and perform polymerization.

A substituted amino group is an amino group having no active hydrogen or a structure in which active hydrogen is protected.

Examples of the alkyllithium compound having an amino group without an active hydrogen include, but are not limited to, 3-dimethylaminopropyllithium, 3-diethylaminopropyllithium, 4-(methylpropylamino)butyllithium, and and 4-hexamethyleneiminobutyllithium.

Examples of the alkyllithium compound having an amino group having an active hydrogen protected structure include, but are not limited to, 3-bistrimethylsilylaminopropyllithium and 4-trimethylsilylmethylaminobutyllithium.

Examples of the dialkylaminolithium include, but are not limited to, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium dibutylamide, lithium di-n-hexylamide, lithium diheptylamide, and lithium. Diisopropylamide, lithium dioctylamide, lithium-di-2-ethylhexylamide, lithium didecylamide, lithium ethylpropylamide, lithium ethylbutylamide, lithium ethylbenzylamide, lithium methylphenethylamide, lithium hexamethylene Mead, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, lithium morpholide, 1-thioazacyclooctane, 6-lithio-1,3,3-trimethyl-6-azabicyclo[3.2 .1] octane, and 1-lithio-1,2,3,6-tetrahydropyridine.

These organic monolithium compounds having a substituted amino group are oligomeric organic monolithium compounds obtained by reacting a small amount of a polymerizable monomer, for example, a monomer such as 1,3-butadiene, isoprene, or styrene, and solubilizing it in normal hexane or cyclohexane. can also be used as

The organic monolithium compound is preferably an alkyllithium compound from the viewpoints of industrial availability and easy control of the polymerization reaction. In this case, a conjugated diene polymer having an alkyl group at the polymerization initiating terminal is obtained.

Examples of the alkyllithium compound include, but are not limited to, n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and stilbenelithium. there is.

As the alkyllithium compound, n-butyllithium and sec-butyllithium are preferable from the viewpoints of industrial availability and easy control of the polymerization reaction.

These organic monolithium compounds may be used individually by 1 type, or may use 2 or more types together. Moreover, you may use together with another organometallic compound.

Examples of the other organometallic compounds include alkaline earth metal compounds, other alkali metal compounds, and other organometallic compounds.

Examples of the alkaline earth metal compound include, but are not limited to, organic magnesium compounds, organic calcium compounds, and organic strontium compounds. Further, compounds of alkoxides, sulfonates, carbonates, and amides of alkaline earth metals are also included.

As an organomagnesium compound, dibutyl magnesium and ethyl butyl magnesium are mentioned, for example. As another organometallic compound, an organoaluminium compound is mentioned, for example.

In the polymerization step, the polymerization reaction mode is not limited to the following, but examples thereof include a batch type (also referred to as "batch type") and a continuous polymerization reaction mode.

In the continuous mode, one or two or more connected reactors may be used. As for the continuous type reactor, a tubular or tubular one equipped with an agitator is used, for example. In the continuous type, preferably, a monomer, an inert solvent, and a polymerization initiator are continuously fed into a reactor, a polymer solution containing a polymer is obtained in the reactor, and the polymer solution is continuously discharged.

As the batch type reactor, a tank reactor equipped with an agitator is used, for example. In the batch mode, preferably, a monomer, an inert solvent, and a polymerization initiator are fed, and monomers are continuously or intermittently added during polymerization as necessary to obtain a polymer solution containing the polymer in the reactor, and the polymerization is terminated. Afterwards the polymer solution is discharged.

In the method for producing a conjugated diene-based polymer of the present embodiment, in order to obtain a conjugated diene-based polymer having an active end at a high rate, a continuous method is preferable, in which the polymer can be continuously discharged and used for the next reaction in a short time. .

In the polymerization step of the conjugated diene polymer, polymerization in an inert solvent is preferred, and a solvent compatible with the conjugated diene polymer is more preferred.

As a preferable solvent, hydrocarbon solvents, such as a saturated hydrocarbon and an aromatic hydrocarbon, are mentioned, for example. Although it is not limited to the following as a specific hydrocarbon-type solvent, For example, Aliphatic hydrocarbons, such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene, and hydrocarbons containing mixtures thereof.

Before subjecting to the polymerization reaction, by treating allenes and acetylenes as impurities with an organometallic compound, a conjugated diene-based polymer having a high concentration of active ends tends to be obtained, and a modified conjugated diene-based polymer having a high modification rate is obtained. It is desirable because it tends to

<Polar compound (polar substance)>

In the polymerization step, while polymerizing at least a conjugated diene compound and an aromatic vinyl compound in a solvent containing a polar compound (sometimes referred to as a polar substance in this specification) using the above-mentioned organolithium compound as a polymerization initiator. , A branching agent is added to obtain a conjugated diene-based polymer having a main chain branched structure.

By adding a polar compound to the solvent, the aromatic vinyl compound can be randomly copolymerized with the conjugated diene compound, and it also tends to function effectively as a vinylating agent for controlling the microstructure of the conjugated diene portion.

Further, the polar compound tends to be effective also in accelerating the polymerization reaction in the polymerization of the conjugated diene compound. Therefore, in the case of industrial production of conjugated diene-based polymers, it is common to add a certain amount of polar compounds to improve productivity.

In addition, from a viewpoint other than production efficiency, if the addition amount of the polar compound is reduced, the polymerization time is too long and the rate at which the active end of the polymer is deactivated on the way increases, and the ratio of the low molecular weight component increases, or the coupling rate and And/or adverse effects such as the inability to increase the denaturation rate may also occur. Conventionally, a polymer design in which the polymer chain is branched by reacting a polyfunctional coupling agent containing nitrogen or the like with the polymerization end terminal has been used. Also can't do the settings. That is, it is difficult to independently control the amount of vinyl bonds, branching degree, and/or modification rate due to the fact that the vinylizing agent also serves as a polymerization accelerator.

In contrast, as in the production method of the present embodiment, by branching the polymer chain with a branching agent, since the formation of a branched structure does not depend only on the coupling reaction of the active end of the polymer, in order to produce a polymer having a low vinyl bond amount, vinyl It is possible to produce a polymer having a high degree of branching even when the addition amount of the agent is reduced. Therefore, while controlling the weight average molecular weight to 45 × 10 ⁴ or more and 500 × 10 ⁴ or less, the content of the aromatic vinyl monomer unit in the conjugated diene polymer is in the range of 30 to 45% by mass, and the branching degree (Bn) is 7 As described above, production of a conjugated diene-based polymer having a value of the content (% by mass) of the aromatic vinyl monomer unit is larger than the value of the amount of vinyl bonds (mol%) in the conjugated diene monomer unit is industrially possible.

Examples of the polar compound include, but are not limited to, tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, ethers such as dimethoxybenzene and 2,2-bis(2-oxolanyl)propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, and quinuclidine; alkali metal alkoxide compounds such as potassium-tert-amylate, potassium-tert-butyrate, sodium-tert-butyrate and sodium amylate; Phosphine compounds, such as triphenylphosphine, etc. can be used.

These polar compounds may be used individually by 1 type, or may use 2 or more types together.

Many polar compounds tend to have an effective randomization effect in copolymerization of a conjugated diene compound and an aromatic vinyl compound at the same time, and can be used as an agent for adjusting the distribution of aromatic vinyl monomer units or adjusting the amount of styrene blocks.

The amount of the polar compound used correlates with the amount of active end of the polymer, and the amount of active end of the polymer depends on the amount of the polymerization initiator.

The amount of the polar compound used is preferably 0.01 mol or more and 1 mol or less, and preferably 0.1 mol or more and 0.8 mol or less with respect to 1 mol of the polymerization initiator.

By setting it below the said upper limit, in the conjugated diene type polymer of this embodiment, content (mass %) of an aromatic vinyl monomer unit is 30-45 mass %, and the value of content (mass %) of an aromatic vinyl monomer unit is conjugated A conjugated diene polymer larger than the value of the amount of vinyl bonds (mol%) in the diene monomer unit is obtained. Moreover, by making it more than the lower limit, it is easy to maintain the active end of the polymer, the polymerization reaction is accelerated, and the coupling rate of the end is improved. From the viewpoint of abrasion resistance and tensile strength, the content of the aromatic vinyl monomer unit in the conjugated diene polymer is 30% by mass or more, preferably 32% by mass or more, more preferably 34% by mass or more, and still more preferably 36% by mass or more. desirable.

As a method for randomizing a conjugated diene compound and an aromatic vinyl compound, as described in, for example, Japanese Unexamined Patent Publication No. 59-140211, a copolymerization reaction is initiated with the entire amount of styrene and a part of 1,3-butadiene, Alternatively, a method of intermittently adding the remaining 1,3-butadiene in the middle of the copolymerization reaction may be used.

<Addition of branching agent>

In the method for producing the conjugated diene polymer of the present embodiment, as described above, a branching agent is added while polymerizing the conjugated diene compound and the aromatic vinyl compound to obtain a conjugated diene polymer having a main chain branched structure.

The addition amount of the branching agent is not particularly limited and can be selected according to the purpose and the like, but is preferably 0.03 mol or more and 0.5 mol or less, more preferably 0.05 mol or more and 0.4 mol or less, and 0.01 mol or more and 0.25 mol or less with respect to 1 mol of the polymerization initiator. it is more preferable

The branching agent can be used in an appropriate amount depending on the number of branch points in the main chain branching structure of the conjugated diene moiety of the target conjugated diene polymer.

In addition, by adding a branching agent during the polymerization of the conjugated diene polymer, the active end of the conjugated diene polymer can be reduced from the addition amount of the polymerization initiator, and the active end of the polymer can be maintained by promoting the reaction at least in the initial stage of polymerization by the polar compound. do. This makes it possible to obtain a conjugated diene-based polymer in which the value of the content (% by mass) of the aromatic vinyl monomer unit is larger than the value of the amount of vinyl bonds (mol%) of the conjugated diene monomer unit, and the coupling rate or modification rate is A high conjugated diene polymer can be obtained, and furthermore, the branching degree (Bn) of the conjugated diene polymer can be 7 or more.

When the branching agent is not added, even if the addition amount of the polar compound is selected to achieve a predetermined microstructure ratio, the ability to randomize the aromatic vinyl compound and the conjugated diene compound becomes small, and the content of the above-mentioned aromatic vinyl monomer unit is 30 to 45 In the conjugated diene type polymer of mass %, the polymerization end tends to become an aromatic vinyl monomer unit. In such a state, it tends to be difficult to obtain a conjugated diene-based polymer having a high coupling rate or modification rate, and it tends to be difficult to set the branching degree (Bn) to 7 or more.

As described above, the inventors of the present invention, in the conjugated diene-based polymer having an aromatic vinyl monomer unit content of 30 to 45 (mass %), examined by changing the addition amount of the polar compound, found that the amount of vinyl bonds in the conjugated diene monomer unit. It was found that the smaller the (mol%) was, the better the tensile strength and abrasion resistance tended to be.

In particular, when compared with conjugated diene polymers having the same glass transition temperature, conjugated diene polymers in which the content (mass %) of aromatic vinyl monomer units is larger than the value of the amount of vinyl bonds (mol %) of conjugated diene monomer units have tensile strength. It was found that the wear resistance was excellent.

In the process of designing and manufacturing normal conjugated diene polymers, the content of aromatic vinyl monomer units is set by mass, and the amount of vinyl bonds is set by mol%. Therefore, comparing these absolute values has arithmetic significance Although it is difficult to think that there is, as a result of repeating experiments by widely varying the addition amount of the polar compound in the polymerization step, the value of (mass %) of the aromatic vinyl monomer unit and the amount of vinyl bond (mol%) of the conjugated diene monomer unit was compared, and it was found that the tensile strength and abrasion resistance of the polymer of the present embodiment were high when the value of the content of the aromatic vinyl monomer unit was large.

The timing of adding the branching agent is not particularly limited and can be selected according to the purpose and the like, but from the viewpoint of improving the absolute molecular weight of the conjugated diene-based polymer and improving the modification rate, the timing at which the conversion rate of the raw material is 20% or more after addition of the polymerization initiator is It is preferably 40% or more, more preferably 50% or more, still more preferably 65% or more, and still more preferably 75% or more.

By setting it as the said range, even when there is little amount of polar compound, the conjugated diene type polymer of high modification|denaturation rate is obtained.

Further, after adding the branching agent, a desired monomer may be additionally added by lot, and the polymerization step may be continued after branching, or the above description may be repeated.

The monomer added is not particularly limited, but from the viewpoint of improving the modification rate of the conjugated diene-based polymer, the total amount of the conjugated diene-based monomers used in the polymerization step, for example, the total amount of butadiene, is preferably 5% or more, and preferably 10% or more. More preferably, it is more preferably 15% or more, even more preferably 20% or more, and still more preferably 25% or more.

When the amount of the added monomer is within the above range, the molecular weight between the branching point by the branching agent and the branching point by the coupling agent tends to increase, resulting in a molecular structure with high linearity.

By setting the molecular structure with high linearity, entanglement between molecular chains of the conjugated diene-based polymer increases when used as a vulcanizate, and a rubber composition excellent in abrasion resistance, handling stability and breaking strength tends to be obtained.

The polymerization temperature in the polymerization step is preferably a temperature at which living anionic polymerization proceeds, more preferably 0°C or higher, and still more preferably 120°C or lower, from the viewpoint of productivity. By being within this range, there is a tendency that a sufficient amount of reaction of the modifier to the active end after polymerization can be secured. More preferably, it is 50 degreeC or more and 100 degreeC or less.

Further, from the viewpoint of sufficiently completing the polymerization reaction of the aromatic vinyl monomer in the conjugated diene polymer of the present embodiment and controlling the content of the aromatic vinyl monomer unit to 30 to 45% by mass, the temperature is preferably 60°C or higher, and the temperature is preferably 65°C or higher. It is more preferable, and it is more preferable that it is 70 degreeC or more.

In the method for producing the conjugated diene-based polymer of the present embodiment, the addition amount of the branching agent in the branching step of forming the main chain branching structure is as described above.

The branching agent is a branching point of the main chain branching structure of the conjugated diene portion of the conjugated diene-based polymer, and may be used in an appropriate amount according to the desired number of branching points.

(Coupling process)

In the manufacturing method of the conjugated diene type polymer of this embodiment, it is preferable to have the coupling process which couples the conjugated diene type polymer obtained through the above-mentioned polymerization and branching process with a coupling agent.

As the coupling step, for example, using a bifunctional or more reactive compound (hereinafter also referred to as "coupling agent") with respect to the active end of the conjugated diene polymer, or using a modifier having a nitrogen atom-containing group A coupling step to be performed is preferred.

In the coupling step, for example, a conjugated diene polymer can be obtained by subjecting one end of the active end of the conjugated diene polymer to a coupling reaction with a coupling agent or a modifier having a nitrogen atom-containing group.

<Coupling agent>

When the method for producing the conjugated diene-based polymer of the present embodiment includes a coupling step, the coupling agent is not particularly limited, but any structure can be preferably used as long as it is a bifunctional or more reactive compound, and a bifunctional having a nitrogen atom. The above reactive compounds are more preferable.

<Modifier having a nitrogen atom-containing group>

Examples of the modifier having a nitrogen atom-containing group include, but are not limited to, isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, carbonyl compounds having a nitrogen atom-containing group, and vinyl compounds having a nitrogen atom-containing group. , an epoxy compound having a nitrogen atom-containing group, and the like.

In the modifier having a nitrogen atom-containing group, the nitrogen atom-containing group is preferably an amine compound having no active hydrogen. As the modifier having the nitrogen atom-containing group, for example, a tertiary amine compound or the active hydrogen A protected amine compound substituted with a protecting group, an imine compound represented by the general formula -N=C, and an alkoxysilane compound bonded to the above nitrogen atom-containing group are exemplified.

The isocyanate compound, which is a modifier having a nitrogen atom-containing group, is not limited to the following, and examples thereof include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, and polymeric type diphenyl. Methane diisocyanate (C-MDI), phenyl isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, butyl isocyanate, 1,3,5-benzene triisocyanate, etc. are mentioned.

Examples of the isocyanuric acid derivative, which is a denaturant having a nitrogen atom-containing group, are not limited to the following, but include, for example, 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate, 1,3, 5-tris(3-triethoxysilylpropyl)isocyanurate, 1,3,5-tri(oxiran-2-yl)-1,3,5-triazinane-2,4,6-trione , 1,3,5-tris(isocyanatomethyl)-1,3,5-triazinane-2,4,6-trione, 1,3,5-trivinyl-1,3,5-triazinane -2,4,6-trion etc. are mentioned.

Examples of the carbonyl compound as a modifier having a nitrogen atom-containing group include, but are not limited to, 1,3-dimethyl-2-imidazolidinone and 1-methyl-3-ethyl-2-imidazolidinone. , 1-methyl-3-(2-methoxyethyl)-2-imidazolidinone, N-methyl-2-pyrrolidone, N-methyl-2-piperidone, N-methyl-2-quinolone, 4 , 4'-bis (diethylamino) benzophenone, 4,4'-bis (dimethylamino) benzophenone, methyl-2-pyridyl ketone, methyl-4-pyridyl ketone, propyl-2-pyridyl ketone, Di-4-pyridylketone, 2-benzoylpyridine, N,N,N',N'-tetramethylurea, N,N-dimethyl-N',N'-diphenylurea, N,N-diethylcarb Methyl bamate, N,N-diethylacetamide, N,N-dimethyl-N',N'-dimethylaminoacetamide, N,N-dimethylpicolinic acid amide, N,N-dimethylisonicotinic acid amide, etc. can

Examples of the vinyl compound as a modifier having a nitrogen atom-containing group include, but are not limited to, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-methylmaleimide, and N-methylphthalamide. Mead, N,N-bistrimethylsilylacrylamide, morpholinoacrylamide, 3-(2-dimethylaminoethyl)styrene, (dimethylamino)dimethyl-4-vinylphenylsilane, 4,4'-vinylidenebis( N,N-dimethylaniline), 4,4'-vinylidenebis(N,N-diethylaniline), 1,1-bis(4-morpholinophenyl)ethylene, 1-phenyl-1-(4- N,N-dimethylaminophenyl) ethylene etc. are mentioned.

Examples of the epoxy compound as a modifier having a nitrogen atom-containing group include, but are not limited to, hydrocarbon compounds containing an epoxy group bonded to an amino group, and may also have an epoxy group bonded to an ether group. Although not limited to the following as such an epoxy compound, For example, the epoxy compound represented by General formula (i) is mentioned.

In the above formula (i), R ⁷ is a divalent hydrocarbon group, or a polar group having oxygen such as ether, epoxy, ketone and ketone, a polar group having sulfur such as thioether and thioketone, a tertiary amino group, and It is a divalent organic group having at least one kind of polar group selected from the group consisting of polar groups having nitrogen such as no group.

The divalent hydrocarbon group is a saturated or unsaturated hydrocarbon group which may be linear, branched or cyclic, and includes an alkylene group, an alkenylene group, a phenylene group and the like. Preferably, it is a divalent hydrocarbon group having 1 to 20 carbon atoms. For example, methylene, ethylene, butylene, cyclohexylene, 1,3-bis(methylene)-cyclohexane, 1,3-bis(ethylene)-cyclohexane, o-, m-, p-phenylene, m-, p-xylene, bis(phenylene)-methane, etc. are mentioned.

In the formula (i), R ⁸ and R ⁶ represent a hydrogen atom or a monovalent alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R ⁸ and R ⁶ may be the same as or different from each other.

R ⁹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (ii).

R ⁸ and R ⁶ may have a cyclic structure bonded to each other.

Further, when R ⁹ is a monovalent hydrocarbon group, a cyclic structure bonded to R ⁸ may be used. However, only when N bonded to R ⁹ and R ⁸ are directly bonded, R ⁹ may be a hydrogen atom.

In said formula (i), o is an integer greater than or equal to 1.

In the formula (ii), R ¹ and R ² are each defined in the same way as R ⁷ and R ⁸ in the formula (i). R ¹ and R ² may be the same as or different from R ⁷ and R ⁸ , respectively.

As the epoxy compound which is a modifier having a nitrogen atom-containing group, compounds having at least one diglycidylamino group and at least one glycidoxy group in the molecule are particularly preferred.

Examples of the epoxy compound used as the modifier having a nitrogen atom-containing group include, but are not limited to, N,N-diglycidyl-4-glycidoxyaniline and 1-N,N-diglycidyl. Aminomethyl-4-glycidoxy-cyclohexane, 4-(4-glycidoxyphenyl)-(N,N-diglycidyl)aniline, 4-(4-glycidoxyphenoxy)-(N, N-diglycidyl)aniline, 4-(4-glycidoxybenzyl)-(N,N-diglycidyl)aniline, 4-(N,N'-diglycidyl-2-piperazinyl )-glycidoxybenzene, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylenediamine, 4,4 -Methylene-bis(N,N-diglycidylaniline), 1,4-bis(N,N-diglycidylamino)cyclohexane, N,N,N',N'-tetraglycidyl- p-phenylenediamine, 4,4'-bis(diglycidylamino)benzophenone, 4-(4-glycidylpiperazinyl)-(N,N-diglycidyl)aniline, 2-[2] -(N,N-diglycidylamino)ethyl]-1-glycidylpyrrolidine, N,N-diglycidylaniline, 4,4'-diglycidyl-dibenzylmethylamine, N, N-diglycidyl aniline, N,N-diglycidyl orthotoluidine, N,N-diglycidylaminomethylcyclohexane, and the like. Among these, particularly preferable examples include N,N-diglycidyl-4-glycidoxyaniline and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane.

Examples of the alkoxysilane compound as a modifier having a nitrogen atom-containing group include, but are not limited to, 3-dimethylaminopropyltrimethoxysilane, 3-dimethylaminopropylmethyldimethoxysilane, and 3-diethylaminopropyltri Ethoxysilane, 3-morpholinopropyltrimethoxysilane, 3-piperidinopropyltriethoxysilane, 3-hexamethyleneiminopropylmethyldiethoxysilane, 3-(4-methyl-1-piperazino )Propyltrimethoxysilane, 3-(4-methyl-1-piperazino)propyltriethoxysilane, 1-[3-(triethoxysilyl)-propyl]-3-methylhexahydropyrimidine, 3 -(4-trimethylsilyl-1-piperazino)propyltriethoxysilane, 3-(3-triethylsilyl-1-imidazolidinyl)propylmethyldiethoxysilane, 3-(3-trimethylsilyl-1 -Hexahydropyrimidinyl)propyltrimethoxysilane, 3-dimethylamino-2-(dimethylaminomethyl)propyltrimethoxysilane, bis(3-dimethoxymethylsilylpropyl)-N-methylamine, bis(3 -trimethoxysilylpropyl)-N-methylamine, bis(3-triethoxysilylpropyl)methylamine, tris(trimethoxysilyl)amine, tris(3-trimethoxysilylpropyl)amine, N,N ,N',N'-tetra(3-trimethoxysilylpropyl)ethylenediamine, 3-isocyanatopropyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 2,2-dimethoxy-1- (3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2 ,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza -2-silacyclopentane, 2,2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, 2,2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2 ,2-dimethoxy-1-methyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-8-(4-methylpiperazinyl)methyl-1,6-dioxa-2-silacyclo Octane, 2,2-dimethoxy-8-(N,N-diethylamino)methyl-1,6-dioxa-2-silacyclooctane, etc. are mentioned.

As a protected amine compound capable of forming a primary or secondary amine with a nitrogen atom-containing group-containing modifier, the compound having an unsaturated bond and a protected amine in the molecule is not limited to the following, for example, 4,4'-vinylidenebis[N,N-bis(trimethylsilyl)aniline], 4,4'-vinylidenebis[N,N-bis(triethylsilyl)aniline], 4,4'-vinylidene Bis [N, N-bis (t-butyldimethylsilyl) aniline], 4,4'-vinylidene bis [N-methyl-N- (trimethylsilyl) aniline], 4,4'-vinylidene bis [N- Ethyl-N-(trimethylsilyl)aniline], 4,4'-vinylidenebis[N-methyl-N-(triethylsilyl)aniline], 4,4'-vinylidenebis[N-ethyl-N-( triethylsilyl)aniline], 4,4'-vinylidenebis[N-methyl-N-(t-butyldimethylsilyl)aniline], 4,4'-vinylidenebis[N-ethyl-N-(t- butyldimethylsilyl)aniline], 1-[4-N,N-bis(trimethylsilyl)aminophenyl]-1-[4-N-methyl-N-(trimethylsilyl)aminophenyl]ethylene, 1-[4- N,N-bis(trimethylsilyl)aminophenyl]-1-[4-N,N-dimethylaminophenyl]ethylene; and the like.

A compound having an alkoxysilane and a protected amine in a molecule as a protected amine compound that is a modifier having a nitrogen atom-containing group and capable of forming a primary or secondary amine is not limited to the following, for example, N,N-bis(trimethylsilyl)aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)aminopropylmethyldimethoxysilane, N,N-bis(trimethylsilyl)aminopropyltriethoxysilane, N, N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane, N,N-bis(trimethylsilyl)aminoethylmethyldiethoxysilane, N,N- Bis(triethylsilyl)aminopropylmethyldiethoxysilane, 3-(4-trimethylsilyl-1-piperazino)propyltriethoxysilane, 3-(3-triethylsilyl-1-imidazolidinyl)propyl Methyldiethoxysilane, 3-(3-trimethylsilyl-1-hexahydropyrimidinyl)propyltrimethoxysilane, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza- 2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxy Silylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy- 1-phenyl-1-aza-2-silacyclopentane, 2,2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-methyl-1-aza- 2-silacyclopentane, N-(1,3-dimethylbutylidene)-3-methyl(dimethoxysilyl)-1-propanamine, N-(1,3-dimethylbutylidene)-3-methyl( Diethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-(triethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-(tri Methoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-methyl(dimethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-methyl( Diethoxysilyl)-1-propanamine, N-ethylidene-3-(triethoxysilyl)-1-propanamine, N-ethylidene-3-(trimethoxysilyl)-1-propanamine, N- Ethylidene-3-methyl (dimethoxysilyl) -1-propanamine and N-ethylidene-3-methyl (diethoxysilyl) -1-propanamine are exemplified.

Further, as a protected amine compound capable of forming a primary or secondary amine with a modifier having a nitrogen atom-containing group, as a compound having an alkoxysilane and a protected amine in a molecule, N-(1-methylpropylidene) -3-(triethoxysilyl)-1-propanamine, N-(1-methylpropylidene)-3-(trimethoxysilyl)-1-propanamine, N-(1-methylpropylidene)-3 -Methyl(dimethoxysilyl)-1-propanamine, N-(1-methylpropylidene)-3-methyl(diethoxysilyl)-1-propanamine, N-benzylidene-3-methyl(dimethoxysilyl) Propan-1-amine, N-benzylidene-3-methyl (diethoxysilyl) propan-1-amine, N-4-methylbenzylidene-3- (triethoxysilyl) propan-1-amine, N-4 -Methylbenzylidene-3-(trimethoxysilyl)propan-1-amine, N-4-methylbenzylidene-3-methyl(dimethoxysilyl)propan-1-amine, N-4-methylbenzylidene-3 -Methyl (diethoxysilyl) propan-1-amine, N-naphthylidene-3- (triethoxysilyl) propan-1-amine, N-naphthylidene-3- (trimethoxysilyl) propan-1 -Amine, N-naphthylidene-3-methyl(dimethoxysilyl)propan-1-amine, -1,1-(1,4-phenylene)bis(N-(3-methyl(dimethoxysilyl)propyl )methanamine), 1,1-(1,4-phenylene)bis(N-(3-methyl(diethoxysilyl)propyl)methanamine), 2-ethoxy-2-methyl-1-(benzylidene) Aminoethyl)-1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1-(methylisobutylideneaminoethyl)-1-aza-2-silacyclopentane, etc. are mentioned.

Although it is not limited to the following as an especially preferable alkoxysilane compound which is a modifier which has a nitrogen atom containing group, For example, tris (3-trimethoxysilylpropyl) amine, tris (3-triethoxysilylpropyl) amine, tris(3-tripropoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, 3- (4-methylpiperazin-1-yl)propyltrimethoxysilane, 3-(4-methylpiperazin-1-yl)propyltriethoxysilane, tetrakis(3-trimethoxysilylpropyl)-1, 3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, Tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-methyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis(3-triene Toxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-aza Cyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-( 2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane.

In addition, as an especially preferable alkoxysilane compound which is a modifier having a nitrogen atom-containing group, tetrakis(3-trimethoxysilylpropyl)-1,6-hexamethylenediamine, pentakis(3-trimethoxysilylpropyl)-di Ethylenetriamine, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane , bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris[3-(2,2-dimethoxy- 1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[ 3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]silane, 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane )ethoxy]silyl-1-trimethoxysilylpropane, 1-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-3,4,5-tris (3-trimethoxysilylpropyl)-cyclohexane, 1-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-3,4,5-tris(3-tris Methoxysilylpropyl)-cyclohexane, 3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexyl-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]ether, (3-trimethoxysilylpropyl)phosphate, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]phosphate , bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)phosphate, tris[3-(2,2-dimethoxy-1 -Aza-2-silacyclopentane)propyl]phosphate, N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propanamine, N-(1,3-dimethylbutylly) Den)-3-(trimethoxysilyl)-1-propanamine, N-benzylidene-3-(triethoxysilyl)propan-1-amine, N-benzylidene-3-(trimethoxysilyl)propane -1-amine, 1,1-(1,4-phenylene)bis(N-(3(triethoxysilyl)propyl)methanamine), 1,1-(1,4-phenylene)bis(N -(3(trimethoxysilyl)propyl)methanamine), 2-methoxy-2-methyl-1-(benzylideneaminoethyl)-1-aza-2-silacyclopentane, 2-methoxy-2- methyl-1-(4-methoxybenzylideneaminoethyl)-1-aza-2-silacyclopentane.

These denaturants may be used individually by 1 type, or may use 2 or more types together.

(Preferred structure of conjugated diene polymer)

The conjugated diene-based polymer of the present embodiment preferably includes a structure derived from a compound having a nitrogen atom-containing group represented by the following general formula (i) or any of (A) to (E).

In the above formula (i), R ⁷ is a divalent hydrocarbon group, or a polar group having oxygen such as ether, epoxy, ketone and ketone, a polar group having sulfur such as thioether and thioketone, a tertiary amino group, and It is a divalent organic group having at least one kind of polar group selected from the group consisting of polar groups having nitrogen such as no group.

The divalent hydrocarbon group is a saturated or unsaturated hydrocarbon group which may be linear, branched or cyclic, and includes an alkylene group, an alkenylene group, a phenylene group and the like. Preferably, it is a divalent hydrocarbon group having 1 to 20 carbon atoms. For example, methylene, ethylene, butylene, cyclohexylene, 1,3-bis(methylene)-cyclohexane, 1,3-bis(ethylene)-cyclohexane, o-, m-, p-phenylene, m-, p-xylene, bis(phenylene)-methane, etc. are mentioned.

In the formula (i), R ⁸ and R ⁶ represent a hydrogen atom or a monovalent alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R ⁸ and R ⁶ may be the same as or different from each other. .

R ⁹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (ii).

R ⁸ and R ⁶ may have a cyclic structure bonded to each other.

Further, when R ⁹ is a monovalent hydrocarbon group, a cyclic structure bonded to R ⁸ may be used. However, only when N bonded to R ⁹ and R ⁸ are directly bonded, R ⁹ may be a hydrogen atom. In formula (i), o is an integer greater than or equal to 1.

In the formula (ii), R ¹ and R ² are each defined in the same way as R ⁷ and R ⁸ in the formula (i). R ¹ and R ² may be the same as or different from R ⁷ and R ⁸ , respectively.

(In formula (A), R ¹² to R ¹⁵ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R ¹⁶ represents an alkylene group having 1 to 10 carbon atoms, and R ¹⁷ represents an alkylene group having 1 to 20 carbon atoms.

q represents an integer of 1 or 2, r represents an integer of 2 or 3, and (q+r) represents an integer of 4 or greater. R ¹² to R ¹⁵ in the case of multiple presence are independent of each other.)

(In formula (B), R ¹⁸ to R ²³ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ²⁴ to R ²⁶ are each independently represents an alkylene group.

s, t, and u each independently represent an integer of 1 to 3, and (s+t+u) represents an integer of 4 or greater. R ¹⁸ to R ²³ in the case of a plurality of presence are independent of each other.)

(In formula (C), R ²⁷ to R ²⁹ each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms, and R ³⁰ to R ³³ and R ³⁵ each independently have 1 to 20 carbon atoms represents an alkyl group, R ³⁴ and R ³⁷ each independently represent an alkylene group having 1 to 20 carbon atoms, and R ³⁶ represents an alkyl group or trialkylsilyl group having 1 to 20 carbon atoms.

w represents an integer of 1 to 3, and x represents 1 or 2.

R ²⁷ to R ³⁷ , w and k in the case where there are a plurality of them respectively are independent, and may be the same or different.

i represents an integer of 0 to 6, j represents an integer of 0 to 6, k represents an integer of 0 to 6, and (i+j+k) is an integer of 4 to 10.

A represents a hydrocarbon group having 1 to 20 carbon atoms or an organic group having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom, and a phosphorus atom, and having no active hydrogen. )

(In formula (D), R ³⁶ represents an alkylene group having 1 to 20 carbon atoms, and R ³⁷ , R ³⁹ , and R ⁴⁰ are each independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms) group, R ³⁸ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and z represents an integer of 1 to 3.)

In Formula (E), R ⁴¹ to R ⁴⁴ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ⁴⁵ to R ⁴⁷ each independently represent an alkyl group having 1 to 20 carbon atoms represents a lengi.

m and n represent integers of 1 to 3, and may be the same or different.

R ⁴¹ to R ⁴⁷ in the case of a plurality of presence are independent of each other.

Examples of the modifier having a nitrogen atom-containing group represented by the formula (A) include, but are not limited to, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza- 2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxy Silylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(5-trimethoxysilylpentyl)-1-aza-2-silacycloheptane, 2,2-dimethoxy- 1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silacyclopentane , 2-methoxy-2-methyl-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-ethoxy,2-ethyl-1-(3-triethoxysilyl Propyl)-1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, and 2-ethoxy- and 2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silacyclopentane.

Among these, from the viewpoint of the reactivity and interaction of the functional group of the modifier having a nitrogen atom-containing group and the inorganic filler such as silica, and from the viewpoint of workability, q is preferably 2 and r is 3. Specifically, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, and 2,2-diethoxy-1-(3-triethoxysilyl Preferred is propyl)-1-aza-2-silacyclopentane.

The reaction temperature, reaction time, etc., when reacting the polymer active end with the modifier having a nitrogen atom-containing group represented by the formula (A) 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 desirable to do

The total number of moles of alkoxy groups bonded to silyl groups in the compound of the modifier having a nitrogen atom-containing group represented by the formula (A) is 0.6 times or more and 3.0 times or less the number of moles of alkali metal compound and/or alkaline earth metal compound added in the polymerization initiator. It is preferably in the range of 0.8 times or more and 2.5 times or less, more preferably in the range of 0.8 times or more and 2.0 times or less. From the viewpoint of obtaining a sufficient modification rate and molecular weight and branched structure of the conjugated diene polymer obtained, it is preferable to set it to 0.6 times or more, and in addition to that it is preferable to obtain a branched polymer component by coupling polymer terminals to each other to improve processability , It is preferable to set it as 3.0 times or less from a viewpoint of the cost of a denaturant.

The number of moles of the more specific polymerization initiator is preferably 3.0 times mole or more, and more preferably 4.0 times mole or more relative to the mole number of the modifier.

Examples of the modifier having a nitrogen atom-containing group represented by the formula (B) include, but are not limited to, tris(3-trimethoxysilylpropyl)amine and tris(3-methyldimethoxysilylpropyl)amine. , tris (3-triethoxysilylpropyl) amine, tris (3-methyldiethoxysilylpropyl) amine, tris (trimethoxysilylmethyl) amine, tris (2-trimethoxysilylethyl) amine, and tris ( and 4-trimethoxysilylbutyl)amine.

Among these, it is preferable that s, t, and u all represent 3 from the viewpoint of the reactivity and interaction of the functional group of the modifier and the inorganic filler such as silica, and from the viewpoint of processability. Preferred specific examples include tris(3-trimethoxysilylpropyl)amine and tris(3-triethoxysilylpropyl)amine.

The reaction temperature, reaction time, etc., when reacting the polymer active end with the modifier having a nitrogen atom-containing group represented by the formula (B) 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 desirable to do

It is preferable that the total number of moles of alkoxy groups bonded to silyl groups in the compound of the modifier represented by the formula (B) is in the range of 0.6 times or more and 3.0 times or less, and is 0.8 times or more times the number of moles of lithium constituting the above-mentioned polymerization initiator. It is more preferably in the range of 2.5 times or less, and more preferably in the range of 0.8 times or more and 2.0 times or less. From the viewpoint of obtaining a sufficient modification rate and molecular weight and branched structure in the conjugated diene polymer, it is preferable to set it to 0.6 times or more, and in addition to that it is preferable to obtain a branched polymer component by coupling polymer terminals to each other to improve processability , It is preferable to set it as 3.0 times or less from a viewpoint of the cost of a denaturant.

The number of moles of the more specific polymerization initiator is preferably 4.0 times mole or more, more preferably 5.0 times mole or more relative to the mole number of the modifier.

In the formula (C), A is preferably represented by any one of the following general formulas (II) to (V).

(In formula (II), B ¹ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. When a plurality of B ¹ are present, each is independent.)

(In formula (III), B ² represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, B ³ represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. Multiple presence, respectively. B ² and B ³ in this case are independent.)

(In formula (IV), B ⁴ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. When a plurality of B ⁴ are present, each is independent.)

(In formula (V), B ⁵ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. When a plurality of B ⁵ are present, each is independent.)

In the formula (C), examples of the modifier having a nitrogen atom-containing group when A is represented by formula (II) include, but are not limited to, tris(3-trimethoxysilylpropyl)amine; Bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, bis[3-(2,2-dimethoxy-1- Aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)amine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tris( 3-ethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]amine, bis[3-( 2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)amine, tris[3-(2,2-diethoxy-1-aza-2-sila Cyclopentane)propyl]amine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1- Aza-2-silacyclopentane)propyl]-1,3-propanediamine, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane )Propyl]-1,3-propanediamine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3- Propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis(3-trimethoxysilylpropyl)-[3-(2,2- dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine; Bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1 -Sila-2-azacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1- Methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-propanediamine, tetrakis (3-triethoxysilylpropyl) -1,3-propanediamine, tris (3 -triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)- Bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-diethoxy-1-aza-2- Silacyclopentane)propyl]-(3-triethoxysilylpropyl)-1,3-propanediamine, tetrakis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]- 1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propane Diamine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl -1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-tri ethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine.

In the above formula (C), as the modifier having a nitrogen atom-containing group when A is represented by formula (II), tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane )Propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)- 1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bis Aminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane , tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tetrakis[3 -(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2 -Trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1 -aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis [3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1- Sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-( 1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis(3-triethoxysilylpropyl)-1,3-propane Diamine, tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3 -triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2, 2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-1,3-propanediamine, tetrakis[3-(2,2-diethoxy-1- Aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-aza Cyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl] -[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis[3-(2,2-diethoxy- 1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]- 1,3-bisaminomethylcyclohexane, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1 -sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tetrakis (3-trimethoxysilylpropyl) -1,6-hexamethylenediamine, and pentakis (3-trimethine oxysilylpropyl)-diethylenetriamine.

In the above formula (C), the modifier having a nitrogen atom-containing group in case A is represented by formula (III) is not limited to the following, but, for example, tris(3-trimethoxysilylpropyl)-methyl -1,3-propanediamine, bis(2-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propane Diamine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tris(3- Triethoxysilylpropyl)-methyl-1,3-propanediamine, bis(2-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl] -Methyl-1,3-propanediamine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-methyl-1,3 -propanediamine, N ¹ ,N ^1' -(propane-1,3-diyl)bis(N ¹ -methyl- ^{N 3} ,N ³ -bis(3-(trimethoxysilyl)propyl)-1,3- propanediamine), and N ¹ -(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N ¹ -methyl-N ³ -(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl) )propyl)amino)propyl)-N ³ -(3-(trimethoxysilyl)propyl)-1,3-propanediamine.

In the above formula (C), the modifier having a nitrogen atom-containing group in case A is represented by formula (IV) is not limited to the following, but, for example, tetrakis[3-(2,2-dimethoxy -1-aza-2-silacyclopentane)propyl]silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)silane , tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) Propyl]silane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, (3-trimethoxysilyl)- [3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane , Bis[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl ]Silane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)- [3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl] Silane, bis[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-bis(3-trimethoxysilylpropyl)silane, and bis(3-trimethoxy silylpropyl)-bis[3-(1-methoxy-2-methyl-1-sila-2-azacyclopentane)propyl]silane.

In the above formula (C), the modifier having a nitrogen atom-containing group in case A is represented by formula (V) is not limited to the following, but, for example, 3-tris[2-(2,2-dimethine) Toxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-(2,2-dimethoxy-1-aza-2-silacyclopentane)propane, and 3-tris[2-(2,2 -Dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-trimethoxysilylpropane.

In the formula (C), A is preferably represented by formula (II) or formula (III), and k represents 0.

Modifiers having such a nitrogen atom-containing group tend to be readily available, and tend to have better wear resistance and low hysteresis loss performance when the conjugated diene polymer is used as a vulcanizate. Examples of the modifier having a nitrogen atom-containing group include, but are not limited to, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclo) Pentane) propyl] amine, tris (3-trimethoxysilylpropyl) amine, tris (3-triethoxysilylpropyl) amine, tris (3-trimethoxysilylpropyl) -[3- (2,2-dimethyi) Toxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1, 3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3- Trimethoxysilylpropyl)-methyl-1,3-propanediamine, and bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trismethoxysilylpropyl )-methyl-1,3-propanediamine.

In the formula (C), A is more preferably represented by formula (II) or formula (III), k represents 0, and in formula (II) or formula (III), a is Represents an integer from 2 to 10.

This tends to result in better wear resistance and low hysteresis loss performance during vulcanization.

Examples of the modifier having a nitrogen atom-containing group include, but are not limited to, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3- Propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, and N ¹ -(3 -(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N ¹ -methyl-N ³ -(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N ³ -(3-(trimethoxysilyl)propyl)-1,3-propanediamine.

The addition amount of the compound represented by the formula (C) as a modifier having a nitrogen atom-containing group can be adjusted so that the modifier reacts so as to have a desired stoichiometric ratio with the number of moles of lithium constituting the polymerization initiator described above. The desired star-shaped hyperbranched structure tends to be achieved.

The number of moles of lithium constituting the specific polymerization initiator is preferably 5.0 times mole or more, more preferably 6.0 times mole or more with respect to the mole number of the modifier.

In this case, in formula (C), the number of functional groups ((w-1)×i+x×j+k) of the modifier is preferably an integer of 5 to 10, and more preferably an integer of 6 to 10.

Examples of the modifier having a nitrogen atom-containing group represented by the formula (D) include, but are not limited to, N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1 -Propanamine, N-(1,3-dimethylbutylidene)-3-(trimethoxysilyl)-1-propanamine, N-(1,3-dimethylbutylidene)-3-methyl(dimethoxy Silyl)-1-propanamine, N-(1,3-dimethylbutylidene)-3-methyl(diethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-(tri Ethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-(trimethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-methyl( Dimethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-methyl(diethoxysilyl)-1-propanamine, N-ethylidene-3-(triethoxysilyl)-1 -Propanamine, N-ethylidene-3-(trimethoxysilyl)-1-propanamine, N-ethylidene-3-methyl(dimethoxysilyl)-1-propanamine, N-ethylidene-3-methyl (diethoxysilyl)-1-propanamine, N-(1-methylpropylidene)-3-(triethoxysilyl)-1-propanamine, N-(1-methylpropylidene)-3-(trimethine) Toxysilyl)-1-propanamine, N-(1-methylpropylidene)-3-methyl(dimethoxysilyl)-1-propanamine, N-(1-methylpropylidene)-3-methyl(diethoxysilyl )-1-propanamine, N-benzylidene-3-(triethoxysilyl)propan-1-amine, N-benzylidene-3-(trimethoxysilyl)propan-1-amine, N-benzylidene- 3-methyl(dimethoxysilyl)propan-1-amine, N-benzylidene-3-methyl(diethoxysilyl)propan-1-amine, N-4-methylbenzylidene-3-(triethoxysilyl)propane -1-amine, N-4-methylbenzylidene-3-(trimethoxysilyl)propan-1-amine, N-4-methylbenzylidene-3-methyl(dimethoxysilyl)propan-1-amine, N -4-methylbenzylidene-3-methyl(diethoxysilyl)propan-1-amine, N-naphthylidene-3-(triethoxysilyl)propan-1-amine, N-naphthylidene-3-( Trimethoxysilyl) propan-1-amine, N-naphthylidene-3-methyl (dimethoxysilyl) propan-1-amine, etc. are mentioned, 1,1-(1,4-phenylene) bis( N-(3(triethoxysilyl)propyl)methanamine), 1,1-(1,4-phenylene)bis(N-(3(trimethoxysilyl)propyl)methanamine), 1,1- (1,4-phenylene)bis(N-(3-methyl(dimethoxysilyl)propyl)methanamine), 1,1-(1,4-phenylene)bis(N-(3-methyl(diethoxy) Silyl) propyl) methanamine), 2-methoxy-2-methyl-1- (benzylideneaminoethyl) -1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1- (p- Methoxybenzylideneaminoethyl)-1-aza-2-silacyclopentane, 2-ethoxy-2-methyl-1-(benzylideneaminoethyl)-1-aza-2-silacyclopentane, 2-methoxy -2-methyl-1-(methylisobutylideneaminoethyl)-1-aza-2-silacyclopentane;

The reaction temperature, reaction time, etc., when reacting the polymer active end with the modifier having a nitrogen atom-containing group represented by the formula (D) 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 desirable to do

It is preferable that the total number of moles of alkoxy groups bonded to silyl groups in the compound of the modifier represented by the formula (D) is in the range of 0.2 times or more and 2.0 times or less, and is 0.3 times or more times the number of moles of lithium constituting the above-mentioned polymerization initiator. It is more preferable that it is the range which becomes 1.5 times or less. From the viewpoint of obtaining a sufficient modification rate and molecular weight in the conjugated diene polymer, it is preferably 0.3 times or more, and from the viewpoint of the cost of the modifier, it is preferably 2.0 times or less.

The number of moles of the more specific polymerization initiator is preferably 0.5 times mole or more, more preferably 1.0 times mole or more relative to the mole number of the modifier.

Examples of the modifier having a nitrogen atom-containing group represented by the formula (E) include, but are not limited to, N-(3-(1H-imidazol-1-yl)propyl)-3-(trie). Toxysilyl)-N-(3-(triethoxysilyl)propyl)propan-1-amine, N-(3-(1H-imidazol-1-yl)propyl)-3-(trimethoxysilyl)- N-(3-(trimethoxysilyl)propyl)propan-1-amine, N-(3-(1H-imidazol-1-yl)propyl)-3-(ethyldiethoxysilyl)-N-(3 -(Ethyldiethoxysilyl)propyl)propan-1-amine, N-(3-(1H-imidazol-1-yl)propyl)-3-(methyldimethoxysilyl)-N-(3-(methyldimethylate) Toxysilyl)propyl)propan-1-amine, N-(3-(1H-imidazol-1-yl)propyl)-3-(diethylethoxysilyl)-N-(3-(diethylethoxysilyl) )Propyl)propan-1-amine, N-(3-(1H-imidazol-1-yl)propyl)-3-(dimethylmethoxysilyl)-N-(3-(dimethylmethoxysilyl)propyl)propane -1-amine is mentioned.

The reaction temperature, reaction time, etc. when reacting the polymer active end with the modifier having a nitrogen atom-containing group represented by the above formula (E) are not particularly limited, but the reaction is performed at 0°C or more and 120°C or less for 30 seconds or more. It is desirable to do

It is preferable that the total number of moles of alkoxy groups bonded to silyl groups in the compound of the modifier represented by the formula (E) is in the range of 0.2 times or more and 2.0 times or less, and is 0.3 times or more times the number of moles of lithium constituting the above-mentioned polymerization initiator. It is more preferable that it is the range which becomes 1.5 times or less. From the viewpoint of obtaining a sufficient modification rate and molecular weight in the conjugated diene polymer, it is preferably 0.3 times or more, and from the viewpoint of the cost of the modifier, it is preferably 2.0 times or less.

In the conjugated diene-based polymer of the present embodiment, the ratio of the nitrogen atom-containing polymer in the conjugated diene-based polymer is expressed as a modification rate.

The modification rate is preferably 60% by mass or more, more preferably 65% by mass or more, even more preferably 70% by mass or more, still more preferably 75% by mass or more, still more preferably 80% by mass or more, Especially preferably, it is 82 mass % or more.

By setting the modification rate to 60% by mass or more, processability when used as a vulcanized product tends to be excellent, and wear resistance and low hysteresis loss performance when used as a vulcanized product tend to be more excellent.

In this embodiment, after the coupling step or before the coupling step, you may perform the condensation reaction step made to condensate in the presence of a condensation accelerator.

The conjugated diene polymer of this embodiment may hydrogenate the conjugated diene part.

A method for hydrogenating the conjugated diene portion of the conjugated diene polymer is not particularly limited, and a known method can be used.

As a suitable method of hydrogenation, a method of hydrogenation by blowing gaseous hydrogen into a polymer solution in the presence of a catalyst is exemplified.

Examples of the catalyst include, but are not particularly limited to, heterogeneous catalysts such as catalysts in which a noble metal is supported on a porous inorganic substance; Homogeneous catalysts, such as catalysts obtained by reacting solubilized salts such as nickel and cobalt with organic aluminum, and catalysts using metallocenes such as titanocene, are exemplified. Among these, a titanocene catalyst is preferable from the viewpoint of being able to select mild hydrogenation conditions.

In addition, hydrogenation of an aromatic group can be performed by using a noble metal supported catalyst.

Examples of the hydrogenation catalyst include, but are not limited to, (1) a supported heterogeneous hydrogenation catalyst in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like; (2) So-called Ziegler-type hydrogenation catalysts using organic acid salts such as Ni, Co, Fe, and Cr or transition metal salts such as acetylacetone salts and reducing agents such as organic aluminum, (3) organic metals such as Ti, Ru, Rh, and Zr So-called organometallic complexes, such as a compound, etc. are mentioned. In addition, it is not particularly limited as a hydrogenation catalyst, but, for example, Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication Hei 1 Known hydrogenation catalysts described in Japanese Patent Publication No. -37970, Japanese Patent Publication No. Hei 1-53851, Japanese Patent Publication No. Hei 2-9041, and Japanese Unexamined Patent Publication No. Hei 8-109219 are also included. As a preferable hydrogenation catalyst, a reaction mixture of a titanocene compound and a reducible organometallic compound is exemplified.

In the manufacturing method of the conjugated diene type polymer of this embodiment, you may add a deactivator, a neutralizing agent, etc. to a polymer solution after a coupling process as needed.

Although it is not limited to the following as a deactivator, For example, water; Alcohols, such as methanol, ethanol, and isopropanol, etc. are mentioned.

Examples of the neutralizer include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and versatic acid (a highly branched carboxylic acid mixture having 9 to 11 carbon atoms and containing 10 carbon atoms); An aqueous solution of an inorganic acid and carbon dioxide gas are exemplified.

In the method for producing the conjugated diene-based polymer of the present embodiment, it is preferable to add a stabilizer for rubber from the viewpoint of preventing gel formation after polymerization and improving stability during processing.

The stabilizer for rubber is not limited to the following, and a known stabilizer can be used. For example, 2,6-di-tert-butyl-4-hydroxytoluene (hereinafter also referred to as "BHT"), n Oxidation of octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenol)propionate, 2-methyl-4,6-bis[(octylthio)methyl]phenol, etc. Inhibitors are preferred.

[Conjugated diene polymer composition]

In order to further improve the productivity of the conjugated diene polymer of the present embodiment and the processability when the rubber composition is blended with a filler or the like, a conjugated diene polymer composition may be prepared by adding a rubber softener as needed.

Examples of the softener for rubber include, but are not particularly limited to, extender oil, liquid rubber, and resin.

The method for adding the softener for rubber to the conjugated diene-based polymer is not limited to the following, but the softener for rubber is added to the conjugated diene-based polymer solution, mixed, and the polymer solution containing the softener for rubber is desolvated. method is preferred.

As a preferable extender oil, aroma oil, naphthenic oil, paraffin oil, etc. are mentioned, for example. Among these, from the viewpoint of environmental safety, and from the viewpoint of oil bleed prevention and wet grip characteristics, an aroma replacement oil having a polycyclic aromatic (PCA) component of 3% by mass or less according to the IP346 method is preferable. Examples of aroma replacement oils include TDAE (Treatated Distillate Aromatic Extracts), MES (Mild Extraction Solvate), etc. as shown in Kautschuk Gummi Kunststoffe 52 (12) 799 (1999), as well as RAE (Residual Aromatic Extracts).

Although it is not limited to the following as a preferable liquid rubber, For example, liquid polybutadiene, liquid styrene-butadiene rubber, etc. are mentioned.

As an effect of adding liquid rubber, in addition to improving processability when a rubber composition in which a conjugated diene polymer and a filler are blended, the glass transition temperature of the rubber composition can be shifted to the low temperature side, thereby It tends to improve wear resistance, low hysteresis loss, and low-temperature characteristics when used as a vulcanizate.

Preferred resins as the softener for rubber are not limited to the following, but include, for example, aromatic petroleum resins, coumarone-indene resins, terpene resins, rosin derivatives (including tung oil resins), tall oil, and tall oil derivatives. , rosin ester resins, natural and synthetic terpene resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, mixed aliphatic/aromatic hydrocarbon resins, coumarin-indene resins, phenolic resins, p-tert-butylphenol-acetylene resins, phenol-formaldehyde resins , xylene-formaldehyde resins, oligomers of monoolefins, oligomers of diolefins, hydrogenated aromatic hydrocarbon resins, cyclic aliphatic hydrocarbon resins, hydrogenated hydrocarbon resins, hydrocarbon resins, hydrogenated copper oil resins, hydrogenated oil resins, hydrogenated oil resins and monofunctional or polyfunctional esters of functional alcohols; and the like. These resins may be used by one type, or may use 2 or more types together. In the case of hydrogenation, all unsaturated groups may be hydrogenated, or a part may be left.

As an effect of adding a resin as a softener for rubber, in addition to improving processability when a rubber composition in which a conjugated diene polymer and a filler are blended, improving the breaking strength when used as a vulcanizate there is a tendency

In the conjugated diene polymer composition of the present embodiment, the amount of the extender oil, liquid rubber or resin added as a softener for rubber is not particularly limited, but is 1 part by mass with respect to 100 parts by mass of the conjugated diene polymer of the present embodiment. It is 60 parts by mass or less, preferably 5 parts by mass or more and 50 parts by mass or less, more preferably 10 parts by mass or more and 37.5 parts by mass or less.

When a softener for rubber is added within the above range, processability when a rubber composition containing a conjugated diene polymer and a filler or the like is blended tends to be improved, and breaking strength and wear resistance when used as a vulcanized product tend to be improved.

(Desolvation process)

As described above, a softener for rubber (eg, extender oil) is added to a conjugated diene-based polymer solution and mixed to obtain a polymer solution containing a softener for rubber. As a method for obtaining a conjugated diene-based polymer composition, A known method can be used. For example, a method of obtaining a polymer by separating the solvent by steam stripping or the like, then filtering the polymer and further dewatering and drying it, a method of concentrating in a flushing tank and further devolatilizing with a vent extruder, etc., a drum dryer and the like.

[Rubber composition]

The rubber composition of the present embodiment contains a rubber component and a filler of 5.0 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the rubber component.

In addition, the rubber component is 10 parts by mass of the above-described conjugated diene-based polymer or the above-described conjugated diene-based polymer composition relative to the total amount (100 parts by mass) of the rubber component, from the viewpoint of improving fuel economy performance, processability, and abrasion resistance. include more

(Silica-based inorganic filler)

The filler preferably includes a silica-based inorganic filler.

The rubber composition of the present embodiment, by dispersing the silica-based inorganic filler, tends to have better processability when used as a vulcanizate, and tends to be superior in low hysteresis loss, tensile strength, and abrasion resistance when used as a vulcanized product. there is.

When the rubber composition of the present embodiment is used for automobile parts such as tires and anti-vibration rubber, and vulcanized rubber applications such as shoes, it is particularly preferable to include a silica-based inorganic filler.

(rubber polymer)

In the rubber composition of the present embodiment, a rubbery polymer other than the above-described conjugated diene-based polymer of the present embodiment (hereinafter simply referred to as "other rubbery polymer") is combined with the above-described conjugated diene-based polymer of the present embodiment. Can be used in combination.

Although it is not limited to the following as said other rubbery polymer, For example, a conjugated diene type polymer or its hydrogenated substance, a random copolymer of a conjugated diene type compound and a vinyl aromatic compound or its hydrogenated substance, a conjugated diene type compound, Block copolymers of vinyl aromatic compounds or hydrogenated products thereof, non-diene polymers, and natural rubbers are exemplified.

Specifically, butadiene rubber or its hydrogenated product, isoprene rubber or its hydrogenated product, styrene-butadiene rubber or its hydrogenated product, styrene-butadiene block copolymer or its hydrogenated product, styrene-isoprene block copolymer or its hydrogenated product, etc. A styrenic elastomer, an acrylonitrile-butadiene rubber, or its hydrogenated product is mentioned.

Examples of the non-diene polymer include, but are not limited to, ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, and ethylene-octene rubber. Olefin elastomers, butyl rubber, brominated butyl rubber, acrylic rubber, fluororubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β-unsaturated nitrile-acrylic acid ester-conjugated diene copolymer rubber, urethane rubber, and polysulfurized rubber.

Although it is not limited to the following as a natural rubber, For example, RSS3-5 which are smoked sheets, SMR, and epoxidized natural rubber are mentioned.

The various other rubbery polymers described above may be modified rubbers to which a functional group having a polarity such as a hydroxyl group or an amino group is provided. When used for tires, butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber are preferably used.

The weight average molecular weight of the other rubbery polymers is preferably 2000 or more and 2000000 or less, and more preferably 5000 or more and 1500000 or less, from the viewpoint of the balance between performance and processing properties. In addition, as other rubbery polymers, low molecular weight rubbery polymers, so-called liquid rubbers, can also be used.

Other rubbery polymers may be used individually by 1 type, or may use 2 or more types together.

In the case where the rubber composition of the present embodiment is a rubber composition containing the above-described conjugated diene-based polymer of the present embodiment and other rubbery polymers, the content ratio of the above-described conjugated diene-based polymer relative to the other rubbery polymers (Mass ratio) is 10/90 or more and 100/0 or less, preferably 20/80 or more and 90/10 or less, as (the above-mentioned conjugated diene polymer/other rubbery polymer), 30/70 or more and 80/20 The following is more preferable.

Therefore, the rubber component contains 10 parts by mass or more and 100 parts by mass or less of the conjugated diene-based polymer of the present embodiment described above with respect to the total amount (100 parts by mass) of the rubber component, preferably 20 parts by mass or more and 90 parts by mass. It contains less than part, More preferably, it contains 30 parts by mass or more and 80 parts by mass or less.

When the content ratio of (the above-described conjugated diene polymer/other rubbery polymer) is within the above range, the tensile strength, abrasion resistance, and low hysteresis loss property when used as a vulcanized product are excellent.

(filler)

The filler included in the rubber composition of the present embodiment is not limited to the following, but examples thereof include carbon black, metal oxides, and metal hydroxides in addition to the silica-based inorganic fillers described above. Among these, silica-based inorganic fillers are preferable.

A filler may be used individually by 1 type, and may use 2 or more types together.

The content of the filler in the rubber composition of the present embodiment is 5.0 parts by mass or more and 150 parts by mass, preferably 20 parts by mass or more and 100 parts by mass or less, based on 100 parts by mass of the rubber component containing the above-mentioned conjugated diene polymer. Part by mass or more and 90 parts by mass or less are more preferable.

In the rubber composition of the present embodiment, the content of the filler is 5.0 parts by mass or more with respect to 100 parts by mass of the rubber component from the viewpoint of exhibiting the effect of adding the filler, sufficiently dispersing the filler, and improving the workability and mechanical strength of the composition. From the viewpoint of making it practically sufficient, it is 150 parts by mass or less with respect to 100 parts by mass of the rubber component.

The silica-based inorganic filler is not particularly limited, and a known filler can be used. Solid particles containing SiO ₂ or Si ₃ Al as a constituent unit are preferred, and solids containing SiO ₂ or Si ₃ Al as a main component of the constituent unit. Particles are more preferred. Here, the main component refers to a component contained in the silica-based inorganic filler at 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more.

Specific examples of the silica-based inorganic filler include, but are not limited to, inorganic fibrous substances such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber.

Further, a silica-based inorganic filler having a hydrophobic surface and a mixture of a silica-based inorganic filler and a non-silica inorganic filler are also included.

Among these, from the viewpoints of strength and abrasion resistance, silica and glass fibers are preferred, and silica is more preferred.

As silica, dry silica, wet silica, and synthetic silicate silica are mentioned, for example. Among these silicas, wet silica is preferable from the viewpoint of the effect of improving tensile strength.

From the viewpoint of obtaining practically good abrasion resistance and fracture strength in the rubber composition of the present embodiment, the silica-based inorganic filler preferably has a nitrogen adsorption specific surface area determined by the BET adsorption method of 100 m 2 /g or more and 300 m 2 /g or less. And, it is more preferable that they are 170 m2/g or more and 250 m2/g or less. Further, if necessary, a silica-based inorganic filler having a relatively small specific surface area (eg, a specific surface area of less than 200 m 2 / g) and a silica-based inorganic filler having a relatively large specific surface area (eg, 200 m 2 / g or more) can be used in combination. In particular, in the case of using a silica-based inorganic filler having a relatively large specific surface area (eg, 200 m 2 /g or more), the rubber composition containing the conjugated diene-based polymer of the present embodiment described above is the silica-based inorganic filler It tends to be effective in improving dispersibility and, in particular, in improving wear resistance, and can highly balance good breaking strength and low hysteresis loss.

The content of the silica-based inorganic filler in the rubber composition of the present embodiment is preferably 5.0 parts by mass or more and 150 parts by mass, and preferably 20 parts by mass or more and 100 parts by mass, based on 100 parts by mass of the rubber component containing the conjugated diene polymer of the present embodiment described above. Part by mass or less is more preferred. In the rubber composition of the present embodiment, the content of the silica-based inorganic filler is preferably 5.0 parts by mass or more with respect to 100 parts by mass of the rubber component from the viewpoint of expressing the effect of adding the silica-based inorganic filler. It is preferably 150 parts by mass or less with respect to 100 parts by mass of the rubber component from the viewpoint of sufficiently dispersing and practically sufficient processability and mechanical strength of the rubber composition.

The rubber composition of this embodiment may contain carbon black. Although it is not limited to the following as carbon black, For example, carbon black of each class, such as SRF, FEF, HAF, ISAF, and SAF, is mentioned. Among these, carbon black having a nitrogen adsorption specific surface area of 50 m 2 /g or more and a dibutyl phthalate (DBP) oil absorption of 80 mL / 100 g or less is preferable.

In the rubber composition of the present embodiment, the carbon black content is preferably 0.5 parts by mass or more and 100 parts by mass or less, and 3.0 parts by mass or more and 100 parts by mass or more with respect to 100 parts by mass of the rubber component containing the conjugated diene polymer of the present embodiment. Part by mass or less is more preferable, and 5.0 parts by mass or more and 50 parts by mass or less are still more preferable. In the rubber composition of the present embodiment, the carbon black content is 0.5 parts by mass or more with respect to 100 parts by mass of the rubber component from the viewpoint of exhibiting performance required for applications such as tires, such as dry grip performance and conductivity. It is preferable, and it is preferable to set it as 100 mass parts or less with respect to 100 mass parts of rubber components from a dispersible viewpoint.

(Metal Oxide, Metal Hydroxide)

The rubber composition of the present embodiment may contain a metal oxide or metal hydroxide in addition to the silica-based inorganic filler and carbon black.

The metal oxide refers to solid particles having the chemical formula MxOy (M represents a metal atom, and x and y each independently represent an integer of 1 to 6) as a main component of a structural unit.

Although it is not limited to the following as a metal oxide, For example, alumina, titanium oxide, magnesium oxide, and zinc oxide are mentioned.

Although it is not limited to the following as a metal hydroxide, For example, aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide are mentioned.

(Silane coupling agent)

The rubber composition of this embodiment may also contain a silane coupling agent. The silane coupling agent has a function of making the interaction between the rubber component and the inorganic filler closer. In particular, when a silica-based inorganic filler is used as the inorganic filler, the silane coupling agent has an affinity or bonding group for each of the rubber component and the silica-based inorganic filler, and the sulfur-bonded moiety and the alkoxysilyl group or silanol group moiety are 1 Compounds in the molecule are preferred. Examples of such a compound include, but are not limited to, bis-[3-(triethoxysilyl)-propyl]-tetrasulfide and bis-[3-(triethoxysilyl)-propyl]-disulfide. , bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide.

In the rubber composition of the present embodiment, the content of the silane coupling agent is preferably 0.1 part by mass or more and 30 parts by mass or less, more preferably 0.5 part by mass or more and 20 parts by mass or less, based on 100 parts by mass of the inorganic filler described above. 1.0 mass part or more and 15 mass parts or less are more preferable. When the content of the silane coupling agent is within the above range, the effect of the addition of the silane coupling agent tends to be more remarkable.

(softener for rubber)

From the viewpoint of improving the processability of the rubber composition of the present embodiment, a rubber softener may be added in a step different from the rubber softener added to the conjugated diene-based polymer of the present embodiment described above.

The addition amount of the softener for rubber is the amount of the softener for rubber contained in the above-described conjugated diene polymer or other rubber-like polymer with respect to 100 parts by mass of the rubber component containing the above-mentioned conjugated diene polymer, and the rubber composition It is expressed as the total amount of softener for rubber added at the time of

As the rubber softener, mineral oil or a liquid or low molecular weight synthetic softener is suitable.

Mineral oil-based rubber softeners called process oils or extender oils, which are used for softening, thickening, and improving processability of rubber, are mixtures of aromatic rings, naphthenic rings, and paraffin chains, and the number of carbon atoms in the paraffin chains is all carbon. Those occupying 50% or more of these are called paraffinic, those having 30% or more and 45% or less of the total carbon atoms of the naphthenic ring are called naphthenics, and those occupying more than 30% of the total carbon atoms are called aromatics. When the conjugated diene polymer of the present embodiment is a copolymer of a conjugated diene compound and a vinyl aromatic compound, the rubber softener to be used is preferably one having an appropriate aromatic content because affinity with the copolymer tends to be good.

In the rubber composition of the present embodiment, the content of the softener for rubber is preferably 0 parts by mass or more and 100 parts by mass or less, more preferably 10 parts by mass or more and 90 parts by mass or less, and 30 parts by mass with respect to 100 parts by mass of the rubber component. Part or more and 90 parts by mass or less are more preferable. When the content of the softener for rubber is 100 parts by mass or less with respect to 100 parts by mass of the rubber component, bleed-out is suppressed and stickiness on the surface of the rubber composition tends to be suppressed.

[Method for producing rubber composition]

The rubber composition of the present embodiment is a rubber component containing the conjugated diene-based polymer of the present embodiment and other rubbery polymers, a silica-based inorganic filler, carbon black and other fillers, a silane coupling agent, and various rubber softeners. It can be prepared by mixing additives. The mixing method thereof is not limited to the following, but, for example, a melt kneading method using a common mixer such as an open roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, a multi screw screw extruder, and each component After dissolving and mixing, a method of heating and removing the solvent is exemplified. Among these, melt-kneading methods using rolls, Banbury mixers, kneaders, and extruders are preferable from the viewpoint of productivity and good kneading properties. In addition, either a method of kneading the rubber component, the filler, the silane coupling agent, and the additives at one time or a method of dividing and mixing the rubber component a plurality of times are applicable.

The rubber composition of the present embodiment may be a vulcanized composition subjected to vulcanization with a vulcanizing agent. Examples of the vulcanizing agent include, but are not limited to, radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur compounds. Sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, and polymeric polysulfur compounds.

In the rubber composition of the present embodiment, the content of the vulcanizing agent is preferably 0.01 part by mass or more and 20 parts by mass or less, and more preferably 0.1 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the rubber component. As the vulcanization method, a conventionally known method can be applied, and the vulcanization temperature is preferably 120°C or higher and 200°C or lower, more preferably 140°C or higher and 180°C or lower.

In the case of vulcanization, you may use a vulcanization accelerator as needed. As the vulcanization accelerator, conventionally known materials can be used, and are not limited to the following, and examples thereof include sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, and thiourea. and dithiocarbamate-based vulcanization accelerators.

In addition, in the case of vulcanization, you may use a vulcanization adjuvant as needed. Although it is not limited to the following as a vulcanization adjuvant, For example, zincating and stearic acid are mentioned. The content of the vulcanization accelerator is preferably 0.01 part by mass or more and 20 parts by mass or less, and more preferably 0.1 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the rubber component.

In the rubber composition of the present embodiment, various additives such as other softeners and fillers, heat-resistant stabilizers, antistatic agents, weathering stabilizers, anti-aging agents, colorants, and lubricants other than those described above are included within the range not impairing the purpose of the present embodiment. You can also use As other softening agents, known softening agents can be used. Although it is not limited to the following as another filler, For example, calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate are mentioned. As the heat-resistant stabilizer, antistatic agent, weathering stabilizer, anti-aging agent, colorant, and lubricant, known materials can be used, respectively.

〔tire〕

The rubber composition of this embodiment is suitably used as a rubber composition for tires.

Examples of the rubber composition for tires include, but are not limited to, various tires such as fuel economy tires, all-season tires, high-performance tires, and studless tires: each part of the tire such as tread, carcass, sidewall, bead portion, etc. can be used for In particular, since the rubber composition for tires is excellent in abrasion resistance, tensile strength, and low hysteresis loss when used as a vulcanized product, it is suitably used for treads of fuel economy tires and high-performance tires.

[Example]

Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples, but the present embodiment is not limited at all by the following examples and comparative examples.

Various physical properties in Examples and Comparative Examples were measured by the methods shown below.

In the following, the conjugated diene polymer before the coupling reaction is described as "conjugated diene polymer before coupling reaction" and the conjugated diene polymer coupled is described as "coupling conjugated diene polymer", as these generic terms, It may be described as "conjugated diene polymer".

(Physical Property 1) Molecular Weight

Measurement condition 1:

Using a GPC measuring device (trade name "HLC-8320GPC" manufactured by Tosoh Corporation) in which three columns using a conjugated diene polymer or a coupling conjugated diene polymer as a sample before the coupling reaction and a polystyrene gel as a filler are connected, , The chromatogram was measured using an RI detector (trade name "HLC8020" manufactured by Tosoh Corporation), and based on a calibration curve obtained using standard polystyrene, the weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw) /Mn) was obtained.

As the eluent, 5 mmol/L of triethylamine-containing THF (tetrahydrofuran) was used. The column was used by connecting three "TSKgel SuperMultiporeHZ-H", trade name, manufactured by Tosoh Corporation, and connecting "TSKguardcolumn SuperMP (HZ)-H", trade name, manufactured by Tosoh Corporation, as a guard column to the front end thereof.

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

Among the various samples measured under the above measurement condition 1, samples having a molecular weight distribution (Mw/Mn) of less than 1.6 were measured again under the following measurement condition 2.

Measurement was performed under measurement condition 1, and for samples having a molecular weight distribution value of 1.6 or more, measurement was performed under measurement condition 1, and the measured value was adopted.

Measurement condition 2:

A chromatogram was measured using a GPC measuring device in which three columns with a polystyrene gel as a filler were connected using the conjugated diene polymer or the coupling conjugated diene polymer before the coupling reaction as a sample, and the chromatogram was measured using standard polystyrene. Based on the calibration curve, the weight average molecular weight (Mw) and number average molecular weight (Mn) were determined.

THF containing 5 mmol/L of triethylamine was used as the eluent. As for the column, guard column: trade name "TSKguardcolumn SuperH-H" manufactured by Tosoh Corporation, column: trade name "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000" manufactured by Tosoh Corporation were used.

An RI detector (trade name "HLC8020" manufactured by Tosoh Corporation) was used under conditions of an oven temperature of 40°C and a THF flow rate of 0.6 mL/min. 10 mg of the sample for measurement was dissolved in 20 mL of THF to make a measurement solution, and 20 µL of the measurement solution was injected into a GPC measuring device to measure.

Measurement was performed under measurement condition 1, and for the sample whose molecular weight distribution value was less than 1.6, measurement was performed under measurement condition 2, and the measured value was employed.

(Physical Property 2) Polymer Mooney Viscosity

Using the conjugated diene polymer or the coupling conjugated diene polymer before the coupling reaction as a sample, using a Mooney viscometer (trade name "VR1132" manufactured by Uejima Seisakusho Co., Ltd.), in accordance with ISO289, using an L-shaped rotor Mooney viscosity was measured.

The measurement temperature was 110°C in the case of using the conjugated diene-based polymer before the coupling reaction as a sample, and 120°C in the case of using the coupling conjugated diene-based polymer as the sample.

First, after preheating the sample at the test temperature for 1 minute, the rotor was rotated at 2 rpm, and the torque after 4 minutes was measured to obtain Mooney viscosity (ML ₍₁₊₄₎ ).

(Physical Property 3) Branching (Bn)

The branching degree (Bn) of the conjugated diene-based polymer was measured as follows by a GPC-light scattering measurement method with a viscosity detector.

Using a gel permeation chromatography (GPC) measuring device (trade name "GPCmax VE-2001" manufactured by Malvern) in which three columns are connected using a coupling conjugated diene polymer as a sample and a polystyrene gel as a filler, light scattering Measurement was performed using three detectors connected in sequence: a detector, an RI detector, and a viscosity detector (trade name "TDA305" manufactured by Malvern), and based on standard polystyrene, the absolute molecular weight was determined from the results of the light scattering detector and the RI detector. Intrinsic viscosity was obtained from the result of the viscosity detector.

The straight-chain polymer was used as having an intrinsic viscosity [η] = -3.883M ^0.771 , and a shrinkage factor (g') as a ratio of intrinsic viscosities corresponding to respective molecular weights was calculated. In addition, in formula, M represents absolute molecular weight.

Then, a branching degree (Bn) defined as g'=6Bn/{(Bn+1)(Bn+2)} was calculated using the obtained contraction factor (g').

As the eluent, 5 mmol/L triethylamine-containing tetrahydrofuran (hereinafter also referred to as "THF") was used.

The column was used by connecting trade names "TSKgel G4000HXL", "TSKgel G5000HXL", and "TSKgel G6000HXL" manufactured by Tosoh Corporation.

20 mg of the sample for measurement was dissolved in 10 mL of THF to make a measurement solution, and 100 µL of the measurement solution was injected into a GPC measuring device, and the measurement was performed under conditions of an oven temperature of 40°C and a THF flow rate of 1 mL/min.

(Physical property 4) Denaturation rate

The denaturation rate of the conjugated diene polymer was measured by the column adsorption GPC method as follows.

Coupling conjugated diene-based polymer was used as a sample and measured by applying the property of adsorption of the modified basic polymer component to a GPC column using silica gel as a filler.

The amount of adsorption to the silica-based column was measured from the difference between the chromatogram measured with the polystyrene-based column and the chromatogram measured with the silica-based column for the sample solution containing the sample and the low-molecular-weight internal standard polystyrene, and the denaturation rate was determined. did

Specifically, it is as showing below. In addition, when measured under the measurement condition 1 of the above (physical property 1), the following measurement condition 3 was used for samples whose molecular weight distribution value was 1.6 or more, and the following measurement condition 4 was used for the samples whose molecular weight distribution value was less than 1.6. measured.

<Preparation of sample solution>:

10 mg of the sample and 5 mg of standard polystyrene were dissolved in 20 mL of THF to obtain a sample solution.

GPC measurement conditions using a polystyrene column:

Measurement condition 3:

Using a trade name "HLC-8320GPC" manufactured by Tosoh Corporation, using 5 mmol/L triethylamine-containing THF as an eluent, injecting 10 µL of the sample solution into the apparatus, a column oven temperature of 40 °C and a THF flow rate of 0.35 mL/min. Conditions, a chromatogram was obtained using an RI detector. The column was used by connecting three "TSKgel SuperMultiporeHZ-H", trade name, manufactured by Tosoh Corporation, and connecting "TSKguardcolumn SuperMP (HZ)-H", trade name, manufactured by Tosoh Corporation, as a guard column to the front end thereof.

Measurement condition 4:

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

GPC measurement conditions using a silica-based column:

Using a product name "HLC-8320GPC" manufactured by Tosoh Corporation, using THF as an eluent, injecting 50 µL of the sample solution into the apparatus, using a RI detector under the conditions of a column oven temperature of 40 ° C. and a THF flow rate of 0.5 ml / min. A chromatogram was obtained. The column was used by connecting trade names "Zorbax PSM-1000S", "PSM-300S", and "PSM-60S", and using a trade name "DIOL 4.6 x 12.5 mm 5micron" connected to the front end as a guard column.

How to Calculate Denaturation Rate:

The total peak area of the chromatogram using the polystyrene column is 100, the peak area of the sample is P1, the peak area of the standard polystyrene is P2, and the total peak area of the chromatogram using the silica column is 100. The peak area of P3 and the peak area of standard polystyrene were set to P4, and the modification rate (%) was determined from the following formula.

Denaturation rate (%) = [1- (P2 × P3) / (P1 × P4)] × 100

(However, P1+P2=P3+P4=100)

(Physical Property 5) Amount of Combined Styrene

A coupling conjugated diene polymer containing no rubber softener was used as a sample, and 100 mg of the sample was dissolved in chloroform as a 100 mL solution to obtain a measurement sample.

The amount of bound styrene (mass%) relative to 100% by mass of the coupling conjugated diene polymer as a sample was measured by the amount of absorption at the ultraviolet absorption wavelength (near 254 nm) by the phenyl group of styrene (measurement device: manufactured by Shimadzu Seisakusho Co., Ltd.) spectrophotometer "UV-2450" of).

(Physical property 6) Microstructure of butadiene part (1,2-vinyl bond amount)

A coupling conjugated diene polymer containing no rubber softener was used as a sample, and 50 mg of the sample was dissolved in 10 mL of carbon disulfide to obtain a measurement sample. Using a solution cell, the infrared spectrum was measured in the range of 600 to 1000 cm ^-1 , and the absorbance at a predetermined wave number was determined by Hampton's method (RRHampton, Analytical Chemistry ₂₁ , the method described in 923 (1949)). According to the calculation formula, the microstructure of the butadiene portion, that is, the amount of 1,2-vinyl bonds (mol%) was determined (measuring device: Nippon Bunko Co., Ltd. Fourier transform infrared spectrophotometer "FT-IR230").

(Physical property 7) Molecular weight (absolute molecular weight) measured by GPC-light scattering method

A chromatogram was measured using a GPC-light scattering measuring instrument in which a coupling conjugated diene polymer was used as a sample and three columns with a polystyrene gel as a filler were connected, and the weight average molecular weight was determined based on the solution viscosity and light scattering method. (Mw-i) was determined (also referred to as "absolute molecular weight").

As the eluent, a mixed solution of tetrahydrofuran and triethylamine (THF in TEA: prepared by mixing 5 mL of triethylamine with 1 L of tetrahydrofuran) was used.

The column was used by connecting a guard column: trade name "TSKguardcolumn HHR-H" manufactured by Tosoh Corporation, and a column: trade name "TSKgel G6000HHR", "TSKgel G5000HHR", and "TSKgel G4000HHR" manufactured by Tosoh Corporation.

Under conditions of an oven temperature of 40°C and a THF flow rate of 1.0 mL/min, a GPC-light scattering measuring device (trade name "Viscotek TDAmax" manufactured by Malvern Co., Ltd.) was used. 10 mg of the sample for measurement was dissolved in 20 mL of THF to make a measurement solution, and 200 μL of the measurement solution was injected into a GPC measuring device to measure.

(Physical Property 8) Glass Transition Temperature (Tg)

When the coupling conjugated diene-based polymer is a dielectric product, the coupling conjugated diene-based polymer after extracting the extender oil is used as a sample, and in accordance with ISO22768: 2006, using a differential scanning calorimeter "DSC3200S" manufactured by Mac Science, A DSC curve was recorded while the temperature was raised from -100°C to 20°C/min under flow of 50 mL/min of helium, and the peak top (inflection point) of the DSC differential curve was taken as the glass transition temperature.

(Physical Property 9) Nitrogen content

When the coupling conjugated diene-based polymer is an oilfield product, the coupling conjugated diene-based polymer after extracting the extender oil is used as a sample, in accordance with JIS-2609: Crude oil and petroleum products-Nitrogen content test method, chemiluminescence method, trace amount Nitrogen content was calculated|required using the total nitrogen analyzer ("TN-2100H" by the Mitsubishi Chemical Analytec company).

[Preparation of conjugated diene polymer]

(Example 1) Coupling Conjugated Diene Polymer (A1)

The internal volume is 10L, the ratio (L/D) of the internal height (L) and diameter (D) is 4.0, has an inlet at the bottom and an outlet at the top, and has an agitator, which is a tank reactor equipped with an agitator, and a jacket for temperature control. Two tank-type pressure vessels were connected as polymerization reactors.

1,3-butadiene, which had previously been dehydrated, was mixed under conditions of 17.7 g/min, styrene at 10.9 g/min, and cyclohexane at 175.2 g/min. In a static mixer provided in the middle of a piping supplying the mixed solution to the inlet of the reactor, n-butyllithium for inactivation of residual impurities was added at 0.103 mmol/min, mixed, and then continuously supplied to the bottom of the reactor. In addition, 1 mixture of 2,2-bis(2-oxolanyl)propane as a polar substance at a rate of 0.064 mmol/min and n-butyllithium as a polymerization initiator at a rate of 0.134 mmol/min with a stirrer was vigorously mixed. The first was supplied to the bottom of the reactor, and the internal temperature of the reactor was maintained at 77°C.

The polymer solution was continuously withdrawn from the top of the first reactor, continuously supplied to the bottom of the second reactor, continued reaction at 82°C, and supplied to the static mixer from the top of the second reactor. When the polymerization is sufficiently stable, while copolymerizing 1,3-butadiene and styrene, trimethoxy(4-vinylphenyl)silane as a branching agent is added at a rate of 0.007 mmol/min from the bottom of the second reactor, and the main chain A polymerization reaction and a branching reaction were performed to obtain a conjugated diene-based polymer having a branched structure. In addition, when the polymerization reaction and the branching reaction are stable, a small amount of the conjugated diene polymer solution before adding the coupling agent is extracted, an antioxidant (BHT) is added so as to be 0.2 g per 100 g of the polymer, and then the solvent is removed, and various molecular weight (physical properties) 1) and Mooney viscosity (physical property 2) were measured. Physical properties are shown in Table 1.

Subsequently, N-benzylidene-3-(triethoxysilyl)propan-1-amine (abbreviated as "a" in the table) was added at 0.043 mmol// as a coupling agent to the polymer solution flowing out from the outlet of the reactor. It was continuously added at a rate of 20 min, mixed using a static mixer, and subjected to a coupling reaction. At this time, the time until the coupling agent was added to the polymer solution flowing out of the reactor was 4.8 minutes, the temperature was 68 ° C, and the difference between the temperature in the polymerization process and the temperature until the coupling agent was added was 2 ° C. was A small amount of the conjugated diene-based polymer solution after the coupling reaction was extracted, an antioxidant (BHT) was added so as to be 0.2 g per 100 g of the polymer, and then the solvent was removed, and the amount of bound styrene (physical property 5) and the microstructure of the butadiene portion ( Amount of 1,2-vinyl bond: physical property 6) was measured.

The measurement results are shown in Table 1.

Next, to the polymer solution subjected to the coupling reaction, an antioxidant (BHT) was continuously added at a rate of 0.055 g/min (n-hexane solution) so as to be 0.2 g per 100 g of the polymer, and the coupling reaction was terminated. Simultaneously with the antioxidant, as a softener for rubber, SRAE oil (JOMO Process NC140, manufactured by JX Nikko Nippon Energy Co., Ltd.) was added continuously in an amount of 25.0 g per 100 g of the polymer, and mixed with a static mixer. The solvent is removed by steam stripping, and a branching agent (hereinafter also referred to as “branching agent structure (1)”), which is a compound represented by the following formula (1) in a part of the main chain, has a branched structure derived from, and a coupling agent A coupling conjugated diene-based polymer (A1) having a derived three-branched star-shaped polymer structure was obtained. The physical properties of A1 are shown in Table 1. In addition, for the polymer before addition of the branching agent, the polymer after addition of the branching agent, and the polymer in each step after addition of the coupling agent, by comparing the molecular weight by GPC measurement and the degree of branching by GPC measurement with a viscometer, the coupling conjugate The structure of the diene polymer was identified. Hereinafter, the structure of each sample was similarly identified.

(In Formula (1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.

R ² to R ³ each independently represent an alkyl group of 1 to 20 carbon atoms or an aryl group of 6 to 20 carbon atoms, and may have a branched structure at a part thereof.

R ¹ to R ³ in the case of a plurality of presence are independent of each other.

X ¹ represents an independent halogen atom.

m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.)

(Example 2) Coupling conjugated diene polymer (A2)

A coupling diene copolymer (A2) was obtained in the same manner as in Example 1, except that 2,2-bis(2-oxolanyl)propane, which is a polar substance, was 0.055 mmol/min. The physical properties of A2 are shown in Table 1.

(Example 3) Coupling conjugated diene polymer (A3)

0.152 mmol/min of n-butyllithium as polymerization initiator, 0.070 mmol/min of 2,2-bis(2-oxolanyl)propane, 0.008 mmol/min of trimethoxy(4-vinylphenyl)silane as branching agent, The coupling agent was prepared from N-benzylidene-3-(triethoxysilyl)propan-1-amine to tetrakis(3-trimethoxysilylpropyl-1,3 propanediamine (abbreviated as "b" in the table). , and the addition amount of the coupling agent was changed to 0.015 mmol/min, and a coupling conjugated diene copolymer (A3) was obtained in the same manner as in Example 1. The physical properties of A3 are shown in Table 1.

(Example 4) Coupling conjugated diene polymer (A4)

The coupling agent was changed from N-benzylidene-3-(triethoxysilyl)propan-1-amine to tetraethoxysilane (abbreviated as "c" in the table), and the addition amount of the coupling agent was 0.018 mmol/min. Except having set it as, it carried out similarly to Example 1, and obtained the coupling conjugated diene copolymer (A4). The physical properties of A4 are shown in Table 1.

(Example 5) Coupling conjugated diene polymer (A5)

Coupling was performed in the same manner as in Example 1 except that 1,3-butadiene was 15.8 g/min, styrene was 12.8 g/min, and 2,2-bis(2-oxolanil)propane was 0.070 mmol/min. A conjugated diene copolymer (A5) was obtained. The physical properties of A5 are shown in Table 1.

(Example 6) Coupling conjugated diene polymer (A6)

1,3-butadiene was 20.0 g/min, styrene was 8.6 g/min, and 2,2-bis(2-oxolanyl)propane was 0.058 mmol/min, and the rubber softener was SRAE oil 37.5 per 100 g of polymer. Except having set it as g, it carried out similarly to Example 1, and obtained the coupling conjugated diene copolymer (A6). The physical properties of A6 are shown in Table 1.

(Example 7) Coupling conjugated diene polymer (A7)

0.103 mmol/min of n-butyllithium as polymerization initiator, 0.045 mmol/min of 2,2-bis(2-oxolanyl)propane, 0.005 mmol/min of trimethoxy(4-vinylphenyl)silane as branching agent, couple A coupling conjugated diene copolymer (A7) was obtained in the same manner as in Example 1, except that the addition amount of the ring agent was 0.033 mmol/min. The physical properties of A7 are shown in Table 2.

(Example 8) Coupling conjugated diene polymer (A8)

0.188 mmol/min of n-butyllithium as polymerization initiator, 0.089 mmol/min of 2,2-bis(2-oxolanyl)propane, and 0.009 mmol/min of trimethoxy(4-vinylphenyl)silane as branching agent A coupling conjugated diene copolymer (A8) was obtained in the same manner as in Example 1, except that the addition amount of the coupling agent was 0.060 mmol/min. The physical properties of A8 are shown in Table 2.

(Example 9) Coupling conjugated diene polymer (A9)

0.152 mmol/min of n-butyllithium as polymerization initiator, 0.016 mmol/min of 2,2-bis(2-oxolanyl)propane, and 0.008 mmol/min of trimethoxy(4-vinylphenyl)silane as branching agent , The coupling agent is tetrakis(3-trimethoxysilylpropyl-1,3 propanediamine from N-benzylidene-3-(triethoxysilyl)propan-1-amine (abbreviated as "b" in the table). ), except that the addition amount of the coupling agent was 0.015 mmol/min, a coupling conjugated diene copolymer (A9) was obtained in the same manner as in Example 1. The physical properties of A9 are shown in Table 2.

(Example 10) Coupling Conjugated Diene Polymer (A10)

The polymerization initiator was a mixed solution of piperidinolithium (also referred to as "1-thiopiperidine") and n-butyllithium (the molar ratio of the mixed solution was set at 0.75:0.25) as lithium amide prepared in advance. Other than that, in the same manner as in Example 8, a coupling diene copolymer (A10) was obtained. The physical properties of A10 are shown in Table 2.

(Example 11) Coupling Conjugated Diene Polymer (A11)

The addition amount of N-benzylidene-3-(triethoxysilyl)propan-1-amine was 0.0130 mmol/min and the addition amount of tetrakis(3-trimethoxysilylpropyl-1,3 propanediamine was 0.0075 A coupling diene copolymer (A11) was obtained in the same manner as in Example 1, except that the mixed solution (abbreviated as "a/b" in the table) was adjusted in advance to have a rate of mmol/min. is shown in Table 2.

(Example 12) Coupling Conjugated Diene Polymer (A12)

In the same manner as in Example 11, except that the coupling agent was changed from N-benzylidene-3-(triethoxysilyl)propan-1-amine to 3-(4-methylpiperazin-1-yl)propyltrimethoxysilane. , A mixed solution with tetrakis(3-trimethoxysilylpropyl-1,3propanediamine (abbreviated as "d/b" in the table) was prepared, other conditions were the same as in Example 1, and A ring diene copolymer (A12) was obtained, and the physical properties of A12 are shown in Table 2.

(Comparative Example 1) Coupling Conjugated Diene Polymer (B1)

The internal volume is 10L, the ratio (L/D) of the internal height (L) and diameter (D) is 4.0, has an inlet at the bottom and an outlet at the top, and has an agitator, which is a tank reactor equipped with an agitator, and a jacket for temperature control. Two tank-type pressure vessels were connected as polymerization reactors.

1,3-butadiene from which water was removed in advance was mixed under the conditions of 18.6 g/min, styrene at 10.0 g/min, and cyclohexane at 175.2 g/min to obtain a mixed solution.

In a static mixer provided in the middle of a piping supplying the mixed solution to the inlet of the reactor, n-butyllithium for inactivation of residual impurities was added at 0.103 mmol/min, mixed, and then continuously supplied to the bottom of the reactor. In addition, 1 mixture of 2,2-bis(2-oxolanyl)propane as a polar substance at a rate of 0.072 mmol/min and n-butyllithium as a polymerization initiator at a rate of 0.134 mmol/min with a stirrer was vigorously mixed. The first was supplied to the bottom of the reactor, and the internal temperature of the reactor was maintained at 77°C.

The polymer solution was continuously withdrawn from the top of the first reactor, continuously supplied to the bottom of the second reactor, the reaction was continued at 82°C, and further supplied to the static mixer from the top of the second reactor. A small amount of the conjugated diene polymer solution before addition of the coupling agent was extracted, and after adding an antioxidant (BHT) so as to be 0.2 g per 100 g of the polymer, the solvent was removed, and the Mooney viscosity at 110 ° C. and various molecular weights were measured. Physical properties are shown in Table 3.

Then, N-benzylidene-3-(triethoxysilyl)propan-1-amine as a coupling agent was continuously added to the polymer solution flowing out from the outlet of the reactor at a rate of 0.043 mmol/min, and the static mixer was Mixed using and coupling reaction was carried out. At this time, the time until the coupling agent was added to the polymer solution flowing out of the reactor was 4.8 minutes, the temperature was 68 ° C, and the difference between the temperature in the polymerization process and the temperature until the coupling agent was added was 2 ° C. was A small amount of the conjugated diene-based polymer solution after the coupling reaction was extracted, an antioxidant (BHT) was added so as to be 0.2 g per 100 g of the polymer, and then the solvent was removed, and the amount of bound styrene (physical property 5) and the microstructure of the butadiene portion ( Amount of 1,2-vinyl bond: physical property 6) was measured. The measurement results are shown in Table 3.

Next, to the polymer solution subjected to the coupling reaction, an antioxidant (BHT) was continuously added at a rate of 0.055 g/min (n-hexane solution) so as to be 0.2 g per 100 g of the polymer, and the coupling reaction was terminated. Simultaneously with the antioxidant, as a softener for rubber, SRAE oil (JOMO Process NC140, manufactured by JX Nikko Nippon Energy Co., Ltd.) was added continuously in an amount of 25.0 g per 100 g of the polymer, and mixed with a static mixer. The solvent was removed by steam stripping to obtain a coupling conjugated diene polymer (B1). The physical properties of B1 are shown in Table 3. The structure of the coupling conjugated diene polymer was identified by comparing the molecular weight by GPC measurement and the branching degree by GPC measurement with a viscometer for the polymer in each step after addition of the coupling agent.

(Comparative Example 2) Coupling conjugated diene polymer (B2)

1,3-butadiene at 17.7 g/min, styrene at 10.9 g/min, n-butyllithium as the polymerization initiator at 0.152 mmol/min, and 2,2-bis(2-oxolanyl)propane at 0.070 mmol/min. and no branching agent was added. In addition, the coupling agent is N-benzylidene-3-(triethoxysilyl)propan-1-amine to tetrakis(3-trimethoxysilylpropyl-1,3 propanediamine (abbreviated as "b" in the table) .), except that the addition amount of the coupling agent was 0.015 mmol/min, a coupling conjugated diene copolymer (B2) was obtained in the same manner as in Comparative Example 1. The physical properties of B2 are shown in Table 3.

(Comparative Example 3) Coupling conjugated diene polymer (B3)

0.152 mmol/min of n-butyllithium as the polymerization initiator and 0.093 mmol/min of 2,2-bis(2-oxolanyl)propane, and no branching agent was added. In addition, the coupling agent was selected from N-benzylidene-3-(triethoxysilyl)propan-1-amine to tetrakis(3-trimethoxysilylpropyl-1,3-propanediamine (abbreviated as "b" in the table) ), and a coupling conjugated diene copolymer (B3) was obtained in the same manner as in Comparative Example 1, except that the addition amount of the coupling agent was 0.015 mmol/min. Table 3 shows the physical properties of B3.

(Comparative Example 4) Coupling conjugated diene polymer (B4)

1,3-butadiene at 14.3 g/min, styrene at 14.3 g/min, n-butyllithium as the polymerization initiator at 0.152 mmol/min, and 2,2-bis(2-oxolanyl)propane at 0.103 mmol/min. and trimethoxy (4-vinylphenyl) silane as a branching agent was 0.008 mmol/min, and tetrakis (3- Coupling conjugation in the same manner as in Comparative Example 1, except that trimethoxysilylpropyl-1,3-propanediamine (abbreviated as "b" in the table) was changed and the addition amount of the coupling agent was 0.015 mmol/min. A diene copolymer (B4) was obtained, and the physical properties of B4 are shown in Table 3.

(Comparative Example 5) Coupling Conjugated Diene Polymer (B5)

Coupling was performed in the same manner as in Comparative Example 4 except that 1,3-butadiene was 21.4 g/min, styrene was 7.2 g/min, and 2,2-bis(2-oxolanil)propane was 0.042 mmol/min. A conjugated diene copolymer (B5) was obtained. Table 3 shows the physical properties of B5.

(Examples 13 to 24 and Comparative Examples 6 to 10)

Samples A1 to A12 and B1 to B5 shown in Tables 1 to 3 were used as raw rubber, and rubber compositions containing each raw rubber were obtained according to the formulation shown below.

Coupling conjugated diene polymer (A1 to A12, and B1 to B5: 100 parts by mass (excluding oil)

Silica 1 (trade name "Ultrasil 7000GR" manufactured by Evonik Degussa Co., Ltd., nitrogen adsorption specific surface area 170 m ² /g): 75.0 parts by mass

Carbon black (trade name "Cyst KH (N339)" manufactured by Tokai Carbon Co., Ltd.): 5.0 parts by mass

Silane coupling agent (trade name "Si75" manufactured by Evonik Degussa, bis (triethoxysilylpropyl) disulfide): 6.0 parts by mass

S-RAE oil (trade name "Process NC140" manufactured by JX Nikko Nisseki Energy Co., Ltd.): 37.5 parts by mass

(Including the amount added as a softener for rubber contained in samples A1 to A12 and B1 to B5 in advance)

Zincification: 2.5 parts by mass

Stearic acid: 2.0 parts by mass

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

Sulfur: 1.7 parts by mass

Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazyl sulfinamide): 1.7 parts by mass

Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass

The above materials were kneaded by the following method to obtain a rubber composition. Raw rubber (samples A1 to A12, B1 to B5) under conditions of a filling rate of 65% and a rotor rotation speed of 30 to 50 rpm as the first stage kneading using a closed kneader (net volume: 0.3 L) equipped with a temperature control device. ), filler (silica 1, silica 2, carbon black), silane coupling agent, process oil, zinc oxide, and stearic acid were kneaded. At this time, the temperature of the airtight mixer was controlled, and each rubber composition (formulation) was obtained at a discharge temperature of 155 to 160°C.

Subsequently, as the second stage of kneading, after cooling the mixture obtained above to room temperature, an antioxidant was added and kneaded again to improve silica dispersion. Also in this case, the discharge temperature of the compound was adjusted to 155 to 160°C by temperature control of the mixer. After cooling, as the third stage of kneading, sulfur and vulcanization accelerators 1 and 2 were added and kneaded with an open roll set at 70°C. After that, it was molded and vulcanized by a vulcanization press at 160°C for 20 minutes. The rubber composition before vulcanization and the rubber composition after vulcanization were evaluated. Specifically, it was evaluated by the following method. The results are shown in Tables 4 to 6.

(Evaluation 1) Tensile strength

Tensile strength was measured in accordance with the tensile test method of JIS K6251, and the result of Comparative Example 6 was indexed as 100. The larger the index, the better the tensile strength and tensile elongation.

(Evaluation 2) Wear resistance

Using an Akron abrasion tester (manufactured by Yasuda Seki Seisakusho Co., Ltd.), the amount of abrasion at a load of 44.4 N and 1000 revolutions was measured in accordance with JIS K6264-2, and the result of Comparative Example 6 was indexed as 100. The larger the index, the better the abrasion resistance.

(Evaluation 3) Fuel economy

Viscoelastic parameters were measured in torsion mode using a viscoelasticity tester "ARES" manufactured by Rheometrics Scientific. For each measured value, the result for the rubber composition of Comparative Example 6 was indexed as 100. The tan δ measured at 0°C at a frequency of 10 Hz and a strain of 1% was used as an index of wet grip properties. It shows that wet grip property is so good that an index|index is large. In addition, tan δ measured at 50° C. at a frequency of 10 Hz and a strain of 3% was used as an index of fuel economy (RR performance). The larger the index, the better the fuel economy.

As shown in Tables 4 to 6, Examples 13 to 24 using the coupling conjugated diene polymers (A1 to A12) of Examples 1 to 12 use the coupling conjugated diene polymers of Comparative Examples 1 to 5 Compared with Comparative Examples 6 to 10, it was confirmed that the balance of tensile strength, abrasion resistance, and low hysteresis loss properties when used as a vulcanized product was excellent.

The rubber composition according to the present invention has industrial applicability in fields such as tire treads, automobile interior and exterior products, anti-vibration rubber, belts, shoes, foams, and various industrial product applications.

Claims (13)

The branching degree (Bn) by the GPC-light scattering method with a viscosity detector is 7 or more,
A conjugated diene-based polymer having a weight average molecular weight of 45 × 10 ⁴ or more and 500 × 10 ⁴ or less,
The content of the aromatic vinyl monomer unit in the conjugated diene polymer is 30 to 45% by mass,
The value of the content (mass%) of the aromatic vinyl monomer unit is greater than the value of the amount of vinyl bonds (mol%) in the conjugated diene monomeric unit,
Conjugated diene-based polymers. The method of claim 1, wherein the denaturation rate measured by the column adsorption GPC method of the conjugated diene-based polymer,
A conjugated diene-based polymer that is 60% by mass or more. The conjugated diene polymer according to claim 1 or 2, which contains a nitrogen atom and a silicon atom. The method of claim 1 or 2, wherein the conjugated diene-based polymer has a three or more branched star-shaped polymer structure,
At least one star-shaped branched chain has a portion derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group, and a main chain branch point by a portion derived from the vinyl-based monomer containing the alkoxysilyl group or halosilyl group. is formed and has a main chain branching structure in which the polymer chain extends from the main chain branch point
Conjugated diene-based polymers. The method of claim 4, wherein the vinyl-based monomer containing the alkoxysilyl group or halosilyl group,
A compound represented by the following formula (1) or (2),
Conjugated diene-based polymers.

(In Formula (1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.
R ² to R ³ each independently represent an alkyl group of 1 to 20 carbon atoms or an aryl group of 6 to 20 carbon atoms, and may have a branched structure at a part thereof.
R ¹ to R ³ in the case of a plurality of presence are independent of each other.
X ¹ represents an independent halogen atom.
m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.)
(In formula (2), each of R ² to R ⁵ independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof. R in the case of multiple presence ² to R ⁵ are each independent.
X ² to X ³ represent independent halogen atoms.
m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.
a represents an integer of 0 to 2, b represents an integer of 0 to 3, and c represents an integer of 0 to 3. (a+b+c) represents 3.) The conjugated diene-based polymer according to claim 5, which has a monomer unit based on the compound represented by the formula (1), wherein R ¹ is a hydrogen atom and m=0 in the formula (1). The conjugated diene polymer according to claim 5, which has a monomer unit based on the compound represented by the formula (2), wherein m = 0 and b = 0 in the formula (2). The monomer unit based on the compound represented by the formula (1) according to claim 5, wherein in the formula (1), R ¹ is a hydrogen atom, m=0, l=0, and n=3. Conjugated diene-based polymer having. The method according to claim 5, wherein m = 0, l = 0, n = 3, a = 0, b = 0, and c = 3 in the above formula (2), represented by the above formula (2) A conjugated diene-based polymer having a monomer unit based on a compound. A method for producing the conjugated diene-based polymer according to claim 1 or 2,
Using an organolithium compound as a polymerization initiator, adding a branching agent while polymerizing at least a conjugated diene compound and an aromatic vinyl compound in a solvent containing a polar compound to obtain a conjugated diene polymer having a main chain branched structure; A method for producing a conjugated diene-based polymer. The method for producing a conjugated diene-based polymer according to claim 10, further comprising a step of reacting a coupling agent with the conjugated diene-based polymer having the main chain branched structure. 100 parts by mass of the conjugated diene polymer according to claim 1 or 2;
1 to 60 parts by mass of softener for rubber
A conjugated diene-based polymer composition containing a. A rubber composition comprising a rubber component and 5.0 parts by mass or more and 150 parts by mass or less of a filler with respect to 100 parts by mass of the rubber component,
A rubber composition in which the rubber component contains 10 parts by mass or more of the conjugated diene-based polymer according to claim 1 or 2 with respect to 100 parts by mass of the total amount of the rubber component.