JP7356881B2 - Conjugated diene polymer composition and tire - Google Patents

Description

The present invention relates to a conjugated diene polymer composition and a tire.

In recent years, winter tires have been required to have improved running performance on wet road surfaces (wet performance) in addition to improved running performance on snowy roads (snow performance).
In addition, due to social demands for reducing global environmental impact, there is an increasing demand for longer tire life, and there is a strong demand for improved wear resistance in tire performance.

Conventionally, in order to improve snow performance, the amount of filler added to rubber compositions has been reduced in order to reduce the elastic modulus at low temperatures and ensure high conformability of tread rubber to the snowy road surface. Methods such as increasing the amount of oil added have been proposed.
However, such a method has a problem in that it tends to cause a decrease in wet performance and wear resistance.

On the other hand, in order to improve wet performance, methods have been proposed to increase energy loss by increasing the glass transition temperature of the rubber composition or increasing the amount of filler added.
However, such a method has a problem in that the elastic modulus at low temperatures increases, and snow performance tends to deteriorate.
Particularly in recent years, improvements in winter road conditions have progressed, and it has become increasingly important for winter tires to improve their performance not only on snowy roads but also on wet roads.

Conventionally, rubber compositions have been proposed in which both snow performance and wet performance are improved by blending rubbers having different glass transition temperatures (for example, see Patent Document 1).

Japanese Patent Application Publication No. 2005-154473

However, in the rubber composition described in Patent Document 1, the reactivity between the modifying group of the terminal-modified styrene-butadiene rubber and silica is insufficient, and there is still room for further improvement in improving both snow performance and wet performance. It has some problems.

Therefore, an object of the present invention is to provide a conjugated diene polymer composition that has good dispersibility of silica as a filler and can provide a rubber composition with an improved balance between snow performance and wet performance. shall be.

As a result of intensive research and study in order to solve the problems of the prior art described above, the present inventors have developed a conjugated diene polymer composition containing two types of rubber component A and rubber component B with different glass transition temperatures. The rubber component A has a conjugated diene copolymer (A1) having an absolute molecular weight within a predetermined range and a degree of branching (Bn) within a specific range. The present inventors have discovered that a rubber composition with improved wet performance balance can be obtained, and have completed the present invention.
That is, the present invention is as follows.

[1]
20 to 99 parts by mass of a rubber component (A) which is a conjugated diene polymer having a glass transition temperature of -35°C or higher;
A conjugated diene polymer composition containing 1 to 90 parts by mass of a rubber component (B) having a glass transition temperature of −50° C. or lower,
The rubber component (A) contains a conjugated diene polymer (A1) containing an aromatic vinyl compound and a conjugated diene compound,
The conjugated diene polymer (A1) has an absolute molecular weight of 40×10 ⁴ or more and 5000×10 ⁴ or less as measured by GPC-light scattering method with a viscosity detector, and The degree of branching (Bn) according to the law is 8 or more,
Conjugated diene polymer composition.
[2]
The conjugated diene polymer composition according to [1] above, wherein the conjugated diene polymer (A1) is a modified conjugated diene polymer having a modification rate of 60% by mass or more.
[3]
The conjugated diene polymer composition according to [1] or [2] above, wherein the rubber component (B) is natural rubber.
[4]
The conjugated diene polymer (A1) is a conjugated diene polymer having a star-shaped polymer structure with three or more branches, and contains an alkoxysilyl group or a halosilyl group in at least one branch chain of the star-shaped structure. [1] to [3] above, which has a portion derived from a vinyl monomer, and has an additional main chain branched structure in the portion derived from the vinyl monomer containing the alkoxysilyl group or halosilyl group. The conjugated diene polymer composition according to any one of the above.
[5]
The portion derived from the vinyl monomer containing the alkoxysilyl group or halosilyl group of the conjugated diene polymer (A1) is a monomer unit based on a compound represented by the following formula (1) or (2). and has a branching point of a polymer chain by a monomer unit based on a compound represented by the following formula (1) or (2),
The conjugated diene polymer composition according to [4] above, wherein at least one end of the conjugated diene polymer (A1) is coupled using a coupling agent.

(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 a portion thereof may have a branched structure.
R ² to R ³ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a portion thereof may have a branched structure.
When a plurality of R ¹ to R ³ exist, each of them is independent.
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) indicates 3. )
(In formula (2), R ² to R ⁵ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, even if a portion thereof has a branched structure. Good. When a plurality of R ² to R ⁵ exist, they 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) indicates 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. (m+n+l) indicates 3. )

[6]
In the formula (1), R ¹ is a hydrogen atom, m = 0, a conjugated diene polymer (A1) having a monomer unit based on the compound represented by the formula (1), The conjugated diene polymer composition described in [5] above.
[7]
In the formula (2), m = 0 and b = 0, the conjugated diene polymer (A1) having a monomer unit based on the compound represented by the formula (2), The conjugated diene polymer composition according to [5].
[8]
A conjugated diene polymer having a monomer unit based on a compound represented by the formula (1), in which R ¹ is a hydrogen atom, m = 0, and l = 0. The conjugated diene polymer composition according to [5] or [6] above, which contains (A1).
[9]
In the formula (2), a conjugated diene polymer (A1 ) The conjugated diene polymer composition according to [5] or [7] above.
[10]
In the formula (1), R ¹ is a hydrogen atom, l = 0, and n = 3, a conjugated diene polymer having a monomer unit based on the compound represented by the formula (1). The conjugated diene polymer composition according to any one of [5], [6], and [8] above, which contains (A1).
[11]
A tire containing the conjugated diene polymer composition according to any one of [1] to [10] above.

According to the present invention, it is possible to provide a conjugated diene polymer composition from which a rubber composition with highly excellent balance between snow performance and wet performance can be obtained.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "this embodiment") will be described in detail.
Note that the following embodiment is an illustration for explaining the present invention, and the present invention is not limited to the following embodiment. The present invention can be implemented with appropriate modifications within the scope of its gist.

[Conjugated diene polymer composition]
The conjugated diene polymer composition of this embodiment is
20 to 99 parts by mass of a rubber component (A) which is a conjugated diene polymer having a glass transition temperature of −35° C. or higher;
Contains 1 to 90 parts by mass of a rubber component (B) having a glass transition temperature of -50°C or lower.
The rubber component (A) contains a conjugated diene polymer (A1) containing an aromatic vinyl compound and a conjugated diene compound,
The conjugated diene polymer (A1) has an absolute molecular weight of 40 × 10 ⁴ or more and 5000 × 10 ⁴ or less as measured by GPC-light scattering method with a viscosity detector,
The degree of branching (Bn) measured by the GPC-light scattering measurement method with a viscosity detector is 8 or more.
According to the conjugated diene polymer composition of the present embodiment, a rubber composition with highly excellent balance between snow performance and wet performance can be obtained.

(Rubber component (A))
The rubber component (A) contained in the conjugated diene polymer composition of the present embodiment has a glass transition temperature of −35° C. or higher, and includes a conjugated diene polymer (A1) described below.
The conjugated diene polymer (A1) has an absolute molecular weight of 40×10 ⁴ or more and 5000×10 ⁴ or less as measured by the GPC-light scattering method with a viscosity detector, and the absolute molecular weight is 40×10 4 or more and 5000×10 4 or less, and The degree of branching (Bn) is 8 or more, and contains an aromatic vinyl compound and a conjugated diene compound.
The conjugated diene polymer (A1) may contain components other than the aromatic vinyl compound and the conjugated diene compound, but the aromatic vinyl compound and the conjugated diene compound are the main components, and the ratio of these is 90% by mass or more. The content is preferably 95% by mass or more, and more preferably 95% by mass or more. Rubber components for tire treads generally do not contain components other than aromatic vinyl compounds and conjugated diene compounds.
Further, from the viewpoint of improving wear resistance, the rubber component (A) preferably contains 20% by mass or more of the conjugated diene polymer (A1), based on the total mass of the rubber component (A), and preferably contains 40% by mass or more of the conjugated diene polymer (A1). It is more preferably 60% by mass or more, and even more preferably 60% by mass or more.

<Glass transition temperature of rubber component (A)>
The glass transition temperature of the rubber component (A) is -35°C or higher as described above. The glass transition temperature is controlled within the above numerical range by controlling the microstructure of the conjugated diene polymer (A1), that is, by controlling the amount of aromatic vinyl compound and the amount of vinyl in the conjugated diene polymer (A1). can do.
Specifically, the glass transition temperature can be improved by increasing the amount of the aromatic vinyl compound or by increasing the amount of the vinyl compound in the conjugated diene polymer. A method for adjusting the glass transition temperature of the rubber component (A) to -35°C or higher is, for example, by adjusting the amount of aromatic vinyl to 20 to 45% by mass and the amount of vinyl compound in the conjugated diene polymer compound to 10 to 70% by mass. By doing so, it is possible to keep the glass transition temperature within the above range. When the glass transition temperature is within the above range, wet performance tends to be further improved.
Regarding the glass transition temperature, according to ISO 22768:2006, a DSC curve is recorded while increasing the temperature in a predetermined temperature range, and the peak top (inflection point) of the DSC differential curve is taken as the glass transition temperature. Specifically, it can be measured by the method described in Examples below. The upper limit of the glass transition temperature of the rubber component (A) is not particularly limited, but is preferably −10° C. or lower. When it is within this range, snow performance tends to be even better.
The conjugated diene polymer (A1) contained in the rubber component (A) will be explained below.

(Conjugated diene polymer (A1))
<Absolute molecular weight>
The rubber component includes a conjugated diene polymer (A1) containing an aromatic vinyl compound and a conjugated diene compound, and the conjugated diene polymer (A1) has the following properties from the viewpoint of wear resistance and fracture properties: The value of the absolute molecular weight determined by GPC-light scattering measurement with a viscosity detector is 40×10 ⁴ or more and 5000×10 ⁴ or less.
Generally, a polymer having a branched structure tends to have a smaller molecular size when compared to a linear polymer having the same molecular weight. Therefore, the molecular weight of a polymer with a branched structure is underestimated by the polystyrene equivalent molecular weight determined by gel permeation chromatography (GPC) measurement, which is a relative comparison method with a standard polystyrene sample that sieves based on the molecular size of the polymer. There is a tendency to
On the other hand, the absolute molecular weight measured by the GPC-light scattering measurement method with a viscosity detector is compared with the polystyrene equivalent molecular weight determined by the gel permeation chromatography (GPC) measurement, and the molecular size is directly observed by the light scattering method. However, since it measures molecular weight (absolute molecular weight), it is not affected by the structure of the polymer or interaction with column packing material. Therefore, the molecular weight can be accurately measured without being influenced by the polymer structure such as the branched structure of the conjugated diene polymer.

The absolute molecular weight of the conjugated diene polymer (A1) is 40×10 ⁴ or more, preferably 50×10 ⁴ or more, more preferably 60×10 ⁴ or more, and still more preferably 80×10 ⁴ It is above, and even more preferably 100×10 ⁴ or more.
Further, the absolute molecular weight of the conjugated diene polymer (A1) is 5000×10 ⁴ or less, preferably 4500×10 ⁴ or less, more preferably 4000×10 ⁴ or less, even more preferably 3500× It is 10 ⁴ or less, and even more preferably 3000×10 ⁴ or less.
When the absolute molecular weight is 40×10 ⁴ or more, the abrasion resistance when made into a vulcanizate is excellent. Moreover, since the absolute molecular weight is 5000×10 ⁴ or less, the processability and filler dispersibility when forming a vulcanizate are excellent, and the wet performance is excellent.
The absolute molecular weight of the conjugated diene polymer (A1) can be measured by the method described in the Examples below.
In addition, the absolute molecular weight of the conjugated diene polymer (A1) depends on the amount of the polymerization initiator added, the number of functional groups of the branching agent, the amount of the branching agent added, the timing of adding the branching agent, the coupling agent, the modification By adjusting the amount of the agent added, it can be controlled within the above numerical range.

<Branching degree>
The conjugated diene polymer (A1) has a degree of branching (Bn) of 8 or more from the viewpoint of processability and wet performance.
The degree of branching (Bn) of 8 or more means that the conjugated diene polymer (A1) has 8 or more side polymer chains with respect to the substantially longest polymer main chain. means.
The degree of branching (Bn) of the conjugated diene polymer (A1) is determined using the contraction factor (g') measured by GPC-light scattering measurement method with a viscosity detector, g'=6Bn/[(Bn+1) (Bn+2)].

Generally, a branched polymer tends to have a smaller molecular size when compared to a linear polymer having the same absolute molecular weight.
The shrinkage factor (g') is a measure of the ratio of the size of a molecule to a linear polymer of assumedly the same absolute molecular weight. That is, as the degree of branching of a polymer increases, the shrinkage factor (g') tends to decrease.
For this shrinkage factor, in this embodiment, intrinsic viscosity is used as an index of molecular size, and a linear polymer follows the relational expression of intrinsic viscosity [η]=-3.883M ^0.771 . In the above formula, M is the absolute molecular weight.
However, the shrinkage factor (g') expresses the rate of decrease in molecular size and does not accurately express the branched structure of the polymer.
Therefore, the degree of branching (Bn) of the conjugated diene polymer (A1) is calculated using the value of the contraction factor (g') at each absolute molecular weight of the conjugated diene polymer (A1). The calculated "degree of branching (Bn)" accurately expresses the number of polymers that are directly or indirectly bonded to each other with respect to the longest main chain structure.

The calculated degree of branching (Bn) serves as an index expressing the branched structure of the conjugated diene polymer (A1). For example, in the case of a typical four-branched star-shaped polymer (four polymer chains connected to the center), two polymer chain arms are connected to the longest highly branched main chain structure. , the degree of branching (Bn) is evaluated as 2.
In the case of a general 8-branched star-shaped polymer, six polymer chain arms are bonded to the longest highly branched main chain structure, and the degree of branching (Bn) is evaluated as 6.
The conjugated diene polymer (A1) has a degree of branching (Bn) of 8 or more, but in such a case, the conjugated diene polymer has branches similar to a star-shaped polymer structure with 10 branches as a star-shaped polymer structure. It means that.
Here, "branch" is formed by directly or indirectly bonding one polymer to another polymer. Moreover, "branching degree (Bn)" is the number of polymers that are directly or indirectly bonded to each other with respect to the longest main chain structure.
Since the degree of branching (Bn) is 8 or more, the conjugated diene polymer (A1) has excellent processability and wet performance when made into a vulcanizate.
Generally, as the absolute molecular weight increases, processability tends to deteriorate, and when the absolute molecular weight is increased in a linear polymer structure, the viscosity of the vulcanizate increases significantly, resulting in a significant deterioration in processability. Therefore, even if a large number of functional groups are introduced into the polymer to improve its affinity and/or reactivity with the silica blended as a filler, the silica cannot be sufficiently dispersed in the polymer during the kneading process. I can't do it. As a result, the function of the introduced functional group is not exhibited, and the originally expected effect of improving wet performance due to the introduction of the functional group is not exhibited.
On the other hand, the conjugated diene polymer (A1) is specified to have a degree of branching (Bn) of 8 or more, so that the increase in the viscosity of the vulcanizate due to the increase in the absolute molecular weight is significantly suppressed. In the kneading step, the silica and the like are sufficiently mixed, making it possible to disperse the silica around the conjugated diene polymer (A1). As a result, it is possible to improve wear resistance by setting the molecular weight of the conjugated diene polymer (A1) large, and by dispersing silica around the polymer by sufficient kneading, the functional groups can act and / Alternatively, since it becomes possible to react, it becomes possible to have practically sufficient wet performance.
The absolute molecular weight of the conjugated diene polymer (A1) can be measured by the method described in the Examples below.

The degree of branching (Bn) of the conjugated diene polymer (A1) is 8 or more, preferably 10 or more, more preferably 12 or more, and still more preferably 15 or more.
The conjugated diene polymer (A1) having a degree of branching (Bn) within this range tends to have excellent processability when made into a vulcanizate.
Further, the upper limit of the degree of branching (Bn) is not particularly limited, and may be higher than the detection limit, but is preferably 84 or less, more preferably 80 or less, still more preferably 64 or less, Even more preferably it is 57 or less.
When it is 84 or less, it tends to have excellent abrasion resistance when made into a vulcanized product.
The degree of branching of the conjugated diene polymer (A1) can be controlled to 8 or more by a combination of the amount of branching agent added and the amount of terminal modifier added. Specifically, the degree of branching can be controlled by adjusting the number of functional groups of the branching agent, the amount of branching agent added, the timing of addition of the branching agent, and the amount of modifier added. More specifically, it is shown in [Method for producing conjugated diene polymer] described below.

<Denaturation rate>
From the viewpoint of improving fuel efficiency, the conjugated diene polymer (A1) preferably has a modification rate of 60% by mass or more based on the total amount of the conjugated diene polymer.
In this specification, "modification rate" represents the mass ratio of the conjugated diene polymer having a nitrogen-containing functional group to the total amount of the conjugated diene polymer.
For example, when a nitrogen-containing modifier is reacted at the terminal end, the mass ratio of the conjugated diene polymer having a nitrogen-containing functional group to the total amount of the conjugated diene polymer caused by the nitrogen-containing modifier is expressed as the modification rate. be done.
On the other hand, even if a polymer is branched using a nitrogen-containing branching agent, the resulting conjugated diene polymer will have nitrogen-containing functional groups, so this branched polymer will also be used in calculating the modification rate. will be counted at that time.
That is, in this specification, when the conjugated diene polymer is a modified "modified conjugated diene polymer", the coupling polymer and/or the nitrogen-containing functional group using a modifier having a nitrogen-containing functional group is used. The total mass proportion of branched polymers by branching agents having groups is the modification rate.
The modification rate of the conjugated diene polymer (A1) is preferably 65% by mass or more, more preferably 70% by mass or more, even more preferably 75% by mass or more, even more preferably 80% by mass or more, even more preferably It is 82% by mass or more.
By setting the modification rate to 60% by mass or more, the fuel efficiency when made into a vulcanizate tends to be more excellent.
In this specification, unless otherwise specified, the term "conjugated diene polymer" includes a modified (containing a functional group) conjugated diene polymer.

The modification rate can be measured by chromatography, which can separate functional group-containing modified components and non-modified components.
This chromatography method uses a gel permeation chromatography column packed with a polar substance such as silica that adsorbs specific functional groups, and quantifies the non-adsorbed components using an internal standard for comparison. There are several methods.
More specifically, the denaturation rate is calculated from the difference between the chromatogram of a sample solution containing a sample and a low molecular weight internal standard polystyrene on a polystyrene gel column and the chromatogram measured on a silica column. Obtained by measuring the amount. More specifically, the modification rate can be measured by the method described in the Examples.

In the conjugated diene polymer (A1), the modification rate can be controlled by adjusting the amount of modifier added and the reaction method, and thereby can be controlled to 60% by mass or more.
For example, a method of polymerizing using an organolithium compound having at least one nitrogen atom in the molecule as described below as a polymerization initiator, a method of copolymerizing a monomer having at least one nitrogen atom in the molecule, which will be described later. The above modification rate can be achieved by combining a method using a modifier having the structural formula and controlling the polymerization conditions.

<Structure of conjugated diene polymer (A1)>
From the viewpoint of processability and wear resistance balance, the conjugated diene polymer (A1) is a conjugated diene polymer having a star-shaped polymer structure with three or more branches, and at least one branched chain of the star-shaped structure. has a part derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, and has a further main chain branched structure in the part derived from the vinyl monomer containing an alkoxysilyl group or a halosilyl group. It is preferable that the conjugated diene polymer has the following properties.
The term "star-shaped polymer structure" as used herein refers to a structure in which multiple polymer chains (arms) are connected from one central branch point.
Moreover, one central branch point here has a "substituent containing an atom derived from a coupling agent" or "a substituent containing a nitrogen atom derived from a modifier."
The "main chain branched structure" as used herein means that the polymer chain forms a branch point at a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, and further extends from the branch point to the polymer chain. A structure in which the (arm) is extended.

From the viewpoint of increasing the number of branches Bn, the conjugated diene polymer (A1) preferably has four main chain branching points constituted by a moiety derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group. The branched structure derived from the star-shaped polymer structure formed by the modifier in the reaction step is preferably 3 or more branches, more preferably 4 or more branches, and 8 or more branches. is even more preferable.
Note that the number of branches Bn increases both when modifying with a coupling agent that creates a star-shaped structure and when introducing a branching agent into the polymer, but in the case where the entire polymer chain is branched using a coupling agent, has a large contribution to the number of branches Bn.
In designing a polymer, the number of branches Bn can be controlled by selecting the coupling agent and selecting the type and amount of the branching agent. It tends to become easier.

<Main chain branched structure>
The main chain branched structure is a branch point in a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, and has two or more branch points, preferably three or more branch points, and four branch points. It is more preferable that it is above.
Further, the branch point forming the main chain branched structure preferably has at least two or more polymer chains, more preferably has three or more polymer chains that are not main chains, and Preferably, it has four or more polymer chains that are not main chains.
In particular, in main chain branched structures made of vinyl monomers containing alkoxysilyl groups or halosilyl groups, signal detection using ²⁹ Si-NMR shows a range of -45 ppm to -65 ppm, more specifically - A peak derived from the main chain branched structure is detected in the range of 50 ppm to -60 ppm.

<Star-shaped polymer structure>
The conjugated diene polymer (A1) preferably has a star-shaped polymer structure, preferably has three or more branches derived from the star-shaped polymer structure, and more preferably has four or more branches. Preferably, the number of branches is 6 or more, more preferably 6 or more, and even more preferably 8 or more.

The conjugated diene polymer (A1) is a conjugated diene polymer having a star-shaped polymer structure with three or more branches, and a vinyl containing an alkoxysilyl group or a halosilyl group in at least one branch chain of the star-shaped structure. Regarding a method for obtaining a conjugated diene-based polymer having a portion derived from a vinyl-based monomer and having an additional main chain branched structure in the portion derived from a vinyl-based monomer containing the alkoxysilyl group or halosilyl group, The above-mentioned "star-shaped polymer structure" can be formed by adjusting the number of functional groups of the modifier and the amount of the modifier added, and the "main chain branched structure" can be formed by adjusting the number of functional groups of the branching agent and the amount of the branching agent added. , can be controlled by adjusting the timing of addition of the branching agent.

A conjugated diene polymer having a star-shaped polymer structure with three or more branches, in which at least one branch chain of the star-shaped structure has a moiety derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group. In order to obtain a conjugated diene polymer having an additional main chain branched structure in the moiety derived from the vinyl monomer containing the alkoxysilyl group or halosilyl group, for example, an organolithium compound may be used as a polymerization initiator. , a method of performing polymerization, adding a branching agent that gives a specific branching point during or after the polymerization, and continuing the polymerization and then modifying using a modifier that gives a specific branching rate.
Means for controlling such polymerization conditions will be described in the production method in Examples described later.

<Detailed structure of main chain branched structure>
The conjugated diene polymer (A1) is a monomer unit in which the portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group is based on a compound represented by the following formula (1) or (2). The conjugated diene polymer has a branching point in the polymer chain formed by a monomer unit based on a compound represented by the following formula (1) or (2), and at least one end of the conjugated diene polymer is coupled using a coupling agent. It is preferable to use a ring-shaped conjugated diene polymer, and it is more preferable that at least one end of the conjugated diene polymer is modified with a nitrogen atom-containing group.

(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 a portion thereof may have a branched structure.
R ² to R ³ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a portion thereof may have a branched structure. When a plurality of R ¹ to R ³ exist, each of them is independent.
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) indicates 3. )
(In formula (2), R ² to R ⁵ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, even if a part thereof has a branched structure. Good. When a plurality of R ² to R ⁵ exist, they 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) indicates 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. (m+n+l) represents an integer of 3. )

The conjugated diene polymer (A1) has monomer units based on the compound represented by the above formula (1), in which R ¹ in the above formula (1) is a hydrogen atom and m = 0. It is preferable that
This increases the number of branches, resulting in improved wear resistance and workability.

Further, the conjugated diene polymer (A1) has a monomer unit based on a compound represented by the formula (2), where m=0 and b=0. Preferably.
This provides the effect of improving wear resistance and workability.

In addition, the conjugated diene polymer (A1) is a monomer based on a compound represented by the formula (1), in which R ¹ in the above formula (1) is a hydrogen atom, m = 0, and l = 0. It is preferable that it has a mer unit.
This increases the degree of branching and provides the effects of improved wear resistance and workability.

The conjugated diene polymer (A1) is a monomer based on a compound represented by the formula (2), where m=0, l=0, a=0, b=0. A conjugated diene polymer having a mer unit is preferable.
This provides the effect of improving wear resistance and workability.

The conjugated diene polymer (A1) is a compound represented by the formula (1), in which R ¹ is a hydrogen atom, l=0, and n=3. A conjugated diene polymer having a monomer unit based on
This improves the modification rate and degree of branching, resulting in improved fuel efficiency, wear resistance, and workability.

(branching agent)
In the conjugated diene polymer (A1), when constructing the main chain branched structure, it is preferable to use a branching agent represented by the following formula (1) or formula (2) as the branching agent.

(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 a portion thereof may have a branched structure.
R ² to R ³ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a portion thereof may have a branched structure.
When a plurality of R ¹ to R ³ exist, each of them is independent.
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) indicates 3. )
(In formula (2), R ² to R ⁵ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, even if a part thereof has a branched structure. good.
When a plurality of R ² to R ⁵ are present, each of them is 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) indicates 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. (m+n+l) indicates 3. )

The branching agent used when constructing the main chain branched structure of the conjugated diene polymer (A1) is one in which R ¹ in formula (1) is a hydrogen atom, from the viewpoint of continuity of polymerization and improvement of the degree of branching. , m=0.

In addition, from the viewpoint of improving the degree of branching, the branching agent used when constructing the main chain branched structure of the conjugated diene polymer (A1) is such that in formula (2), m = 0 and b = It is preferable that it is a compound of 0.

In addition, the branching agent used when constructing the main chain branched structure of the conjugated diene polymer (A1) is R ¹ of formula (1) from the viewpoint of continuity of polymerization, improvement of modification rate and degree of branching. It is more preferable that the compound is a hydrogen atom, m=0, and l=0.

In addition, from the viewpoint of improving the modification rate and degree of branching, the branching agent used when constructing the main chain branched structure of the conjugated diene polymer (A1) is It is more preferable that the compound be a compound where =0, a=0, and b=0.

In addition, the branching agent used when constructing the main chain branched structure of the conjugated diene polymer (A1) is selected from the above formula (1) from the viewpoint of continuity of polymerization, improvement of modification rate, and degree of branching. More preferably, R ¹ is a hydrogen atom, l=0, and n=3.

The branching agent represented by the formula (1) is not limited to the following, but examples include trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, and tripropoxy(4-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, dimethoxymethyl(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, diisopropoxymethyl(2-vinylphenyl)silane, dimethylmethoxy(4-vinylphenyl)silane, dimethylethoxy(4-vinyl) phenyl)silane, dimethylpropoxy(4-vinylphenyl)silane, 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, -vinylphenyl)silane, dimethylpropoxy(2-vinylphenyl)silane, dimethylbutoxy(2-vinylphenyl)silane, dimethylisopropoxy(2-vinylphenyl)silane, trimethoxy(4-isopropenylphenyl)silane, triethoxy(4-vinylphenyl)silane -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, 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, 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)silane, dimethylmethoxy(3-isopropenylphenyl)silane, dimethylethoxy(3-isopropenylphenyl)silane, nylphenyl)silane, dimethylpropoxy(3-isopropenylphenyl)silane, dimethylbutoxy(3-isopropenylphenyl)silane, dimethylisopropoxy(3-isopropenylphenyl)silane, dimethylmethoxy(2-isopropenylphenyl)silane, dimethyl Ethoxy(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, dichloromethyl (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 Examples include (3-vinylphenyl)silane and dimethylbromo(2-vinylphenyl)silane.
Among these, trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, tripropoxy(4-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, Trichloro(4-vinylphenyl)silane is preferred, and trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, tripropoxy(4-vinylphenyl)silane, tributoxy(4-vinylphenyl)silane triisopropoxy (4-vinylphenyl)silane is more preferred.

The branching agent represented by the formula (2) is not limited to the following, but for example,
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, 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-triiso propoxysilylphenyl)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-(diethylethoxysilyl)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, 1,1-bis(4-trimethoxysilylphenyl)ethylene, is more preferable.

[Method for producing conjugated diene polymer (A1)]
The method for producing the conjugated diene polymer (A1) is as follows:
a polymerization/branching step of polymerizing at least a conjugated diene compound in the presence of an organolithium compound and using at least one of the various branching agents described above to obtain a conjugated diene polymer having a main chain branched structure; ,
The method includes a step of coupling the conjugated diene polymer using a coupling agent and/or a step of modifying the conjugated diene polymer with a modifying agent having a nitrogen atom-containing group.
Conjugated diene polymers constituting the modified conjugated diene polymer include a homopolymer of a single conjugated diene compound, a polymer or copolymer of different types of conjugated diene compounds, a conjugated diene compound and an aromatic vinyl It may be a copolymer with a compound.

(Polymerization/branching process)
The polymerization/branching step in the method for producing a conjugated diene polymer (A1) is performed by using an organic lithium compound, for example, an organic monolithium compound as a polymerization initiator, polymerizing at least the conjugated diene compound, and adding a branching agent. , a conjugated diene polymer having a main chain branched structure is obtained.
In the polymerization step, it is preferable to carry out polymerization by a growth reaction using a living anion polymerization reaction, whereby a conjugated diene polymer having an active terminal can be obtained. After that, main chain branching can be appropriately controlled in the branching process using a branching agent, and by continuing polymerization to the active end after main chain branching, a modified conjugated diene with a high modification rate can be produced. There is a tendency that it is possible to obtain a type polymer.

<Polymerization initiator>
As the polymerization initiator, an organic lithium compound is used, and at least an organic monolithium compound is preferably used.
Examples of the organic monolithium compound include, but are not limited to, low molecular weight compounds and solubilized oligomeric organic monolithium compounds.
In addition, examples of the organic monolithium compound include compounds having a carbon-lithium bond, compounds having a nitrogen-lithium bond, and compounds having a tin-lithium bond in terms of the bonding mode between the organic group and the lithium.

The amount of the organic monolithium compound used as a polymerization initiator is preferably determined depending on the molecular weight of the target conjugated diene polymer.
The amount of monomer such as a conjugated diene compound used relative to the amount of polymerization initiator used is related to the degree of polymerization of the target conjugated diene polymer. That is, it tends to be related 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 polymerization initiator may be decreased, and in order to decrease the molecular weight, the amount of polymerization initiator may be increased.

The organic monolithium compound is preferably an alkyllithium compound having a substituted amino group or dialkylaminolithium from the viewpoint of being used as one method for introducing a nitrogen atom into a conjugated diene polymer.
In this case, a conjugated diene polymer having a nitrogen atom consisting of an amino group at the polymerization initiation terminal is obtained.

A substituted amino group is an amino group that does not have an active hydrogen or has a structure in which the active hydrogen is protected.
Examples of alkyllithium compounds having an amino group without active hydrogen include, but are not limited to, 3-dimethylaminopropyllithium, 3-diethylaminopropyllithium, 4-(methylpropylamino)butyllithium, and 4-dimethylaminopropyllithium, and 4-(methylpropylamino)butyllithium. - Hexamethyleneiminobutyllithium.
Examples of the alkyllithium compound having an amino group with a protected active hydrogen structure include, but are not limited to, 3-bistrimethylsilylaminopropyllithium and 4-trimethylsilylmethylaminobutyllithium.

Examples of the dialkylamino lithium include, but are not limited to, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium dibutylamide, lithium di-n-hexylamide, lithium diheptylamide, lithium diisopropylamide, and lithium dioctylamide. , lithium-di-2-ethylhexylamide, lithium didecylamide, lithium ethylpropylamide, lithium ethylbutyramide, lithium ethylbenzylamide, lithium methylphenethylamide, lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, Lithium heptamethyleneimide, lithium morpholide, 1-lithioazacyclooctane, 6-lithio-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane, and 1-lithio-1,2, 3,6-tetrahydropyridine is mentioned.

These organic monolithium compounds having substituted amino groups are made by reacting a small amount of a polymerizable monomer, such as 1,3-butadiene, isoprene, or styrene, to make them solubilized in n-hexane or cyclohexane. It can also be used as an oligomeric organomonolithium compound.

The organic monolithium compound is preferably an alkyllithium compound from the viewpoint of industrial availability and ease of controlling the polymerization reaction. In this case, a conjugated diene polymer having an alkyl group at the polymerization initiation 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.
As the alkyllithium compound, n-butyllithium and sec-butyllithium are preferred from the viewpoint of industrial availability and ease of controlling the polymerization reaction.

These organic monolithium compounds may be used alone or in combination of two or more. It may also be used in combination with other organometallic compounds.
Examples of the other organometallic compounds include alkaline earth metal compounds, other alkali metal compounds, and other organometallic compounds.
Examples of alkaline earth metal compounds include, but are not limited to, organic magnesium compounds, organic calcium compounds, and organic strontium compounds. Also included are alkaline earth metal alkoxide, sulfonate, carbonate, and amide compounds.
Examples of organomagnesium compounds include dibutylmagnesium and ethylbutylmagnesium. Examples of other organometallic compounds include organoaluminum compounds.

In the polymerization process, the polymerization reaction mode is not limited to the following, but includes, for example, a batch type (also referred to as "batch type") and a continuous type polymerization reaction mode.
In continuous mode, one or more connected reactors can be used. As the continuous reactor, for example, a tank type or a tube type with a stirrer is used. In the continuous system, preferably, monomers, inert solvents, and polymerization initiators are continuously fed into a reactor, a polymer solution containing a polymer is obtained in the reactor, and polymerization is continuously carried out. The combined solution is drained.
As the batch reactor, for example, a tank type reactor equipped with a stirrer is used. In the batch system, preferably the monomer, inert solvent, and polymerization initiator are fed, and if necessary, the monomer is added continuously or intermittently during the polymerization to form the polymer in the reactor. A polymer solution containing the polymer is obtained, and the polymer solution is discharged after the polymerization is completed.
In the method for producing a conjugated diene polymer (A1), in order to obtain a conjugated diene polymer having a high proportion of active terminals, it is possible to continuously discharge the polymer and use it for the next reaction in a short time. A continuous type is preferred.

The conjugated diene polymer is preferably polymerized in an inert solvent.
Examples of the inert solvent include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specific hydrocarbon solvents include, but are not limited to, aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic solvents such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; Hydrocarbons include aromatic hydrocarbons such as benzene, toluene, and xylene, and hydrocarbons consisting of mixtures thereof.
By treating allenes and acetylenes, which are impurities, with an organometallic compound before subjecting them to the polymerization reaction, a conjugated diene polymer with a high concentration of active terminals tends to be obtained, resulting in a high modification rate. This is preferable because it tends to yield a conjugated diene polymer.

In the polymerization step, a polar compound may be added. This allows the aromatic vinyl compound to be randomly copolymerized with the conjugated diene compound, and the polar compound tends to also be used as a vinylating agent to control the microstructure of the conjugated diene moiety. It also tends to be effective in promoting polymerization reactions.

Examples of polar compounds 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, dimethoxybenzene, 2,2-bis(2-oxolanyl). ) Ethers such as propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclidine; potassium-tert-amylate, potassium-tert-butyrate, sodium-tert-butyrate, Alkali metal alkoxide compounds such as sodium amylate; phosphine compounds such as triphenylphosphine, etc. can be used.
These polar compounds may be used alone or in combination of two or more.

The amount of the polar compound to be used is not particularly limited and can be selected depending on the purpose, etc., but it is preferably 0.01 mol or more and 100 mol or less with respect to 1 mol of the polymerization initiator.
Such a polar compound (vinylating agent) can be used in an appropriate amount as a regulator of the microstructure of the conjugated diene moiety of the conjugated diene polymer, depending on the desired amount of vinyl bonds.
Many polar compounds have an effective randomizing effect in the copolymerization of conjugated diene compounds and aromatic vinyl compounds, and tend to be used as agents to adjust the distribution of aromatic vinyl compounds and adjust the amount of styrene blocks. It is in.
As a method of randomizing the conjugated diene compound and the aromatic vinyl compound, for example, as described in JP-A-59-140211, the total amount of styrene and a part of 1,3-butadiene are combined. A method may be used in which the polymerization reaction is started and the remaining 1,3-butadiene is added intermittently during the copolymerization reaction.

The polymerization temperature in the polymerization step is preferably a temperature at which living anion polymerization proceeds, and from the viewpoint of productivity, it is more preferably 0°C or higher, and even more preferably 120°C or lower. By falling within this range, it tends to be possible to ensure a sufficient amount of the modifier to react with the active end after completion of polymerization. Even more preferably, the temperature is 50°C or more and 100°C or less.

In the method for producing a conjugated diene polymer (A1), the amount of branching agent added in the branching step for forming a main chain branched structure is not particularly limited and can be selected depending on the purpose, etc. It 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 per mol of the initiator. It is more preferable that it is the following.
The branching agent can be used in an appropriate amount depending on the number of branching points in the main chain branching structure of the conjugated diene moiety of the desired conjugated diene polymer (A1).

The timing of adding the branching agent in the branching step is not particularly limited and can be selected depending on the purpose, etc., but from the viewpoint of increasing the absolute molecular weight and modification rate of the conjugated diene polymer, it is important to After adding the agent, the timing is preferable when the raw material conversion rate is 20% or more, more preferably 40% or more, even more preferably 50% or more, even more preferably 65% or more, and even more preferably 75%. It is even more preferable that the condition is above.
Further, after adding the branching agent, a desired raw material may be further added to continue the polymerization step after branching, or the above-mentioned contents may be repeated.
The monomer to be added is not particularly limited, but from the viewpoint of improving the modification rate of the conjugated diene polymer, it is preferably 5% or more of the total amount of conjugated diene monomers used in the polymerization step, for example, the total amount of butadiene. It is more preferably 10% or more, even more preferably 15% or more, even more preferably 20% or more, even more preferably 25% or more.

In the method for producing a conjugated diene polymer (A1), the conjugated diene polymer obtained in the polymerization/branching step and before the modification reaction step must have a Mooney viscosity of 10 or more and 150 or less when measured at 110°C. It is preferably 15 or more and 140 or less, and even more preferably 20 or more and 130 or less.
Within this range, the conjugated diene polymer composition of this embodiment tends to have excellent processability and wear resistance.

The conjugated diene polymer (A1) of the present embodiment is a polymer containing an aromatic vinyl compound and a conjugated diene polymer, and is a polymer of a conjugated diene monomer, an aromatic vinyl monomer, and a branching agent. Alternatively, it may be a copolymer with a conjugated diene monomer, an aromatic vinyl monomer, a branching agent, or a monomer other than these.
For example, if the conjugated diene monomer is butadiene or isoprene, and this is polymerized with a branching agent containing an aromatic vinyl moiety, the polymer chain will be so-called polybutadiene or polyisoprene, and the branched moiety will contain a structure derived from the aromatic vinyl. Becomes a polymer. By having such a structure, it is possible to improve the linearity of each polymer chain and to improve the crosslinking density after vulcanization, which has the effect of improving the wear resistance of the polymer. Therefore, it is suitable for applications such as tires, resin modification, interior and exterior parts of automobiles, anti-vibration rubber, and footwear.
When using a conjugated diene polymer for tire tread applications, a copolymer of a conjugated diene monomer, an aromatic vinyl monomer, and a branching agent is suitable, and the amount of bonded conjugated diene in the copolymer for this use is 40% by mass. % or more and 100% by mass or less, more preferably 55% by mass or more and 80% by mass or less.
Further, the amount of bonded aromatic vinyl in the conjugated diene polymer (A1) is not particularly limited, but is preferably 0% by mass or more and 60% by mass or less, and preferably 20% by mass or more and 45% by mass or less. More preferred.
When the amount of bonded conjugated diene and the amount of bonded aromatic vinyl are within the above ranges, the balance between low hysteresis loss property and wet performance, as well as wear resistance and fracture properties when made into a vulcanized product, tends to be excellent.
Here, the amount of bonded aromatic vinyl can be measured by ultraviolet absorption of the phenyl group, and from this, the amount of bonded conjugated diene can also be determined. Specifically, it is measured according to the method described in the Examples described later.

In the conjugated diene polymer (A1), the amount of vinyl bonds in the conjugated diene bond units is not particularly limited, but is preferably 10 mol% or more and 75 mol% or less, and 20 mol% or more and 65 mol% or less. It is more preferable.
When the amount of vinyl bonds is within the above range, the vulcanizate tends to have a better balance between low hysteresis loss and wet performance, wear resistance, and fracture strength.
Here, when the conjugated diene polymer (A1) is a copolymer of butadiene and styrene, the butadiene bond is The amount of vinyl bonds (1,2-bond amount) in the unit can be determined. Specifically, it is measured by the method described in Examples below.

Regarding the microstructure of the conjugated diene polymer (A1), the amount of each bond in the conjugated diene polymer (A1) is within the numerical range mentioned above, and the glass transition temperature of the conjugated diene polymer (A1) is When the temperature is in the range of -70°C or higher and -15°C or lower, it tends to be possible to obtain a vulcanizate with an even better balance between fuel efficiency and wet performance.
Regarding the glass transition temperature, according to ISO 22768:2006, a DSC curve is recorded while increasing the temperature in a predetermined temperature range, and the peak top (inflection point) of the DSC differential curve is taken as the glass transition temperature. Specifically, it is measured by the method described in Examples below.

When the conjugated diene polymer (A1) is a conjugated diene-aromatic vinyl copolymer, it is preferable that the number of blocks in which 30 or more aromatic vinyl units are linked is small or absent. More specifically, when the conjugated diene polymer (A1) is a butadiene-styrene copolymer, Kolthoff's method (IM. KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946)) is used. In a known method of decomposing a copolymer and analyzing the amount of polystyrene insoluble in methanol by the method described in The content is preferably 5.0% by mass or less, more preferably 3.0% by mass or less.

When the conjugated diene polymer (A1) is a conjugated diene-aromatic vinyl copolymer, from the viewpoint of improving fuel efficiency, it is preferable that the aromatic vinyl unit exists alone in a large proportion.
Specifically, in the case where the conjugated diene polymer (A1) is a butadiene-styrene copolymer, the above-mentioned method using ozonolysis is known as the method of Tanaka et al. (Polymer, 22, 1721 (1981)). When the conjugated diene polymer is decomposed and the styrene chain distribution is analyzed by GPC, the amount of isolated styrene is 40% by mass or more based on the total amount of bonded styrene, and the chain styrene structure with 8 or more styrene chains is found. It is preferably 5.0% by mass or less.
In this case, the resulting vulcanized rubber exhibits excellent performance with particularly low hysteresis loss.

(Reaction process)
In the method for producing a conjugated diene polymer (A1), a coupling agent such as a trifunctional or higher functional reactive compound is applied to the active end of the conjugated diene polymer obtained through the polymerization/branching step described above. and/or a step of modifying using a modifier having a nitrogen atom-containing group (preferably a coupling agent having a nitrogen atom-containing group).
Hereinafter, the coupling step and/or the modification step will be referred to as a reaction step.
In the reaction step, one end of the active end of the conjugated diene polymer is subjected to a modification reaction with a coupling agent or a nitrogen atom-containing group to obtain a modified conjugated diene polymer.

<Coupling agent>
The coupling agent used in the reaction step of the method for producing a conjugated diene polymer (A1) may have any structure as long as it is a trifunctional or more reactive compound, but is preferably a trifunctional compound having a silicon atom. It is more preferable that the above-mentioned reactive compound has at least four silicon-containing functional groups. A more preferred coupling agent is a compound in which at least one silicon atom constitutes an alkoxysilyl group or silanol group having 1 to 20 carbon atoms. Examples of such coupling agents include tetramethoxysilane and tetraethoxysilane.

<Modifier>
Modifiers include, but are not limited to, 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, 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-triethoxysilylpropyl)-[3-(2,2 -diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis( Tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]- 1,3-bisaminomethylcyclohexane, tetrakis(3-trimethoxysilylpropyl)-1,6-hexamethylenediamine, pentakis(3-trimethoxysilylpropyl)-diethylenetriamine, 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-sila cyclopentane)propyl]-3,4,5-tris(3-trimethoxysilylpropyl)-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, and tris[3-( 2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]phosphate.

The modifier preferably contains a compound represented by any one of the following general formulas (A) to (C).

(In formula (A), R ¹ to R ⁴ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ⁵ represents a carbon number 1 to 10 aryl group. It represents an alkylene group, and R ⁶ represents an alkylene group having 1 to 20 carbon atoms.
m represents an integer of 1 or 2, n represents an integer of 2 or 3, and (m+n) represents an integer of 4 or more. When a plurality of R ¹ to R ⁴ are present, each of them is independent. )

(In formula (B), R ¹ to R ⁶ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ⁷ to R ⁹ each independently , represents an alkylene group having 1 to 20 carbon atoms.
m, n, and l each independently represent an integer of 1 to 3, and (m+n+l) represents an integer of 4 or more. When a plurality of R ¹ to R ⁶ are present, each of them is independent. )

(In formula (C), R ¹² to R ¹⁴ each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms, and R ¹⁵ to R ¹⁸ and R ²⁰ each independently represent 1 to 20 carbon atoms. R ¹⁹ and R ²² each independently represent an alkylene group having 1 to 20 carbon atoms, and R ²¹ represents an alkyl group or trialkylsilyl group having 1 to 20 carbon atoms.
m represents an integer of 1 to 3, and p represents 1 or 2.
When a plurality of R ¹² to R ²² , m, and p are each independent, they may be the same or different.
i represents an integer from 0 to 6, j represents an integer from 0 to 6, k represents an integer from 0 to 6, and (i+j+k) represents an integer from 4 to 10.
A has a hydrocarbon group having 1 to 20 carbon atoms, or at least one atom selected from the group consisting of oxygen atom, nitrogen atom, silicon atom, sulfur atom, and phosphorus atom, and has no active hydrogen. Represents an organic group. )

The modifier represented by the formula (A) is not limited to the following, but for example, 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-(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-tri methoxysilylpropyl)-1-aza-2-silacyclopentane, 2-ethoxy,2-ethyl-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-methoxy,2- Methyl-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, and 2-ethoxy,2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2- Examples include silacyclopentane.
Among these, those in which m is 2 and n is 3 are preferred from the viewpoint of reactivity and interaction between the functional group of the modifier and an inorganic filler such as silica, and from the viewpoint of processability. Specifically, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, and 2,2-diethoxy-1-(3-triethoxysilylpropyl)- 1-aza-2-silacyclopentane is preferred.

The reaction temperature, reaction time, etc. when reacting the modifier represented by the formula (A) with the polymerization active terminal are not particularly limited, but the reaction should be carried out at a temperature of 0°C or more and 120°C or less for 30 seconds or more. is preferred.
The total number of moles of the alkoxy groups bonded to the silyl groups in the modifier compound represented by the formula (A) is 0.0% of the number of moles added of the alkali metal compound and/or alkaline earth metal compound of the polymerization initiator. The range is preferably 6 times or more and 3.0 times or less, more preferably the range is 0.8 times or more and 2.5 times or less, and the range is 0.8 times or more and 2.0 times or less. It is more preferable that From the viewpoint of obtaining a sufficient modification rate, molecular weight, and branched structure of the resulting modified conjugated diene polymer, it is preferable that the ratio is 0.6 times or more, and the polymer terminals are coupled to each other to improve processability. In addition to the fact that it is preferable to obtain a branched polymer component, from the viewpoint of modifier cost, it is preferable that the amount is 3.0 times or less.
More specifically, the number of moles of the polymerization initiator is preferably 3.0 times or more, more preferably 4.0 times or more, relative to the number of moles of the modifier.

The modifier represented by the formula (B) is not limited to the following, but includes, for example, tris(3-trimethoxysilylpropyl)amine, tris(3-methyldimethoxysilylpropyl)amine, and tris(3-trimethoxysilylpropyl)amine. tris(3-methyldiethoxysilylpropyl)amine, tris(trimethoxysilylmethyl)amine, tris(2-trimethoxysilylethyl)amine, and tris(4-trimethoxysilylbutyl)amine can be mentioned.
Among these, from the viewpoint of reactivity and interaction between the functional group of the modifier and inorganic filler such as silica, and from the viewpoint of processability, it is preferable that n, m, and l all represent 3. preferable. Preferred specific examples include tris(3-trimethoxysilylpropyl)amine and tris(3-triethoxysilylpropyl)amine.

The reaction temperature, reaction time, etc. when reacting the modifier represented by the formula (B) with the polymerization active terminal are not particularly limited, but the reaction should be carried out at a temperature of 0°C or more and 120°C or less for 30 seconds or more. is preferred.
The total number of moles of alkoxy groups bonded to silyl groups in the modifier compound represented by formula (B) is 0.6 times or more and 3.0 times the number of moles of lithium constituting the above-mentioned polymerization initiator. It is preferably in the following range, more preferably in the range from 0.8 times to 2.5 times, even more preferably in the range from 0.8 times to 2.0 times. From the viewpoint of obtaining a sufficient modification rate, molecular weight, and branched structure in the modified conjugated diene polymer, the ratio is preferably 0.6 times or more, and in order to improve processability, the ends of the polymer are coupled together and branched. In addition to the fact that it is preferable to obtain a polymer component having a shape of 3.0 times or less, from the viewpoint of the cost of the modifier, it is preferable that the amount is 3.0 times or less.
More specifically, the number of moles of the polymerization initiator is preferably 4.0 times or more, more preferably 5.0 times or more, relative to the number of moles 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 there is a plurality of B ¹ s, each independently )

(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. (B ² and B ³ are independent when there are multiple B 2 and B 3.)

(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 there is a plurality of B ⁴ s, each independently )

(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 there is a plurality of B ⁵ s, each independently )

In formula (C), the modifier when A is represented by formula (II) is not limited to the following, but includes, for example, tris(3-trimethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)amine, methoxysilylpropyl)-[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-sila) cyclopentane)propyl]-(3-triethoxysilylpropyl)amine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)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-aza) cyclopentane)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-propanediamine, 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-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, 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-bisaminomethylcyclohexane,
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-bisaminomethyl Cyclohexane, tetrakis(3-triethoxysilylpropyl)-1,3-propanediamine,
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-azacyclopentane)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-trimethoxysilylpropyl)-diethylenetriamine.

In formula (C), the modifier when 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-propanediamine, 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) -N ³ -(3-(trimethoxy Examples include silyl)propyl)-1,3-propanediamine.

In formula (C), the modifier when 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-trimethoxysilyl) propyl)-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-trimethoxysilylpropyl)-bis[3-(1-methoxy-2-methyl-1-sila-2-azacyclopentane)propyl]silane can be mentioned.

In the above formula (C), when A is represented by formula (V), the modifier is not limited to the following, but for example, 3-tris[2-(2,2-dimethoxy-1-aza) -2-silacyclopentane)ethoxy]silyl-1-(2,2-dimethoxy-1-aza-2-silacyclopentane)propane, and 3-tris[2-(2,2-dimethoxy-1-aza- Examples include 2-silacyclopentane)ethoxy]silyl-1-trimethoxysilylpropane.

In the formula (C), A is preferably represented by formula (II) or formula (III), and k represents 0.
Such a modifier tends to be easily available, and also improves the wear resistance when the conjugated diene polymer composition of this embodiment containing the conjugated diene polymer (A1) is made into a vulcanized product. This tends to result in better performance and low hysteresis loss performance.
Such modifiers include, but are not limited to, the following, for example, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl] Amine, Tris(3-trimethoxysilylpropyl)amine, Tris(3-triethoxysilylpropyl)amine, Tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-) silacyclopentane)propyl]-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-tri methoxysilylpropyl)-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 2 to 10 indicates an integer.
This tends to result in better wear resistance and low hysteresis loss performance upon vulcanization.
Examples of such modifiers 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-(trimethoxy silyl)propyl)amino)propyl) -N ¹ -methyl-N ³ -(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl) -N ³ -(3-(trimethoxysilyl)propyl) -1,3-propanediamine is mentioned.

The amount of the compound represented by the formula (C) as a modifier is determined so that the number of moles of the conjugated diene polymer to the number of moles of the modifier becomes a desired stoichiometric ratio. The polymer can be tailored to react with a modifier, which tends to achieve the desired star-shaped hyperbranched structure.
The specific number of moles of the conjugated diene polymer is preferably 5.0 times or more, more preferably 6.0 times or more, relative to the number of moles of the modifier.
In this case, in formula (C), the number of functional groups ((m-1)×i+p×j+k) of the modifier is preferably an integer of 5 to 10, more preferably an integer of 6 to 10.

In the modified conjugated diene polymer (A1), the proportion of the modified group-containing polymer in the conjugated diene polymer (A1) is expressed as a modification rate.
In the conjugated diene polymer (A1), 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, even more preferably 75% by mass or more, and even more preferably Preferably it is 80% by mass or more, particularly preferably 82% by mass or more.
By setting the modification rate to 60% by mass or more, the processability when forming a vulcanizate tends to be excellent, and the wear resistance and low hysteresis loss performance when forming a vulcanizate tend to be excellent.

In the production process of the conjugated diene polymer (A1), a condensation reaction process in which the condensation reaction is carried out in the presence of a condensation promoter may be performed after or before the above-mentioned reaction process.

The conjugated diene polymer (A1) may have a hydrogenated conjugated diene moiety.
The method for hydrogenating the conjugated diene moiety of the conjugated diene polymer (A1) is not particularly limited, and any known method can be used.
A suitable hydrogenation method includes a hydrogenation method in which gaseous hydrogen is blown into the polymer solution in the presence of a catalyst.
As a catalyst, for example, a heterogeneous catalyst such as a catalyst in which a noble metal is supported on a porous inorganic substance; a catalyst in which a salt such as nickel or cobalt is solubilized and reacted with an organoaluminium, etc., or a metallocene such as titanocene is used. Examples include homogeneous catalysts such as catalysts. Among these, titanocene catalysts are preferred from the viewpoint of being able to select mild hydrogenation conditions.
Further, hydrogenation of aromatic groups can be carried out by using a supported noble metal catalyst.

Hydrogenation catalysts include, but are not limited to, the following: (1) Supported heterogeneous hydrogenation in which metals such as Ni, Pt, Pd, and Ru are supported on carbon, silica, alumina, diatomaceous earth, etc.; Catalyst, (2) So-called Ziegler hydrogenation catalyst using an organic acid salt such as Ni, Co, Fe, Cr or a transition metal salt such as acetylacetone salt and a reducing agent such as organoaluminum, (3) Ti, Ru, Examples include so-called organometallic complexes such as organometallic compounds such as Rh and Zr. Further, as a hydrogenation catalyst, for example, Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-37970, Japanese Patent Publication No. 1-53851, Also mentioned are known hydrogenation catalysts described in Hei 2-9041 and JP-A-8-109219. Preferred hydrogenation catalysts include reaction mixtures of titanocene compounds and reducing organometallic compounds.

In the method for producing a conjugated diene polymer (A1), after the reaction step, a deactivator, a neutralizing agent, etc. may be added to the polymer solution as necessary.
Examples of the deactivator include, but are not limited to, water; alcohols such as methanol, ethanol, and isopropanol; and the like.
Examples of the neutralizing agent include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and versatic acid (a mixture of highly branched carboxylic acids with 9 to 11 carbon atoms, mainly 10 carbon atoms). Acids: Examples include aqueous solutions of inorganic acids and carbon dioxide gas.

It is preferable to add a rubber stabilizer to the conjugated diene polymer (A1) from the viewpoint of preventing gel formation after polymerization and from the viewpoint of improving stability during processing.
The rubber stabilizer is not limited to the following, and any known stabilizer can be used, such as 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl-3 Antioxidants such as -(4'-hydroxy-3',5'-di-tert-butylphenol)propinate and 2-methyl-4,6-bis[(octylthio)methyl]phenol are preferred.

(Extended conjugated diene polymer)
The conjugated diene polymer (A1) is produced by adding at least one selected from the group consisting of extender oil, liquid rubber, and resin to the conjugated diene polymer obtained by the above-mentioned manufacturing process. It may also be a diene polymer.
Note that the extended conjugated diene polymer includes not only oil-extended conjugated diene polymers containing oil, but also those containing liquid polybutadiene other than oil and various resins.
Thereby, the processability of the conjugated diene polymer can be further improved.
The method of adding the extender oil to the conjugated diene polymer is not limited to the following method, but the extender oil is added to the conjugated diene polymer solution, mixed, and the extended polymer solution is desolvated. The method is preferred.
Examples of the extender oil include aroma oil, naphthenic oil, paraffin oil, and the like. Among these, from the viewpoint of environmental safety, oil bleed prevention and wet performance, aromatic alternative oils containing 3% by mass or less of polycyclic aromatic (PCA) components according to the IP346 method are preferred. As aroma substitute oils, TDAE (Treated Distillate Aromatic Extracts), MES (Mild Extraction Solva) shown in Kautschuk Gummi Kunststoffe 52 (12) 799 (1999) te), and RAE (Residual Aromatic Extracts).
Examples of the liquid rubber include, but are not limited to, liquid polybutadiene, liquid styrene-butazine rubber, and the like.
Examples of the resin include, but are not limited to, aromatic petroleum resins, coumaron/indene resins, terpene resins, rosin derivatives (including tung oil resins), tall oil, 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 resin, monoolefin oligomer, diolefin oligomer, aromatic hydrocarbon resin, aromatic petroleum resin, hydrogenated aromatic hydrocarbon resin, cycloaliphatic hydrocarbon resin, hydrogenated hydrocarbon resin, Examples include hydrocarbon resins, hydrogenated tung oil resins, hydrogenated oil resins, and esters of hydrogenated oil resins and monofunctional or polyfunctional alcohols.
These resins may be used alone or in combination of two or more. When hydrogenating, all unsaturated groups may be hydrogenated, or some may remain.
The amount of at least one selected from the group consisting of extender oil, liquid rubber, and resin is not particularly limited, but is preferably 1 to 60 parts by weight, and 10 to 60 parts by weight, based on 100 parts by weight of the conjugated diene polymer. parts, and even more preferably 15 to 37.5 parts by mass.

(Desolvation step)
A known method can be used to obtain the conjugated diene polymer (A1) from a polymer solution. For example, after separating the solvent by steam stripping, etc., the conjugated diene polymer is filtered out, and then dehydrated and dried to obtain the conjugated diene polymer, and concentrated in a flushing tank. Furthermore, there are methods of devolatilizing with a vent extruder or the like, and methods of directly devolatilizing with a drum dryer or the like.

(Composition of conjugated diene polymer composition)
The conjugated diene polymer composition of the present embodiment contains 20 to 99 parts by mass of the rubber component (A), which is a conjugated diene polymer having a glass transition temperature of -35°C or higher, and a glass transition temperature of -50°C or lower. Contains 1 to 90 parts by mass of rubber component (B).
The rubber component (A) preferably contains the conjugated diene polymer (A1) in an amount of 20% by mass or more based on the total mass of the rubber component (A).

(Rubber component (B))
The conjugated diene polymer composition of the present embodiment contains a rubber component (B) having a glass transition temperature of -50°C or lower.
By containing the rubber component (B), the rigidity at low temperatures when made into a vulcanizate is reduced, and snow performance is improved.
The lower limit of the glass transition temperature of the rubber component (B) is not particularly limited, but is preferably -100°C or higher. By setting the glass transition temperature to -100°C or higher, fracture strength tends to improve and wear resistance tends to be excellent.

The rubber component (B) is preferably at least one selected from the group consisting of natural rubber, high-cis polybutadiene rubber, and polyisoprene rubber.
Natural rubber is a substance whose main component is cis-type polyisoprene contained in the sap of rubber trees, and is produced by addition polymerization in vivo. Through visual inspection, they are graded and sorted into special grades from RSS1 to RSS5 according to international standards.
The above polyisoprene rubber is a type of synthetic rubber that is polyisoprene obtained by chemically polymerizing isoprene. There are some structural differences between polyisoprene rubber and natural rubber polyisoprene. First, the synthetic polyisoprene contained in polyisoprene rubber cannot currently contain 100% cis isomer, and contains a small amount of trans isomer. Natural rubber also contains trace amounts of proteins and fatty acids in addition to polyisoprene, but synthetic polyisoprene does not contain such impurities. Examples of the polyisoprene rubber include JSR IR1220 (trade name) manufactured by JSR Corporation.
The above-mentioned high-cis polybutadiene rubber is, for example, polybutadiene produced by solution polymerization using a Ziegler-Natta type coordination catalyst based on titanium, cobalt, and nickel, or in the presence of an alkyllithium compound. , refers to polybutadiene with a high amount of 1,4-cis bonds, such as UBEPOL BR manufactured by Ube Industries, Ltd.
From the viewpoint of improving the breaking strength when made into a vulcanizate, the rubber component (B) is preferably natural rubber. Natural rubber has a higher molecular weight than synthetic rubber and tends to have superior breaking strength. Furthermore, when made into a vulcanizate, natural rubber becomes incompatible with a conjugated diene polymer mainly composed of styrene-butadiene rubber.
When the conjugated diene polymer composition of the present embodiment contains a silica-based inorganic filler (C), which will be described later, silica generally has a high interaction with styrene-butadiene rubber, and when made into a vulcanizate. , the silica-based inorganic filler (C) tends to be localized in the styrene-butadiene rubber phase. Localization of the silica-based inorganic filler (C) in the styrene-butadiene phase tends to improve the rigidity of the styrene-butadiene phase and improve the fracture strength of the vulcanizate.

The conjugated diene polymer rubber composition of the present embodiment contains 20 to 99 parts by mass of rubber component (A) and 1 to 90 parts by mass of rubber component (B).
By containing 20 parts by mass or more of the rubber component (A), an excellent balance between fuel efficiency and wet performance can be obtained, and by containing 99 parts by mass or less, the filler can be sufficiently dispersed and the conjugated diene-based heavy The processability of the combined composition can be made practically sufficient.
In addition, from the viewpoint of improving snow performance, the rubber component (B) is 1 part by mass or more, and from the viewpoint of making the processability of the conjugated diene polymer composition practically sufficient, it is 90 parts by mass or less. be.

(Silica-based inorganic filler (C))
The conjugated diene polymer composition of this embodiment preferably contains a silica-based inorganic filler (C). From the viewpoint of developing rolling resistance, processability, cut resistance, and fatigue resistance, the blending amount of the silica-based inorganic filler is determined to be the same as the rubber component (A) and the rubber component ( The total amount of B) is preferably 0.5 to 300 parts by weight, more preferably 5 to 200 parts by weight, and even more preferably 20 to 100 parts by weight.

The silica-based inorganic filler (C) is not particularly limited, and for example, known ones can be used.
Specifically, the silica-based inorganic filler is preferably solid particles containing SiO ₂ or Si ₃ Al as a constituent unit, and more preferably contains SiO ₂ or Si ₃ Al as the main constituent unit. Here, "containing as a main component" means that the target component is contained in the silica-based inorganic filler in an amount of 50% by mass or more. The silica-based inorganic filler preferably contains SiO ₂ or Si ₃ Al in an amount of 70% by mass or more, more preferably 80% by mass or more.

More specific examples of the silica-based inorganic filler (C) include inorganic fibrous substances such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber.
Furthermore, a silica-based inorganic filler whose surface has been made hydrophobic or a mixture of a silica-based inorganic filler and an inorganic filler other than silica-based filler can also be used.
Among these, from the viewpoint of strength, abrasion resistance, etc., silica and glass fiber are preferred, and silica is more preferred. Examples of the silica include dry silica, wet silica, and synthetic silicate silica. Among these, wet silica is preferred.
Examples of the above-mentioned dry-processed silica include those obtained by reacting purified silicon tetrachloride in a high-temperature flame, which has higher purity than wet-processed silica, has finer particles, and has an extremely low moisture content.In general, silicone It is widely used as a rubber filler, a resin thickener, a reinforcing agent, a powder fluidizing agent, and a raw material for ceramics.
The above-mentioned wet silica is, for example, a fluffy and light white powder obtained by neutralizing an aqueous solution of sodium silicate made from silica sand to precipitate silica, filtering and drying it. It is generally used as a reinforcing filler for synthetic rubber, to prevent powdering and caking of liquids such as agricultural chemicals, to prevent printing ink from bleed through lightweight paper, to prevent thickening and dripping of paints and inks, as insulation materials, and as abrasives. It will be done.

In the conjugated diene polymer composition of the present embodiment, from the viewpoint of obtaining better rolling resistance characteristics, the nitrogen adsorption specific surface area of the silica-based inorganic filler determined by the BET adsorption method is 100 to 300 m ² /g. It is preferably from 170 to 250 m ² /g, and more preferably from 170 to 250 m 2 /g.

(Carbon black)
In the conjugated diene polymer composition of the present embodiment, the total of the rubber component (A) and the rubber component (B) is 100 parts by mass, and in addition to the silica-based inorganic filler (C), 0.00 parts of carbon black is further added. It is preferable to contain 5 to 100 parts by mass from the viewpoint of reinforcing tensile properties and the like.
The carbon black is not particularly limited, and for example, carbon blacks of various classes such as SRF, FEF, HAF, ISAF, and SAF can be used. Among these, from the viewpoint of extrusion moldability and rolling resistance characteristics, 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 more is preferred.
The amount of carbon black to be blended is 0.5 to 100 parts by mass, taking the total of rubber component (A) and rubber component (B) as 100 parts by mass, from the viewpoint of the balance of rolling resistance characteristics, extrusion processability, and cut resistance. Parts by weight are preferable, 3 to 100 parts by weight are more preferable, and even more preferably 5 to 50 parts by weight.

(metal oxide, metal hydroxide)
The conjugated diene polymer composition of this embodiment may contain a metal oxide or a metal hydroxide in addition to the silica-based inorganic filler and carbon black.
A metal oxide refers to a solid particle whose main constituent unit is the chemical formula MxOy (M represents a metal atom, and x and y each independently represent an integer from 1 to 6), and for example, Examples include alumina, titanium oxide, magnesium oxide, zinc oxide, and the like. Furthermore, a mixture of a metal oxide and an inorganic filler other than the metal oxide can also be used. The metal hydroxide is not particularly limited, and examples thereof include aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, and the like.

Although the method for identifying the type and content ratio of the rubber component contained in the conjugated diene polymer composition of this embodiment is not particularly limited, it can be identified by using NMR.
For example, in a previous report (JSR TECHNICAL REVIEW No.126/2019), by using solid 13C-NMR, styrene units, 1,2-vinyl, 1,4-vinyl, The ratio of 1,4-cis bonds and isoprene units can be quantitatively calculated.

(Silane coupling agent)
The conjugated diene polymer composition of this embodiment may contain a silane coupling agent. The silane coupling agent has an affinity or bonding group for each of the rubber component, the rubbery polymer, and the silica-based inorganic filler, and has the function of strengthening the interaction between them. There is. Generally, a compound having a sulfur bonding moiety, an alkoxysilyl group, and a silanol group moiety in one molecule is used.
Examples of the silane coupling agent include, but are not limited to, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, ethoxy (3-mercaptopropyl)bis(3,6,9,12,15-pentaoxaoctacosan-1-yloxy)silane [manufactured by Evonik Degussa: Si363], NXT-Z30, NXT-Z45, manufactured by Momentive, Silane coupling agents containing mercapto groups such as NXTZ60 and NXT silane, bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, bis -[2-(triethoxysilyl)-ethyl]-tetrasulfide, bis(3-triethoxysilylpropyl)trisulfide, bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide, bis(3-trisulfide) methoxysilylpropyl) tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane , 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyltetra Sulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzolyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis(3- Examples include diethoxymethylsilylpropyl)tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide, dimethoxymethylsilylpropylbenzothiazolyltetrasulfide, and the like. Among them, from the viewpoint of high reinforcing effect, bis-[3-(triethoxysilyl)-propyl]-disulfide, ethoxy(3-mercaptopropyl)bis(3,6,9,12,15-pentaoxaoctacosan) Silane coupling agents containing mercapto groups such as NXT-Z30, NXT-Z45, NXTZ60, and NXT silanes manufactured by Momentive, bis-[3-( Triethoxysilyl)-propyl]-tetrasulfide is preferred. These silane coupling agents can be used alone or in combination of two or more.

The blending amount of the silane coupling agent is determined between the rubber component (A) and the rubber component (B) from the viewpoint of making the effect of increasing the interaction between the rubber component and the silica-based inorganic filler more pronounced. The total amount is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, and even more preferably 1 to 15 parts by weight.

(Rubber softener)
The conjugated diene polymer composition of this embodiment may contain a rubber softener in order to improve processability. As the rubber softener, for example, mineral oil-based rubber softeners and liquid or low molecular weight synthetic softeners are suitable. The mineral oil-based rubber softener is also called process oil or extender oil, and is used to soften rubber, increase volume, and improve processability. The mineral oil-based rubber softener is a mixture of aromatic rings, naphthene rings, and paraffin chains, and those in which the number of carbon atoms in the paraffin chain accounts for 50% or more of the total carbon are called paraffin-based softeners. Those with a ring carbon number of 30 to 45% are called naphthenic, and those with an aromatic carbon number of more than 30% are called aromatic. As a rubber softener to be used with the modified conjugated diene-aromatic vinyl copolymer, one having an appropriate aromatic content is preferred because it tends to have good affinity with the copolymer.
The blending amount of the rubber softener is preferably 0 to 100 parts by mass, more preferably 10 to 90 parts by mass, and 30 to 90 parts by mass, based on 100 parts by mass of the total amount of rubber component (A) and rubber component (B). Parts by mass are more preferred.
By controlling the blending amount of the rubber softener to 100 parts by mass or less per 100 parts by mass of the total amount of rubber components (A) and (B), the occurrence of bleed-out can be suppressed and the conjugated diene polymer composition can be improved. It can prevent stickiness from forming on the surface.

(Kneading method)
This embodiment includes rubber components containing conjugated diene polymers (A) and (B), silica-based inorganic fillers, carbon black and other fillers, silane coupling agents, rubber softeners, and other additives. Methods for mixing the constituent materials of the conjugated diene polymer composition include, but are not limited to, the following methods, for example, an open roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, and a multi-screw extruder. Examples include a melt-kneading method using a general mixer such as a screw extruder, and a method in which each component is dissolved and mixed and then the solvent is removed by heating.
Among these, melt-kneading methods using rolls, Banbury mixers, kneaders, and extruders are preferred from the viewpoint of productivity and good kneading properties. Furthermore, either a method of kneading the constituent materials of the rubber composition of the present embodiment at once or a method of mixing them in a plurality of batches can be applied.

The conjugated diene polymer composition of this embodiment may be a vulcanized composition subjected to vulcanization treatment using 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, polymeric polysulfur compounds, and the like.
The content of the vulcanizing agent is preferably 0.01 parts by mass or more and 20 parts by mass or less, and 0.01 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the rubber component (A) and rubber component (B) containing the conjugated diene polymer (A1). .1 part by mass or more and 15 parts by mass or less is more preferable. As the vulcanization method, conventionally known methods can be applied, and the vulcanization temperature is preferably 120°C or more and 200°C or less, more preferably 140°C or more and 180°C or less.

During vulcanization, a vulcanization accelerator may be used if necessary.
As the vulcanization accelerator, conventionally known materials can be used, including, but not limited to, sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based. , thiourea-based, and dithiocarbamate-based vulcanization accelerators.
In addition, the vulcanization aid is not limited to the following, but includes, for example, zinc white and stearic acid.
The content of the vulcanization accelerator is preferably 0.01 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the rubber component (A) and rubber component (B) containing the conjugated diene polymer (A1). More preferably 0.1 parts by mass or more and 15 parts by mass or less.

The conjugated diene polymer composition of this embodiment may include other softeners, fillers, heat stabilizers, antistatic agents, weather stabilizers, Various additives such as anti-aging agents, colorants, and lubricants may also be used.
As other softeners, known softeners can be used.
Specific examples of other fillers include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate.
As the above-mentioned heat stabilizer, antistatic agent, weather stabilizer, anti-aging agent, colorant, and lubricant, known materials can be used.

〔tire〕
The conjugated diene polymer composition of this embodiment is suitably used as a rubber composition for tires. That is, the tire of this embodiment is made using the conjugated diene polymer composition of this embodiment.

The conjugated diene polymer composition for tires of this embodiment is not limited to the following, but includes, for example, various tires such as fuel-saving tires, all-season tires, high-performance tires, and studless tires: treads, carcass, and side tires. It can be used in various parts of the tire such as the wall and bead.
In particular, rubber compositions for tires have a good balance between low hysteresis loss and wet performance and have excellent wear resistance when made into a vulcanized product, so they are suitable for use in treads of fuel-efficient tires and high-performance tires. Suitably used.

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 to the following examples and comparative examples.
Various physical properties in Examples and Comparative Examples were measured by the methods shown below.
In the following Examples and Comparative Examples, the modified conjugated diene polymer is referred to as a "modified conjugated diene polymer." When it is unmodified, it is described as "unmodified conjugated diene polymer." Furthermore, modified and unmodified polymers may be collectively referred to as "conjugated diene polymers."

(Physical Properties 1) Amount of Bound Styrene Using a modified conjugated diene polymer as a sample, 100 mg of the sample was diluted to 100 mL with chloroform and dissolved to prepare a measurement sample. The amount of bound styrene (mass %) with respect to 100 mass % of the sample modified conjugated diene polymer was measured based on the absorption amount of ultraviolet absorption wavelength (near 254 nm) by the phenyl group of styrene (Shimadzu Corporation's spectrophotometer). Photometer "UV-2450").

(Physical property 2) Microstructure of butadiene moiety (1,2-vinyl bond amount)
Using a modified conjugated diene polymer as a sample, 50 mg of the sample was dissolved in 10 mL of carbon disulfide to prepare a measurement sample.
Using a solution cell, the infrared spectrum is measured in the range of 600 to 1000 cm ^-1 and the absorbance at a predetermined wave number is determined by Hampton's method (method described in R.R. Hampton, Analytical Chemistry 21, 923 (1949)). The microstructure of the butadiene moiety, that is, the amount of 1,2-vinyl bonds (mol%) was determined according to the calculation formula (Fourier transform infrared spectrophotometer "FT-IR230" manufactured by JASCO Corporation).

(Physical property 3) Molecular weight Measurement conditions 1: Using an unmodified conjugated diene polymer or a modified conjugated diene polymer as a sample, a GPC measurement device (manufactured by Tosoh Corporation) consisting of three columns connected with polystyrene gel as a packing material. Measure the chromatogram using an RI detector (trade name "HLC8020" manufactured by Tosoh Corporation) using a chromatogram (trade name "HLC-8320GPC"), and based on the calibration curve obtained using standard polystyrene, The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw/Mn) were determined.
THF (tetrahydrofuran) containing 5 mmol/L of triethylamine was used as the eluent. Three columns, manufactured by Tosoh Corporation under the trade name "TSKgel SuperMultiporeHZ-H", were connected, and a guard column manufactured by Tosoh Corporation under the trade name "TSKguardcolumn SuperMP (HZ)-H" was connected in front of the column.
10 mg of a measurement sample was dissolved in 10 mL of THF to obtain a measurement solution, and 10 μL of the measurement solution was injected into a GPC measuring device, and measurement was performed under the conditions of an oven temperature of 40° C. and a THF flow rate of 0.35 mL/min.
Among the various samples measured under measurement condition 1 above, samples whose molecular weight distribution (Mw/Mn) value was less than 1.6 were measured again under measurement condition 2 below. Tables 1 to 3 show the results of measurements under measurement conditions 1 for samples whose molecular weight distribution values were 1.6 or higher when measured under measurement conditions 1.

Measurement conditions 2: Using an unmodified conjugated diene polymer or a modified conjugated diene polymer as a sample, measure the chromatogram using a GPC measuring device connected to three columns using polystyrene gel as a packing material. The weight average molecular weight (Mw) and number average molecular weight (Mn) were determined based on a calibration curve using standard polystyrene.
THF containing 5 mmol/L of triethylamine was used as the eluent. The columns used were a guard column: "TSKguardcolumn SuperH-H" manufactured by Tosoh Corporation, and a column: "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000" manufactured by Tosoh Corporation.
An RI detector (trade name "HLC8020" manufactured by Tosoh Corporation) was used under the conditions of an oven temperature of 40° C. and a THF flow rate of 0.6 mL/min. 10 mg of a sample for measurement was dissolved in 20 mL of THF to prepare a measurement solution, and 20 μL of the measurement solution was injected into a GPC measuring device for measurement.
Tables 1 to 3 show the results of measurements under measurement conditions 2 for samples whose molecular weight distribution values were less than 1.6 when measured under measurement conditions 1.

(Property 4) Contraction factor (g')
Using a modified conjugated diene polymer as a sample, a GPC measuring device (trade name: "GPCmax VE-2001" manufactured by Malvern Co., Ltd.) having three columns connected with polystyrene gel as a filler was used. Measurements were carried out using three detectors connected in this order: a light scattering detector, an RI detector, and a viscosity detector (trade name "TDA305" manufactured by Malvern). Based on standard polystyrene, the light scattering The absolute molecular weight was determined from the measurement results of the detector and the RI detector, and the intrinsic viscosity was determined from the measurement results of the RI detector and the viscosity detector.
The linear polymer was used as having an intrinsic viscosity [η]=-3.883M ^0.771 , and the shrinkage factor (g') as a ratio of the intrinsic viscosity corresponding to each molecular weight was calculated.
THF containing 5 mmol/L of triethylamine was used as the eluent.
The columns used were those manufactured by Tosoh Corporation under the trade names "TSKgel G4000HXL,""TSKgelG5000HXL," and "TSKgel G6000HXL."
20 mg of a sample for measurement was dissolved in 10 mL of THF to prepare a measurement solution, and 100 μL of the measurement solution was injected into a GPC measuring device, and measurement was performed under the conditions of an oven temperature of 40° C. and a THF flow rate of 1 mL/min.

(Physical property 5) Polymer Mooney viscosity Using an unmodified conjugated diene polymer or a modified conjugated diene polymer as a sample, use a Mooney viscometer (trade name "VR1132" manufactured by Uejima Seisakusho Co., Ltd.) to measure according to JIS K6300. , Mooney viscosity was measured using an L-shaped rotor.
The measurement temperature was 110° C. when an unmodified conjugated diene polymer was used as a sample, and 100° C. when a modified conjugated diene polymer was used as a 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 and defined as Mooney viscosity (ML ₍₁₊₄₎ ).

(Physical property 6) Glass transition temperature (Tg)
Using a modified conjugated diene polymer as a sample, temperature was measured from -100°C to 20°C/min under helium flow of 50 mL/min using a differential scanning calorimeter "DSC3200S" manufactured by Mac Science in accordance with ISO 22768:2006. A DSC curve was recorded while increasing the temperature, and the peak top (inflection point) of the DSC differential curve was taken as the glass transition temperature.

(Physical property 7) Modification rate Using a modified conjugated diene polymer as a sample, it was measured by applying the property that the modified basic polymer component adsorbs to a GPC column using silica gel as a filler.
The amount of adsorption to the silica column is measured from the difference between the chromatogram measured using a polystyrene column and the chromatogram measured using a silica column for a sample solution containing a sample and a low molecular weight internal standard polystyrene, and the denaturation rate is determined. I asked for it.
Specifically, it is as shown below.
In addition, for samples whose molecular weight distribution value was 1.6 or more when measured under measurement condition 1 in (physical property 3) above, measurement was performed under measurement condition 3 below. Measurement was performed under measurement condition 1 of the above (physical property 3), and for samples whose molecular weight distribution value was less than 1.6, measurement was performed under measurement condition 4 below. The results are shown in Tables 1 to 3.

Preparation of sample solution: 10 mg of sample and 5 mg of standard polystyrene were dissolved in 20 mL of THF to prepare a sample solution.
Measurement conditions 3: GPC measurement conditions using a polystyrene column:
Using Tosoh Corporation's product name "HLC-8320GPC", 10 μL of the sample solution was injected into the device using THF containing 5 mmol/L triethylamine as the eluent, the column oven temperature was 40°C, and the THF flow rate was 0.35 mL/L. A chromatogram was obtained using an RI detector under the conditions of 10 minutes.
Three columns, manufactured by Tosoh Corporation under the trade name "TSKgel SuperMultiporeHZ-H", were connected, and a guard column manufactured by Tosoh Corporation under the trade name "TSKguardcolumn SuperMP (HZ)-H" was connected in front of the column.

Measurement conditions 4: GPC measurement conditions using a polystyrene column:
Using "HLC-8320GPC" manufactured by Tosoh Corporation, 20 μL of the sample solution was injected into the device and measured using THF containing 5 mmol/L triethylamine as the eluent.
The columns used were a guard column: "TSKguardcolumn SuperH-H" manufactured by Tosoh Corporation, and a column: "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000" manufactured by Tosoh Corporation. A chromatogram was obtained by measuring using an RI detector (HLC8020 manufactured by Tosoh Corporation) under the conditions of a column oven temperature of 40° C. and a THF flow rate of 0.6 mL/min.

GPC measurement conditions using a silica column: Using Tosoh's product name "HLC-8320GPC", using THF as the eluent, injecting 50 μL of the sample solution into the device, column oven temperature 40°C, THF flow rate. A chromatogram was obtained using an RI detector at 0.5 ml/min. Columns with the product name "Zorbax PSM-1000S", "PSM-300S", and "PSM-60S" are connected and used, and the product name "DIOL 4.6 x 12.5 mm 5 micron" is used as a guard column in the preceding stage. Connected and used.

Calculation method for denaturation rate: Taking the total peak area of the chromatogram using a polystyrene column as 100, the peak area of the sample is P1, the peak area of standard polystyrene is P2, and the peak area of the chromatogram using a silica column is The modification rate (%) was determined from the following formula, setting the total as 100, setting the peak area of the sample as P3, and setting the peak area of standard polystyrene as P4.
Denaturation rate (%) = [1-(P2×P3)/(P1×P4)]×100
(However, P1+P2=P3+P4=100)

(Physical property 8) Branching degree (Bn)
Using a modified conjugated diene polymer as a sample, a GPC measuring device (trade name: "GPCmax VE-2001" manufactured by Malvern Co., Ltd.) having three columns connected with polystyrene gel as a filler was used. The measurement was performed using three detectors connected in this order: a light scattering detector, an RI detector, and a viscosity detector (trade name "TDA305" manufactured by Malvern). Based on standard polystyrene, the absolute molecular weight was determined from the results of the light scattering detector and the RI detector, and the intrinsic viscosity was determined from the results of the RI detector and the viscosity detector.
The linear polymer was used as having an intrinsic viscosity [η]=-3.883M ^0.771 , and the shrinkage factor (g') as a ratio of the intrinsic viscosity corresponding to each molecular weight was calculated.
Thereafter, the degree of branching (Bn) defined as g'=6Bn/[(Bn+1)(Bn+2)] was calculated using the obtained contraction factor (g').
THF containing 5 mmol/L of triethylamine was used as the eluent.
The columns used were those manufactured by Tosoh Corporation under the trade names "TSKgel G4000HXL,""TSKgelG5000HXL," and "TSKgel G6000HXL."
20 mg of a sample for measurement was dissolved in 10 mL of THF to prepare a measurement solution, and 100 μL of the measurement solution was injected into a GPC measuring device, and measurement was performed under the conditions of an oven temperature of 40° C. and a THF flow rate of 1 mL/min.

(Physical property 9) Molecular weight (absolute molecular weight) measured by GPC-light scattering method
Using a modified conjugated diene polymer as a sample, a chromatogram was measured using a GPC-light scattering measurement device with three columns connected with polystyrene gel as a filler, and the results were determined based on the solution viscosity and light scattering method. The weight average molecular weight (Mw-i) was determined (also referred to as "absolute molecular weight").
A mixed solution of tetrahydrofuran and triethylamine (THF in TEA: prepared by mixing 5 mL of triethylamine with 1 L of tetrahydrofuran) was used as the eluent.
The columns were used by connecting a guard column: "TSKguardcolumn HHR-H" manufactured by Tosoh Corporation, and columns: "TSKgel G6000HHR", "TSKgel G5000HHR", and "TSKgel G4000HHR" manufactured by Tosoh Corporation.
A GPC-light scattering measuring device (trade name "Viscotek TDAmax" manufactured by Malvern) was used under the conditions of an oven temperature of 40° C. and a THF flow rate of 1.0 mL/min.
10 mg of a sample for measurement was dissolved in 20 mL of THF to prepare a measurement solution, and 200 μL of the measurement solution was injected into a GPC measuring device for measurement.

[Conjugated diene polymer]
(Modified conjugated diene polymer (sample 1))
A tank-type reactor with an internal volume of 10 L, a ratio of internal height (L) to diameter (D) (L/D) of 4.0, an inlet at the bottom, an outlet at the top, and a stirrer. Two tank-type pressure vessels each having a stirrer and a jacket for temperature control were connected as a polymerization reactor.
1,3-butadiene, from which water had been removed in advance, was mixed at 18.6 g/min, styrene at 10.0 g/min, and n-hexane at 175.2 g/min. In a static mixer installed in the middle of the pipe that supplies this mixed solution to the inlet of the reaction group, n-butyllithium for inactivating residual impurities was added at a rate of 0.103 mmol/min and mixed, and then added to the bottom of the reaction group. Supplied continuously. Furthermore, 2,2-bis(2-oxolanyl)propane as a polar substance was mixed vigorously with a stirrer at a rate of 0.081 mmol/min, and n-butyllithium was mixed as a polymerization initiator at a rate of 0.143 mmol/min. The reactor was supplied to the bottom of the reactor, and the reactor internal temperature was maintained at 67°C.
The polymer solution was continuously extracted from the top of the first reactor, continuously supplied to the bottom of the second reactor, where the reaction was continued at 70°C, and further supplied to the static mixer from the top of the second reactor. When the polymerization is sufficiently stable, 0.0190 mmol/min of trimethoxy(4-vinylphenyl)silane (abbreviated as "BS-1" in the table) is added as a branching agent from the bottom of the second reactive group. When the polymerization reaction and branching reaction were stabilized, a small amount of the conjugated diene polymer solution before addition of the modifier was extracted and the antioxidant (BHT) was added at a concentration of 0.2 g per 100 g of polymer. After the addition, the solvent was removed, and the Mooney viscosity at 110°C and various molecular weights were measured. Other physical properties are also shown in Table 1.

Next, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (in the table, " A) was continuously added at a rate of 0.0360 mmol/min, mixed using a static mixer, and subjected to a modification reaction. At this time, the time until the modifier was added to the polymerization solution flowing out from the outlet of the reactor was 4.8 minutes, and the temperature was 68°C. The difference was 2°C. An antioxidant (BHT) was continuously added to the modified polymer solution at a rate of 0.055 g/min (n-hexane solution) at a rate of 0.2 g per 100 g of the polymer to complete the modification reaction. Simultaneously with the antioxidant, 37.5 g of oil (JOMO Process NC140, manufactured by JX Nippon Oil & Energy Corporation) was continuously added to 100 g of the polymer, and mixed using a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (Sample 1). Table 1 shows the physical properties of Sample 1.

(Modified conjugated diene polymer (sample 2))
The modifier was 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table). ), and the amount added was changed to 0.0250 mmol/min, but in the same manner as (Sample 1), a modified conjugated diene polymer (Sample 2) was obtained. Table 1 shows the physical properties of Sample 2.

(Modified conjugated diene polymer (sample 3))
The modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (in the table, A modified conjugated diene polymer (Sample 3) was obtained in the same manner as (Sample 1) except that the amount added was changed to 0.0190 mmol/min. Table 1 shows the physical properties of Sample 3.

(Modified conjugated diene polymer (sample 4))
The modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (in the table, A modified conjugated diene polymer (Sample 4) was obtained in the same manner as (Sample 1) except that the amount added was changed to 0.0160 mmol/min. Table 1 shows the physical properties of Sample 4.

(Modified conjugated diene polymer (sample 5))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to dimethylmethoxy(4-vinylphenyl)silane (abbreviated as "BS-2" in the table), and the amount added was changed to 0.0350 mmol/min. Except for this, a modified conjugated diene polymer (Sample 5) was obtained in the same manner as (Sample 1). Table 1 shows the physical properties of Sample 5.

(Modified conjugated diene polymer (sample 6))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to dimethylmethoxy(4-vinylphenyl)silane (abbreviated as "BS-2" in the table), and the amount added was changed to 0.0350 mmol/min. The modifier was 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table). ), and the amount added was changed to 0.0250 mmol/min, but in the same manner as (Sample 1), a modified conjugated diene polymer (Sample 6) was obtained. Table 1 shows the physical properties of Sample 6.

(Modified conjugated diene polymer (sample 7))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to dimethylmethoxy(4-vinylphenyl)silane (abbreviated as "BS-2" in the table), and the amount added was changed to 0.0350 mmol/min. The modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (in the table, A modified conjugated diene polymer (Sample 7) was obtained in the same manner as (Sample 1) except that the amount added was changed to 0.0160 mmol/min. Table 1 shows the physical properties of Sample 7.

(Modified conjugated diene polymer (sample 8))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-(dimethylmethoxysilyl)phenyl)ethylene (abbreviated as "BS-3" in the table), and the amount added was 0. A modified conjugated diene polymer (Sample 8) was obtained in the same manner as (Sample 1) except that the rate was changed to .0120 mmol/min. Table 1 shows the physical properties of Sample 8.

(Modified conjugated diene polymer (sample 9))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-(dimethylmethoxysilyl)phenyl)ethylene (abbreviated as "BS-3" in the table), and the amount added was 0. .0120 mmol/min, and the modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (in the table , abbreviated as "B") and the amount added was changed to 0.0250 mmol/min, a modified conjugated diene polymer (Sample 9) was obtained in the same manner as (Sample 1). Table 1 shows the physical properties of Sample 9.

(Modified conjugated diene polymer (sample 10))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-(dimethylmethoxysilyl)phenyl)ethylene (abbreviated as "BS-3" in the table), and the amount added was 0. .0120 mmol/min, and the modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3 - Modified conjugated diene polymer (Sample 10) was prepared in the same manner as (Sample 1) except that propanediamine (abbreviated as "C" in the table) was used and the amount added was changed to 0.0160 mmol/min. ) was obtained. Table 1 shows the physical properties of sample 10.

(Modified conjugated diene polymer (sample 11))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-trimethoxysilylphenyl)ethylene (abbreviated as "BS-4" in the table), and the amount added was 0.0210 mmol. A modified conjugated diene polymer (Sample 11) was obtained in the same manner as (Sample 1) except that the time was changed to /min. Table 2 shows the physical properties of Sample 11.

(Modified conjugated diene polymer (sample 12))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-trimethoxysilylphenyl)ethylene (abbreviated as "BS-4" in the table), and the amount added was 0.0210 mmol. /min, and the modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (in the table, A modified conjugated diene polymer (Sample 12) was obtained in the same manner as (Sample 1) except that the amount added was changed to 0.0250 mmol/min. Table 2 shows the physical properties of Sample 12.

(Modified conjugated diene polymer (sample 13))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-trimethoxysilylphenyl)ethylene (abbreviated as "BS-4" in the table), and the amount added was 0.0210 mmol. /min, and the modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propane. Modified conjugated diene polymer (Sample 13) was prepared in the same manner as (Sample 1) except that diamine (abbreviated as "C" in the table) was used and the amount added was changed to 0.0160 mmol/min. Obtained. Table 2 shows the physical properties of Sample 13.

(Modified conjugated diene polymer (sample 14))
Modification was carried out in the same manner as (Sample 1) except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to trichloro(4-vinylphenyl)silane (abbreviated as "BS-5" in the table). A conjugated diene polymer (Sample 14) was obtained. Table 2 shows the physical properties of Sample 14.

(Modified conjugated diene polymer (sample 15))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to trichloro(4-vinylphenyl)silane (abbreviated as "BS-5" in the table), and the modifier was changed to 2,2-dimethoxy-1-(3 -Trimethoxysilylpropyl)-1-aza-2-silacyclopentane was replaced with tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table), and the amount added was 0.0250 mmol/min. A modified conjugated diene polymer (Sample 15) was obtained in the same manner as (Sample 1) except that Table 2 shows the physical properties of Sample 15.

(Modified conjugated diene polymer (sample 16))
The branching agent was changed from trimethoxy(4-vinylphenyl)silane to trichloro(4-vinylphenyl)silane (abbreviated as "BS-5" in the table), and the modifier was changed to 2. ,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (in the table, "C" and A modified conjugated diene polymer (Sample 16) was obtained in the same manner as (Sample 1) except that the amount added was changed to 0.0160 mmol/min. Table 2 shows the physical properties of sample 16.

(Modified conjugated diene polymer (sample 17))
The amount of trimethoxy(4-vinylphenyl)silane (abbreviated as "BS-1" in the table) as a branching agent was changed to 0.0100 mmol/min, and the modifier was changed to 2,2-dimethoxy-1-(3 -Trimethoxysilylpropyl)-1-aza-2-silacyclopentane was replaced with tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table), and the amount added. A modified conjugated diene polymer (Sample 17) was obtained in the same manner as (Sample 1) except that the amount was changed to 0.0160 mmol/min. Table 2 shows the physical properties of sample 17.

(Modified conjugated diene polymer (sample 18))
The amount of trimethoxy(4-vinylphenyl)silane (abbreviated as "BS-1" in the table) as a branching agent was changed to 0.0250 mmol/min, and the modifying agent was changed to 2,2-dimethoxy-1-(3 -Trimethoxysilylpropyl)-1-aza-2-silacyclopentane was replaced with tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table), and the amount added. A modified conjugated diene polymer (Sample 18) was obtained in the same manner as (Sample 1) except that the amount was changed to 0.0160 mmol/min. Table 2 shows the physical properties of Sample 18.

(Modified conjugated diene polymer (sample 19))
The amount of trimethoxy(4-vinylphenyl)silane (abbreviated as "BS-1" in the table) as a branching agent was changed to 0.0350 mmol/min, and the modifying agent was changed to 2,2-dimethoxy-1-(3 -Trimethoxysilylpropyl)-1-aza-2-silacyclopentane was replaced with tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table), and the amount added. A modified conjugated diene polymer (Sample 19) was obtained in the same manner as (Sample 1) except that the amount was changed to 0.0160 mmol/min. Table 2 shows the physical properties of Sample 19.

(Conjugated diene polymer (sample 20))
The modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetraethoxysilane (abbreviated as "D" in the table) as a coupling agent. A conjugated diene polymer (Sample 20) was obtained in the same manner as (Sample 1) except that the addition amount was changed to 0.0250 mmol/min. Table 2 shows the physical properties of sample 20.

(Conjugated diene polymer (sample 21))
An unmodified conjugated diene polymer (Sample 21) was obtained in the same manner as (Sample 1) except that no modifier was added. Table 2 shows the physical properties of Sample 21.
In Table 2, the amount of bound styrene, amount of vinyl bonds, glass transition temperature, degree of branching, and absolute molecular weight are listed in the column of modified conjugated diene polymer.

(Modified conjugated diene polymer (sample 22))
A tank-type reactor with an internal volume of 10 L, a ratio of internal height (L) to diameter (D) (L/D) of 4.0, an inlet at the bottom, an outlet at the top, and a stirrer. Two tank-type pressure vessels each having a stirrer and a jacket for temperature control were connected as a polymerization reactor.
1,3-butadiene, from which water had been removed in advance, was mixed at 18.6 g/min, styrene at 10.0 g/min, and n-hexane at 175.2 g/min. In a static mixer installed in the middle of the pipe that supplies this mixed solution to the inlet of the reaction group, n-butyllithium for inactivating residual impurities was added at a rate of 0.103 mmol/min and mixed, and then added to the bottom of the reaction group. Supplied continuously. Furthermore, 2,2-bis(2-oxolanyl)propane as a polar substance was mixed vigorously with a stirrer at a rate of 0.081 mmol/min, and n-butyllithium was mixed as a polymerization initiator at a rate of 0.143 mmol/min. The reactor was supplied to the bottom of the reactor, and the reactor internal temperature was maintained at 67°C.
The polymer solution was continuously extracted from the top of the first reactor, continuously supplied to the bottom of the second reactor, where the reaction was continued at 70°C, and further supplied to the static mixer from the top of the second reactor. When the polymerization was sufficiently stabilized, a small amount of the polymer solution before addition of the modifier was extracted, an antioxidant (BHT) was added at a concentration of 0.2 g per 100 g of the polymer, the solvent was removed, and a Mooney tube was heated at 110°C. The viscosity and various molecular weights were measured. Other physical properties are also shown in Table 3.

Next, a modifier was added to the polymer solution flowing out from the outlet of the reactor.
Continuously add 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (abbreviated as "A" in the table) at a rate of 0.0360 mmol/min. The mixture was mixed using a static mixer to perform a denaturation reaction. At this time, the time until the modifier was added to the polymerization solution flowing out from the outlet of the reactor was 4.8 minutes, and the temperature was 68°C. The difference was 2°C. An antioxidant (BHT) was continuously added to the modified polymer solution at a rate of 0.055 g/min (n-hexane solution) at a rate of 0.2 g per 100 g of the polymer to complete the modification reaction. Simultaneously with the antioxidant, 37.5 g of oil (JOMO Process NC140, manufactured by JX Nippon Oil & Energy Corporation) was continuously added to 100 g of the polymer, and mixed using a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (Sample 22). Table 3 shows the physical properties of sample 22.

(Modified conjugated diene polymer (sample 23))
The modifier was 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table). ), and a modified conjugated diene polymer (Sample 23) was obtained in the same manner as (Sample 22) except that the amount added was changed to 0.0250 mmol/min. Table 3 shows the physical properties of sample 23.

(Modified conjugated diene polymer (sample 24))
The modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (in the table, A modified conjugated diene polymer (Sample 24) was obtained in the same manner as (Sample 22) except that the amount added was changed to 0.0190 mmol/min. Table 3 shows the physical properties of sample 24.

(Modified conjugated diene polymer (sample 25))
Change the amount of 2,2-bis(2-oxolanyl)propane added as a polar substance to a rate of 0.105 mmol/min, and change the amount of n-butyllithium added as a polymerization initiator to a rate of 0.188 mmol/min. , the amount of trimethoxy(4-vinylphenyl)silane (abbreviated as "BS-1" in the table) as a branching agent was changed to 0.0350 mmol/min, and the amount of 2,2-dimethoxy-1- as a modifier was changed to 0.0350 mmol/min. The modified conjugated diene polymer (sample 25) was obtained. Table 3 shows the physical properties of sample 25.

(Modified conjugated diene polymer (sample 26))
A tank-type reactor with an internal volume of 0.5L, a ratio of internal height (L) to diameter (D) (L/D) of 4.0, an inlet at the bottom, an outlet at the top, and an agitator. One tank-type pressure vessel with a stirrer and a jacket for temperature control, an internal volume of 10 L, and a ratio of internal height (L) to diameter (D) (L/D) of 4.0. Two tank-type pressure vessels with an inlet at the bottom and an outlet at the top, a stirrer and a jacket for temperature control are connected as polymerization reactors, and a total of three reactors are connected. Ta.
Using n-hexane from which water has been removed in advance at a rate of 175.2 g/min, 2,2-bis(2-oxolanyl)propane as a polar substance at a rate of 0.081 mmol/min, and n-butyllithium as a polymerization initiator. was added at a rate of 0.143 mmol/min, n-butyllithium for residual impurity inactivation treatment was added at a rate of 0.103 mmol/min, and trimethoxy(4-vinylphenyl)silane (in the table, "BS- 1") at a rate of 0.0190 mmol/min, vigorously mixed with a stirrer, and maintaining the reactor internal temperature at 67° C. to construct a polymer block component.
The polymer solution was continuously extracted from the top of the first reactor and continuously supplied to the bottom of the second reactor, and 18.6 g/min of 1,3-butadiene and 10 g/min of styrene were removed from the water in advance. The mixture was fed from the bottom of the second vessel and mixed under the condition of 0 g/min.
The reaction continues at 70°C, and the polymer solution is continuously extracted from the top of the second reactor, continuously supplied to the bottom of the third reactor, and further supplied to the static mixer from the top of the third reactor. did. This mixed solution was supplied to a static mixer provided in the middle of the piping that was supplied to the inlet of the third reactor. When the polymerization was sufficiently stabilized, a small amount of the polymer solution before addition of the modifier was extracted, an antioxidant (BHT) was added at a concentration of 0.2 g per 100 g of the polymer, the solvent was removed, and a Mooney tube was heated at 110°C. The viscosity and various molecular weights were measured. Other physical properties are also shown in Table 3.

Next, a modifier was added to the polymer solution flowing out from the outlet of the reactor.
Continuously add 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (abbreviated as "A" in the table) at a rate of 0.0360 mmol/min. The mixture was mixed using a static mixer to perform a denaturation reaction. At this time, the time until the modifier was added to the polymerization solution flowing out from the outlet of the reactor was 4.8 minutes, and the temperature was 68°C. The difference was 2°C. An antioxidant (BHT) was continuously added to the modified polymer solution at a rate of 0.055 g/min (n-hexane solution) at a rate of 0.2 g per 100 g of the polymer to complete the modification reaction. Simultaneously with the antioxidant, 37.5 g of oil (JOMO Process NC140, manufactured by JX Nippon Oil & Energy Corporation) was continuously added to 100 g of the polymer, and mixed using a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (Sample 26). Table 3 shows the physical properties of sample 26.

[Examples 1 to 21] and [Comparative Examples 1 to 5]
Using the conjugated diene polymers shown in Tables 1 to 3 above (samples 1 to 26) and natural rubber as raw material rubbers, conjugated diene polymer compositions containing the respective raw material rubbers were obtained according to the formulations shown below. .
(Example 1)
Conjugated diene polymer (sample 1): 70 parts by mass (without oil)
Natural rubber (glass transition temperature: -70°C): 30 parts by mass Silica (product name: "Ultrasil 7000GR" manufactured by Evonik Degussa) Nitrogen adsorption specific surface area 170 m2/g): 50.0 parts by mass Carbon black (manufactured by Tokai Carbon Co., Ltd.) Product name "Seest KH (N339)"): 5.0 parts by mass Silane coupling agent (product name "Si75" manufactured by Evonik Degussa, bis(triethoxysilylpropyl) disulfide): 6.0 parts by mass S-RAE Oil (trade name "Process NC140" manufactured by JX Nippon Oil & Energy Corporation): 37.5 parts by mass Zinc white: 2.5 parts by mass Stearic acid: 1.0 parts by mass Anti-aging agent (N-(1,3- (dimethylbutyl)-N'-phenyl-p-phenylenediamine): 2.0 parts by mass Sulfur: 2.2 parts by mass Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazylsulfinamide): 1.7 parts by mass Parts Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass Total: 239.4 parts by mass

(Example 22)
A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw material rubber was changed to the formulation shown below.
Conjugated diene polymer (sample 1): 50 parts by mass (without oil)
Natural rubber: 50 parts by mass

(Example 23)
A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw material rubber was changed to the formulation shown below.
Conjugated diene polymer (sample 1): 20 parts by mass (without oil)
Natural rubber: 80 parts by mass

(Example 24)
A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw material rubber was changed to the formulation shown below.
Conjugated diene polymer (sample 1): 90 parts by mass (without oil)
Natural rubber: 10 parts by mass

(Example 25)
A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw material rubber was changed to the formulation shown below.
Conjugated diene polymer (sample 1): 99 parts by mass (without oil)
Natural rubber: 1 part by mass

(Example 26)
A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw material rubber was changed to the formulation shown below.
Conjugated diene polymer (sample 1): 70 parts by mass (without oil)
High-cis polybutadiene rubber (product “BR150” manufactured by Ube Industries, Ltd.): 30 parts by mass

(Comparative example 7)
A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw material rubber was changed to the formulation shown below.
Conjugated diene polymer (sample 1): 100 parts by mass (without oil)

(Comparative example 8)
A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw material rubber was changed to the formulation shown below.
Conjugated diene polymer (sample 1): 10 parts by mass (oil removed)
Natural rubber: 80 parts by mass

(Comparative Example 9)
A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw material rubber was changed to the formulation shown below.
Styrene-butadiene rubber (manufactured by Asahi Kasei Co., Ltd., Tuffden 1834, glass transition temperature: -70°C): 70 parts by mass (oil removed)
Natural rubber: 30 parts by mass

(Comparative Example 10)
A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw material rubber was changed to the formulation shown below.
Conjugated diene polymer (sample 1): 70 parts by mass (without oil)
Styrene-butadiene rubber (manufactured by Arlanxeo, BUNA2353, glass transition temperature: -48°C): 30 parts by mass (oil removed)

The above materials were kneaded by the following method to obtain a rubber composition. Raw rubber (samples 1 to 26, natural Rubber), fillers (silica 1, silica 2, carbon black), silane coupling agent, process oil, zinc white, and stearic acid were kneaded. At this time, the temperature of the closed mixer was controlled, and each rubber composition (compound) was obtained at a discharge temperature of 155 to 160°C.

Next, in the second stage of kneading, the mixture obtained above was cooled to room temperature, an antiaging agent was added, and the mixture was kneaded again in order to improve the dispersion of silica. In this case as well, the discharge temperature of the blend was adjusted to 155-160° C. by temperature control of the mixer. After cooling, sulfur and vulcanization accelerators 1 and 2 were added and kneaded using open rolls set at 70° C. as the third stage of kneading. Thereafter, it was molded and vulcanized in a vulcanization press at 160° C. for 20 minutes. The characteristics of 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 7.

[Evaluation of characteristics]
(Evaluation 1) Mooney viscosity of the compound Using the compound obtained above after the second stage kneading and before the third stage kneading as a sample, using a Mooney viscometer, based on JIS K6300-1, After preheating at 130° C. for 1 minute, the viscosity was measured after rotating the rotor at 2 revolutions per minute for 4 minutes. The results of Comparative Example 1 were set as 100 and indexed. The smaller the index, the better the workability.

(Evaluation 2) Viscoelastic parameters Viscoelastic parameters were measured in torsion mode using a viscoelasticity tester "ARES" manufactured by Rheometrics Scientific. Each measurement value was expressed as an index, with the result for the rubber composition of Comparative Example 1 set 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 performance. The larger the index, the better the wet performance. Further, tan δ measured at 50° C., frequency of 10 Hz, and strain of 3% was used as an index of fuel efficiency. The smaller the index, the better the fuel efficiency.
Furthermore, the storage modulus (G') measured at -20° C. at a frequency of 10 Hz and a strain of 1% was used as an index of snow performance. The smaller the index, the better the snow performance.

(Evaluation 3) Tensile strength and tensile elongation Tensile strength and tensile elongation were measured according to the tensile test method of JIS K6251, and the results of Comparative Example 1 were set as 100 and indexed. The larger the index, the better the tensile strength and tensile elongation, and the better the breaking strength.

(Evaluation 4) Wear resistance Using an Akron abrasion tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.), the amount of wear was measured at a load of 44.4N and 1000 revolutions in accordance with JIS K6264-2, and the results of Comparative Example 1 were was set as 100 and indexed. The larger the index, the better the wear resistance.

As shown in Tables 4 to 7, it was confirmed that Examples 1 to 26 had an excellent balance between wet performance and snow performance when made into vulcanizates, compared to Comparisons 1 to 10.
It was also confirmed that the compound had a low Mooney viscosity when made into a vulcanizate, exhibited good processability, and had good abrasion resistance.
It was also confirmed that it had practically sufficient breaking strength when made into a vulcanized product.

The conjugated diene polymer composition of the present invention can be used industrially as a material for tire treads, interior and exterior parts of automobiles, anti-vibration rubber, belts, footwear, foams, various industrial products, etc. .

Claims (10)

Rubber component (A) 20-99 which is a conjugated diene polymer with a glass transition temperature of -35°C or higher
Mass part;
A conjugated diene polymer composition containing 1 to 90 parts by mass of a rubber component (B) having a glass transition temperature of −50° C. or lower,
The rubber component (A) contains a conjugated diene polymer (A1) containing an aromatic vinyl compound and a conjugated diene compound,
The conjugated diene polymer (A1) is a conjugated diene having a star-shaped polymer structure with three or more branches.
system polymer, in which at least one star-shaped branch chain has an alkoxysilyl group or a halo group.
It has a moiety derived from a vinyl monomer containing a silyl group, and the alkoxysilyl group or halo
The portion derived from the vinyl monomer containing a silyl group has an additional main chain branched structure, and has an absolute molecular weight of 40 x 10 ⁴ or more and 5000 x 10 ⁴ or less as measured by GPC-light scattering method with a viscosity detector. and the degree of branching (Bn) as measured by the GPC-light scattering measurement method with a viscosity detector is 8 or more,
Conjugated diene polymer composition. The conjugated diene polymer (A1) is a modified conjugated diene polymer having a modification rate of 60% by mass or more,
The conjugated diene polymer composition according to claim 1. The conjugated diene polymer composition according to claim 1 or 2, wherein the rubber component (B) is natural rubber. The portion derived from the vinyl monomer containing the alkoxysilyl group or halosilyl group of the conjugated diene polymer (A1) is a monomer unit based on a compound represented by the following formula (1) or (2). and has a branching point of a polymer chain by a monomer unit based on a compound represented by the following formula (1) or (2),
The conjugated diene polymer composition according to claim 1 , wherein at least one end of the conjugated diene polymer (A1) is coupled using a coupling agent.

(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 a portion thereof may have a branched structure.
R ² to R ³ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a portion thereof may have a branched structure.
When a plurality of R ¹ to R ³ exist, each of them is independent.
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) indicates 3. )
(In formula (2), R ² to R ⁵ are each independently an alkyl group having 1 to 20 carbon atoms or a carbon number 6 to
20 aryl groups, and a portion thereof may have a branched structure. When a plurality of R ² to R ⁵ are present, each of them is 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) indicates 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.
(m+n+l) indicates 3. ) In the formula (1), R ¹ is a hydrogen atom, m = 0, a conjugated diene polymer (A1) having a monomer unit based on the compound represented by the formula (1), The conjugated diene polymer composition according to claim 4 . A claim comprising a conjugated diene polymer (A1) having a monomer unit based on a compound represented by the formula (2), where m = 0 and b = 0. Item 4. Conjugated diene polymer composition according to item 4 . In the formula (1), R ¹ is a hydrogen atom, m=0, and l=0.
The conjugated diene polymer composition according to claim 4 or 5 , comprising a conjugated diene polymer (A1) having a monomer unit based on a compound represented by: In the formula (2), a conjugated diene polymer (A1 ) The conjugated diene polymer composition according to claim 4 or 6 , comprising: In the above formula (1), R ¹ is a hydrogen atom, l=0, and n=3, the above formula (1)
The conjugated diene polymer composition according to any one of claims 4, 5, and 7 , comprising a conjugated diene polymer (A1) having a monomer unit based on a compound represented by: A tire containing the conjugated diene polymer composition according to any one of claims 1 to 9 .