JP7387247B2 - Modified conjugated diene polymer, modified conjugated diene polymer composition, and tire - Google Patents

Description

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

In recent years, from the viewpoint of resource conservation and environmental measures, there has been an increasing demand for tires with low fuel consumption, and low heat generation and low fuel consumption (low hysteresis) are becoming more important.
In order to improve low hysteresis, it is common to use a rubber composition with low heat build-up to lower rolling resistance.
As a rubber composition that meets these demands, there is a rubber composition that uses silica as a reinforcing filler contained in the rubber composition, and has a combination of low heat build-up and braking performance on wet roads (wet skid resistance). It is known for its excellent balance.
However, silica with a hydrophilic surface has the problem of particles agglomerating together in a composition obtained by blending it with a highly hydrophobic conjugated diene rubber, resulting in poor dispersibility. are doing. Therefore, by introducing a functional group that interacts with the silica surface into the conjugated diene rubber, it increases its affinity with the silica surface and improves the dispersibility of silica in the rubber composition, resulting in low hysteresis. Efforts are being made to make it even better.

For example, Patent Documents 1 and 2 disclose modified diene conjugated rubbers obtained by reacting amino group-containing alkoxysilanes with polymer terminals, and compositions of these and silica.
Further, Patent Document 3 discloses a modified conjugated diene rubber obtained by initiating polymerization using an initiator containing an amino group and reacting an alkoxysilane containing an amino group with the terminal of the polymer. There is.

Japanese Patent Application Publication No. 2004-18795 Korean Publication Patent No. 2016-0063227 US Patent Application Publication No. 2016/0159957

As the performance of automobiles increases, the demand for high-performance tires with high dynamic performance is increasing, and there is a growing demand for improved performance for safe driving, especially under high-speed conditions.
When automobiles run at high speeds, tires are exposed to high temperatures due to the generation of frictional heat, so there is a particular need for the development of rubber compositions that have excellent fracture properties at high temperatures as rubber materials for such tires.
However, although tires using the rubber compositions described in Patent Documents 1 to 3 mentioned above have the effect of low heat generation, they still do not have sufficient breaking characteristics at high temperatures for tires for high-speed automobiles. The problem is that there is no.

Therefore, in view of the problems of the prior art described above, it is an object of the present invention to provide a modified conjugated diene polymer that has excellent fracture properties at high temperatures when made into a vulcanized product.

As a result of intensive studies to solve the above-mentioned problems of the prior art, the present inventors found that the Mooney relaxation rate at 110°C is more than a predetermined value, the modification rate is more than a predetermined value, and the weight average molecular weight It was discovered that a modified conjugated diene polymer having a molecular weight distribution within a predetermined range and a molecular weight distribution within a predetermined range has good fracture characteristics at high temperatures when made into a vulcanizate, and the present invention was completed. .
That is, the present invention is as follows.

[1]
Mooney relaxation rate at 110°C is 0.52 or more,
The modification rate is 75% by mass or more,
The weight average molecular weight (Mw) is 500,000 or more and 3,000,000 or less,
The molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) is 1.5 or more and 3.5 or less,
Modified conjugated diene polymer.
[2]
The modified conjugated diene polymer according to the above [1], wherein the content of nitrogen atoms is 25 mass ppm or more based on the total amount of the modified conjugated diene polymer.
[3]
The modified conjugated diene polymer described in [1] or [2] above, which is represented by the following general formula (A) or (B).

(In general formula (A), R ²¹ to R ²⁴ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ²⁵ and R ²⁶ each independently represent , represents an alkylene group having 1 to 20 carbon atoms, and R ²⁷ represents a hydrogen atom, a silyl group substituted with a hydrocarbon, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. a , b, c, and d are each independently an integer of 1 or 2, and b and d are integers of 0 or 1, as long as (a+b) and (c+d) are each independently an integer of 2 or less. (Polym) represents a conjugated diene polymer, and at least one terminal thereof is a functional group represented by any of the following general formulas (1) to (4). ²¹ and R ²³ and multiple (Polym) are each independent and may be the same or different.)

(In the general formula (B), R ²⁸ to R ³³ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ³⁴ to R ³⁶ each independently , represents an alkylene group having 1 to 20 carbon atoms.a, b, c, d, e, and f are a, as long as (a+b), (c+d), and (e+f) each independently represent an integer of 2 or less; c and e each independently represent an integer of 1 or 2, and b, d, and f each independently represent an integer of 0 or 1. (Polym) represents a conjugated diene polymer, and at least one terminal thereof is a functional group represented by any of the following general formulas (1) to (4). R ²⁸ , R ³⁰ , and R ³² when a plurality exists, and (Polym) when a plurality exists, each independently (They may be the same or different.)

(In general formula (1), R ¹⁰ and R ¹¹ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group. R ¹⁰ and R ¹¹ may be bonded together to form a cyclic structure with adjacent nitrogen atoms, and in this case, R ¹⁰ and R ¹¹ have 5 carbon atoms. ~12 alkyl groups, and a portion thereof may have an unsaturated bond or a branched structure.The protecting group is an alkyl-substituted silyl group.)

(In general formula (2), R ¹² and R ¹³ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group. At least one selected from the group consisting of:
R ¹² and R ¹³ may be bonded together to form a cyclic structure with an adjacent nitrogen atom, and in this case R ¹² and R ¹³ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof is unsaturated. It may have a saturated bond or a branched structure.
Note that the protecting group is an alkyl-substituted silyl group.
R ¹⁴ represents an alkylene group having 1 to 30 carbon atoms which may have an aliphatic or aromatic substituent, or a conjugated diene polymer chain having 1 to 20 carbon atoms. )

(In general formula (3), R ¹⁵ and R ¹⁶ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 20 carbon atoms, and a protecting group. At least one selected from the group consisting of:
R ¹⁵ and R ¹⁶ may be bonded together to form a cyclic structure with an adjacent nitrogen atom, and in this case, R ¹⁵ and R ¹⁶ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof is branched. It may have a structure. Note that the protecting group is an alkyl-substituted silyl group. )

(In the general formula (4), R ¹⁷ represents a hydrocarbon group having 2 to 10 carbon atoms, and may have an unsaturated bond or a branched structure in a portion thereof. R ¹⁸ represents a hydrocarbon group having 1 to 10 carbon atoms. 12 alkyl groups or protective groups, and a portion thereof may have a branched structure.The protective group is an alkyl-substituted silyl group.)

[4]
The modified conjugated diene polymer according to any one of [1] to [3] above, which has a Mooney relaxation rate at 110°C of less than 0.60.
[5]
The modified conjugated diene polymer according to any one of [1] to [3] above, which has a Mooney relaxation rate of 0.60 or more and 0.80 or less at 110°C.
[6]
The modified conjugated diene polymer according to any one of [1] to [5] above, having a modification rate of 95% by mass or less.
[7]
The modified conjugated diene polymer according to any one of [1] to [6] above, wherein the amount of vinyl bonds in the conjugated diene bond units is 30 mol% or more.
[8]
rubber component,
5.0 parts by mass or more and 150 parts by mass or less of a silica-based inorganic filler based on 100 parts by mass of the rubber component;
including;
The rubber component contains 10% by mass or more of the modified conjugated diene polymer according to any one of [1] to [7] above, based on the total amount of the rubber component.
Modified conjugated diene polymer composition.
[9]
The rubber component contains 10% by mass or more of natural rubber based on the total amount of the rubber component,
The modified conjugated diene polymer composition according to [8] above.
[10]
A tire comprising the modified conjugated diene polymer composition described in [8] or [9] above.

According to the present invention, a modified conjugated diene polymer having good fracture properties at high temperatures when made into a vulcanizate is obtained.

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

[Modified conjugated diene polymer]
The modified conjugated diene polymer of this embodiment is
Mooney relaxation rate at 110°C is 0.45 or more,
The modification rate is 75% by mass or more,
The weight average molecular weight (Mw) is 200,000 or more and 3,000,000 or less,
The molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) is 1.5 or more and 3.5 or less.

The modified conjugated diene polymer of the present embodiment has a Mooney relaxation rate of 0.45 or more at 110° C., that is, measured at a temperature of 110° C., from the viewpoint of fracture strength at high temperatures.
Hereinafter, it is also simply referred to as "Mooney relaxation rate" or "MSR."
The Mooney relaxation rate is an index of the molecular entanglement of the modified conjugated diene copolymer, and the lower it is, the more the molecular entanglement is, and it is an index of the branched structure and molecular weight.

A modified conjugated diene polymer having an MSR of 0.45 or more tends to have excellent fracture properties at high temperatures when made into a vulcanizate.
The upper limit of MSR is not particularly limited, but is preferably 0.80 or less. A modified conjugated diene polymer having an MSR in the range of 0.45 or more and less than 0.60 tends to have a lower Mooney viscosity when made into a vulcanizate and has excellent processability.
Furthermore, a modified conjugated diene polymer having an MSR in the range of 0.60 or more and 0.80 or less tends to have better fracture properties in a wider temperature range than when made into a vulcanized product.
From the viewpoint of fracture characteristics at high temperatures and workability when made into a vulcanizate, MSR is more preferably 0.46 or more and 0.75 or less, and even more preferably 0.48 or more and 0.70. .

The MSR of a modified conjugated diene polymer is an index of the molecular weight and number of branches of the modified conjugated diene polymer.
For example, as the MSR increases, the molecular weight and number of branches of the modified conjugated diene polymer (for example, the number of branches of a star-shaped polymer (also referred to as "number of arms of a star-shaped polymer")) tend to decrease. be. When comparing modified conjugated diene polymers having the same Mooney viscosity, which will be described later, the MSR increases as the number of branches in the modified conjugated diene polymer decreases, so the MSR in this case can be used as an index of the number of branches. can.

MSR is measured using a Mooney viscometer as follows.
In this embodiment, the temperature at which the Mooney relaxation rate is measured is 110°C. First, after preheating the sample for 1 minute, the rotor is rotated at 2 rpm, and the torque after 4 minutes is measured, and the measured value is defined as the Mooney viscosity (ML _{(1+4) )} . Then, immediately stop the rotation of the rotor, record the torque every 0.1 seconds for 1.6 seconds to 5 seconds after stopping, and record the torque in Mooney units. The slope is determined and its absolute value is taken as the Mooney relaxation rate (MSR). More specifically, it can be measured by the method described in Examples below.

In order to make the Mooney relaxation rate 0.45 or more, it is preferable to control the molecular structure of the modified conjugated diene polymer so as to reduce the degree of branching. For example, if the weight average molecular weight of the modified conjugated diene polymer is set to 20×10 ⁴ or more and the degree of branching is set to 3 or less, it tends to be 0.45 or more. Further, the degree of branching can be controlled by, for example, the number of functional groups of the modifier, the amount of the modifier added, or the degree of progress of metalation.

The modified conjugated diene polymer of this embodiment has a modification rate of 75% by mass or more from the viewpoint of breaking strength at high temperatures.
The modification rate means the ratio of the functional group-containing modification component to the total amount of the conjugated diene polymer.
The functional group contained in the modifying component is not particularly limited, and a functional group that interacts with the surface of the filler in the rubber material is preferred. Examples include functional groups containing elements such as nitrogen, oxygen, phosphorus, and tin in the molecule. These elements may contain only one type, or may contain two or more types.
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. measure quantity. More specifically, the modification rate can be measured by the method described in the Examples.
Conjugated diene-based polymers for fuel-efficient tires use modifiers that impart affinity with silica in order to improve the affinity with the silica that is blended into tires, so adsorption onto silica columns is reduced. The method used to measure the denaturation rate is preferably used. In the case of a modifier used for other purposes, it is assumed that it does not show affinity with silica, but in that case, a method for measuring the modification rate can be selected depending on the purpose of the modifier.
The modification rate of the modified conjugated diene polymer of this embodiment is preferably 85% by mass or more, more preferably 90% by mass or more. A modified conjugated diene polymer having a modification rate within this range tends to have an excellent balance between low hysteresis property and wet skid resistance when made into a vulcanized product.

It is more preferable that the modification rate of the modified conjugated diene polymer is 95% by mass or less. By being within this range, it becomes possible to control the dispersion of silica particles in the silica compound within an appropriate range, and the rigidity at high temperatures can be maintained at a high value. Since stiffness at high temperatures is a value that is an index of handling performance during high-speed operation, if the modification rate is 95% by mass or less, handling performance during high-speed operation tends to be excellent.

A method for increasing the modification rate to 75% by mass or more tends to be controlled by the amount of modifier added and the method of adjusting the reaction process.
For example, a method of polymerization using an organolithium compound having at least one nitrogen atom in the molecule as a polymerization initiator, a method of copolymerizing a monomer having at least one nitrogen atom in the molecule, and a structure described later. Examples include a method in which the modifiers of the formula are used alone or in appropriate combinations, and the polymerization conditions are controlled so that the chain transfer reaction is not excessively promoted.
A method for controlling the modification rate to 95% by mass or less is to reduce the amount of the modifier added (adjust so that the number of moles of the functional group to which the modifier is bonded is smaller than the number of moles of the polymer chain). method, and reduce the amount of an organic lithium compound having at least one nitrogen atom in the molecule, which will be described later as a polymerization initiator. (used in combination). Note that the modification rate on the end end side can be adjusted by the amount of modifier added, and the modification rate on the start end side can be adjusted by the amount of organic lithium having a nitrogen atom in the polymerization initiator, but the measured modification rate is Therefore, in order to reduce the modification rate to 95% by mass or less, add a modifying agent or , it is necessary to adjust the amount of organic lithium containing nitrogen atoms in the polymerization initiator.

The modified conjugated diene polymer of this embodiment has a weight average molecular weight of 20×10 ⁴ or more and 300×10 ⁴ or less.
When the weight average molecular weight is 20×10 ⁴ or more, the fracture characteristics at high temperatures when made into a vulcanizate tend to be high.
When the weight average molecular weight is 300×10 ⁴ or less, the Mooney viscosity when made into a vulcanizate tends to be lower and processability tends to be excellent.
The weight average molecular weight of the modified conjugated diene polymer is preferably 50×10 ⁴ or more, more preferably 60×10 ⁴ or more. Further, the weight average molecular weight is preferably 200×10 ⁴ or less, more preferably 100×10 ⁴ or less.

The weight average molecular weight of the modified conjugated diene polymer and the conjugated diene polymer before modification described below is determined by measuring the chromatogram using a GPC measurement device and an RI detector, and using a calibration curve obtained using standard polystyrene. can be measured based on Specifically, it can be measured by the method described in Examples below.

The weight average molecular weight of the modified conjugated diene polymer is controlled by the molecular weight of the conjugated diene polymer chain, which is controlled by the ratio of the amount of polymerization initiator used and the amount of monomer used, and the type and amount of modifier used. be able to.

The modified conjugated diene polymer of this embodiment has a molecular weight distribution (Mw/Mn) of 1.5 or more and 3.5 or less, from the viewpoint of fracture characteristics at high temperatures and processability when made into a vulcanizate. be.
The molecular weight distribution is preferably 1.7 or more and 3.0 or less, more preferably 1.8 or more and 2.5 or less.
The molecular weight distribution can be controlled within the above range by adjusting the molecular weight of the conjugated diene polymer chain, which is controlled by the ratio of the amount of polymerization initiator used and the amount of monomer used, and the type and amount of modifier used, or the polymerization temperature. can be controlled.

The modified conjugated diene polymer of the present embodiment preferably has a nitrogen atom content of 25 mass ppm or more based on the total amount of the modified conjugated diene polymer.
The content of nitrogen atoms (hereinafter also referred to as "nitrogen content") refers to the nitrogen atom content of the nitrogen-containing functional group of the modified conjugated diene polymer, for example, the nitrogen atom of the nitrogen-containing functional group at the starting end, in the main chain, and at the terminal end. This is the total amount.
The nitrogen content of the modified conjugated diene polymer is preferably 25 mass ppm or more, more preferably 40 mass ppm or more, and 60 mass ppm or more, based on the total amount of the modified conjugated diene polymer. It is more preferable that
When the nitrogen content is within this range, the vulcanizate tends to have an excellent balance between low hysteresis and wet skid resistance. In addition, from the viewpoint of processability and filler dispersibility when forming a vulcanizate, the content is preferably 250 mass ppm or less, more preferably 150 mass ppm or less, and even more preferably 100 mass ppm or less. preferable.
The content of nitrogen atoms can be measured by the oxidative combustion-chemiluminescence method (JIS-2609: Crude oil and crude oil products - Nitrogen content test method). The nitrogen atom content can be measured more specifically by the method described in Examples below.

A method of controlling the nitrogen content of the modified conjugated diene polymer to 25 mass ppm or more includes a method of adjusting the amount of a modifier added and the reaction. A conjugated diene polymer having a nitrogen atom, which is obtained by a method of polymerizing using an organolithium compound having at least one nitrogen atom, or a method of copolymerizing a monomer having at least one nitrogen atom in the molecule, A method of reacting with a modifier having at least one nitrogen atom is mentioned.

In the modified conjugated diene polymer of this embodiment, the monomer constituting the polymer chain is composed of a conjugated diene compound, or a conjugated diene compound and another monomer copolymerizable with the conjugated diene compound. .
The conjugated diene compound is preferably a conjugated diene having 4 to 12 carbon atoms, and examples include, but are not limited to, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1 , 3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene.
Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of industrial availability.
These may be used alone or in combination of two or more.
As the other monomer copolymerizable with the conjugated diene compound, for example, a vinyl aromatic compound is preferable, and styrene is more preferable.

<Modifier residue>
When the modified conjugated diene polymer of this embodiment has a modifier residue, the modifier residue is a structural unit of the modified conjugated diene polymer that is bonded to the conjugated diene polymer chain, for example, It is a structural unit derived from a modifier, which is produced by reacting a conjugated diene polymer described later with a modifier.

<Conjugated diene polymer chain containing nitrogen atom>
The modified conjugated diene polymer of this embodiment preferably has a nitrogen atom in at least one conjugated diene polymer chain. An example of a structure in which a conjugated diene polymer chain has a nitrogen atom is a conjugated diene polymer chain having a functional group containing a nitrogen atom at any position, and the position of the functional group is as follows: It may be at the end or in the middle of the main chain.
A conjugated diene polymer chain having a nitrogen atom can be produced, for example, by a polymerization method using an organic lithium compound having at least one nitrogen atom in the molecule as described below as a polymerization initiator; It is obtained by a method of copolymerizing monomers having atoms.

<Modifier residue having silicon atom>
The modified conjugated diene polymer of this embodiment preferably has a silicon atom in the modifier residue. The modifier residue is, for example, a structural unit derived from a modifier, which is caused by the modifier described later having a silicon atom.

<Vinyl bond amount>
In the modified conjugated diene polymer of the present embodiment, the amount of vinyl bonds in the conjugated diene bond units is preferably 30 mol % or more from the viewpoint of excellent compatibility with natural rubber.
The vinyl bond amount is preferably 32 mol% or more and 45 mol% or less, and more preferably 35 mol% or more and 40 mol% or less.
The amount of vinyl bonds in the conjugated diene bond unit can be measured by the method described in the Examples below.
The vinyl bond amount can be controlled as described above by adding a polar compound or adjusting the polymerization temperature.

The modified conjugated diene polymer of this embodiment is preferably a modified conjugated diene polymer represented by the following general formula (A) or (B). This provides an excellent balance between low hysteresis and wet skid resistance when made into a vulcanizate.

In general formula (A), R ²¹ to R ²⁴ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ²⁵ and R ²⁶ each independently represent , represents an alkylene group having 1 to 20 carbon atoms, and R ²⁷ represents a hydrogen atom, a silyl group substituted with a hydrocarbon, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.
a, b, c and d are each independently an integer of 1 or 2, b and d of 0 or 1, as long as (a+b) and (c+d) are each independently an integer of 2 or less. Indicates an integer.
(Polym) represents a conjugated diene compound, or a conjugated diene polymer obtained by polymerizing or copolymerizing a conjugated diene compound and an aromatic vinyl compound, and at least one terminal thereof is expressed by the following general formula (1). Represents a functional group represented by ~(4).
R ²¹ and R ²³ when a plurality of R 21 and R 23 exist, and a plurality of R 23 (Polym) are each independent, and may be the same or different.

The modified conjugated diene polymer of this embodiment can have a star-shaped polymer structure. As for the star-shaped polymer structure, for example, in the modified conjugated diene polymer represented by formula (A), the Si atom bonded to R ²⁵ is used as a branch point, and the branch point is a linear molecule. Examples include structures in which the chain (arm) is bonded to R ²⁵ , (OR ²¹ ) _3-ab , R ²² _b and (Polym) _a .

In the general formula (B), R ²⁸ to R ³³ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ³⁴ to R ³⁶ each independently , represents an alkylene group having 1 to 20 carbon atoms.
a, b, c, d, e and f, as long as (a+b), (c+d) and (e+f) each independently represent an integer of 2 or less, a, c and e are each independently 1 or 2; , b, d and f each independently represent an integer of 0 or 1.
(Polym) indicates a conjugated diene compound, or a conjugated diene polymer obtained by polymerizing or copolymerizing a conjugated diene compound and an aromatic vinyl compound, and at least one terminal thereof is expressed by the following general formula (1). Indicates a functional group represented by any of (4).
R ²⁸ , R 30 , and R 32 when a plurality of R 28 , R ³⁰ , and R ³² exist, and a plurality of R 32 (Polym) are each independent, and may be the same or different.

The modified conjugated diene polymer of this embodiment can have a star-shaped polymer structure. As the star-shaped polymer structure, for example, in a modified conjugated diene polymer represented by the general formula (B), the Si atom bonded to R ³⁴ is used as a branch point, and the branch point is a linear molecule. Examples include structures in which the chain (arm) is bonded to R ³⁴ , (OR ²⁸ ) _3-ab , R ²⁹ _b , and (Polym) _a .

In the general formula (1), R ₁₀ and R ₁₁ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group. Represents at least one species selected from the group consisting of.
R ₁₀ and R ₁₁ may be bonded together to form a cyclic structure together with the adjacent nitrogen atom; in this case, R ₁₀ and R ₁₁ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof is unsaturated. It may have a saturated bond or a branched structure. Note that the protecting group is an alkyl-substituted silyl group.

In the general formula (2), R ₁₂ and R ₁₃ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group. At least one selected from the group consisting of:
R ₁₂ and R ₁₃ may be bonded together to form a cyclic structure with an adjacent nitrogen atom, and in this case R ₁₂ and R ₁₃ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof is unsaturated. It may have a saturated bond or a branched structure.
Note that the protecting group is an alkyl-substituted silyl group.
R ₁₄ represents an alkylene group having 1 to 30 carbon atoms which may have an aliphatic or aromatic substituent, or a conjugated diene polymer chain having 1 to 20 carbon atoms.

In the general formula (3), R ₁₅ and R ₁₆ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 20 carbon atoms, and a protecting group. At least one selected from the group consisting of:
R ₁₅ and R ₁₆ may be bonded together to form a cyclic structure with an adjacent nitrogen atom, and in this case, R ₁₅ and R ₁₆ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof is branched. It may have a structure. Note that the protecting group is an alkyl-substituted silyl group.

In the general formula (4), R ₁₇ represents a hydrocarbon group having 2 to 10 carbon atoms, and a portion thereof may have an unsaturated bond or a branched structure.
R ₁₈ represents an alkyl group having 1 to 12 carbon atoms or a protective group, and a portion thereof may have a branched structure. Note that the protecting group is an alkyl-substituted silyl group.

In general formula (A), R ²¹ to R ²⁴ each independently preferably represent an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms.
R ²⁵ and R ²⁶ each independently preferably represent an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms.
R ²⁷ preferably represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably represents a hydrogen atom.
Furthermore, what R ²¹ to R ²⁴ represent is not limited to the following, but includes, for example, a methyl group, an ethyl group, a propyl group, a butyl group, and an isobutyl group, with methyl and ethyl groups being preferred. .
Examples of what R ²⁵ and R ²⁶ represent include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentylene group, and preferably an ethylene group, a propylene group, and a butylene group.
Examples of what R ²⁷ represents include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, and an isobutyl group, and preferably a hydrogen atom, a methyl group, and an ethyl group.

In general formula (A), the number average molecular weight of (Polym) is not particularly limited, but is preferably 250,000 or more and 1,500,000 or less, more preferably 350,000 or more and 900,000 or less. preferable.

In the general formula (B), R ²⁸ to R ³³ each independently preferably represents an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms.
R ³⁴ and R ³⁵ each independently preferably represent an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms.
Examples of R ²⁸ to R ³³ include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, and preferably a methyl group and an ethyl group.
Examples of R ³⁴ to R ³⁶ include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentylene group, and preferably an ethylene group, a propylene group, and a butylene group.

In general formula (B), the number average molecular weight of (Polym) is not particularly limited, but is preferably 250,000 or more and 1,500,000 or less, more preferably 350,000 or more and 900,000 or less. preferable.

In general formula (1), when R ₁₀ and R ₁₁ represent an alkyl group, R ¹⁰ and R ₁₁ preferably represent an alkyl group having 1 to 6 carbon atoms.
When R ₁₀ and R ₁₁ represent a cycloalkyl group, R ₁₀ and R ₁₁ preferably represent a cycloalkyl group having 5 to 7 carbon atoms.
When R ₁₀ and R ₁₁ represent an aralkyl group, R ₁₀ and R ₁₁ preferably represent an aralkyl group having 6 to 8 carbon atoms.
When R ₁₀ and R ₁₁ combine to form a cyclic structure together with adjacent nitrogen atoms, R ₁₀ and R ₁₁ preferably represent an alkyl group having 5 to 7 carbon atoms.
Further, what R ₁₀ and R ₁₁ represent is not limited to the following, but examples include methyl group, ethyl group, propyl group, butyl group, and isobutyl group, and preferably butyl group and isobutyl group. .
When R ₁₀ and R ₁₁ combine to form a cyclic structure with adjacent nitrogen atoms, R ₁₀ and R ₁₁ represent, but are not limited to, the following, for example, a methylene group, ethylene, etc. group, a propylene group, a butylene group, a pentylene group, and a hexylene group, and preferably a butylene group, a pentylene group, and a hexylene group.

In the general formula (2), R ₁₂ and R ₁₃ may be bonded together to form a cyclic structure with the adjacent nitrogen atom, in which case R ₁₂ and R ₁₃ are an alkyl group having 5 to 12 carbon atoms. shows.
Further, what R ₁₂ and R ₁₃ represent is not limited to the following, but includes, for example, a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, and preferably a butyl group or an isobutyl group. be.
When R ₁₂ and R ₁₃ combine to form a cyclic structure with adjacent nitrogen atoms, what R ₁₂ and R ₁₃ represent is not limited to the following, but for example, methylene group, ethylene group, etc. group, a propylene group, a butylene group, a pentylene group, and a hexylene group, and preferably a butylene group, a pentylene group, and a hexylene group.

In general formula (2), R ₁₄ preferably represents an alkylene group having 1 to 8 carbon atoms. Furthermore, what R ₁₄ represents is not limited to the following, but includes, for example, a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group, and preferably an ethylene group and a propylene group. , is a butylene group.

In the general formula (3), what R ₁₅ and R ₁₆ represent is not limited to the following, but includes, for example, a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, and preferably a methyl group. group, ethyl group.

In general formula (4), R ₁₇ preferably represents an alkyl group having a total of 4 to 6 carbon atoms.
R ₁₈ preferably represents an alkyl group having 1 to 4 carbon atoms.
Furthermore, what R ₁₇ represents is not limited to the following, but examples thereof include a butylene group, a pentylene group, and a hexylene group, and preferably a pentylene group and a hexylene group.
Examples of what R ₁₈ represents include, but are not limited to, a methyl group, an ethyl group, a propyl group, a butyl group, and an isobutyl group, with a methyl group and an ethyl group being preferred.

[Production method of modified conjugated diene polymer]
As an example of the method for producing the modified conjugated diene polymer of the present embodiment, an organic lithium compound having at least one nitrogen atom in the molecule is used as a polymerization initiator, and at least a conjugated diene compound and, if necessary, other monomers are added. a polymerization step for obtaining a conjugated diene polymer by polymerizing the conjugated diene polymer; A method having a denaturation step of denaturing according to the above method is mentioned.
The conjugated diene polymer constituting the modified conjugated diene polymer may be a homopolymer of a single conjugated diene compound, a polymer or copolymer of different types of conjugated diene compounds, or a conjugated diene compound and an aromatic vinyl compound. It is a copolymer with

(Polymerization process)
In the polymerization step, it is preferable to use an organic lithium compound having at least one nitrogen atom in the molecule as the polymerization initiator.

<Polymerization initiator>
As the polymerization initiator, a polymerization initiator system containing an organic lithium compound can be used.
The polymerization initiator system preferably has at least one nitrogen atom in the molecule.
For the polymerization initiator system, an organic lithium compound having at least one nitrogen atom in the molecule may be prepared in advance in a predetermined reactor, or it may be prepared in a reactor for polymerization or copolymerization as described below. The organic lithium may be reacted with a compound having at least one nitrogen atom in the molecule simultaneously with or before the polymerization or copolymerization.
As the compound having at least one nitrogen atom in the molecule, compounds represented by the following general formulas (5) to (7) can be used.

In the general formula (5), R ₁₀ and R ₁₁ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group. Represents at least one species selected from the group consisting of.
R ₁₀ and R ₁₁ may be bonded together to form a cyclic structure together with the adjacent nitrogen atom; in this case, R ₁₀ and R ₁₁ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof is unsaturated. It may have a saturated bond or a branched structure.
Note that the protecting group is an alkyl-substituted silyl group.

In the general formula (6), R ₁₂ and R ₁₃ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group. At least one selected from the group consisting of:
R ₁₂ and R ₁₃ may be bonded together to form a cyclic structure with the adjacent nitrogen atom; in this case, R ₁₂ and R ₁₃ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof is unsaturated. It may have a saturated bond or a branched structure.
Note that the protecting group is an alkyl-substituted silyl group.
R ₁₄ represents an alkylene group having 1 to 30 carbon atoms which may have an aliphatic or aromatic substituent, or a conjugated diene polymer chain having 1 to 20 carbon atoms.
X represents a Cl atom, a Br atom, an I atom, or a hydrogen atom.

In general formula (7), R ₁₅ and R ₁₆ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 20 carbon atoms, and a protecting group. represents at least one species selected from the group consisting of:
R ₁₅ and R ₁₆ may be bonded together to form a cyclic structure with the adjacent nitrogen atom, and in this case, R ₁₅ and R ₁₆ represent an alkyl group having 5 to 12 carbon atoms, and a part thereof has a branched structure. It may have a structure.
Note that the protecting group is an alkyl-substituted silyl group.

In general formula (5), R ₁₀ and R ₁₁ represent, but are not limited to, the following, for example, methyl group, ethyl group, propyl group, butyl group, octyl group, cyclopropyl group, cyclohexyl group, -phenyl-1-propyl group, isobutyl group, decyl group, heptyl group, and phenyl group.
Examples of the compound represented by formula (5) include, but are not limited to, dimethylamine, diethylamine, dibutylamine, dipropylamine, diheptylamine, dihexylamine, dioctylamine, di-2- Examples include ethylhexylamine, didecylamine, ethylpropylamine, ethylbutylamine, ethylbenzylamine, methylphenethylamine and the like.
The compound represented by the general formula (5) is not limited to these, but includes analogs thereof as long as the above conditions are satisfied.
The compound represented by general formula (5) is suitable for reducing hysteresis loss of the modified conjugated diene polymer composition of the present embodiment described later, reducing unpleasant odor of the modified conjugated diene polymer of the present embodiment, and From the viewpoint of controlling the chain transfer reaction described below, dibutylamine and dihexylamine are preferred, and dibutylamine is more preferred.

When R ₁₀ and R ₁₁ combine to form a cyclic structure with the adjacent nitrogen atom, examples of the compound represented by general formula (5) include piperidine, hexamethyleneimine, azacyclooctane, 1 , 3,3-trimethyl-6-azabicyclo[3.2.1]octane, and 1,2,3,6-tetrahydropyridine.
The compound represented by the general formula (5) is not limited to these, but includes analogs thereof as long as the above conditions are satisfied.
The compound represented by general formula (5) is suitable for reducing hysteresis loss of the modified conjugated diene polymer composition of the present embodiment described later, reducing unpleasant odor of the modified conjugated diene polymer of the present embodiment, and From the viewpoint of controlling the chain transfer reaction described below, piperidine, hexamethyleneimine, azacyclooctane, and 1,3,3-trimethyl-6-azabicyclo[3.2.1]octane are preferable, and piperidine and hexamethyleneimine are more preferable. and more preferably piperidine.

In the general formula (6), R ₁₄ represents an alkylene group having 1 to 30 carbon atoms which may have an aliphatic or aromatic substituent, or a conjugated diene polymer chain having 1 to 20 carbon atoms.
Examples of the compound represented by the general formula (6) include, but are not limited to, 3-chloro-dimethylpropan-1-amine, 3-chloro-diethylpropan-1-amine, 3-chloro-dibutylpropan-1-amine, and 3-chloro-dimethylpropan-1-amine. 1-Amine, 3-chloro-dipropylpropan-1-amine, 3-chloro-diheptylpropan-1-amine, 3-chloro-dihexylpropan-1-amine, 3-chloropropyl-ethylhexane-1- Amine, 3-chloro-didecylpropan-1-amine, 3-chloro-ethylpropan-1-amine, 3-chloro-ethylbutan-1-amine, 3-chloro-ethylpropan-1-amine, benzyl-3-amine Chloro-ethylpropan-1-amine, 3-chloro-ethylphenethylpropan-1-amine, 3-chloro-methylphenethylpropan-1-amine, 1-(3-chloropropyl)piperidine, 1-(3-chloropropyl) ) hexamethyleneimine, 1-(3-chloropropyl)azacyclooctane, 6-(3-chloropropyl)-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane, 1-(3 -chloropropyl)-1,2,3,6-tetrahydropyridine, 1-(3-bromopropyl)hexamethyleneimine, 1-(3-iodopropyl)hexamethyleneimine, 1-(3-chlorobutyl)hexamethyleneimine , 1-(3-chloropentyl)hexamethyleneimine, 1-(3-chlorohexyl)hexamethyleneimine, and 1-(3-chlorodecyl)hexamethyleneimine.
The compound represented by the general formula (6) is not limited to these, but includes analogs thereof as long as the above conditions are satisfied.
From the viewpoint of reactivity and interaction with inorganic fillers such as carbon and silica, the compound represented by general formula (6) is selected from 3-chloro-dibutylpropan-1-amine, 1-(3-chloropropyl ) Hexamethyleneimine is preferred, and 1-(3-chloropropyl)hexamethyleneimine is more preferred.

In the general formula (6), when R ₁₄ represents a conjugated diene polymer chain having one repeating unit of the following formulas (8) to (10), X represents a hydrogen atom.

When X represents a hydrogen atom, examples of the compound represented by general formula (6) include, but are not limited to, N,N-dimethyl-2-butenyl-1-amine, N,N-diethyl -2-Butenyl-1-amine, N,N-dibutyl-2-butenyl-1-amine, N,N-dipropyl-2-butenyl-1-amine, N,N-diheptyl-2-butenyl-1 -Amine, N,N-dihexyl-2-butenyl-1-amine, N,N-dioctyl-2-butenyl-1-amine, N,N-(di-2-ethylhexyl)-2-butenyl -1-amine, N,N-didecyl-2-butenyl-1-amine, N,N-ethylpropyl-2-butenyl-1-amine, N,N-ethylbutyl-2-butenyl-1-amine, N, N-ethylbenzyl-2-butenyl-1-amine, N,N-methylphenethyl-2-butenyl-1-amine, N,N-dimethyl-2-methyl-2-butenyl-1-amine, N,N- Diethyl-2-methyl-2-butenyl-1-amine, N,N-dibutyl-2-methyl-2-butenyl-1-amine, N,N-dipropyl-2-methyl-2-butenyl-1-amine, (N,N-diheptyl-2-methyl-2-butenyl-1-amine, N,N-dihexyl-2-methyl-2-butenyl-1-amine, N,N-dimethyl-3-methyl -2-Butenyl-1-amine, N,N-diethyl-3-methyl-2-butenyl-1-amine, N,N-dibutyl-3-methyl-2-butenyl-1-amine, N,N-dipropyl -3-Methyl-2-butenyl-1-amine, N,N-diheptyl-3-methyl-2-butenyl-1-amine, N,N-dihexyl-3-methyl-2-butenyl-1 -Amine, 1-(2-butenyl)piperidine, 1-(2-butenyl)hexamethyleneimine, 1-(2-butenyl)azacyclooctane, 6-(2-butenyl)1,3,3-trimethyl-6 -Azabicyclo[3.2.1]octane, 1-(2-butenyl)-1,2,3,6-tetrahydropyridine, (2-methyl-2-butenyl)hexamethyleneimine, (3-methyl-2- butenyl)hexamethyleneimine.
The compound represented by the general formula (6) is not limited to these, but includes analogs thereof as long as the above conditions are satisfied.
The compound represented by general formula (6) is selected from N,N-dibutyl-2-butenyl 1-amine, 1-( 2-Butenyl)hexamethyleneimine is preferred, more preferably 1-(2-butenyl)piperidine, 1-(2-butenyl)hexamethyleneimine, and still more preferably 1-(2-butenyl)piperidine.

In the polymerization initiator, the compound represented by the general formula (7) is not limited to the following, but includes, for example, N,N-dimethyl-o-toluidine, N,N-dimethyl-m-toluidine, N,N-dimethyl-m-toluidine, N-dimethyl-p-toluidine, N,N-diethyl-o-toluidine, N,N-diethyl-m-toluidine, N,N-diethyl-p-toluidine, N,N-dipropyl-o-toluidine, N, N-dipropyl-m-toluidine, N,N-dipropyl-p-toluidine, N,N-dibutyl-o-toluidine, N,N-dibutyl-m-toluidine, N,N-dibutyl-p-toluidine, o- Piperidinotoluene, p-piperidinotoluene, o-pyrrolidinotoluene, p-pyrrolidinotoluene, N,N,N',N'-tetramethyltolylenediamine, N,N,N',N'- Tetraethyltolylenediamine, N,N,N',N'-tetrapropyltolylenediamine, N,N-dimethylxylidine, N,N-diethylxylidine, N,N-dipropylxylidine, N,N- Dimethylmesidine, N,N-diethylmesidine, (N,N-dimethylamino)tolylphenylmethylamine, 1-(N,N-dimethylamino)-2-methylnaphthalene, 1-(N,N-dimethylamino) )-2-methylanthracene.
The compound represented by the general formula (7) is not limited to these, but includes analogs thereof as long as the above conditions are satisfied.
The compound represented by the general formula (7) is preferably N,N-dimethyl-o-toluidine from the viewpoint of reducing hysteresis loss of the modified conjugated diene polymer composition described below.

Examples of the organic lithium compound used as a polymerization initiator include, but are not limited to, n-butyllithium, sec-butyllithium, tert-butyllithium, n-propyllithium, and iso-propyllithium.

The organolithium compound used as a polymerization initiator preferably has at least one nitrogen atom in the molecule and can be used as a polymerization initiator for anionic polymerization, from the viewpoint of improving the modification rate and improving fuel efficiency. , preferably contains an organic lithium compound represented by any one of the following general formulas (11) to (14).

In the general formula (11), R ₁₀ and R ₁₁ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group. represents at least one species selected from the group consisting of:
R ₁₀ and R ₁₁ may be bonded together to form a cyclic structure together with the adjacent nitrogen atom; in this case, R ₁₀ and R ₁₁ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof is unsaturated. It may have a saturated bond or a branched structure.
Note that the protecting group is an alkyl-substituted silyl group.

In the general formula (12), R ₁₂ and R ₁₃ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group. represents at least one species selected from the group consisting of:
R ₁₂ and R ₁₃ may be bonded together to form a cyclic structure with the adjacent nitrogen atom; in this case, R ₁₂ and R ₁₃ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof is unsaturated. It may have a saturated bond or a branched structure.
The protecting group is an alkyl-substituted silyl group.
R ₁₄ represents an alkylene group having 1 to 30 carbon atoms which may have an aliphatic or aromatic substituent, or a conjugated diene polymer having 1 to 20 carbon atoms.

In general formula (13), R ₁₅ and R ₁₆ each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 20 carbon atoms, and a protecting group. represents at least one species selected from the group consisting of:
R ₁₅ and R ₁₆ may be bonded together to form a cyclic structure with the adjacent nitrogen atom, and in this case, R ₁₅ and R ₁₆ represent an alkyl group having 5 to 12 carbon atoms, and a part thereof has a branched structure. It may have a structure.
Note that the protecting group is an alkyl-substituted silyl group.

In the general formula (14), R ₁₇ represents a hydrocarbon group having 2 to 10 carbon atoms, and a portion thereof may have an unsaturated bond or a branched structure. R ₁₈ represents an alkyl group having 1 to 12 carbon atoms or a protective group, and a portion thereof may have a branched structure.
Note that the protecting group is an alkyl-substituted silyl group.

In the general formula (11), R ¹⁰ and R ¹¹ represent, for example, a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, a silium group, an ethylpropylaminolithium group, an ethylbutylaminolithium group, Examples include ethylbenzylaminolithium group and methylphenethylaminolithium group.
R ¹⁰ and R ¹¹ are not limited to these, but include analogs thereof as long as the above conditions are met.
A dibutylaminolithium group and a dihexylaminolithium group are preferable from the viewpoint of solubility in a solvent, reduction of hysteresis loss of the modified conjugated diene polymer composition of the present embodiment described below, and control of chain transfer reaction described later. , more preferably a dibutylamine group.

In general formula (11), when R ₁₀ and R ₁₁ combine to form a cyclic structure with adjacent nitrogen atoms, the organolithium compound represented by general formula (11) is not limited to the following: For example, piperidinolithium, hexamethyleneiminolithium, lithium azacyclooctane, lithium-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane, 1,2,3,6-tetrahydro Examples include pyridinolithium.
The organolithium compound is not limited to these, but includes analogs thereof as long as the above conditions are met. Piperidinolithium, hexamethyleneiminolithium, lithium azacyclo Octane, lithium-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane is preferred, more preferably piperidinolithium or hexamethyleneiminolithium, even more preferably piperidinolithium. .

In the general formula (12), R ₁₄ represents an alkylene group having 1 to 30 carbon atoms which may have an aliphatic or aromatic substituent, or a conjugated diene polymer chain having 1 to 20 carbon atoms.
The conjugated diene polymer is preferably a conjugated diene polymer chain having a repeating unit represented by any one of the following formulas (15) to (17).

In general formula (12), when R ₁₄ represents an alkylene group having 1 to 20 carbon atoms, from the viewpoint of reactivity and interaction with inorganic fillers such as carbon and silica, R ₁₄ has 2 to 20 carbon atoms. It is preferable to represent an alkylene group having 16 carbon atoms, and more preferably an alkylene group having 3 to 10 carbon atoms.
In addition, when R ₁₄ represents an alkylene group having 1 to 30 carbon atoms which may have an aliphatic or aromatic substituent, the organic lithium compound represented by formula (12) is not limited to the following, but is For example, (3-(dimethylamino)-propyl)lithium, (3-(diethylamino)-propyl)lithium, (3-(dipropylamino)-propyl)lithium, (3-(dibutylamino)-propyl)lithium, (3-(dipentylamino)-propyl)lithium, (3-(dihexylamino)-propyl)lithium, (3-(dioctylamino)-propyl)lithium, (3-(ethylhexylamino)-propyl)lithium, ( 3-(didecylamino)-propyl)lithium, (3-(ethylpropylamino-propyl)lithium, (3-(ethylbutylamino-propyl)lithium), (3-(ethylbenzylamino)-propyl)lithium, (3- (methylphenethylamino)-propyl)lithium, (4-(dibutylamino)-butyl)lithium, (5-(dibutylamino)-pentyl)lithium, (6-(dibutylamino)-hexyl)lithium, (10-( Dibutylamino)-decyl)lithium is mentioned.
The organolithium compound is not limited to these, but includes analogs thereof as long as the above conditions are met. From the viewpoint of reactivity and interaction with inorganic fillers such as carbon and silica, (3-(dibutylamino)-propyl)lithium is more preferred.

In general formula (12), when R ₁₄ represents a conjugated diene polymer chain having repeating units represented by formulas (15) to (17), the organolithium compound represented by general formula (12) is Examples include, but are not limited to, (4-(dimethylamino)-2-butenyl)lithium, (4-(diethylamino)-2-butenyl)lithium, (4-(dibutylamino)-2-butenyl)lithium , (4-(dipropylamino)-2-butenyl)lithium, (4-(diheptylamino)-2-butenyl)lithium, (4-(dihexylamino)-2-butenyl)lithium, (4-( dioctylamino)-2-butenyl)lithium, (4-(di-2-ethylhexylamino)-2-butenyl)lithium, (4-(didecylamino)-2-butenyl)lithium, (4-(ethylpropylamino)) -2-butenyl)lithium, (4-(ethylbutylamino)-2-butenyl)lithium, (4-(ethylbenzylamino)-2-butenyl)lithium, (4-(methylphenethylamino)-2-butenyl) Lithium, (4-(dimethylamino)-2-methyl-2-butenyl)lithium, (4-(diethylamino)-2-methyl-2-butenyl)lithium, (4-(dibutylamino)-2-methyl-2 -butenyl)lithium, (4-(dipropylamino)-2-methyl-2-butenyl)lithium, (4-(diheptylamino)-2-methyl-2-butenyl)lithium, (4-(dihexylamino)-2-methyl-2-butenyl)lithium, (4-(dihexylamino)-2-methyl-2-butenyl)lithium, )-2-methyl-2-butenyl)lithium, (4-(dimethylamino)-3-methyl-2-butenyl)lithium, (4-(diethylamino)-3-methyl-2-butenyl)lithium, (4- (dibutylamino)-3-methyl-2-butenyl)lithium, (4-(dipropylamino)-3-methyl-2-butenyl)lithium, (4-(diheptylamino)-3-methyl-2-butenyl) ) lithium, (4-(dihexylamino)-3-methyl-2-butenyl)lithium.
The organolithium compound is not limited to these, but includes analogs thereof as long as the above conditions are met. From the viewpoint of reactivity as a polymerization initiator and control of chain transfer reaction described later, 4-(dimethylamino)-2-butenyl)lithium, (4-(diethylamino)-2-butenyl)lithium, (4- (Dibutylamino)-2-butenyl)lithium is preferred, and (4-(dibutylamino)-2-butenyl)lithium is more preferred.

In general formula (12), when R ₁₂ and R ₁₃ combine to form a cyclic structure with adjacent nitrogen atoms, the organolithium compound represented by general formula (12) is, for example, (3 -(piperidinyl)propyl)lithium, (3-(hexamethyleneniminyl)propyl)lithium, (3-(heptamethyleneiminyl)propyl)lithium, (3-(octamethyleneiminyl)propyl)lithium, (3 -(1,3,3-trimethyl-6-azabicyclo[3.2.1]octanyl)propyl)lithium, (3-(1,2,3,6-tetrahydropyridinyl)propyl)lithium, (2- (hexamethyleneleniminyl)ethyl)lithium, (4-(hexamethineleniminyl)butyl)lithium, (5-(hexamethineleniminyl)pentyl)lithium, (6-(hexamethyleneleniminyl)hexyl) ) lithium, (10-(hexamethineleniminyl)decyl)lithium, (4-(piperidinyl)-2-butenyl)lithium, (4-(hexamethineleniminyl)-2-butenyl)lithium, (4- (heptamethyleneiminyl)-2-butenyl)lithium, (4-(octamethyleneiminyl)-2-butenyl)lithium, (4-(1,3,3-trimethyl-6-azabicyclo[3.2.1 ]octanyl)-2-butenyl)lithium, (4-(1,2,3,6-tetrahydropyridinyl)-2-butenyl)lithium, (4-(hexamethyleneleniminyl)-2-methyl-2 -butenyl)lithium and (4-(hexamethyleneleniminyl)-3-methyl-2-butenyl)lithium.
The organolithium compound is not limited to these, but includes analogs thereof as long as the above conditions are met. (3-(piperidinyl)propyl)lithium, (3-(hexamethyleneleniminyl)propyl) ) lithium, (3-(1,2,3,6-tetrahydropyridinyl)propyl)lithium, (4-(piperidinyl)-2-butenyl)lithium, (4-(hexamethyleneleniminyl)-2- butenyl)lithium is preferred, and (3-(hexamethyleneleniminyl)propyl)lithium, (4-(piperidinyl)-2-butenyl)lithium, (4-(hexamethyleneleniminyl)-2-butenyl) is preferred. ) lithium, more preferably (4-(piperidinyl)-2-butenyl)lithium.

Examples of the organic lithium compound represented by the general formula (13) include, but are not limited to, N,N-dimethyl-o-toluidinolithium, N,N-dimethyl-m-toluidinolithium, N,N-dimethyl-m-toluidinolithium, , N-dimethyl-p-toluidinolithium, N,N-diethyl-o-toluidinolithium, N,N-diethyl-m-toluidinolithium, N,N-diethyl-p-toluidinolithium , N,N-dipropyl-o-toluidinolithium, N,N-dipropyl-m-toluidinolithium, N,N-dipropyl-p-toluidinolithium, N,N-dibutyl-o-toluidinolithium Norithium, N,N-dibutyl-m-toluidinolithium, N,N-dibutyl-p-toluidinolithium, o-piperidinotoluenolithium, p-piperidinotoluenolithium, o-pyrrolidinolithium Enolithium, p-pyrrolidinotoluene, N,N,N',N'-tetramethyltolylenediaminolithium, N,N,N',N'-tetraethyltolylenediaminolithium, N,N,N',N '-Tetrapropyltolylenediaminolithium, N,N-dimethylxylidinolithium, N,N-diethylxylidinolithium, N,N-dipropylxylidinolithium, N,N-dimethylmesidinolithium, N,N- Diethylmesidinolithium, (N,N-dimethylamino)tolylphenylmethylaminolithium, 1-(N,N-dimethylamino)-2-methylnaphthalenolithium, 1-(N,N-dimethylamino)-2- Examples include methylanthracenolithium.
The organolithium compound is not limited to these, but includes analogs thereof as long as the above conditions are met. From the viewpoint of polymerization activity, N,N-dimethyl-o-toluidinolithium is more preferred.

Examples of the organic lithium compound represented by the general formula (14) include, but are not limited to, 2-(2-methylpiperidinyl)-1-ethyllithium (for example, the product name "AI-" manufactured by FMC Co., Ltd.). 250'').
The organolithium compound is not limited to these, but includes analogs thereof as long as the above conditions are met.

Before the polymerization step, an organic lithium compound having at least one nitrogen atom in the molecule may be prepared in advance, and any known method can be used for the preparation.
The organolithium compound represented by the general formula (11) and having at least one nitrogen atom in the molecule can be obtained by, for example, reacting the compound represented by the formula (5) with the organolithium compound in a hydrocarbon solvent. obtained by
As the hydrocarbon solvent, an appropriate solvent such as hexane, cyclohexane, benzene, etc. may be selected. The reaction temperature is preferably 0°C or more and 80°C or less, from the viewpoint of productivity, 5.0°C or more and 70°C or less, and more preferably 7.0°C or more and 50°C or less.

In the organolithium compound having at least one nitrogen atom in the molecule represented by the general formula (12), R ₁₄ is an alkylene group having 1 to 30 carbon atoms and optionally having an aliphatic or aromatic substituent. When representing, for example, a compound represented by formula (6) and an organic lithium compound are reacted in a hydrocarbon solvent to prepare a lithium amide compound, and a dihalogen represented by the following general formula (C) is added to the lithium amide compound. It can be obtained by reacting an alkyl compound and further reacting an organolithium compound.

In the general formula (C), X ¹ and X ² each independently represent an I atom, a Br atom, or a Cl atom, and R ^3a represents an alkylene group having 1 to 20 carbon atoms, preferably 2 carbon atoms. -16 alkylene group, more preferably an alkylene group having 3 to 10 carbon atoms.

Examples of the compound represented by the general formula (C) include, but are not limited to, 1-bromo-3-chloropropane, 1-bromo-4-chlorobutane, 1-bromo-5-chloropentane, 1-bromo- 6-chlorohexane, 1-bromo-10-chlorodecane, 1-bromo-3-iodopropane, 1-bromo-4-iodobutane, 1-bromo-5-iodopentane, 1-bromo-6-iodohexane, 1- Examples include bromo-10-iododecane, 1-chloro-3-iodopropane, 1-chloro-4-iodobutane, 1-chloro-5-iodopentane, 1-chloro-6-iodohexane, and 1-chloro-10-iododecane. It will be done.
From the viewpoint of reactivity and safety, the compounds represented by general formula (C) are 1-bromo-3-chloropropane, 1-bromo-4-chlorobutane, 1-bromo-5-chloropentane, 1-bromo- 6-chlorohexane and 1-bromo-10-chlorodecane are preferred, and 1-bromo-3-chloropropane, 1-bromo-4-chlorobutane and 1-bromo-6-chlorohexane are more preferred.

The reaction temperature when preparing a lithium amide compound using the compound represented by general formula (6), an organic lithium compound, and a hydrocarbon solvent is as described above.
The reaction temperature when reacting the compound represented by the general formula (C) with the lithium amide compound is preferably -78°C or more and 70°C or less, more preferably -50°C or more and 50°C or less. Thereafter, the reaction temperature when reacting the obtained compound with an organolithium compound is preferably -78°C or more and 70°C or less, more preferably -50°C or more and 50°C or less.

The compound represented by the general formula (13) can be prepared, for example, by reacting the compound represented by the general formula (7) with an organolithium in a hydrocarbon solvent to prepare a lithium amide compound, and then adding the compound represented by the general formula ( It can be obtained by reacting the alkyl dihalide represented by C) and further reacting an organolithium compound.
The reaction temperature when preparing a lithium amide compound using the compound represented by general formula (7), an organic lithium compound, and a hydrocarbon solvent is as described above.
The reaction temperature when reacting the compound represented by general formula (C) with the lithium amide compound is preferably -78°C or higher and 70°C or lower, more preferably -50°C or higher and 50°C or lower. Thereafter, the reaction temperature when reacting the obtained compound with an organolithium compound is preferably -78°C or more and 70°C or less, more preferably -50°C or more and 50°C or less.

The organolithium compound having at least one nitrogen atom in the molecule represented by the general formula (12) is a conjugated compound having a repeating unit in which R ₁₄ is represented by any one of formulas (15) to (17). When a diene polymer is represented, it is synthesized by the following steps (I) to (IV).
(I): A compound represented by general formula (6) and an organic lithium compound are reacted in a hydrocarbon solvent to synthesize a lithium amide compound.
(II): The obtained lithium amide compound is reacted with butadiene or isoprene in a hydrocarbon solvent.
(III): Lithium is deactivated by adding alcohol, and the resulting product is distilled under reduced pressure.
(IV): The product obtained by distillation is reacted with an organic lithium compound in a hydrocarbon solvent.

The reaction temperature in step (I) for preparing lithium amide using the compound represented by general formula (6), an organic lithium compound, and a hydrocarbon solvent is as described above. As the alcohol, common alcohols can be used, but those with a low molecular weight are preferable, and for example, methanol, ethanol, and isopropanol are preferable, and ethanol is more preferable. The reaction temperature in step (IV) is 0°C or higher and 80°C or lower, preferably 10°C or higher and 70°C or lower.

The organic lithium compound having at least one nitrogen atom in the molecule, represented by the general formula (14), is a conjugated compound having a repeating unit in which R ₁₄ is represented by any one of formulas (15) to (17). When a diene polymer is represented, it is synthesized by the following steps (I) to (IV).
(I): A compound represented by general formula (7) and an organic lithium compound are reacted in a hydrocarbon solvent to synthesize a lithium amide compound.
(II): The obtained lithium amide compound is reacted with butadiene or isoprene in a hydrocarbon solvent.
(III): Lithium is deactivated by adding alcohol, and the resulting product is distilled under reduced pressure.
(IV): The product obtained by distillation is reacted with an organic lithium compound in a hydrocarbon solvent.

<Polar compound>
When preparing the above-mentioned organolithium compound, a polar compound may be added to the system. This tends to promote production and solubilization in hydrocarbon solvents. Examples of the polar compound include, but are not limited to, tertiary monoamines, tertiary diamines, and chain or cyclic ethers.

Examples of tertiary monoamines include, but are not limited to, trimethylamine, triethylamine, methyldiethylamine, 1,1-dimethoxytrimethylamine, 1,1-diethoxytrimethylamine, 1,1-diethoxytriethylamine, N,N-dimethylformamide. Examples include diisopropyl acetal and N,N-dimethylformamide dicyclohexyl acetal.

Tertiary diamines include, but are not limited to, N,N,N',N'-tetramethyldiaminomethane, N,N,N',N'-tetramethylethylenediamine, N,N,N', N'-tetramethylpropanediamine, N,N,N',N'-tetramethyldiaminobutane, N,N,N',N'-tetramethyldiaminopentane, N,N,N',N'-tetramethyl Examples include hexanediamine, dipiperidinopentane, dipiperidinoethane.

Examples of the chain ether include, but are not limited to, dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene dimethyl ether.

Examples of the cyclic ether include, but are not limited to, tetrahydrofuran, bis(2-oxolanyl)ethane, 2,2-bis(2-oxolanyl)propane, 1,1-bis(2-oxolanyl)ethane, 2,2 -bis(2-oxolanyl)butane, 2,2-bis(5-methyl-2-oxolanyl)propane, and 2,2-bis(3,4,5-trimethyl-2-oxolanyl)propane.

Among polar compounds, tertiary monoamines trimethylamine and triethylamine; tertiary diamines N,N,N',N'-tetramethylethylenediamine; cyclic ethers tetrahydrofuran and 2,2-bis(2-oxolanyl)propane; is preferred. The polar compounds may be used alone or in combination of two or more.

When adding a polar compound when preparing the above-mentioned organolithium compound, it is preferably added within the range of 30 mass ppm or more and 50,000 mass ppm to the solvent used during preparation, and 200 mass ppm or more. It is more preferable to add within the range of 20,000 mass ppm or less.
In order to sufficiently express the effects of reaction acceleration and solubilization in the solvent, it is preferable to add 30 mass ppm or more, and it is necessary to ensure flexibility in adjusting the microstructure in the subsequent polymerization step and to reduce the amount of solvent after polymerization. Considering the separation from the polymerization solvent in the recovery and purification process, it is preferable to add it in an amount of 50,000 mass ppm or less.

The conjugated diene polymer before modification is conjugated using the above-mentioned organolithium compound having at least one nitrogen atom in the molecule, or a polymerization initiator system containing a compound having at least one nitrogen atom and an organolithium compound. It can be obtained by polymerizing using a diene compound or by copolymerizing a conjugated diene compound and an aromatic vinyl compound.

When producing a conjugated diene polymer containing a nitrogen atom as a conjugated diene polymer before modification, an organic lithium compound having at least one nitrogen atom in the molecule is heated in advance in a predetermined reactor in the polymerization process. The polymerization reaction may be carried out by preparing the conjugated diene compound in advance and supplying it to a reactor for copolymerizing the conjugated diene compound and the aromatic vinyl compound. The compound having atoms and the organolithium compound may be mixed using a static mixer or an in-line mixer.
When using the above-described organic lithium compound having at least one nitrogen atom in the molecule, the polymerization initiator system may be one type or a mixture of two or more types.
The conjugated diene polymer before modification is polymerized using a conjugated diene compound using a polymerization initiator system containing the above-mentioned compound having at least one nitrogen atom in the molecule and an organolithium compound. It is obtained by a polymerization process of copolymerizing the aromatic vinyl compound and the aromatic vinyl compound.

The polymerization process may be carried out either batchwise or continuously; however, from the viewpoint of stably producing a conjugated diene polymer with a high modification rate, high molecular weight, and high branching, continuous mode is preferred. Polymerization is preferred, and more preferred is continuous polymerization in one reactor or in two or more connected reactors.

The polymerization process for organolithium compounds can be carried out either continuously or batchwise, but from the viewpoint of production efficiency, monomers containing a conjugated diene compound and a polymerization initiator are continuously supplied to the polymerization tank, and a continuous process is recommended. A continuous type of polymerization is preferred. In the case of a continuous method, the monomer, solvent, and polymerization initiator used for polymerization may be fed into the polymerization tank separately, or a mixing tank equipped with an agitator may be used, or a static mixer or line mixer may be used in the piping. You may also use a method of continuous mixing using a .

The polymerization temperature is not particularly limited as long as the anionic polymerization proceeds, the chain transfer reaction is controlled, and the number of blocks in which 30 or more aromatic vinyl compound units are chained is small or absent, but from the viewpoint of productivity. Therefore, the temperature is preferably 45°C or higher, and from the viewpoint of controlling the chain transfer reaction and ensuring a sufficient amount of the modifier to react with the active terminal after completion of polymerization, the temperature is preferably 80°C or lower. From the viewpoint of reducing the number of blocks in which 30 or more vinyl units are chained, the temperature is more preferably 50°C or more and 78°C or less, and even more preferably 60°C or more and 75°C or less.

In the polymerization process, from the viewpoint of controlling the chain transfer reaction described above, the solid content, which is the content of the conjugated diene compound, aromatic vinyl compound, etc., relative to the total mass of the conjugated diene compound, aromatic vinyl compound, and solvent. The content (also referred to as "monomer concentration") is preferably 16% by mass or less, more preferably 15% by mass or less, and still more preferably 14% by mass or less. Further, the lower limit of the solid content is not particularly limited, but is preferably 12.5% by mass or more.

<Conjugated diene polymer>
The conjugated diene polymer before modification of the modified conjugated diene polymer of this embodiment is obtained by polymerizing at least a conjugated diene compound in a hydrocarbon solvent, and is obtained by copolymerizing the conjugated diene compound and an aromatic vinyl compound. You can also get it by doing so.
The conjugated diene polymer is preferably obtained by growing an anionic polymerization reaction using a continuous polymerization method using an organolithium compound having at least one nitrogen atom in the molecule as a polymerization initiator. In particular, the conjugated diene polymer is preferably a polymer having active terminals obtained by a growth reaction by living anionic polymerization. Thereby, a modified conjugated diene polymer with a high modification rate can be obtained.

<Conjugated diene compound>
Conjugated diene compounds include, but are not limited to, as long as they are polymerizable monomers, such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, -methyl-1,3-pentadiene, 1,3-heptadiene, and 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

<Aromatic vinyl compound>
Examples of aromatic vinyl compounds include, but are not limited to, as long as they are monomers copolymerizable with a conjugated diene compound, such as styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, Diphenylethylene is mentioned. Among these, styrene is preferred from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

<Solvent>
In the polymerization step, the polymerization is preferably carried out in a solvent. Examples of the 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 hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; Hydrocarbons include aromatic hydrocarbons such as benzene, toluene, xylene, and mixtures thereof.

The amount of bonded conjugated diene in the conjugated diene polymer before modification of the modified conjugated diene polymer of this embodiment is not particularly limited, but is preferably 50% by mass or more and 100% by mass or less, and 60% by mass or more. More preferably, it is 80% by mass or less.
Further, the amount of bonded aromatic vinyl in the conjugated diene polymer before modification of the modified conjugated diene polymer of the present embodiment is not particularly limited, but is preferably 30% by mass or more and 50% by mass or less, and 20% by mass or less. It is more preferable that the amount is 40% by mass or less. When the amount of bonded conjugated diene and the amount of bonded aromatic vinyl are within the above ranges, it is possible to obtain a vulcanizate that has an even better balance between low hysteresis loss property and wet skid resistance, and has more satisfactory abrasion resistance and fracture strength. It tends to be possible. 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 can be measured according to the method described in Examples described later.

In the modified conjugated diene polymer of the present embodiment, the amount of vinyl bonds in the conjugated diene bonding units is not particularly limited, but is preferably 30 mol% or more. When the amount of vinyl bonds is within the above range, the compatibility between the conjugated diene polymer and natural rubber tends to be excellent, so when a composition using these is made into a vulcanized product, it tends to have excellent wear resistance. be. Here, when the modified conjugated diene polymer is a copolymer of butadiene and styrene, the butadiene bonding unit is The vinyl bond amount (1,2-bond amount) can be determined. Specifically, it is measured by the method described in Examples below.

The conjugated diene polymer may be a random copolymer or a block copolymer. Examples of random copolymers include, but are not limited to, butadiene-isoprene random copolymers, butadiene-styrene random copolymers, isoprene-styrene random copolymers, and butadiene-isoprene-styrene random copolymers. It will be done. The composition distribution of each monomer in the copolymer chain is not particularly limited; for example, a completely random copolymer with a composition close to statistically random, a tapered (gradient) random copolymer with a tapered composition distribution, etc. Examples include copolymers. The bonding mode of the conjugated diene, ie, the composition of 1,4-bonds, 1,2-bonds, etc., may be uniform or may be distributed.

Examples of the block copolymer include, but are not limited to, a type 2 block copolymer consisting of two blocks, a type 3 block copolymer consisting of three blocks, and a type 4 block copolymer consisting of four blocks. Can be mentioned. For example, a block made of an aromatic vinyl compound such as styrene is represented by S, and a block made of a conjugated diene compound such as butadiene or isoprene and/or a block made of a copolymer of an aromatic vinyl compound and a conjugated diene compound is represented by B. Specifically, it is represented by an S-B2 type block copolymer, an S-B-S3 type block copolymer, an S-B-S-B4 type block copolymer, etc.

In each of the above equations, the boundaries of each block do not necessarily need to be clearly distinguished. For example, when block B is a copolymer of an aromatic vinyl compound and a conjugated diene compound, the aromatic vinyl compound in block B may be uniformly distributed or tapered. Further, in the block B, a plurality of portions where the aromatic vinyl compound is uniformly distributed and/or a plurality of portions where the aromatic vinyl compound is distributed in a tapered shape may coexist. Furthermore, in block B, a plurality of segments having different contents of aromatic vinyl compounds may coexist. When a plurality of blocks S and B are present in the copolymer, their structures such as molecular weight and composition may be the same or different.

In this embodiment, the conjugated diene polymer obtained by the production method described above is further hydrogenated in an inert solvent to convert all or part of the double bonds into saturated hydrocarbons. can. In that case, heat resistance and weather resistance tend to be improved, and deterioration of the product when processed at high temperatures can be prevented. As a result, it exhibits even better performance in various applications such as automotive applications.

The hydrogenation rate of unsaturated double bonds based on the conjugated diene compound (also simply referred to as "hydrogenation rate") can be arbitrarily selected depending on the purpose and is not particularly limited. When used as a vulcanized rubber, it is preferable that the double bond of the conjugated diene portion remains partially. From this point of view, the hydrogenation rate of the conjugated diene moiety in the polymer is preferably 3.0% or more and 70% or less, more preferably 5.0% or more and 65% or less, and 10% or more and 60% or less. It is more preferable that it is the following. Further, the hydrogenation rate of the aromatic double bond based on the aromatic vinyl compound in the copolymer of the conjugated diene compound and the aromatic vinyl compound is not particularly limited, but it is preferably 50% or less, and 30% or less. % or less, more preferably 20% or less. The hydrogenation rate can be determined using a nuclear magnetic resonance apparatus (NMR).

The hydrogenation method 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 particularly mild hydrogenation conditions. Further, hydrogenation of aromatic groups can be carried out by using a supported noble metal catalyst.

Specific examples of hydrogenation catalysts include, but are not limited to, the following: (1) Supported heterogeneous catalysts in which metals such as Ni, Pt, Pd, and Ru are supported on carbon, silica, alumina, diatomaceous earth, etc. (2) A so-called Ziegler type hydrogenation catalyst using an organic acid salt such as Ni, Co, Fe, or Cr or a transition metal salt such as an acetylacetone salt and a reducing agent such as an organic aluminum, (3) Ti , Ru, Rh, Zr, and other so-called organometallic complexes. 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, Hydrogenation catalysts described in JP-A No. 2-9041 and JP-A-8-109219 may also be mentioned. Preferred hydrogenation catalysts include reaction mixtures of titanocene compounds and reducing organometallic compounds.

If arenes, acetylenes, etc. are contained as impurities in the conjugated diene compound, there is a possibility that the modification reaction described below may be inhibited. Therefore, the total content concentration (mass) of these impurities is preferably 200 mass ppm or less, more preferably 100 mass ppm or less, and 50 mass ppm or less, based on the total amount of the conjugated diene compound. It is more preferable that Examples of arenes include propadiene and 1,2-butadiene. Examples of acetylenes include ethyl acetylene and vinyl acetylene.

When the microstructure (the amount of each bond in the modified conjugated diene copolymer) is within the above range and the glass transition temperature of the copolymer is within the range of -45°C or higher and -15°C or lower, low hysteresis loss can be achieved. A more excellent vulcanizate can be obtained by balancing the properties and wet skid resistance.

Regarding the glass transition temperature, according to ISO22768:2006, 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 before modification of the modified conjugated diene polymer of this embodiment is a copolymer of a conjugated diene compound and an aromatic vinyl compound, a block in which 30 or more aromatic vinyl units are chained is Preferably, the number is small or absent. Specifically, when the copolymer is a butadiene-styrene copolymer, the method of Kolthoff (method described in I.M. KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946)) is used. In a known method of decomposing a polymer and analyzing the amount of polystyrene insoluble in methanol, the block in which 30 or more aromatic vinyl units are linked is preferably 5.0% by mass or less based on the total amount of the polymer, More preferably, it is 3.0% by mass or less.

(denaturation process)
The method for producing a modified conjugated diene polymer of the present embodiment involves modifying a conjugated diene polymer with a modifier having four or more alkoxy groups bonded to a silyl group and a tertiary amino group in one molecule. Includes a denaturation step.

<Modifier>
Modifiers include, but are not limited to, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3 -triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1 -(5-trimethoxysilylpentyl)-1-aza-2-silacycloheptane tris(3-trimethoxysilylpropyl)amine, tris(3-methyldimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl) amine, tris(3-methyldiethoxysilylpropyl)amine.

From the viewpoint of fuel efficiency performance, the modifier preferably contains a modifier represented by any one of the following general formulas (18) to (20).

In the general formula (18), 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 is an alkylene group having 1 to 10 carbon atoms. , R ⁶ represents an alkylene group having 1 to 20 carbon atoms, m represents an integer of 1 or 2, and n represents an integer of 2 or 3. (m+n) is an integer of 4 or more. When a plurality of R ¹ to R ⁴ are present, each of them is independent and may be the same or different.

In the general formula (19), 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 represent a carbon atom. It represents an alkylene group of numbers 1 to 20, 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 and may be the same or different.

In general formula (20), 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 and R ⁶ each independently represent a carbon represents an alkylene group having a number of 1 to 20, m and n each independently represent an integer of 1 to 3, (m+n) represents an integer of 4 or more, and R ⁷ represents an integer of 1 to 20 carbon atoms. represents an alkyl group, an aryl group having 6 to 20 carbon atoms, or a silyl group substituted with a hydrocarbon group. When a plurality of R ¹ to R ⁴ are present, each of them is independent and may be the same or different.

Examples of the modifier represented by general formula (18) include, but are not limited to, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2 , 2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-sila Cyclohexane, 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-trimethoxysilyl) propyl)-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, 2-ethoxy,2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silacyclopentane can be mentioned.
Among these, those in which m represents 2 and n represents 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, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1 -aza-2-silacyclopentane is preferred.

The reaction temperature, reaction time, etc. when reacting the modifier of general formula (18) with the polymerization active terminal are not particularly limited, but it is preferable to react at a temperature of 0° C. or higher and 120° C. or lower for 30 seconds or longer.
The total number of moles of the alkoxy groups bonded to the silyl groups in the modifier compound represented by the general formula (18) is 0.0% of the number of moles added of the alkali metal compound and/or alkaline earth metal compound of the polymerization initiator. It is preferably in a range of 6 times or more and 3.0 times or less, more preferably in a range of 0.8 times or more and 2.5 times or less, and in a range of 0.8 or more and 2.0 times or less. It is even more preferable that there be. From the viewpoint of obtaining a sufficient modification rate, molecular weight, and branched structure of the resulting 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 to each other to form a branched structure. In addition to the fact that it is preferable to obtain a polymer component, from the viewpoint of modifier cost, it is preferable that the amount is 3.0 times or less.

Modifiers represented by general formula (19) include, but are not limited to, tris(3-trimethoxysilylpropyl)amine, tris(3-methyldimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-trimethoxysilylpropyl)amine, silylpropyl)amine, tris(3-methyldiethoxysilylpropyl)amine, tris(trimethoxysilylmethyl)amine, tris(2-trimethoxysilylethyl)amine, tris(4-trimethoxysilylbutyl)amine. .
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. . 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 general formula (19) 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 general formula (19) is 0.6 times or more the number of moles of lithium constituting the above-mentioned polymerization initiator system. It is preferably within a range of 0.8 times or more and 2.5 times or less, and even more preferably within a range of 0.8 times or more and 2.0 times or less. . 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 to each other to form a branched polymer. In addition to the fact that it is preferable to obtain the components, from the viewpoint of modifier cost, it is preferable that the amount is 3.0 times or less.

Examples of the modifier represented by the general formula (20) include, but are not limited to, bis(3-(methylamino)propyl)trimethoxysilane, bis(3-(ethylamino)propyl)trimethoxysilane, Examples include bis(3-(propylamino)propyl)trimethoxysilane and bis(3-(butylamino)propyl)trimethoxysilane. Among these, it is preferable that n, m, and l are all 3 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. Preferred specific examples include bis(3-(methylamino)propyl)trimethoxysilane and bis(3-(ethylamino)propyl)trimethoxysilane.

The reaction temperature, reaction time, etc. when reacting the modifier represented by general formula (20) with the polymerization active terminal are not particularly limited, but the reaction should be carried out at 0°C or higher and 120°C or lower for 30 seconds or more. is preferred.

The modifier is used to obtain a modified conjugated diene polymer that has a high modification rate, high molecular weight, and high branching, and has an excellent balance of fuel efficiency, processability, and wear resistance when made into a vulcanized product. , a modifier represented by the general formula (18) is preferred, and m is 2 and n is 3 in the general formula (18), or a modifier represented by the general formula (19) is preferable. A modifier in which m, n, and l in general formula (19) are all 3 is preferred.

The total number of moles of the alkoxy groups bonded to the silyl groups in the modifier compound represented by the general formula (20) 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 4.0 times or less, more preferably the range is 0.8 times or more and 3.5 times or less, and the range is 0.8 times or more and 3.0 times or less. It is more preferable that
From the viewpoint of obtaining a sufficient modification rate of the obtained modified conjugated diene polymer, it is preferably 0.6 times or more, and in order to improve processability, the polymer terminals are coupled to each other to obtain a branched polymer component. In addition to being preferable, from the viewpoint of modifier cost, it is preferable to make it 4.0 times or less.

From the viewpoint of improving the modification rate, in the modification step, the content of the conjugated diene compound is preferably 100 mass ppm or more and 50,000 mass ppm or less, and 200 mass ppm or more, based on the total amount of all monomers and polymers. It is more preferably 10000 mass ppm or less, and even more preferably 300 mass ppm or more and 5000 mass ppm or less.

In the method for producing a modified conjugated diene polymer of the present embodiment, after the modification reaction is performed, a deactivator, a neutralizing agent, etc. may be added to the copolymer solution as necessary. Examples of the deactivator include, but are not limited to, water; and alcohols such as methanol, ethanol, and isopropanol. Examples of the neutralizing agent include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and versatic acid; aqueous solutions of inorganic acids, and carbon dioxide gas.

It is preferable to add a rubber stabilizer to the modified conjugated diene polymer of this embodiment from the viewpoint of preventing gel formation after polymerization and from the viewpoint of improving stability during processing. The stabilizer for rubber 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.

In order to improve the processability of the modified conjugated diene-based copolymer of this embodiment, extender oil can be added to the modified conjugated diene-based copolymer, if necessary. Methods for adding the extender oil to the modified conjugated diene polymer include, but are not limited to, the following methods: Add the extender oil to the polymer solution, mix, and remove the solvent from the oil-extended copolymer solution. The method is preferred. Examples of the extender oil include aroma oil, naphthenic oil, and paraffin oil. Among these, from the viewpoint of environmental safety, oil bleed prevention and wet grip properties, aromatic alternative oils containing 3% by mass or less of polycyclic aromatic (PCA) components according to the IP346 method are preferred. Examples of aroma substitute oils include TDAE (Treated Distillate Aromatic Extracts) and MES (Mild Extraction Sol) shown in Kautschuk Gummi Kunststoffe 52 (12) 799 (1999). vate) and RAE (Residual Aromatic Extracts). The amount of extension oil added is not particularly limited, but is preferably 10 parts by mass or more and 60 parts by mass or less, more preferably 15 parts by mass or more and 40 parts by mass or less, per 100 parts by mass of the modified conjugated diene polymer.

(Desolvation step)
A known method can be used to obtain the modified conjugated diene polymer of this embodiment from a polymer solution. Examples of this method include, for example, separating the solvent by steam stripping, filtering the polymer, dehydrating and drying it to obtain a polymer, concentrating it in a flushing tank, and then using a vent extruder. Examples include a method of devolatilizing with a drum dryer, and a method of directly devolatilizing with a drum dryer.

[Modified conjugated diene polymer composition]
The modified conjugated diene polymer of this embodiment is suitably used as a vulcanizate.
For example, the vulcanizate may include the modified conjugated diene polymer of this embodiment, an inorganic filler such as a silica-based inorganic filler or carbon black, and a material other than the modified conjugated diene polymer of this embodiment, if necessary. A modified conjugated diene polymer composition is prepared by mixing with a rubbery polymer, a silane coupling agent, a rubber softener, a wax, a vulcanizing agent, a vulcanization accelerator, a vulcanization aid, etc., and then heated. It can be obtained by vulcanization.
The modified conjugated diene polymer composition of the present embodiment includes a rubber component and a filler in an amount of 5.0 parts by mass or more and 150 parts by mass or less based on 100 parts by mass of the rubber component; The modified conjugated diene polymer of this embodiment is contained in an amount of 10% by mass or more based on the total amount of rubber components.

(rubber component)
As the rubber component used in the modified conjugated diene polymer composition, a rubbery polymer other than the modified conjugated diene polymer of this embodiment can be used in combination with the modified conjugated diene polymer of this embodiment.
Examples of such rubbery polymers include, but are not limited to, conjugated diene polymers or hydrogenated products thereof, random copolymers of conjugated diene compounds and vinyl aromatic compounds, or hydrogenated products thereof, Examples include block copolymers of conjugated diene compounds and vinyl aromatic compounds or hydrogenated products thereof, non-diene polymers, and natural rubber.
More specific rubbery polymers include, for example, butadiene rubber or its hydrogenated product, isoprene rubber or its hydrogenated product, styrene-butadiene rubber or its hydrogenated product, styrene-butadiene block copolymer or its hydrogenated product. Examples include styrene elastomers such as rubber, styrene-isoprene block copolymers or hydrogenated products thereof, acrylonitrile-butadiene rubber or hydrogenated products thereof.

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

The various rubbery polymers mentioned above may be modified rubbers to which polar functional groups such as hydroxyl groups and amino groups are added. In addition, from the viewpoint of balance between performance and processing characteristics, the weight average molecular weight is preferably 2,000 or more and 2,000,000 or less, more preferably 5,000 or more and 1,500,000 or less. preferable. The weight average molecular weight can be measured by the same method as the method for measuring modified conjugated diene polymers described in Examples. Furthermore, low molecular weight so-called liquid rubber can also be used as the rubbery polymer. These rubbery polymers may be used alone or in combination of two or more.

In the case of a modified conjugated diene polymer composition containing the modified conjugated diene polymer of this embodiment and the rubber-like polymer described above, the blending ratio (mass ratio) of these is (modified conjugated diene polymer). 20/80 or more and 100/0 or less, more preferably 30/70 or more and 90/10 or less, and even more preferably 50/50 or more and 80/20 or less. When the (modified conjugated diene polymer/rubber-like polymer) is within the above range, the vulcanizate has a better balance between low hysteresis loss property and wet skid resistance, and has even more satisfactory abrasion resistance and fracture strength. There is a tendency to be able to obtain
Furthermore, when combining the modified conjugated diene polymer of the present embodiment with natural rubber, it is preferable that 10% by mass or more of natural rubber is contained based on the total amount of rubber components. This provides the effect of improving wear resistance.

The modified conjugated diene polymer composition of the present embodiment includes a rubber component and a filler in an amount of 5.0 parts by mass or more and 150 parts by mass or less based on 100 parts by mass of the rubber component.
Particularly preferred is one containing 100 parts by mass of a rubber component containing 20% by mass or more of the above-mentioned modified conjugated diene polymer and 0.5 parts by mass or more and 150 parts by mass or less of a silica-based inorganic filler.
By dispersing a silica-based inorganic filler in the modified conjugated diene-based polymer of this embodiment, when made into a vulcanized product, it has an excellent balance between low hysteresis loss property and wet skid resistance, and is sufficient for practical use. It has excellent wear resistance and fracture strength, and tends to be able to provide excellent processability when made into a vulcanizate.
The modified conjugated diene polymer composition of the present embodiment preferably contains a silica-based inorganic filler also when used for vulcanized rubber applications such as tires, automobile parts such as anti-vibration rubber, and shoes.

The silica-based inorganic filler is not particularly limited and any known one can be used, but solid particles containing SiO ₂ or Si ₃ Al as a constituent unit are preferred, and SiO ₂ or Si ₃ Al is the main constituent unit. It is more preferable to use it as a component. Here, the main component refers to a component contained in the silica-based inorganic filler in an amount of 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more.

Examples of the silica-based inorganic filler include, but are not limited to, inorganic fibrous substances such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber. As a commercially available product of silica, for example, the product name "Ultrasil 7000GR" manufactured by Evonik Degussa may be mentioned. Also included are silica-based inorganic fillers whose surfaces have been made hydrophobic, and mixtures of silica-based inorganic fillers and inorganic fillers other than silica-based fillers. Among these, from the viewpoint of strength and abrasion resistance, silica and glass fiber are preferred, and silica is more preferred. Examples of silica include dry silica, wet silica, and synthetic silicate silica. Among these, wet silica is more preferred from the viewpoint of improving fracture properties and having an excellent balance of wet skid resistance. In the modified conjugated diene polymer composition, from the viewpoint of obtaining practically good wear resistance and fracture characteristics, the nitrogen adsorption specific surface area of the silica-based inorganic filler determined by the BET adsorption method is 100 m ² /g or more and 300 m ² /g or less, and more preferably 170 m ² /g or more and 250 m ² /g or less. If necessary, fillers with a relatively small specific surface area (for example, a silica-based inorganic filler with a specific surface area of 200 m ² /g or less) and silica-based inorganic fillers with a relatively large specific surface area (for example, a silica filler with a specific surface area of 200 m ² /g or more) may be used. (based on inorganic fillers) can be used in combination. This makes it possible to achieve a high balance between good wear resistance and fracture properties and low hysteresis loss.

As mentioned above, the blending amount of the silica-based inorganic filler in the modified conjugated diene polymer composition is such that the inorganic filler is sufficiently dispersed and the processability and mechanical strength of the composition are practically sufficient. From the viewpoint of is more preferable, and even more preferably 20 parts by mass or more and 100 parts by mass or less.

The modified conjugated diene polymer composition of this embodiment may contain carbon black. Examples of carbon black include, but are not limited to, carbon blacks of various classes such as SRF, FEF, HAF, ISAF, and SAF. Commercially available products include, for example, the product name "SEAST KH (N339)" manufactured by Tokai Carbon Co., Ltd. Among these, those with a nitrogen adsorption specific surface area of 50 m ² /g or more and a dibutyl phthalate (DBP) oil absorption of 80 mL/100 g or less carbon black is preferred.

The blending amount of carbon black is preferably 0.5 parts by mass or more and 100 parts by mass or less, and 3.0 parts by mass or more and 100 parts by mass or less, based on 100 parts by mass of the rubber component containing the modified conjugated diene polymer of this embodiment. is more preferable, and even more preferably 5.0 parts by mass or more and 50 parts by mass or less. The blending amount of carbon black is preferably 0.5 parts by mass or more from the viewpoint of achieving the performance required for applications such as tires such as dry grip performance and conductivity, and from the viewpoint of dispersibility, it is preferably 100 parts by mass. The following is preferable.

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

The modified conjugated diene polymer composition of this embodiment may contain a silane coupling agent. The silane coupling agent has the function of closely interacting the rubber component and the silica-based inorganic filler, and has groups that have affinity or bonding properties for the rubber component and the silica-based inorganic filler. Generally, a compound having a sulfur bond, an alkoxysilyl group, or a silanol group in one molecule is used. For example, bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, bis-[2-(triethoxysilyl)-ethyl]-tetra Sulfide may be mentioned, and a commercially available product may include, for example, the product name "Si75" manufactured by Evonik Degussa.

The blending amount of the silane coupling agent is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 0.5 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the above-mentioned silica-based inorganic filler. More preferably 1.0 parts by mass or more and 15 parts by mass or less. When the amount of the silane coupling agent is within the above range, the effect of the addition of the silane coupling agent tends to be more pronounced.

The modified conjugated diene polymer composition of this embodiment may contain a rubber softener in order to improve processability. As the rubber softener, mineral oil or a liquid or low molecular weight synthetic softener is suitable. A mineral oil-based rubber softener called process oil or extender oil, which is used to soften, increase volume, and improve processability of rubber, is a mixture of aromatic rings, naphthenic rings, and paraffin chains. Those in which the number of carbon atoms in the paraffin chain accounts for 50% or more of all carbons are called paraffinic, those in which the naphthene ring carbon number is 30% to 45% are naphthenic, and those in which the number of aromatic carbons exceeds 30% are called paraffinic. It is called aromatic. Commercially available products include, for example, S-RAE oil manufactured by Japan Energy Co., Ltd. under the trade name "JOMO Process NC140." As the rubber softener used with the modified conjugated diene-aromatic vinyl copolymer of the present embodiment, one having an appropriate aromatic content is preferred because it tends to be compatible with the copolymer.

The blending amount of the rubber softener is preferably 0 parts by mass or more and 100 parts by mass or less, and 10 parts by mass or more and 90 parts by mass or less, based on 100 parts by mass of the rubber component containing the modified conjugated diene polymer of the present embodiment. is more preferable, and still more preferably 30 parts by mass or more and 90 parts by mass or less. Bleed-out and stickiness on the surface of the composition tend to be suppressed by blending the rubber softener in an amount of 100 parts by mass or less per 100 parts by mass of the rubber component.

About the method of mixing the modified conjugated diene polymer of this embodiment with other rubber-like polymers, silica-based inorganic fillers, carbon black and other fillers, silane coupling agents, rubber softeners, and other additives. is not particularly limited. The method includes, for example, a melt-kneading method using a general mixing machine such as an open roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, a multi-screw extruder, etc., and melting and mixing of each component. After that, the solvent may be 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. Further, it is possible to apply either a method of kneading the modified conjugated diene polymer and various compounding agents at once or a method of mixing the modified conjugated diene polymer and various compounding agents in a plurality of batches.

The modified conjugated diene polymer composition 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 amount of the vulcanizing agent used is preferably 0.01 parts by mass or more and 20 parts by mass or less, and 0.1 parts by mass or more and 15 parts by mass, based on 100 parts by mass of the rubber component containing the modified conjugated diene polymer of the present embodiment. Part 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 the vulcanization, a vulcanization accelerator and a vulcanization aid may be used as necessary. As the vulcanization accelerator, conventionally known materials can be used, such as sulfenamide type, guanidine type, thiuram type, aldehyde-amine type, aldehyde-ammonia type, thiazole type, thiourea type, dithiocarbamate type. Vulcanization accelerators such as Specific compounds include, for example, N-cyclohexyl-2-benzothiazylsulfinamide and diphenylguanidine. Further, the vulcanization aid is not limited to the following, but examples thereof include zinc white and stearic acid. The amount of the vulcanization accelerator used is preferably 0.01 parts by mass or more and 20 parts by mass or less, and 0.1 parts by mass or more, based on 100 parts by mass of the rubber component containing the modified conjugated diene polymer of the present embodiment. More preferably, it is 15 parts by mass or less.

The modified conjugated diene polymer composition of this embodiment may contain other softeners and fillers other than those mentioned above, as long as the purpose of this embodiment is not impaired. Uses various additives such as waxes such as "Sunnock N", heat-resistant stabilizers, antistatic agents, weather-resistant stabilizers, anti-aging agents such as N-isopropyl-N'-phenyl-p-phenylenediamine, colorants, and lubricants. You can. As other softeners, known softeners can be used. 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.

The modified conjugated diene polymer composition of this embodiment can be crosslinked by adding a vulcanizing agent, a vulcanization accelerator, various additives, etc., and can be used as a rubber composition for manufacturing desired rubber products.
A rubber composition obtained by crosslinking a modified conjugated diene polymer composition can be used for tires, anti-vibration rubber, and various industrial products.

Hereinafter, this embodiment will be explained in more detail by giving specific examples and comparative examples, but this embodiment is not limited to the following examples and comparative examples unless it exceeds the gist thereof. .
Various physical properties in Examples and Comparative Examples were measured by the methods shown below.

((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 amount of absorption of ultraviolet absorption wavelength (near 254 nm) by the phenyl group of styrene (product name "UV" manufactured by Shimadzu Corporation). -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 microstructure of the butadiene moiety, that is, the amount of 1,2-vinyl bonds ( (mol%) was determined (trade name "FT-IR230" manufactured by JASCO Corporation).

((Physical property 3) Mooney viscosity and Mooney relaxation rate of polymer)
Using a conjugated diene polymer before adding a modifier or a modified conjugated diene polymer as a sample, JIS K6300 (ISO289-1) and ISO289- 4, Mooney viscosity and Mooney relaxation rate were measured.
The measurement temperature was 110°C.
First, after preheating the sample 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₎ ). Then, when using a modified conjugated diene polymer as a sample, immediately stop the rotation of the rotor, record the torque every 0.1 seconds for 1.6 to 5 seconds after stopping, and record the torque in Mooney units. The slope of the straight line when time (seconds) was plotted logarithmically was determined, and its absolute value was defined as the Mooney relaxation rate (MSR).

((Physical property 4) Modification rate)
Using a modified conjugated diene polymer as a sample, it was measured by applying the property of adsorption of modified components to a GPC column using silica gel as a filler.
The amount of adsorption to the silica column was determined from the difference between the chromatogram measured using a polystyrene gel column and the chromatogram measured using a silica column for a sample solution containing the sample and a low molecular weight internal standard polystyrene, and the denaturation rate was determined. .
Specifically, it is as shown below.

Sample preparation: 10 mg of sample and 5 mg of standard polystyrene were dissolved in 20 mL of tetrahydrofuran (THF).
Polystyrene column GPC measurement conditions: Using THF as an eluent, 200 μL of the sample was injected into the device and measured.
The columns were used by connecting three guard columns: "TSKguardcolumn HHR-H" manufactured by Tosoh Corporation and three columns "TSKgel SuperMultipore HZ-H" manufactured by Tosoh Corporation.
A chromatogram was obtained by measuring the THF in TEA solution at a column oven temperature of 40° C. and a flow rate of 1.0 mL/min using an RI detector (trade name “HLC8020” manufactured by Tosoh Corporation).
Silica column GPC measurement conditions: Using THF as an eluent, 200 μL of a sample was injected into the device and measured.
The column used was the product name "Zorbax" manufactured by DuPont. A chromatogram was obtained by measuring using an RI detector (trade name "HLC8020" manufactured by Tosoh Corporation) under the conditions of a column oven temperature of 40° C. and a THF flow rate of 0.5 mL/min.
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 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 5) Weight average molecular weight, number average molecular weight)
Using a modified conjugated diene polymer or a conjugated diene polymer before addition of a modifier as a sample, measure a 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 obtained using standard polystyrene.
Tetrahydrofuran (THF) was used as the eluent.
The columns were used in connection with three guard columns: "TSKguardcolumn HHR-H" manufactured by Tosoh Corporation, and three columns "TSKgel SuperMultipore HZ-H" 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 in TEA 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.

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

((Physical property 7) Nitrogen atom content (mass ppm))
Using a modified conjugated diene polymer as a sample, a trace total nitrogen analyzer (“TN-2100H” manufactured by Mitsubishi Chemical Analytech) was conducted in accordance with JIS-2609: Crude oil and petroleum products - Nitrogen content test method, chemiluminescence method. Under dehydration conditions, nitrogen monoxide, which is produced by thermal decomposition in a sample under a flow of argon gas and then oxidized by combustion, is reacted with ozone gas under dehydration conditions, and the luminescence intensity in the range 590 to 2500 nm is detected. The nitrogen content was determined from the area value of the luminescence intensity.

[ Reference Example 1] Modified conjugated diene polymer (Sample 1)
It has an internal volume of 10L, a ratio of internal height (L) to diameter (D) (L/D) of 4.0, an inlet at the bottom, an outlet at the top, a stirrer and Two autoclaves each having a jacket for temperature control were connected. Furthermore, a static mixer was connected downstream of the outlet of the second reactor, and 1,3-butadiene, from which impurities such as moisture had been removed, was added at 29.0 g/min.
minutes, styrene was mixed at 18.9 g/min, and n-hexane was mixed at 180.2 g/min. Immediately before this mixed solution enters the first reactor, 0.0.
After being supplied at a rate of 0.087 mmol/min and mixed with a static mixer, it was continuously supplied to the bottom of the first reactor. Furthermore, 2,2-bis(2-oxolanyl)propane was added as a polar substance at a rate of 0.018 g/min, and as a polymerization initiator, piperidinolithium (also referred to as "1-lithiopiperidine") was prepared as lithium amide. ) and n-butyllithium (molar ratio of piperidinolithium and n-butyllithium was 0.75:0.25)
was supplied to the bottom of the first reactor at a rate of 0.180 mmol/min, and the reactor internal temperature was raised to 65 mmol/min.
It was kept at ℃. 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. A small amount of the copolymer solution before addition of the modifier was extracted from the outlet of the second reactor, and an antioxidant (BHT) was added in an amount of 0.2 g per 100 g of polymer, the solvent was removed, and the solution was heated to 110°C. The Mooney viscosity was measured and found to be 51.3.

Next, the modifier 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane shown in Table 1 (Table 1) was added to the copolymer solution flowing continuously in a static mixer. (hereinafter referred to as "AS-1") was added at a rate of 0.07 mmol/min to carry out a modification reaction. An antioxidant (BHT) was continuously added to the polymer solution flowing out from the static mixer in an amount of 0.2 g per 100 g of polymer to terminate the modification reaction, and then the solvent was removed and the modified conjugated diene polymer was added. A coalesce (sample 1) was obtained.

As a result of analyzing sample 1, the Mooney viscosity at 110°C was 118, the amount of bound styrene was 36.9% by mass, the amount of vinyl bonds in the butadiene bond unit (1,2-bond amount) was 39.0 mol%, and the modification rate. was 92.3%. Other physical properties of Sample 1 are also shown in Table 1.

[Example 2] Modified conjugated diene polymer (sample 2)
Except that the amount of modifier added was changed from 0.070 mmol/min to 0.09 mmol/min.
A modified conjugated diene polymer (Sample 2) was obtained in the same manner as in Reference Example 1.
Table 1 shows the physical properties of the sample.

[Example 3] Modified conjugated diene polymer (sample 3)
Except that the amount of modifier added was changed from 0.070 mmol/min to 0.12 mmol/min.
A modified conjugated diene polymer (Sample 3) was obtained in the same manner as in Reference Example 1.
Table 1 shows the physical properties of the sample.

[ Reference Example 4] Modified conjugated diene polymer (Sample 4)
A modified conjugated diene polymer (sample 4) was obtained in the same manner as in Reference Example 1, except that the molar ratio of piperidinolithium and n-butyllithium was changed to 0.90:0.10.
Table 1 shows the physical properties of the sample.

[Example 5] Modified conjugated diene polymer (sample 5)
A modified conjugated diene polymer (sample 5) was obtained in the same manner as in Reference Example 1, except that the molar ratio of piperidinolithium and n-butyllithium was changed to 0.50:0.50.
Table 1 shows the physical properties of the sample.

[ Reference Example 6] Modified conjugated diene polymer (Sample 6)
The amount of the mixed solution of piperidinolithium and n-butyllithium (the molar ratio of piperidinolithium and n-butyllithium was 0.75:0.25) was 0.180 mmol/min to 0.360 mmol/ 0.07 mmol/min to 0.1 min.
A modified conjugated diene polymer (sample 6) was obtained in the same manner as in Reference Example 1 except that the rate was changed to 4 mmol/min.
Table 1 shows the physical properties of the sample.

[ Reference Example 7] Modified conjugated diene polymer (Sample 7)
The amount of the mixed solution of piperidinolithium and n-butyllithium (the molar ratio of piperidinolithium and n-butyllithium was 0.75:0.25) was 0.180 mmol/min to 0.108 mmol/ 0.07 mmol/min, and the amount of modifier added was 0.07 mmol/min.
A modified conjugated diene polymer (sample 7) was obtained in the same manner as in Reference Example 1 except that the flow rate was changed to 42 mmol/min.
Table 1 shows the physical properties of the sample.

[ Reference Example 8] Modified conjugated diene polymer (Sample 8)
A modified conjugated diene polymer (sample 8) was obtained in the same manner as in Reference Example 1, except that the molar ratio of piperidinolithium and n-butyllithium was changed to 0.25:0.75.
Table 1 shows the physical properties of the sample.

[ Reference Example 9] Modified conjugated diene polymer (Sample 9)
2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane was converted into 1,2- bis( triethoxysilyl)ethane (in the table, "AS-2" and Sample 9 was obtained in the same manner as in Reference Example 1 except that the sample was changed to (abbreviated).
Table 1 shows the physical properties of the sample.

[ Reference Example 10] Modified conjugated diene polymer (Sample 10)
The amount of 2,2-bis(2-oxolanyl)propane, which is a polar substance, was adjusted to 0.018g/
Sample 10 was obtained in the same manner as in Reference Example 1 except that the speed was changed from 0.09 g/min to 0.09 g/min.
Table 1 shows the physical properties of the sample.

[Example 11] Modified conjugated diene polymer (Sample 11)
The amount of 2,2-bis(2-oxolanyl)propane, which is a polar substance, was adjusted to 0.019g/
minute to 0.09 g/min, and the amount of piperidinolithium added was changed from 0.162 g/min to 0.09 g/min.
18 g/min, and the amount of n-butyllithium added was changed from 0.018 g/min to 0 g/min.
A modified conjugated diene polymer (sample 11) was obtained in the same manner as in Reference Example 1, except that the amount of the modifier added was changed from 0.07 mmol to 0.09 mmol.
Table 1 shows the physical properties of the sample.

[Example 12] Modified conjugated diene polymer (Sample 12)
The amount of piperidinolithium added was changed from 0.135 g/min to 0.18 g/min, the amount of n-butyllithium added was changed from 0.045 g/min to 0 g/min, and the amount of modifier added was changed to 0.07 m
A modified conjugated diene polymer (sample 12) was obtained in the same manner as in Reference Example 1 except that the mol was changed to 0.09 mmol.
Table 1 shows the physical properties of the sample.

[Example 13] Modified conjugated diene polymer (Sample 13)
The same procedure as in Reference Example 1 was carried out, except that the molar ratio of piperidinolithium and n-butyllithium was changed to 0.25:0.75, and the amount of modifier added was changed from 0.07 mmol to 0.09 mmol. A modified conjugated diene polymer (Sample 13) was obtained.
Table 2 shows the physical properties of the sample.

[ Reference Example 14] Modified conjugated diene polymer (Sample 14)
The amount of piperidinolithium added was changed from 0.135 g/min to 0.27 g/min, the amount of n-butyllithium added was changed from 0.045 g/min to 0.09 g/min, and the amount of modifier added was changed from 0.135 g/min to 0.27 g/min.
A modified conjugated diene polymer (sample 14) was obtained in the same manner as in Reference Example 1 except that the amount was changed from 0.07 mmol to 0.09 mmol.
Table 2 shows the physical properties of the sample.

[Example 15] Modified conjugated diene polymer (Sample 15)
The amount of piperidinolithium added was changed from 0.135 g/min to 0.081 g/min, the amount of n-butyllithium added was changed from 0.045 g/min to 0.027 g/min, and the amount of modifier added was changed to 0.07 mmol. A modified conjugated diene polymer (sample 15) was obtained in the same manner as in Reference Example 1 except that the amount was changed from 0.09 mmol to 0.09 mmol.
Table 2 shows the physical properties of the sample.

[ Reference Example 16] Modified conjugated diene polymer (Sample 16)
2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane was converted into 1,2- bis( triethoxysilyl)ethane (in the table, "AS-2" and A modified conjugated diene polymer (sample 16) was obtained in the same manner as in Reference Example 1, except that the amount of the modifier was changed from 0.07 mmol to 0.09 mmol.
Table 2 shows the physical properties of the sample.

[Example 17] Modified conjugated diene polymer (Sample 17)
The amount of piperidinolithium added was changed from 0.135 g/min to 0.081 g/min, the amount of n-butyllithium added was changed from 0.045 g/min to 0.027 g/min, and the amount of modifier added was changed to 0.07 mmol. A modified conjugated diene polymer (sample 17) was obtained in the same manner as in Reference Example 1 except that the amount was changed from 0.09 mmol to 0.09 mmol.
Table 2 shows the physical properties of the sample.

[Example 18] Modified conjugated diene polymer (Sample 18)
A modified conjugated diene polymer (sample 18) was obtained in the same manner as in Reference Example 1, except that the amount of the modifier added was changed from 0.07 mmol to 0.10 mmol.
Table 2 shows the physical properties of the sample.

[Example 19] Modified conjugated diene polymer (Sample 19)
A modified conjugated diene polymer (sample 19) was obtained in the same manner as in Reference Example 1, except that the amount of the modifier added was changed from 0.07 mmol to 0.080 mmol.
Table 2 shows the physical properties of the sample.

[Example 20] Modified conjugated diene polymer (Sample 20)
A modified conjugated diene polymer (sample 20) was obtained in the same manner as in Reference Example 1, except that the amount of the modifier added was changed from 0.07 mmol to 0.85 mmol.
Table 2 shows the physical properties of the sample.

[Comparative Example 1] Modified conjugated diene polymer (Sample 21)
A modified conjugated diene polymer (sample 21) was obtained in the same manner as in Reference Example 1, except that the amount of the modifier added was changed from 0.070 mmol/min to 0.047 mmol/min.
Table 2 shows the physical properties of the sample.

[Comparative Example 2] Modified conjugated diene polymer (Sample 22)
The amount of the mixed solution of piperidinolithium and n-butyllithium (the molar ratio of piperidinolithium and n-butyllithium was 0.75:0.25) was 0.180 mmol/min to 0.400 mmol/ minutes, and the amount of modifier added was changed to 0.070 mmol/minute to 0.070 mmol/minute.
A modified conjugated diene polymer (sample 22) was obtained in the same manner as in Reference Example 1 except that the flow rate was changed to 155 mmol/min.
Table 2 shows the physical properties of the sample.

[Comparative Example 3] Modified conjugated diene polymer (Sample 23)
A modified conjugated diene polymer (sample 23) was obtained in the same manner as in Reference Example 1, except that the amount of the modifier added was changed from 0.070 mmol/min to 0.021 mmol/min.
Table 2 shows the physical properties of the sample.

[Comparative Example 4] Modified conjugated diene polymer (Sample 24)
The amount of the mixed solution of piperidinolithium and n-butyllithium (the molar ratio of piperidinolithium and n-butyllithium was 0.75:0.25) was 0.180 mmol/min to 0.040 mmol/ minutes, and the amount of modifier added was changed to 0.070 mmol/minute to 0.070 mmol/minute.
A modified conjugated diene polymer (sample 24) was obtained in the same manner as in Reference Example 1 except that the rate was changed to 0.16 mmol/min.
Table 2 shows the physical properties of the sample.

[Comparative Example 5] Modified conjugated diene polymer (Sample 25)
A modified conjugated diene polymer (Sample 25) was obtained in the same manner as in Reference Example 1, except that the molar ratio of piperidinolithium and n-butyllithium was changed to 0:1.
Table 2 shows the physical properties of the sample.

[Reference Example 21, Examples 22-23, Reference Example 24, Example 25, Reference Examples 26-28, Reference Example
29, Reference Example 30, Examples 31 to 33, Reference Example 34, Example 35 , Reference Example 36, Examples 37 to 40, Comparative Examples 6 to 10]
Rubber Composition Using the samples shown in Tables 1 and 2 (Samples 1 to 25) as raw material rubbers, rubber compositions containing the respective raw material rubbers were obtained according to the formulations shown below.
Raw material rubber (modified conjugated diene polymer (samples 1 to 25)): 100.0 parts by mass Filler 1 (silica (trade name "Ultrasil 7000G r" manufactured by Evonik Degussa)): 75.0 parts by mass Filler 2 (Carbon black (trade name "SEAST KH (N339)" manufactured by Tokai Carbon): 5.0 parts by mass Silane coupling agent (trade name "Si75" manufactured by Evonik Degussa): 6.0 parts by mass Process oil (S-RAE oil (trade name "JOMO Process NC140" manufactured by Japan Energy)): 30.0 parts by mass Wax (trade name "Sunnock N" manufactured by Ouchi Shinko Kagaku Co., Ltd.): 1.5 parts by mass Zinc white: 2.5 parts by mass Stearic acid: 2.0 parts by mass Anti-aging agent (N-isopropyl-N'-phenyl-p-phenylenediamine): 2.0 parts by mass Sulfur: 1.8 parts by mass Acceleration of vulcanization Agent 1 (N-cyclohexyl-2-benzothiazylsulfinamide): 1.7 parts by mass Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass Total: 229.5 parts by mass

[ Reference Example 41] Rubber composition 80.0 parts by mass of raw rubber (modified conjugated diene polymer (sample 1)), 2 parts by mass of natural rubber
A rubber composition was obtained in the same manner as in Reference Example 21 except that 0.0 part by mass was added.

[ Reference Example 42] Rubber composition Same formulation as Reference Example 21 except that 80.0 parts by mass of raw rubber (modified conjugated diene polymer (Sample 10)) and 20.0 parts by mass of natural rubber were blended. A rubber composition was obtained.

[Example 43] Rubber composition The same formulation as in Reference Example 21 except that 80.0 parts by mass of raw rubber (modified conjugated diene polymer (Sample 11)) and 20.0 parts by mass of natural rubber were blended. A rubber composition was obtained.

[Comparative Example 11] Rubber composition The same formulation as in Reference Example 21 except that 80.0 parts by mass of raw rubber (modified conjugated diene polymer (Sample 21)) and 20.0 parts by mass of natural rubber were blended. A rubber composition was obtained.

The above materials were kneaded by the following method to obtain a rubber composition.
Using a closed kneader (inner capacity 0.3 L) equipped with a temperature control device, the raw rubber (samples 1 to 25) was mixed at a filling rate of 65% and a rotor rotation speed of 50/57 rpm for the first stage of kneading. , fillers 1 and 2 (silica, carbon black), silane coupling agent, process oil, wax, zinc white, and stearic acid were kneaded. At this time, the temperature of the closed mixer was controlled, and each rubber composition was obtained at a discharge temperature (compound) 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 (compound) was adjusted to 155 to 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 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 3 to 5.

((Evaluation 1) Compound Mooney viscosity)
The mixture obtained above after the second stage kneading and before the third stage kneading was used as a sample and preheated at 130°C for 1 minute according to JIS K6300-1 using a Mooney viscometer. After that, the viscosity was measured after rotating the rotor at 2 revolutions per minute for 4 minutes.
Comparative Example 6 was evaluated in Tables 3 and 4, and Comparative Example 11 was evaluated as 100 in Table 5 using an index.
The smaller the value, the better the workability.

((Evaluation 2) Viscoelastic parameters)
The viscoelastic parameters were measured in torsion mode using a viscoelasticity testing machine "ARES" manufactured by TA Instruments Japan.
Each measured value was evaluated using an index with Comparative Example 6 as 100 in Tables 3 and 4 and Comparative Example 11 as 100 in Table 5.
Tan δ, which was measured at 0° C. at a frequency of 10 Hz and a strain of 1%, was used as an index of wet grip property. The larger the index, the better the wet grip properties.
In addition, tan δ measured at 50° C. at a frequency of 10 Hz and a strain of 3% was used as an index of low hysteresis loss. The smaller the index, the better the low hysteresis loss property.
Further, G' measured at 70° C., frequency of 10 Hz, and strain of 3% was used as an index of handling performance in high-speed operation. The larger the index, the better the handling performance during high-speed driving.

((Evaluation 3) High temperature tensile properties)
In accordance with JIS K 6251 "Vulcanized rubber and thermoplastic rubber - How to determine tensile properties", a tensile test was conducted at a measurement temperature of 100°C using a No. 3 dumbbell-shaped test piece made of a rubber composition sheet, and the fracture was determined. The elongation (EB) was measured and evaluated using an index with Comparative Example 6 as 100 in Tables 3 and 4 and Comparative Example 11 as 100 in Table 5. The larger the value, the higher the heat resistance.

((Evaluation 4) Wear resistance)
Using an Akron wear tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.), the wear amount was measured at a load of 44.4 N and 1000 rotations in accordance with JIS K6264-2. Evaluation was made using an index with Comparative Example 11 as 100. The larger the index, the better the wear resistance.

((Evaluation 5) Roll workability)
The blend obtained above after the first stage kneading was used as a sample and molded using a 3-inch roll to prepare a test piece. The surface of the test piece after molding was evaluated according to the following criteria.
○: The surface is glossy and smooth.
×: Shrinkage was observed after rolling, and the surface was rough.

As shown in Table 3, Table 4, and Table 5, the modified conjugated diene polymer compositions using Samples 1 to 20 of Examples are different from the modified conjugated diene polymer compositions using Samples 21 to 25 of Comparative Examples. It was confirmed that the high-temperature tensile properties of the vulcanizate were extremely superior when compared with It was also confirmed that the material had an excellent balance between low hysteresis loss and wet skid resistance, and abrasion resistance.

The modified conjugated diene polymer according to the present invention has industrial applicability in fields such as tire treads, interior and exterior parts of automobiles, anti-vibration rubber, belts, footwear, foams, and various industrial products.

Claims (9)

Mooney relaxation rate at 110°C is 0.52 or more,
The modification rate is 75% by mass or more,
The weight average molecular weight (Mw) is 500,000 or more and 3,000,000 or less,
The molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) is 1.5 or more and 3.5 or less,
A modified conjugated diene polymer represented by the following general formula (A) or (B).

(In general formula (A), R ²¹ to R ²⁴ are each independently an alkyl group having 1 to 20 carbon atoms or a carbon number
It represents an aryl group having 6 to 20 carbon atoms, and R ²⁵ and R ²⁶ each independently represent an alkyl group having 1 to 20 carbon atoms.
Represents a ren group, and R ²⁷ is a hydrogen atom, a silyl group substituted with a hydrocarbon, or an atom having 1 to 20 carbon atoms.
It represents an alkyl group or an aryl group having 6 to 20 carbon atoms. a, b, c and d are (a+b) and
As long as a and (c+d) are each independently an integer of 2 or less, a and c are each independently 1 or 2.
An integer, b and d represent an integer of 0 or 1, and (Polym) represents a conjugated diene polymer.
, at least one end thereof is a functional group represented by any of the following general formulas (1) to (4).
be. R ²¹ and R ²³ when there are two or more , and (Polym) when there is a plurality, each has its own unique meaning.
They may be the same or different. )

(In general formula (B), R ²⁸ to R ³³ are each independently an alkyl group having 1 to 20 carbon atoms or a carbon number
It represents an aryl group having 6 to 20 carbon atoms, and R ³⁴ to R ³⁶ each independently represents an alkylene group having 1 to 20 carbon atoms.
Indicates a group. a, b, c, d, e, and f are (a+b), (c+d), and (e+f), respectively.
a, c and e are each independently an integer of 1 or 2, b, d, as long as each independently represents an integer of 2 or less;
and f each independently represent an integer of 0 or 1. (Polym) is a conjugated diene polymer.
and at least one terminal thereof is a functional group represented by any of the following general formulas (1) to (4).
It is a functional group. R ²⁸ , R ³⁰ , and R ³² when a plurality exists , and when a plurality exists (Poly
m) are each independent and may be the same or different. )

(In general formula (1), R ¹⁰ and R ¹¹ each independently represent an alkyl group having 1 to 12 carbon atoms, a carbon number
A group consisting of a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group.
At least one selected from the following. R ¹⁰ and R ¹¹ are bonded together with adjacent nitrogen atoms
It may form a cyclic structure, in which case R ¹⁰ and R ¹¹ are alkyl having 5 to 12 carbon atoms.
represents a group, and a portion thereof may have an unsaturated bond or a branched structure. Note that the protecting group is
It is an alkyl-substituted silyl group. )

(In general formula (2), R ¹² and R ¹³ each independently represent an alkyl group having 1 to 12 carbon atoms, a carbon number
A group consisting of a cycloalkyl group having 3 to 14 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, and a protecting group.
At least one selected from the following.
R ¹² and R ¹³ may be bonded to form a cyclic structure with adjacent nitrogen atoms,
In this case, R ¹² and R ¹³ represent an alkyl group having 5 to 12 carbon atoms, and a portion thereof has an unsaturated bond.
It may have a combined or branched structure.
Note that the protecting group is an alkyl-substituted silyl group.
R ¹⁴ is an alkylene group having 1 to 30 carbon atoms which may have an aliphatic or aromatic substituent, or
Indicates a conjugated diene polymer chain having 1 to 20 carbon atoms. )

(In general formula (3), R ¹⁵ and R ¹⁶ each independently represent an alkyl group having 1 to 12 carbon atoms, a carbon number
From the group consisting of a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 20 carbon atoms, and a protecting group
At least one selected type is shown.
R ¹⁵ and R ¹⁶ may be bonded together to form a cyclic structure with adjacent nitrogen atoms,
In this case, R ¹⁵ and R ¹⁶ represent an alkyl group having 5 to 12 carbon atoms, and a part thereof has a branched structure.
It may have. Note that the protecting group is an alkyl-substituted silyl group. )

(In general formula (4), R ¹⁷ represents a hydrocarbon group having 2 to 10 carbon atoms, and a portion thereof is unsaturated.
It may have a bonded or branched structure. R ¹⁸ is an alkyl group having 1 to 12 carbon atoms, or a protected
represents a group, and a portion thereof may have a branched structure. Note that the protecting group is an alkyl-substituted silicon
is a group. ) The content of nitrogen atoms is 25 mass ppm or more with respect to the total amount of the modified conjugated diene polymer,
The modified conjugated diene polymer according to claim 1. The modified conjugated diene polymer according to claim 1 or 2 , which has a Mooney relaxation rate at 110°C of less than 0.60. The modified conjugated diene polymer according to claim 1 or 2 , which has a Mooney relaxation rate of 0.60 or more and 0.80 or less at 110°C. The modified conjugated diene polymer according to any one of claims 1 to 4 , having a modification rate of 95% by mass or less. The modified conjugated diene polymer according to any one of claims 1 to 5 , wherein the amount of vinyl bonds in the conjugated diene bond units is 30 mol% or more. rubber component,
5.0 parts by mass or more and 150 parts by mass or less of a silica-based inorganic filler based on 100 parts by mass of the rubber component;
including;
The rubber component contains 10% by mass or more of the modified conjugated diene polymer according to any one of claims 1 to 6 , based on the total amount of the rubber component.
Modified conjugated diene polymer composition. The modified conjugated diene polymer composition according to claim 7 , wherein the rubber component contains 10% by mass or more of natural rubber based on the total amount of the rubber component. A tire comprising the modified conjugated diene polymer composition according to claim 7 or 8 .