JP2018028047A - Modified conjugated diene polymer and rubber composition thereof, and tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modified conjugated diene polymer that has excellent workability when turned into a vulcanizate; offers a particularly good balance between low hysteresis loss and wet skid resistance as a vulcanizate; has excellent wear resistance; and shows practically sufficient fracture characteristics.SOLUTION: A modified conjugated diene polymer of a specific structure has a weight average molecular weight of 20×10or more and 300×10or less; has a star-shaped branched structure with 5 or more branches in which conjugated diene polymer chains are bound to a modifier residue; and has at least a nitrogen atom and a silicon atom in the modifier residue, with each conjugated diene polymer chain bound to the silicon atom, and the silicon atom bound to at least one alkoxy group.SELECTED DRAWING: None

Description

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

2. Description of the Related Art Conventionally, there is an increasing demand for low fuel consumption for automobiles, and improvement of materials used for automobile tires, particularly tire treads in contact with the ground, has been demanded.
In recent years, development of materials having low rolling resistance, that is, low hysteresis loss has been demanded.
Further, in order to reduce the weight of the tire, it is necessary to reduce the thickness of the tread portion of the tire, and a material with higher wear resistance is also required.
On the other hand, materials used for tire treads are required to have excellent wet skid resistance and practically sufficient fracture characteristics from the viewpoint of safety.

Examples of the material that meets the above-described requirements include a material containing rubber and a reinforcing filler such as carbon black and silica.
For example, when a material containing silica is used, it is possible to improve the balance between low hysteresis loss and wet skid resistance. In addition, by introducing a functional group having affinity or reactivity with silica into the molecular end of a rubber having high mobility, the dispersibility of silica in the material is improved, and further, Attempts have been made to reduce the hysteresis loss by reducing the mobility of the rubber molecule end by bonding.

For example, Patent Document 1 proposes a modified diene rubber obtained by reacting a modifier having a glycidylamino group with a polymer active terminal.
Patent Documents 2 to 4 propose modified diene rubbers obtained by reacting alkoxysilanes containing amino groups with the active terminal of the polymer, and compositions of these with silica.
Further, Patent Documents 5 and 6 propose polymers in which a cyclic azasilacycle compound is reacted with a polymer active terminal to functionalize the polymer.
Furthermore, Patent Document 7 proposes a diene rubber obtained by a coupling reaction between a polymer active terminal and a polyfunctional silane compound.

International Publication No. 01/23467 Pamphlet JP-A-2005-290355 JP-A-11-189616 JP 2003-171418 A Special table 2008-527150 gazette International Publication No. 11/129425 Pamphlet International Publication No. 07/114203 Pamphlet

However, the silica-containing material has a hydrophilic surface with respect to carbon black having a hydrophobic surface, and has a low affinity with the conjugated diene rubber, compared to carbon black, It has the disadvantage of poor dispersibility. Therefore, the material containing silica needs to contain a silane coupling agent or the like separately in order to impart a bond between silica and rubber and improve dispersibility.
In addition, a material in which a functional group having high reactivity with silica is introduced at the molecular terminal of the rubber is kneaded because the reaction with the silica particles proceeds during the kneading process and the viscosity of the composition increases. There is a problem that the workability tends to be deteriorated, such that it becomes difficult or rough skin occurs when the sheet is formed after kneading, or the sheet is easily cut. In addition, when such a material is used as a vulcanized product, particularly when it is used as a vulcanized product containing an inorganic filler such as silica, the balance between low hysteresis loss and wet skid resistance, and wear resistance are obtained. It has the problem that it is not enough.

  Therefore, the present invention is excellent in workability when used as a vulcanized product, particularly excellent in the balance between low hysteresis loss and wet skid resistance when used as a vulcanized product and wear resistance, and practically sufficient destruction. It is an object of the present invention to provide a modified conjugated diene polymer having properties.

As a result of diligent research and studies in order to solve the above-described problems of the prior art, the present inventors have found that a modified conjugated diene polymer having a specific structure and having a weight average molecular weight within a predetermined range. However, when it was used as a vulcanized product, it was found that it was particularly excellent in the balance between low hysteresis loss and wet skid resistance and abrasion resistance, and had practically sufficient fracture characteristics, and the present invention was completed.
That is, the present invention is as follows.

[1]
The weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less,
A modified conjugated diene polymer represented by the following general formula (1).

(In formula (1), P ^{1 to} P ³ each independently represents a conjugated diene polymer chain, and R ³ , R ⁴ and R ⁷ each independently represents an alkylene group having 1 to 20 carbon atoms. R ² , R ⁵ and R ⁸ each independently represents an alkyl group having 1 to 20 carbon atoms, and R ¹ , R ⁶ and R ⁹ each independently represent a hydrogen atom or a carbon atom having 1 to 20 carbon atoms. Indicates an alkyl group.
x, y and z each independently represent an integer of 1 to 2, q, s and u represent an integer of 0 to 3, r represents an integer of 1 to 6, and a conjugated diene polymer. The number of chains (x + (y × r) + z) is an integer of 5 to 20. The number of alkoxysilyl groups (q + (s × r) + u) is 1 or more. )

[2]
The weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less,
A modified conjugated diene polymer represented by the following general formula (2).

(In formula (2), P ^{1 to} P ³ each independently represents a conjugated diene polymer chain, and R ³ , R ⁴ , R ⁷ , R ¹² , and R ¹³ each independently represents 1 carbon atom. Represents an alkylene group having ˜20, R ² , R ⁵ and R ⁸ each independently represents an alkyl group having 1 to 20 carbon atoms, and R ¹ , R ⁶ and R ⁹ are each independently a hydrogen atom or R ¹⁰ and R ¹¹ each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, x, y and z each independently represent 1 to 2 carbon atoms. Q, s and u are integers of 0 to 3, r is an integer of 0 to 6, p and t are integers of 1 to 2, and a conjugated diene polymer chain ((X × p) + (y × r) + (z × t)) is an integer of 7 to 20. This is the number of alkoxysilyl groups ((q × p) + (s × r) + (u × t)) is Or more.)

[3]
100 parts by mass of the modified conjugated diene polymer according to [1] or [2],
1 to 60 parts by mass of extension oil,
An oil-extended modified conjugated diene polymer.
[4]
A rubber component, and 5.0 parts by weight or more and 150 parts by weight of a filler with respect to 100 parts by weight of the rubber component,
The rubber component is a rubber composition containing 10% by mass or more of the modified conjugated diene polymer according to any one of [1] to [3] with respect to the total amount of the rubber component.
[5]
A tire containing the rubber composition according to the above [4].

  According to the modified conjugated diene polymer according to the present invention, it has excellent processability when used as a vulcanized product, and particularly excellent balance between low hysteresis loss and wet skid resistance when used as a vulcanized product. Wearability and practically sufficient fracture characteristics can be obtained.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail.
The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof.

[Modified Conjugated Diene Polymer]
The modified conjugated diene polymer of the present embodiment has a weight average molecular weight of 20 × 10 ⁴ or more and 300 × 10 ⁴ or less. As shown in the general formula (1) or the general formula (2) described later, a conjugated diene polymer is used. The polymer chain has a star-branch structure having five or more branches bonded to the modifier residue, the modifier residue has at least a nitrogen atom and a silicon atom, and each conjugated diene polymer chain is It is a modified conjugated diene polymer having a specific structure in which it is bonded to the silicon atom, and at least one alkoxy group is bonded to the silicon atom.

The modified conjugated diene polymer of the present embodiment has a weight average molecular weight (Mw) 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 balance between the low hysteresis loss and the wet skid resistance and the wear resistance when the vulcanized product is obtained are excellent.
In addition, when the weight average molecular weight is 300 × 10 ⁴ or less, the processability and the dispersibility of the filler when making a vulcanizate are excellent, and practically sufficient fracture characteristics can be obtained.
The weight average molecular weight of the modified conjugated diene polymer is preferably 50 × 10 ⁴ or more, more preferably 64 × 10 ⁴ or more, and further preferably 80 × 10 ⁴ or more. The weight average molecular weight is preferably 250 × 10 ⁴ or less, preferably 180 × 10 ⁴ or less, and more preferably 150 × 10 ⁴ or less.

  The weight average molecular weights of the modified conjugated diene polymer of the present embodiment and the conjugated diene polymer before modification described below are measured using a GPC measuring device, a chromatogram is measured using an RI detector, and standard polystyrene. Can be measured based on a calibration curve obtained using. Specifically, it can measure by the method as described in the Example mentioned later.

  The weight average molecular weight of the modified conjugated diene polymer of this embodiment and the conjugated diene polymer before modification described later is controlled by the ratio of the amount of polymerization initiator used and the amount of monomer used. It can be controlled by the molecular weight of the combined chain and the type and amount of modifier used.

<Conjugated diene polymer chain and star-shaped branched structure>
The modified conjugated diene polymer of the present embodiment has five branches in which 5 or more conjugated diene polymer chains are bonded to a modifier residue as shown in the general formula (1) or general formula (2) described later. It has the above star-shaped branch structure.
The conjugated diene polymer chain is a structural unit of a modified conjugated diene polymer, for example, a structural unit derived from a conjugated diene polymer produced by reacting a conjugated diene polymer and a modifying agent described later. It is.
When the modified conjugated diene polymer of this embodiment has a star-branched structure having 7 or more branches in which 7 or more conjugated diene polymer chains are bonded to the modifier residue, a vulcanized product is obtained. In some cases, particularly excellent balance between low hysteresis loss and wet skid resistance, wear resistance, and practically sufficient fracture characteristics can be obtained.

When the modified conjugated diene polymer of the present embodiment has a star-branched structure having five or more branches in which five or more conjugated diene polymer chains are bonded to a modifier residue, the modification having the star-shaped branch structure is performed. The conjugated diene polymer tends to have a shrinkage factor (g ′) determined by GPC-light scattering measurement with a viscosity detector of 0.67 or less.
Further, a modified conjugated diene polymer having a star-branched structure having a star-branched structure having seven or more branches in which seven or more conjugated diene polymer chains are bonded to a modifier residue The factor (g ′) tends to be 0.61 or less.
When the contraction factor is low, there is a tendency for more branches.
The contraction factor can be measured by the method described in Examples described later.

<Modifier residue>
The modifier residue in the modified conjugated diene polymer of the present embodiment is a constituent unit of the modified conjugated diene polymer bonded to the conjugated diene polymer chain. For example, a conjugated diene polymer described later It is a structural unit derived from a modifying agent, which is produced by reacting the modifying agent with a modifying agent.
The modified conjugated diene polymer of this embodiment has at least a nitrogen atom and a silicon atom in the modifier residue, each conjugated diene polymer chain is bonded to the silicon atom, and the silicon atom Is a modified conjugated diene polymer having a specific structure represented by the following general formula (1) or general formula (2), to which at least one alkoxy group is bonded. By having such a structure, the modified conjugated diene polymer of the present embodiment has a balance between low hysteresis loss and wet skid resistance, which is excellent when used as a vulcanized product, wear resistance, and practical use. Sufficient destructive properties can be obtained.

  The modified diene polymer of this embodiment is a modified conjugated diene polymer represented by the following general formula (1).

(In formula (1), P ^{1 to} P ³ each independently represents a conjugated diene polymer chain, and R ³ , R ⁴ and R ⁷ each independently represents an alkylene group having 1 to 20 carbon atoms. R ² , R ⁵ and R ⁸ each independently represents an alkyl group having 1 to 20 carbon atoms, and R ¹ , R ⁶ and R ⁹ each independently represent a hydrogen atom or a carbon atom having 1 to 20 carbon atoms. Indicates an alkyl group.
x, y and z each independently represents an integer of 1 to 2, q, s and u each independently represents an integer of 0 to 3, r represents an integer of 1 to 6, The number of diene polymer chains (x + (y × r) + z) is an integer of 5 to 20, and the number of alkoxy groups (q + (s × r) + u) is 1 or more. )

  The modified diene polymer of the present embodiment is a modified conjugated diene polymer represented by the following general formula (2).

(In formula (2), P ^{1 to} P ³ each independently represents a conjugated diene polymer chain, and R ³ , R ⁴ , R ⁷ , R ¹² , and R ¹³ each independently represents 1 carbon atom. Represents an alkylene group having ˜20, R ² , R ⁵ and R ⁸ each independently represents an alkyl group having 1 to 20 carbon atoms, and R ¹ , R ⁶ and R ⁹ are each independently a hydrogen atom or R ¹⁰ and R ¹¹ each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, x, y and z each independently represent 1 to 2 carbon atoms. Q, s and u each independently represents an integer of 0 to 3, r represents an integer of 0 to 6, p and t represent an integer of 1 to 2, and a conjugated diene polymer. The number of chains ((x × p) + (y × r) + (z × t)) is an integer of 7 to 20, and is the number of alkoxysilyl groups (q × p) + (s × r) + (u × t) It is greater than or equal to one. )

  The modified conjugated diene polymer having the structure of the general formula (1) or the general formula (2) is prepared by reacting a diene polymer chain and the modifier at a specific ratio using a modifier having a specific structure described later. can get.

The number of alkoxysilyl groups in the modified diene polymer of this embodiment is 1 or more. In that case, the modified conjugated diene polymer has excellent low hysteresis loss and wet skid resistance when used as a vulcanizate. Balance and wear resistance, and practically sufficient fracture characteristics.
Furthermore, the modified conjugated diene polymer having a ratio of the number of alkoxy groups to the number of conjugated diene polymer chains of 0.75 or less has a gradual increase in viscosity during the modification reaction compared to a polymer having the same molecular weight, It tends to be easy to control during manufacturing.
The ratio of the alkoxy group number to the conjugated diene polymer chain number is represented by (q + (s × r) + u) / (x + y + z) in the general formula (1), and ((q × p) in the general formula (2). + (S × r) + (u × t)) / ((x × p) + (y × r) + (z × t)). When the ratio of the number of alkoxy groups to the number of conjugated diene polymer chains is 0.5 or less, the increase in the viscosity of the solution in the modification reaction is smaller and the reaction tends to be easily controlled. When the number of alkoxy groups relative to the number of conjugated diene polymer chains is large, the condensation reaction tends to occur and the change with time tends to occur.

  In the modified conjugated diene polymer of this embodiment, 1 mol of a modifier is reacted with 5 mol or more of a conjugated diene polymer, and the modifier is a functional group that binds to a conjugated diene polymer to a silicon atom. It tends to be obtained by using a predetermined amount of a modifier having a specific structure having a group and at least a nitrogen atom and a silicon atom.

In the modified conjugated diene polymer of the present embodiment, in the general formula (1), the number of conjugated diene polymer chains is 5 to 20, and in the general formula (2), the number of conjugated diene polymer chains is The number is 7-20.
Thereby, it exists in the tendency which is excellent in the workability at the time of setting it as a vulcanizate.
The number of conjugated diene polymer chains can be controlled by adjusting the number of moles of the modifier to be reacted with the conjugated diene polymer having an active end.

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

In the modified conjugated diene polymer of this embodiment, the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.1 or more and 3.5 or less. preferable. A modified conjugated diene polymer having a molecular weight distribution in this range tends to be excellent in processability when it is made into a vulcanized product, and tends to be excellent in abrasion resistance when it is used as a vulcanized product. The molecular weight distribution (Mw / Mn) is more preferably 1.5 or more and 3.0 or less.
The number average molecular weight, weight average molecular weight, and molecular weight distribution for the modified conjugated diene polymer and the conjugated diene polymer described later can be measured by the methods described in the examples described later.

[Method for producing modified conjugated diene polymer]
A preferred method for producing the modified conjugated diene polymer of the present embodiment includes a polymerization step of obtaining a conjugated diene polymer that polymerizes at least a conjugated diene compound in the presence of an organolithium compound, and 5 mol or more of the conjugated diene polymer. And a modification step of reacting a specific modifier having at least 5 nitrogen atoms and silicon atoms, having at least 5 functional groups bonded to the conjugated diene polymer on the silicon atom.
By the production method, a modified conjugated diene-based polymer can be obtained, which has excellent balance between low hysteresis loss and wet skid resistance and abrasion resistance when used as a vulcanizate, and can provide practically sufficient fracture characteristics. There is a tendency.

(Polymerization process)
In the polymerization step in the step of producing the modified conjugated diene polymer of this embodiment, at least a conjugated diene compound is polymerized in the presence of an organolithium compound to obtain a conjugated diene polymer.
In the polymerization step, it is preferable to carry out polymerization by a growth reaction by living anion polymerization reaction, whereby a conjugated diene polymer having an active end can be obtained, and a modified diene polymer having a high modification rate can be obtained. It tends to be possible.

<Conjugated diene polymer>
The conjugated diene polymer is obtained by polymerizing at least a conjugated diene compound as a monomer, and is obtained by copolymerizing a conjugated diene compound and another copolymerizable monomer as necessary.
Although it will not specifically limit if it is a polymerizable conjugated diene compound as a conjugated diene compound, The conjugated diene compound containing 4-12 carbon atoms per molecule is preferable, More preferably, the conjugated diene containing 4-8 carbon atoms A compound. Examples of such conjugated diene compounds 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 preferable from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

The other copolymerizable monomer is not particularly limited as long as it is a monomer copolymerizable with a conjugated diene compound, and examples thereof include a vinyl-substituted aromatic compound. For example, a monovinyl aromatic compound is preferable.
Examples of the monovinyl aromatic compound include, but are not limited to, styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and diphenylethylene. Among these, styrene is preferable from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

If allenes, acetylenes, etc. are contained as impurities in the conjugated diene compound and / or vinyl-substituted aromatic compound, the reaction in the reaction step described later may be hindered. Therefore, the total content concentration (mass) of these impurities is preferably 200 ppm or less, more preferably 100 ppm or less, and even more preferably 50 ppm or less.
Examples of allenes include propadiene and 1,2-butadiene. Examples of acetylenes include ethyl acetylene and vinyl acetylene.

  The conjugated diene polymer may be a random copolymer or a block copolymer. In order to make the conjugated diene polymer into a rubbery polymer, it is preferable to use 40% by mass or more, and 55% by mass or more of the conjugated diene compound based on the whole monomer of the conjugated diene polymer. More preferred.

  The random copolymer is not limited to the following, but for example, a random copolymer comprising two or more conjugated diene compounds such as a butadiene-isoprene random copolymer, a butadiene-styrene random copolymer, and an isoprene-styrene. And a random copolymer comprising a conjugated diene of a random copolymer or a butadiene-isoprene-styrene random copolymer and a vinyl-substituted aromatic compound. The composition distribution of each monomer in the copolymer chain is not particularly limited. For example, a completely random copolymer close to a statistical random composition, a taper (gradient) random in which the composition is distributed in a tapered shape. A copolymer is mentioned. The bonding mode of the conjugated diene, that is, the composition of 1,4-bonds, 1,2-bonds, etc. may be uniform or distributed.

  The block copolymer is not limited to the following, but for example, a 2 type block copolymer (diblock) consisting of 2 blocks, a 3 type block copolymer (triblock) consisting of 3 blocks, 4 4 type block copolymer (tetrablock) which consists of a piece is mentioned. The polymer constituting one block may be a polymer composed of one type of monomer or a copolymer composed of two or more types of monomers. For example, a polymer block composed of 1,3-butadiene is represented by “B”, a copolymer of 1,3-butadiene and isoprene is represented by “B / I”, and a copolymer of 1,3-butadiene and styrene. Is represented by “B / S”, and a polymer block composed of styrene is represented by “S”, a BB / I2 type block copolymer, a BB / S2 type block copolymer, an S-B2 type block It is represented by a copolymer, a BB / S-S3 type block copolymer, an SB-S3 type block copolymer, an SSB-S-B4 type block copolymer, and the like.

  In the above equation, the boundaries of each block need not be clearly distinguished. Further, when one polymer block is a copolymer composed of two types of monomers A and B, A and B in the block may be distributed uniformly or in a tapered shape. Good.

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

The amount of the organic monolithium compound used as a polymerization initiator is preferably determined by the molecular weight of the target conjugated diene polymer or modified conjugated diene polymer.
The amount of the monomer such as the conjugated diene compound used relative to the amount of the polymerization initiator is related to the degree of polymerization, that is, tends to be related to the number average molecular weight and / or the weight average molecular weight. Therefore, in order to increase the molecular weight, it is preferable to adjust in the direction of decreasing the polymerization initiator, and in order to decrease the molecular weight, it is preferable to adjust in the direction of increasing the amount of polymerization initiator.

  From the viewpoint that an organic monolithium compound as a polymerization initiator is used in one method for introducing a nitrogen atom into a conjugated diene polymer, an alkyllithium compound having a substituted amino group or a substituted amino group is used as the polymerization initiator. It is preferable to use a lithium compound. In this case, a conjugated diene polymer having a nitrogen atom composed of an amino group at the polymerization initiation terminal is obtained. The substituted amino group is an amino group having no active hydrogen or having a structure in which active hydrogen is protected.

As the organic lithium compound which is a polymerization initiator, an organic monolithium compound is preferable as described above, and it may or may not have a substituted amino group in the molecule. From the viewpoint of easy industrial availability and easy control of the polymerization reaction, an alkyl lithium compound is preferred. In this case, a conjugated diene polymer having an alkyl group at the polymerization initiation terminal is obtained.
Examples of the alkyl lithium compound include, but are not limited to, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, n-hexyl lithium, benzyl lithium, phenyl lithium, and stilbene lithium. As the alkyllithium compound, n-butyllithium and sec-butyllithium are preferable from the viewpoints of industrial availability and ease of control of the polymerization reaction.

  As a substituted amino group, the hydrogen of an amino group each independently comprises 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. It is an amino group substituted with at least one selected from the group, and the substituent may be bonded to form a cyclic structure with the adjacent nitrogen atom, in which case the substituent has 5 to 12 carbon atoms An alkyl group is shown, and a part thereof may have an unsaturated bond or a branched structure. The protecting group is preferably an alkyl-substituted silyl group.

The polymerization reaction mode applied in the polymerization step is not limited to the following, but examples thereof include batch type (also referred to as “batch type”) and continuous type polymerization reaction modes.
In the continuous mode, one or two or more connected reactors can be used. As the continuous reactor, for example, a tank type with a stirrer or a tube type is used. In the continuous method, preferably, a monomer, an inert solvent, and a polymerization initiator are continuously fed to a reactor, and a polymer solution containing the polymer is obtained in the reactor. The coalescence solution is drained.
As the batch reactor, for example, a tank type equipped with a stirrer is used. In the batch system, preferably, a monomer, an inert solvent, and a polymerization initiator are fed, and if necessary, a monomer is added continuously or intermittently during the polymerization, and the polymer is added in the reactor. A polymer solution is obtained, and after completion of the polymerization, the polymer solution is discharged.
In the polymerization step, in order to obtain a conjugated diene polymer having an active terminal at a high rate, a continuous system is preferred in which the polymer is continuously discharged and can be used for the next reaction in a short time.

In the polymerization step, it is preferable to polymerize the monomer in an inert solvent.
Examples of the inert solvent include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specific hydrocarbon solvents include, but are not limited to, for example, aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclics such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane Hydrocarbons: Hydrocarbons composed of aromatic hydrocarbons such as benzene, toluene, xylene and mixtures thereof. Before being subjected to a polymerization reaction, by treating the allenes and acetylenes that are impurities with an organometallic compound, a conjugated diene polymer having a high concentration of active terminals tends to be obtained, and modification with a high modification rate A conjugated diene polymer is preferred because it tends to be obtained.

  In the polymerization step, a polar compound may be added. An aromatic vinyl compound can be randomly copolymerized with a conjugated diene compound and tends to be used as a vinylating agent for controlling the microstructure of the conjugated diene portion. In addition, the polymerization reaction tends to be effective.

Examples of polar compounds include, but are not limited to, tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, 2,2-bis (2-oxolanyl). ) Ethers such as propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclidine; potassium-tert-amylate, potassium-tert-butyrate, sodium-tert-butyrate, Using alkali metal alkoxide compounds such as sodium amylate; phosphine compounds such as triphenylphosphine It is possible.
These polar compounds may be used alone or in combination of two or more.

  The usage-amount of a polar compound is not specifically limited, Although it can select according to the objective etc., it is preferable that they are 0.01 mol or more and 100 mol or less with respect to 1 mol of polymerization initiators. An appropriate amount of such a polar compound (vinylating agent) can be used as a regulator of the microstructure of the polymer conjugated diene moiety depending on the desired vinyl bond amount. Many polar compounds simultaneously have an effective randomizing effect in the copolymerization of conjugated diene compounds and aromatic vinyl compounds, and tend to be used to adjust the distribution of aromatic vinyl compounds and adjust the amount of styrene block It is in. As a method for randomizing the conjugated diene compound and the aromatic vinyl compound, for example, as described in JP-A-59-140221, the total amount of styrene and a part of 1,3-butadiene may be used together. A method of starting a polymerization reaction and intermittently adding the remaining 1,3-butadiene during the copolymerization reaction may be used.

  In the polymerization step, the polymerization temperature is preferably a temperature at which living anionic polymerization proceeds, more preferably 0 ° C. or more, and further preferably 120 ° C. or less from the viewpoint of productivity. By being in such a range, it exists in the tendency which can fully ensure the reaction amount of the modifier | denaturant with respect to the active terminal after completion | finish of superposition | polymerization. More preferably, it is 50 ° C. or more and 100 ° C. or less, and more preferably 60 ° C. or more and 80 ° C. or less.

  The conjugated diene polymer before the modification reaction step obtained in the polymerization step preferably has a Mooney viscosity measured at 110 ° C. of 10 or more and 90 or less, more preferably 15 or more and 85 or less, and still more preferably. 20 or more and 60 or less. Within this range, the modified conjugated diene polymer of this embodiment tends to be excellent in workability and wear resistance.

The amount of conjugated diene in the conjugated diene polymer obtained in the polymerization step of the production method of the modified conjugated diene polymer of the present embodiment or the modified conjugated diene polymer of the present embodiment is not particularly limited. The mass is preferably from 100% by mass to 100% by mass, and more preferably from 55% by mass to 80% by mass.
The amount of bonded aromatic vinyl in the conjugated diene polymer or modified conjugated diene polymer of the present embodiment is not particularly limited, but is preferably 0% by mass or more and 60% by mass or less, and more preferably 20% by mass or more. More preferably, it is 45 mass% or less.
If the amount of bound conjugated diene and amount of bound aromatic vinyl are in the above ranges, the balance between low hysteresis loss and wet skid resistance when used as a vulcanized product, wear resistance, and fracture characteristics tend to be superior. .
Here, the amount of bonded aromatic vinyl can be measured by ultraviolet absorption of a phenyl group, and the amount of bonded conjugated diene can also be obtained from this. Specifically, it can measure according to the method as described in the Example mentioned later.

In the conjugated diene polymer obtained in the polymerization step of the production method of the modified conjugated diene polymer of the present embodiment or the modified conjugated diene polymer of the present embodiment, the amount of vinyl bonds in the conjugated diene bond unit is particularly limited. However, it is preferably 10 mol% or more and 75 mol% or less, and more preferably 20 mol% or more and 65 mol% or less.
When the vinyl bond amount is in the above range, there is a tendency to be more excellent in the balance of low hysteresis loss and wet skid resistance, wear resistance, and fracture strength when vulcanized. Here, when the modified diene polymer is a copolymer of butadiene and styrene, it is determined by the method of Hampton (RR Hampton, Analytical Chemistry, 21, 923 (1949)) in the butadiene bond unit. A vinyl bond amount (1,2-bond amount) can be determined. Specifically, it can measure by the method as described in the Example mentioned later.

Regarding the microstructure of the modified conjugated diene polymer, the amount of each bond in the modified conjugated diene polymer is in the above range, and the glass transition temperature of the modified conjugated diene polymer is −45 ° C. or more and −15 ° C. When it is in the following range, there is a tendency that a more excellent vulcanizate can be obtained due to the balance between low hysteresis loss and wet skid resistance.
Regarding the glass transition temperature, according to ISO 22768: 2006, the DSC curve is recorded while the temperature is raised in a predetermined temperature range, and the peak top (Inflection point) of the DSC differential curve is set as the glass transition temperature. Specifically, it can measure by the method as described in the Example mentioned later.

  When the modified conjugated diene polymer of the present embodiment is a conjugated diene-aromatic vinyl copolymer, the number of blocks in which 30 or more aromatic vinyl units are linked may be small or not. preferable. More specifically, when the copolymer is a butadiene-styrene copolymer, the Kolthoff method (method described in IM KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946)). In the known method for analyzing the amount of polystyrene insoluble in methanol, the block in which 30 or more aromatic vinyl units are linked is preferably 5.0 relative to the total amount of the copolymer. It is not more than mass%, more preferably not more than 3.0 mass%.

  When the conjugated diene polymer of the present embodiment is a conjugated diene-aromatic vinyl copolymer, it is preferable that the ratio of aromatic vinyl units to be present alone is large. Specifically, when the copolymer is a butadiene-styrene copolymer, the copolymer is decomposed by an ozonolysis method known as Tanaka et al. (Polymer, 22, 1721 (1981)). When the styrene chain distribution is analyzed by GPC, the isolated styrene amount is 40% by mass or more and the chain styrene structure having 8 or more styrene chains is 5.0% by mass or less based on the total amount of styrene bonded. It is desirable. In this case, the obtained vulcanized rubber has excellent performance with particularly low hysteresis loss.

(Modification process)
In the modification step of the method for producing the modified conjugated diene polymer according to the present embodiment, the active terminal of the conjugated diene polymer obtained in the polymerization step has five or more functional groups that can be bonded. The modified conjugated diene polymer has a nitrogen atom and a silicon atom in the modifier molecule, and the silicon atom reacts with a modifier having an alkoxy group to leave an alkoxysilyl group. Get.
Examples of the functional group that can be bonded to the active terminal of the conjugated diene polymer include an alkoxysilyl group, a halogen group, an epoxy group, and a carbonyl group.
Moreover, as a functional group which can be couple | bonded in the modifier used, Preferably they are an alkoxysilyl group and a halogen group, More preferably, it is an alkoxysilyl group.
Further, in the modifier residue, the remaining alkoxysilyl group tends to become silanol (Si—OH group) due to water at the time of finishing.

  The modified conjugated diene polymer of the general formula (1) described above, which is the structure of the modified conjugated diene polymer of the present embodiment, is preferably an active terminal of the conjugated diene polymer obtained in the polymerization step, It can manufacture by the method of making the polyfunctional modifier represented by following General formula (3) react.

(In Formula (3), A ^{1 to} A ³ each independently represents a functional group capable of binding to a conjugated diene polymer chain, and d, e, and f each independently represents an integer of 1 to 3. Each of A ¹ , A ² and A ^{3 in} the case of 2 or more may be a different functional group.
R ³ , R ⁴ and R ⁷ each independently represents an alkylene group having 1 to 20 carbon atoms; R ² , R ⁵ and R ⁸ each independently represents an alkyl group having 1 to 20 carbon atoms; R ¹ , R ⁶ and R ⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and r represents an integer of 1 to 6. )

A ^{1 to} A ³ are functional groups that can be bonded to the conjugated diene polymer chain and have at least one alkoxy group.
The functional group is preferably an alkoxy group, a halogen group, an epoxy group, or a carbonyl group, and more preferably all are alkoxy groups.

Examples of the modifier of the general formula (3) include tris (3-trimethoxysilylpropyl) amine, tris (3-triethoxysilylpropyl) amine, and tris (3) when all the functional groups are alkoxy groups. -Tripropoxysilylpropyl) amine, bis (3-trimethoxysilylpropyl)-(3-dimethoxymethylsilylpropyl) amine, bis (3-triethoxysilylpropyl)-(3-diethoxymethylpropyl) amine, bis ( 3-dimethoxymethylsilylpropyl)-(3-trimethoxysilylpropyl) amine, tetrakis (3-trimethoxysilylpropyl) -1,3-propanediamine, tetrakis (3-triethoxysilylpropyl) -1,3-propane Diamine, tetrakis (3-trimethoxysilylpropylene ) -1,3-bisaminomethylcyclohexane, tetrakis (3-trimethoxysilylpropyl) -1,6-hexamethylenediamine, pentakis (3-trimethoxysilylpropyl) -diethylenetriamine, bis (3-trimethoxysilylpropyl) -Bis (3-dimethoxymethylsilylpropyl) -1,3-propanediamine.
As the denaturing agent of the formula (3), for example, as when the functional group is an alkoxysilyl group and other functional groups, N ^1, N ¹ - bis (3-di-trichloromethyl silyl propyl) -N ² , N ² -bis (3-trimethoxysilylpropyl) -1,3-propanediamine, N ¹ , N ¹ , N ³ , N ³ -tetra (3-trimethoxysilylpropyl) -N ^2- (3-di Chloromethylsilylpropyl) -diethylenetriamine, pentakis (3-trimethoxysilylpropyl) -dipropylenetriamine.
When the functional group is an alkoxy group or another functional group, N ¹ , N ¹ -bis (3-dichloromethylsilylpropyl) -N ² , N ² -bis (3-trimethoxysilylpropyl) -1, ^{3-propanediamine, N 1, N 1, N} 3, N 3 - tetra (3-trimethoxysilylpropyl) -N ² - (3-di-trichloromethyl silyl propyl) - include diethylenetriamine.

  The modified conjugated diene polymer of the above general formula (2), which is the modified conjugated diene polymer structure of this embodiment, is composed of an active terminal of the conjugated diene polymer and a polyfunctional compound represented by the following general formula (4). It can be produced by a method of reacting with a modifier.

(In formula (4), A ^{1 to} A ³ each independently represents a functional group capable of binding to a conjugated diene polymer chain, and d, e and f each independently represents an integer of 1 to 3. Each of A ¹ , A ² and A ^{3 in} the case of 2 or more may be a different functional group.
R ³ , R ⁴ , R ⁷ , R ¹² and R ¹³ each independently represents an alkylene group having 1 to 20 carbon atoms, and R ² , R ⁵ and R ⁸ each independently represent 1 to 20 carbon atoms. R ¹ , R ⁶ and R ⁹ each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ¹⁰ and R ¹¹ each independently represents a hydrogen atom or carbon number. 1-20 alkyl groups are shown. p and t each independently represent an integer of 1 to 2, and r represents an integer of 0 to 6. )

A ^{1 to} A ³ are functional groups capable of binding to the conjugated diene polymer chain, and at least one alkoxy group is present.
The functional group is preferably an alkoxy group, a halogen group, an epoxy group or a hydrocarbon group having a carbonyl group, and more preferably all are alkoxy groups.

Examples of the modifier of the formula (4) include cases where all functional groups are alkoxy groups, such as tris (3-trimethoxysilylpropyl) -methyl-1,3-propanediamine, tris (3-triethoxysilyl). propyl) - ^{methyl-1,3-propanediamine, N 1, N 2, N} 3 - tris (3-trimethoxysilylpropyl) -N ^1, N ³ - dimethyl - include diethylenetriamine.
Further, for example, tetrakis (3-trimethoxysilylpropyl) -1,3-propanediamine, tetrakis (3-triethoxysilylpropyl) -1,3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tetrakis (3-trimethoxysilylpropyl) -1,6-hexamethylenediamine, pentakis (3-trimethoxysilylpropyl) -diethylenetriamine, pentakis (3-trimethoxysilylpropyl) -dipropylenetriamine Bis (3-trimethoxysilylpropyl) -bis (3-dimethoxymethylsilylpropyl) -1,3-propanediamine, when the functional group is an alkoxysilyl group or another functional group, N ¹ , N ^1- Bis (3-dichloromethylsilane Rupuropiru) -N ^2, N ² - bis (3-trimethoxysilylpropyl) ^{-1,3-propanediamine, N 1, N 1, N} 3, N 3 - tetra (3-trimethoxysilylpropyl) -N ² -(3-Dichloromethylsilylpropyl) -diethylenetriamine is mentioned.

When all the functional groups in the modifier used in the modification step are alkoxy groups, the number of alkoxy groups in the modifier may be the sum of the number of conjugated diene polymers to be bonded and the number of alkoxy groups to remain. preferable.
When the functional group is an alkoxy group and another functional group, it is preferable to use a method in which the alkoxy group remains unreacted depending on the reaction rate. For example, in the case of an alkoxysilyl group and a halogen group, since the reaction of the halogen group is fast, the reaction between the terminal of the conjugated diene polymer and the halogen group occurs first, and the alkoxy group tends to remain. In that case, the number of halogens in the modifier is equal to or less than the number of conjugated diene polymers to be bonded, and the number of alkoxy groups in the modifier is equal to or greater than the number of alkoxy groups to remain. Is preferred.
When halogen forms a silyl halide group, when the halogen group remains unreacted, it tends to hydrolyze in alkaline water to form a silanol group.
When a halogen group is used, neutralization may be necessary so that the halogen or hydrogen halide does not become corrosive.

  In the modification step, all of the alkoxy groups in the modifier may not always react. For example, when reacting the active terminal of 3 moles of nitrogen-containing conjugated diene polymer with 3 alkoxy groups per silicon atom, that is, 1 mole of trialkoxysilyl group, up to 2 moles of nitrogen Although reaction with the conjugated diene-based polymer occurs, 1 mol of alkoxy group tends to remain unreacted. This is confirmed by the fact that 1 mol of nitrogen-containing conjugated diene polymer remains as an unreacted polymer without reacting. In addition, by making many alkoxy groups react, it exists in the tendency which can suppress that a polymer viscosity changes greatly resulting from causing a condensation reaction at the time of finishing and storage. In particular, 2 moles of conjugated diene copolymer reacted with 1 mole of trialkoxysilane group is 4 or more in the modified conjugated diene copolymer, that is, the degree of branching is 8 or more, and other reactions. When possible alkoxy groups are not present in the modified conjugated diene copolymer, the condensation reaction tends to be suppressed.

The addition amount of the modifier is such that the ratio of the number of moles of all the reactive groups of the added modifier to the number of moles of the conjugated diene polymer having an active terminal is the number of moles of all the reactive groups of the added modifier. The number of moles of the conjugated diene polymer having an active terminal is preferably 0.5 or more and 2.0 or less, more preferably 0.7 or more and 1.8 or less, and 0.8 or more and 1.5 or less. It is more preferable that By controlling the addition amount of the modifier within this range, a high modification rate tends to be obtained.
However, a reactive group is counted as 2 moles per mole of trialkoxysilyl group, and a reactive group is counted as 1 mole per mole of dialkoxysilyl group.

The modification rate of the modified conjugated diene polymer of the present embodiment is preferably 30% by mass or more, more preferably 50% by mass or more, and further preferably 70% by mass or more.
When the modification rate is 30% by mass or more, the dispersibility of the filler added when the vulcanized product is used, such as silica, tends to be improved.
The modification rate can be measured by the method described in Examples described later.

  The reaction temperature in the modification step is preferably the same as the polymerization temperature of the conjugated diene polymer, more preferably 0 ° C. or more and 120 ° C. or less, and further preferably 50 ° C. or more and 100 ° C. or less. The temperature change from the polymerization step to the addition of the modifier is preferably 10 ° C. or less, more preferably 5 ° C. or less.

  The reaction time in the denaturation step is preferably 10 seconds or longer, more preferably 30 seconds or longer. The time from the end of the polymerization step to the start of the modification step is preferably shorter, but more preferably within 5 minutes. By doing so, a high modification rate tends to be obtained.

  Mixing in the denaturation step may be either mechanical stirring, stirring with a static mixer, or the like. When the polymerization step is continuous, the modification step is also preferably continuous. As the reactor in the denaturation step, for example, a tank type with a stirrer or a tube type is used. The modifier may be continuously supplied to the reactor after being diluted with an inert solvent. When the polymerization process is batch-type, the modification process may be performed by transferring the modification agent to a polymerization reactor or by transferring it to another reactor.

In the method for producing the modified conjugated diene polymer of the present embodiment, a deactivator, a neutralizing agent, and the like may be added to the copolymer solution after the modification step, if necessary.
Examples of the quenching agent include, but are not limited to, water; alcohols such as methanol, ethanol, and isopropanol.
Examples of the neutralizing agent include, but are not limited to, for example, carboxylic acids such as stearic acid, oleic acid, and versatic acid (a mixture of carboxylic acids having 9 to 11 carbon atoms, mainly 10 and having many branches). Acid; An aqueous solution of an inorganic acid, carbon dioxide gas.

  In the present embodiment, a condensation reaction step in which a condensation reaction is performed in the presence of a condensation accelerator may be provided after the reaction step or before the reaction step.

In the modified conjugated diene polymer of the present embodiment, it is preferable to add a rubber stabilizer from the viewpoint of preventing gel formation after polymerization and improving the stability during processing.
The rubber stabilizer is not limited to the following, and known ones can be used. For example, 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.

The modified conjugated diene polymer of this embodiment is an oil-extended modified conjugated diene polymer in which an extender oil is added to the modified conjugated diene copolymer as necessary in order to further improve processability. Also good.
The method of adding the extender oil to the modified conjugated diene polymer is not limited to the following, but the extender oil is added to the polymer solution and mixed to remove the solvent from the oil-extended copolymer solution. The method is preferred.
Examples of the extending oil include aroma oil, naphthenic oil, paraffin oil, and the like. Among these, from the viewpoint of environmental safety, oil bleed prevention and wet grip characteristics, an aromatic substitute oil having a polycyclic aromatic (PCA) component of 3% by mass or less by the IP346 method is preferable. Examples of the aroma substitute oil include TDAE (Treated Distillate Aromatic Extracts) and MES (Mil Extraction Solvate), e.g.
Although the addition amount of extending oil is not specifically limited, 1 mass part or more and 60 mass parts or less are preferable with respect to 100 mass parts of modified conjugated diene polymers, and 5 mass parts or more and 37.5 mass parts or less are more preferable.

  As a method for obtaining the modified conjugated diene polymer of the present embodiment from the polymer solution, a known method can be used. Although not limited to the following, for example, after separating the solvent by steam stripping or the like, the polymer is separated by filtration, and further, it is dehydrated and dried to obtain the polymer, and concentrated in a flushing tank. Further, a method of devolatilization with a vent extruder or the like, and a method of devolatilization directly with a drum dryer or the like are mentioned.

The modified conjugated diene polymer of this embodiment is suitably used as a vulcanizate.
Examples of the vulcanizate include tires, hoses, shoe soles, vibration-insulating rubbers, automobile parts, and vibration-insulating rubbers, and also include resin-reinforced rubbers such as impact-resistant polystyrene and ABS resin.
In particular, the modified conjugated diene polymer is suitably used for a tread rubber composition for tires.
The vulcanized product may be, for example, a modified conjugated diene polymer of the present embodiment, if necessary, an inorganic filler such as a silica-based inorganic filler or carbon black, or a modified conjugated diene polymer of the present embodiment. A modified conjugated diene polymer composition is kneaded with a rubber-like polymer, a silane coupling agent, a rubber softener, a vulcanizing agent, a vulcanization accelerator, a vulcanization aid, etc. It can be obtained by sulfuration.

(Rubber composition)
The rubber composition of this embodiment contains a rubber component and a filler of 5.0 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the rubber component.
The rubber component contains 10% by mass or more of the modified conjugated diene polymer of the present embodiment described above with respect to the total amount (100% by mass) of the rubber component.
Moreover, it is preferable that the said filler contains a silica type inorganic filler.
The rubber composition tends to be more excellent in processability when it is made into a vulcanizate by dispersing a silica-based inorganic filler, and the balance between low hysteresis loss and wet skid resistance when made into a vulcanizate. In addition, they tend to be more excellent in wear resistance and breaking strength.
Also when the rubber composition of this embodiment is used for vulcanized rubber applications such as tires, automobile parts such as anti-vibration rubber, and shoes, it is preferable that a silica-based inorganic filler is included.

In the rubber composition, a rubbery polymer other than the modified conjugated diene polymer of the present embodiment (hereinafter simply referred to as “rubbery polymer”) is used in combination with the modified diene polymer of the present embodiment. it can.
Examples of such rubbery polymers include, but are not limited to, for example, conjugated diene polymers or hydrogenated products thereof, random copolymers of conjugated diene compounds and vinyl aromatic compounds, or hydrogenated products thereof. Products, block copolymers of conjugated diene compounds and vinyl aromatic compounds or hydrogenated products thereof, non-diene polymers, and natural rubber.
Specific rubbery polymers are not limited to the following, but include, for example, butadiene rubber or hydrogenated product thereof, isoprene rubber or hydrogenated product thereof, styrene-butadiene rubber or hydrogenated product thereof, and styrene-butadiene block. Examples thereof include styrene elastomers such as a copolymer or a hydrogenated product thereof, a styrene-isoprene block copolymer or a hydrogenated product thereof, acrylonitrile-butadiene rubber or a hydrogenated product thereof.

  The non-diene polymer is not limited to the following, but for example, olefins such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, ethylene-octene rubber, etc. Elastomer, butyl rubber, brominated butyl rubber, acrylic rubber, fluoro rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β-unsaturated nitrile-acrylate ester-conjugated diene copolymer rubber, urethane rubber, and polysulfide rubber Is mentioned.

  Examples of natural rubber include, but are not limited to, the following: smoked sheet RSS 3-5, SMR, and epoxidized natural rubber.

  The various rubber-like polymers described above may be modified rubbers having functional groups having polarity such as hydroxyl groups and amino groups. When used for tires, butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber are preferably used.

  The weight average molecular weight of the rubber-like polymer is preferably from 2,000 to 2,000,000, more preferably from 5,000 to 1,500,000, from the viewpoint of a balance between performance and processing characteristics. A low molecular weight rubbery polymer, so-called liquid rubber, can also be used. These rubber-like polymers may be used individually by 1 type, and may use 2 or more types together.

In the rubber composition containing the modified conjugated diene polymer and the rubber-like polymer of the present embodiment, the content ratio (mass ratio) of the modified conjugated diene polymer to the rubber-like polymer is (modified conjugated diene). System polymer / rubbery polymer) is preferably 10/90 or more and 100/0 or less, more preferably 20/80 or more and 90/10 or less, and even more preferably 50/50 or more and 80/20 or less. Therefore, the rubber component preferably contains the modified conjugated diene-based polymer of the present embodiment with respect to the total amount of the rubber component (100 parts by mass), preferably 10 parts by mass or more and 100 parts by mass or less, more preferably 20 parts by mass. More than 90 parts by mass and more preferably 50 parts by mass to 80 parts by mass.
When the content ratio of (modified conjugated diene polymer / rubber-like polymer) is in the above range, the balance between low hysteresis loss and wet skid resistance when used as a vulcanizate, and excellent wear resistance, and High fracture strength is also obtained.

The filler used in the rubber composition of the present embodiment is not limited to the following, and examples thereof include silica-based inorganic filler, carbon black, metal oxide, and metal hydroxide. Among these, a silica type inorganic filler is preferable.
These may be used alone or in combination of two or more.

The content of the filler in the rubber composition is preferably 5.0 parts by mass or more and 150 parts by mass with respect to 100 parts by mass of the rubber component containing the modified conjugated diene polymer, and 20 parts by mass or more and 100 parts by mass. The following is more preferable.
The content of the filler is 5.0 parts by mass or more from the viewpoint of the effect of adding the filler, and the filler is sufficiently dispersed, so that the workability and mechanical strength of the composition are practically sufficient. From the viewpoint of, it is 150 parts by mass or less.

The silica-based inorganic filler is not particularly limited, but may be a known, solid particles preferably comprise SiO ₂ or Si ₃ Al as a constituent unit, the main structural units of SiO ₂ or Si ₃ Al Solid particles contained as a component are more preferable. Here, a main component means the component contained in a silica type inorganic filler 50 mass% or more, Preferably it is 70 mass% or more, More preferably, it is 80 mass% or more.

Examples of the silica-based inorganic filler include, but are not limited to, inorganic inorganic substances such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber.
Moreover, the mixture of the silica type inorganic filler which hydrophobized the surface, and a silica type inorganic filler and inorganic fillers other than a silica type is also mentioned.
Among these, silica and glass fiber are preferable, and silica is more preferable from the viewpoints of strength and wear resistance. Examples of silica include dry silica, wet silica, and synthetic silicate silica. Among these silicas, wet silica is preferable from the viewpoint of excellent balance between fracture property improvement effect and wet skid resistance.

From the viewpoint of obtaining practically good wear resistance and fracture characteristics of the rubber composition, the nitrogen adsorption specific surface area determined by the BET adsorption method of the silica-based inorganic filler is 100 m ² / g or more and 300 m ² / g or less. Is more preferably 170 m ² / g or more and 250 m ² / g or less.
If necessary, a silica-based inorganic filler having a relatively small specific surface area, for example, a specific surface area of 200 m ² / g or less, and a silica-based inorganic filler having a relatively large specific surface area, for example, 200 m ² / g or more. It can be used in combination with an agent.
In this embodiment, particularly when a silica-based inorganic filler having a relatively large specific surface area, for example, 200 m ² / g or more is used, the modified conjugated diene-based polymer improves the dispersibility of silica, and particularly wear resistance. There is an effect in improving the property, and there is a tendency that a good balance between good fracture characteristics and low hysteresis loss can be achieved.

The content of the silica-based inorganic filler in the rubber composition is preferably 5.0 parts by mass or more and 150 parts by mass with respect to 100 parts by mass of the rubber component containing the modified conjugated diene polymer. The amount is more preferably 100 parts by mass or less.
The content of the silica-based inorganic filler in the rubber composition is 5.0 parts by mass or more from the viewpoint of exhibiting the effect of adding the inorganic filler, and the inorganic filler is sufficiently dispersed, and the processability of the composition And from a viewpoint of making mechanical strength practically sufficient, it is 150 mass parts or less.

The carbon black is not limited to the following, and examples thereof include carbon blacks of each class such as SRF, FEF, HAF, ISAF, and SAF.
Among these, carbon black having a nitrogen adsorption specific surface area of 50 m ² / g or more and a dibutyl phthalate (DBP) oil absorption of 80 mL / 100 g or less is preferable.

The content of carbon black is preferably 0.5 parts by mass or more and 100 parts by mass or less, more preferably 3.0 parts by mass or more and 100 parts by mass or less, with respect to 100 parts by mass of the rubber component including the modified conjugated diene polymer. More preferably, it is 5.0 parts by mass or more and 50 parts by mass or less.
The content of carbon black is preferably 0.5 parts by mass or more from the viewpoint of expressing the performance required for applications such as dry grip performance and conductivity, and from the viewpoint of dispersibility, 100 parts by mass. The following is preferable.

The metal oxide refers to solid particles whose main component is a chemical unit MxOy (M represents a metal atom, and x and y each independently represents an integer of 1 to 6). .
Examples of the metal oxide include, but are not limited to, alumina, titanium oxide, magnesium oxide, and zinc oxide.
Examples of the metal hydroxide include, but are not limited to, aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

The rubber composition may contain a silane coupling agent.
The silane coupling agent has a function to close the interaction between the rubber component and the inorganic filler, and has an affinity or binding group for each of the rubber component and the silica-based inorganic filler. A compound having a sulfur bond portion and an alkoxysilyl group or silanol group portion in one molecule is preferable.
Such compounds include, for example, bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl] -disulfide, bis- [2- (triethoxy Silyl) -ethyl] -tetrasulfide.

  The content 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, with respect to 100 parts by mass of the filler described above. More preferably, it is at least 15 parts by mass. When the content of the silane coupling agent is within the above range, the addition effect of the silane coupling agent tends to be more remarkable.

The rubber composition may contain a rubber softener from the viewpoint of improving processability.
As the rubber softener, mineral oil or a liquid or low molecular weight synthetic softener is suitable.
Mineral oil-based rubber softeners called process oils or extender oils that are used to soften, increase volume and improve processability of rubbers are mixtures of aromatic, naphthenic and paraffin chains. A paraffin chain having 50% or more carbon atoms in the total carbon is called paraffinic, and a naphthenic ring having 30% or more and 45% or less carbon atoms in the total carbon is naphthenic or aromatic. What accounts for over 30% of carbon is called aromatic.
When the modified conjugated diene polymer of the present embodiment is a copolymer of a conjugated diene compound and a vinyl aromatic compound, the rubber softener to be used is one having an appropriate aromatic content with the copolymer. This is preferable because it tends to be familiar.

The content of the rubber softening agent is preferably 0 parts by mass or more and 100 parts by mass or less, more preferably 10 parts by mass or more and 90 parts by mass or less, with respect to 100 parts by mass of the rubber component containing the modified conjugated diene polymer. 30 parts by mass or more and 90 parts by mass or less are more preferable.
When the content of the rubber softening agent is 100 parts by mass or less with respect to 100 parts by mass of the rubber component, bleeding out tends to be suppressed and stickiness of the rubber composition surface tends to be suppressed.

For the method of mixing the modified conjugated diene polymer and other rubbery polymers, silica inorganic fillers, carbon black and other fillers, silane coupling agents, rubber softeners, etc. Although not limited to those, for example, an open roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, a melt kneading method using a general mixer such as a multi-screw extruder, A method of removing the solvent by heating after dissolution and mixing can be mentioned.
Of these, a melt kneading method using a roll, a Banbury mixer, a kneader, or an extruder is preferred from the viewpoint of productivity and good kneading properties.
In addition, any of a method of kneading the rubber component and other fillers, silane coupling agents, and additives at a time, and a method of mixing in multiple times can be applied.

The rubber composition may be a vulcanized composition that has been vulcanized with a vulcanizing agent. Examples of the vulcanizing agent include, but are not limited to, radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur compounds. Sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, polymeric polysulfur compounds, and the like.
The content of the vulcanizing agent is preferably 0.01 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the rubber component used in the rubber composition. As the vulcanization method, a conventionally known method can be applied, and the vulcanization temperature is preferably 120 ° C. or higher and 200 ° C. or lower, more preferably 140 ° C. or higher and 180 ° C. or lower.

In vulcanization, a vulcanization accelerator and a vulcanization aid may be used as necessary.
As the vulcanization accelerator, conventionally known materials can be used, and are not limited to the following, but examples thereof include sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, and thiazole-based materials. Thiourea and dithiocarbamate vulcanization accelerators.
Moreover, as a vulcanization | cure adjuvant, although not limited to the following, For example, zinc white and a stearic acid are mentioned.
The content of the vulcanization accelerator is preferably 0.01 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the rubber component.

In the rubber composition, other softening agents other than those described above, other fillers other than those described above, heat stabilizers, antistatic agents, weathering stabilizers, anti-aging agents, within the scope not impairing the object of the present embodiment Various additives such as a colorant and a lubricant may be used.
As other softeners, known softeners can be used.
Examples of other fillers include, but are not limited to, calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate.
Known materials can be used as the above heat stabilizer, antistatic agent, weathering stabilizer, anti-aging agent, colorant, and lubricant.
In the rubber composition, other softening agents other than those described above, other fillers other than those described above, heat stabilizers, antistatic agents, weathering stabilizers, anti-aging agents, within the scope not impairing the object of the present embodiment Various additives such as a colorant and a lubricant may be used.
As other softeners, known softeners can be used.
Examples of other fillers include, but are not limited to, calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate.
Known materials can be used as the above heat stabilizer, antistatic agent, weathering stabilizer, anti-aging agent, colorant, and lubricant.

〔tire〕
The rubber composition of this embodiment is suitably used as a rubber composition for tires.
That is, the tire of this embodiment contains a rubber composition.
The rubber composition of the present embodiment is not limited to the following. For example, various tires such as fuel-saving tires, all-season tires, high-performance tires, studless tires: tires such as treads, carcass, sidewalls, and bead portions It can be used for each part. In particular, since the rubber composition of the present embodiment is excellent in the balance between low hysteresis loss and wet skid resistance and wear resistance when used as a vulcanized product, it is suitable for fuel-saving tires and treads for high-performance tires. And more preferably used.

Hereinafter, although a specific Example and a comparative example are given and this embodiment is described in detail, this embodiment is not limited at all by the following example and a comparative example.
Various physical properties in Examples and Comparative Examples described later were measured by the methods shown below.

(Physical property 1) Amount of bound styrene Using a modified conjugated diene polymer as a sample, 100 mg of the sample was made up to 100 mL with chloroform and dissolved to prepare a measurement sample.
The amount of bound styrene (% by mass) with respect to 100% by mass of the modified conjugated diene polymer as a sample was measured by the amount of absorption at the ultraviolet absorption wavelength (around 254 nm) by the phenyl group of styrene (Spectra manufactured by Shimadzu Corporation). Photometer “UV-2450”).

(Physical property 2) Microstructure of butadiene part (1,2-vinyl bond amount)
Using the 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 method of Hampton is determined by the absorbance at a predetermined wave number (the method described in RR Hampton, Analytical Chemistry 21, 923 (1949)). The microstructure of the butadiene portion, that is, the 1,2-vinyl bond amount (mol%) was determined (Fourier transform infrared spectrophotometer “FT-IR230” manufactured by JASCO Corporation).

(Physical property 3) Molecular weight GPC measuring device (trade name “HLC-8320GPC” manufactured by Tosoh Corporation) in which three columns using a conjugated diene polymer or a modified conjugated diene polymer as a sample and a polystyrene gel as a filler were connected. ), A chromatogram is measured using an RI detector (trade name “HLC8020” manufactured by Tosoh Corporation), and based on a calibration curve obtained using standard polystyrene, the weight average molecular weight (Mw) and Number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) were determined.
The eluent used was THF (tetrahydrofuran) containing 5 mmol / L triethylamine.
As the column, three product names “TSKgel SuperMultiporeHZ-H” manufactured by Tosoh Corporation were connected, and a product name “TSKguardcolumn SuperMP (HZ) -H” manufactured by Tosoh Corporation was connected and used as a guard column at the preceding stage.
A 10 mg sample for measurement was dissolved in 10 mL of THF to prepare a measurement solution, and 10 μL of the measurement solution was injected into a GPC measurement device, and measurement was performed under conditions of an oven temperature of 40 ° C. and a THF flow rate of 0.35 mL / min.

(Physical property 4) Contractile factor (g ')
Using a modified conjugated diene polymer as a sample and a GPC measuring apparatus (trade name “GPCmax VE-2001” manufactured by Malvern) in which three columns using polystyrene gel as a filler are connected, a light scattering detector , RI detector, viscosity detector (trade name “TDA305” manufactured by Malvern) were measured in order using three detectors, and based on standard polystyrene, a light scattering detector and an RI detector The absolute molecular weight was determined from the results, and the intrinsic viscosity was determined from the results of the RI detector and the viscosity detector.
The linear polymer was ^assumed to conform to intrinsic viscosity [η] = 3.883M ^0.771 , and the shrinkage factor (g ′) as a ratio of intrinsic viscosity corresponding to each molecular weight was calculated. In the above formula, M is an absolute molecular weight.
The average shrinkage factor (g ′) at an absolute molecular weight of 1 million to 2 million was used as the shrinkage factor (g ′) of the conjugated diene polymer.
The eluent used was THF containing 5 mmol / L triethylamine. As the column, Tosoh Corporation trade names “TSKgel G4000HXL”, “TSKgel G5000HXL”, and “TSKgel G6000HXL” were used. A 20 mg sample for measurement was dissolved in 10 mL of THF to prepare a measurement solution, and 100 μL of the measurement solution was injected into a GPC measurement device, and measurement was performed under conditions of an oven temperature of 40 ° C. and a THF flow rate of 1 mL / min.

(Physical property 5) Polymer Mooney viscosity Using a conjugated diene polymer or a modified conjugated diene polymer as a sample, a Mooney viscometer (trade name “VR1132” manufactured by Ueshima Seisakusho Co., Ltd.) is used and conforms to JIS K6300. The Mooney viscosity was measured using a rotor.
The measurement temperature was 110 ° C. when a conjugated diene polymer was used as a sample, and 100 ° C. when a modified conjugated diene polymer was used as a sample.
First, after preheating the sample at the test temperature for 1 minute, the rotor was rotated at 2 rpm, and the torque after 4 minutes was measured to obtain the Mooney viscosity (ML _{(1 + 4)} ).

(Physical property 6) Glass transition temperature (Tg)
Using a modified conjugated diene-based polymer as a sample, in accordance with ISO 22768: 2006, a differential scanning calorimeter “DSC3200S” manufactured by Mac Science Co. was used. The DSC curve was recorded while the temperature was raised at, and the peak top (Inflection point) of the DSC differential curve was taken as the glass transition temperature.

(Physical property 7) Modification rate The modified conjugated diene polymer was used as a sample and measured by applying the property of adsorbing the modified basic polymer component to a GPC column using silica gel as a filler.
The amount of adsorption on the silica column is measured from the difference between the chromatogram measured with the polystyrene column and the chromatogram measured with the silica column of the sample solution containing the sample and the low molecular weight internal standard polystyrene. Asked.
Specifically, it is as shown below.

-Preparation of sample solution 10 mg of a sample and 5 mg of standard polystyrene were dissolved in 20 mL of THF to prepare a sample solution.
GPC measurement conditions using a polystyrene column Using a trade name “HLC-8320GPC” manufactured by Tosoh Corporation, 5 mmol / L of triethylamine-containing THF was used as an eluent, and 10 μL of a sample solution was injected into the apparatus. A chromatogram was obtained using an RI detector at a temperature of 40 ° C. and a THF flow rate of 0.35 mL / min. As the column, three product names “TSKgel SuperMultiporeHZ-H” manufactured by Tosoh Corporation were connected, and a product name “TSKguardcolumn SuperMP (HZ) -H” manufactured by Tosoh Corporation was connected and used as a guard column at the preceding stage.

GPC measurement conditions using silica-based column Using a trade name “HLC-8320GPC” manufactured by Tosoh Corporation, using THF as an eluent, 50 μL of a sample solution was injected into the apparatus, column oven temperature 40 ° C., THF flow rate A chromatogram was obtained using an RI detector at 0.5 ml / min.
The column uses the product names “Zorbax PSM-1000S”, “PSM-300S”, “PSM-60S” and uses the product name “DIOL 4.6 × 12.5 mm 5 micron” as a guard column in the front stage. Connected and used.

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

(Physical property 8) Presence / absence of nitrogen atom The same measurement as in (Physical property 7) was performed, and when the calculated modification rate was 10% or more, it was judged to have a nitrogen atom.
Thereby, it confirmed that the modified conjugated diene polymer of Examples 1-8 and the comparative example 1 had a nitrogen atom, and the modified conjugated diene polymer of the comparative example 2 did not have a nitrogen atom.

(Physical property 9) Presence / absence of silicon atom Using 0.5 g of a modified conjugated diene polymer as a sample, an ultraviolet-visible spectrophotometer (trade name “UV-manufactured by Shimadzu Corporation” in accordance with JIS K 0101 44.3.1) 1800 ") and quantified by molybdenum blue absorptiometry.
Thereby, when the silicon atom was detected (detection lower limit 10 mass ppm), it was judged that it had a silicon atom.
Thereby, it confirmed that the modified conjugated diene type polymer of Examples 1-8 and Comparative Examples 1-2 had a silicon atom.

[Example 1] Modified conjugated diene polymer (Sample 1)
The polymerization reactor was a tank-type pressure vessel having an internal volume of 10 L, an inlet at the bottom, an outlet at the top, a tank reactor with a stirrer, and a temperature control jacket.
Water was previously removed, and 1,3-butadiene was mixed at 17.9 g / min, styrene at 9.8 g / min, and n-hexane at 145.3 g / min. In a static mixer provided in the middle of the pipe for supplying this mixed solution to the inlet of the reactive group, n-butyllithium for residual impurity inactivation treatment was added and mixed at 0.130 mmol / min, and then at the bottom of the reactive group. Feeded continuously. Further, polymerization in which 2,2-bis (2-oxolanyl) propane as a polar substance is vigorously mixed with a stirrer at a rate of 0.0249 g / min and n-butyllithium as a polymerization initiator at a rate of 0.245 mmol / min. The reaction was continuously fed to the bottom of the reactor.
The temperature was controlled so that the temperature of the polymerization solution at the reactor top outlet was 75 ° C. When the polymerization is sufficiently stable, a small amount of the polymer solution before the addition of the modifier is withdrawn from the outlet at the top of the reactor, and the solvent is removed after adding an antioxidant (BHT) to 0.2 g per 100 g of the polymer. The Mooney viscosity at 110 ° C. and various molecular weights were measured.
Other physical properties are also shown in Table 1.

Next, 0.0242 mmol / tetrakis (3-trimethoxysilylpropyl) -1,3-propanediamine (abbreviated as “A” in the table) as a modifier is added to the polymer solution flowing out from the outlet of the reactor. The polymer solution was continuously added at a rate of minutes, and the polymer solution to which the modifier was added was mixed and modified by passing through a static mixer.
At this time, the time until the modifier is added to the polymerization solution flowing out from the outlet of the polymerization reactor is 4.8 minutes, the temperature is 71 ° C., the temperature in the polymerization step, and the temperature until the modifier is added. The difference was 4 ° C.
Antioxidant (BHT) was continuously added to the modified polymer solution at a rate of 0.25 g per 100 g of the polymer at 0.055 g / min (n-hexane solution) to complete the modification.
Simultaneously with the antioxidant, an oil (JOMO process NC140 manufactured by JX Nippon Oil & Energy Corporation) was continuously added to 100 g of the polymer so as to be 37.5 g, and mixed with a static mixer.
The solvent was removed by steam stripping to obtain modified conjugated diene polymers (sample 1) of the general formulas (1) and (2). Table 1 shows the physical properties of Sample 1.

[Example 2] Modified conjugated diene polymer (Sample 2)
The amount of modifier added was 0.0303 mmol / min. Other conditions were the same as in [Example 1] to obtain modified conjugated diene polymers (sample 2) of the general formulas (1) and (2). Table 1 shows the physical properties of Sample 2.

[Example 3] Modified conjugated diene polymer (sample 3)
The addition amount of the modifier was 0.0455 mmol / min. Other conditions were the same as in [Example 1], and modified conjugated diene polymers (sample 3) of the general formulas (1) and (2) were obtained. Table 1 shows the physical properties of Sample 3.

[Example 4] Modified conjugated diene polymer (sample 4)
The polymerization initiator n-butyllithium was 0.302 mmol / min, the polar substance was 0.0288 g / min, and the amount of modifier added was 0.0264 mmol / min. Other conditions were the same as in [Example 1] to obtain modified conjugated diene polymers (sample 4) of the general formulas (1) and (2). Table 1 shows the physical properties of Sample 4.

[Example 5] Modified conjugated diene polymer (Sample 5)
The modifier was tetrakis (3-triethoxysilylpropyl) -1,3-propanediamine (abbreviated as “B” in the table), and the amount of modifier added was 0.0303 mmol / min. Other conditions were the same as in [Example 1], and modified conjugated diene polymers (sample 5) of the general formulas (1) and (2) were obtained. Table 1 shows the physical properties of Sample 5.

[Example 6] Modified conjugated diene polymer (Sample 6)
Two tank-type pressure vessels having an internal volume of 10 L, an inlet at the bottom, an outlet at the top, and a tank reactor with a stirrer and a jacket for temperature control were connected to form a polymerization reactor.
Water was previously removed, and 1,3-butadiene was mixed at 25.3 g / min, styrene at 14.0 g / min, and n-hexane at 206.3 g / min. In a static mixer provided in the middle of a pipe for supplying this mixed solution to the inlet of the first reactive group, n-butyllithium for residual impurity inactivation treatment was added at 0.123 mmol / min, mixed, Continuously fed to the bottom of the eye reactive group. Further, a first polymerization reactor in which 2,2-bis (2-oxolanyl) propane as a polar substance is vigorously mixed with a stirrer at a rate of 0.0267 g / min and a polymerization initiator at a rate of 0.307 mmol / min. The polymerization reaction was continued continuously. The temperature was controlled so that the temperature of the polymerization solution at the top outlet of the first reactor was 73 ° C. By connecting the top of the first reactor and the bottom of the second reactor, the polymer solution was continuously supplied from the top of the first reactor to the bottom of the second reactor. The temperature was controlled so that the temperature of the polymer at the top outlet of the second reactor was 78 ° C. When the polymerization is sufficiently stable, a small amount of the polymer solution before addition of the modifier is withdrawn from the top outlet of the second reactor, and after adding an antioxidant (BHT) to 0.2 g per 100 g of the polymer. The solvent was removed, and the Mooney viscosity at 110 ° C. and various molecular weights were measured. Other physical properties are also shown in Table 1.

  Next, tris (3-trimethoxysilylpropyl) amine (abbreviated as “C” in the table) as a modifier is added to the polymer solution flowing out from the outlet of the second reactor at a rate of 0.0409 mmol / min. The polymer solution to which the modifier was added was mixed and modified by passing through a static mixer. At this time, the time until the modifier is added to the polymerization solution flowing out from the outlet of the reactor is 3.4 minutes, the temperature is 75 ° C., the temperature in the polymerization step, and the temperature until the modifier is added. The difference was 3 ° C. To the modified polymer solution, an antioxidant (BHT) was continuously added at a rate of 0.25 g per 100 g of the polymer at 0.055 g / min (n-hexane solution) to complete the modification reaction. Simultaneously with the antioxidant, an oil (JOMO process NC140 manufactured by JX Nippon Oil & Energy Corporation) was continuously added to 100 g of the polymer so as to be 37.5 g, and mixed with a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (sample 6) of the general formula (1). Table 1 shows the physical properties of Sample 6.

[Example 7] Modified conjugated diene polymer (Sample 7)
The amount of modifier added was 0.0512 mmol / min. Other conditions were the same as in [Example 6], to obtain a modified conjugated diene polymer (sample 7) of the general formula (1). Table 1 shows the physical properties of Sample 7.

Example 8 Modified Conjugated Diene Polymer (Sample 8)
The modifier was tris (3-triethoxysilylpropyl) amine (abbreviated as “D” in the table), and the amount of modifier added was 0.0512 mmol / min. Other conditions were the same as in [Example 6], to obtain a modified conjugated diene polymer (sample 8) of the general formula (1). Table 1 shows the physical properties of Sample 8.

[Comparative Example 1]
The polymerization reactor was a tank-type pressure vessel having an internal volume of 10 L, an inlet at the bottom, an outlet at the top, a tank reactor with a stirrer, and a temperature control jacket.
Water was previously removed, and 1,3-butadiene was mixed at 17.9 g / min, styrene at 9.8 g / min, and n-hexane at 145.3 g / min. In a static mixer provided in the middle of the pipe for supplying this mixed solution to the inlet of the reactive group, n-butyllithium for residual impurity inactivation treatment was added and mixed at 0.130 mmol / min, and then at the bottom of the reactive group. Continuously fed.
Further, polymerization in which 2,2-bis (2-oxolanyl) propane as a polar substance is vigorously mixed with a stirrer at a rate of 0.0194 g / min and n-butyllithium as a polymerization initiator at a rate of 0.220 mmol / min. The reaction was continuously fed to the bottom of the reactor.
The temperature was controlled so that the temperature of the polymerization solution at the reactor top outlet was 75 ° C. When the polymerization is sufficiently stable, a small amount of the polymer solution before the addition of the modifier is withdrawn from the outlet at the top of the reactor, and the solvent is removed after adding an antioxidant (BHT) to 0.2 g per 100 g of the polymer. The Mooney viscosity at 110 ° C. and various molecular weights were measured. Other physical properties are also shown in Table 1.

Next, bis (3-trimethoxysilylpropyl) methylamine (abbreviated as “E” in the table) as a modifier is continuously added to the polymer solution flowing out from the outlet of the reactor at a rate of 0.0550 mmol / min. The polymer solution to which the modifier was added was mixed by passing through a static mixer to undergo a modification reaction. At this time, the time until the modifier is added to the polymerization solution flowing out from the outlet of the reactor is 4.8 minutes, the temperature is 71 ° C., the temperature in the polymerization step, and the temperature until the modifier is added. The difference was 4 ° C. An antioxidant (BHT) was continuously added to the modified polymer solution at a rate of 0.25 g per 100 g of the polymer at 0.055 g / min (n-hexane solution) for modification. Simultaneously with the antioxidant, an oil (JOMO process NC140 manufactured by JX Nippon Oil & Energy Corporation) was continuously added to 100 g of the polymer so as to be 37.5 g, and mixed with a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (Sample 9). Table 1 shows the physical properties of Sample 9.
The modified conjugated diene polymer of Sample 9 has a four-branched structure, and does not fall under any of the general formulas (1) and (2).

[Comparative Example 2]
The modifying agent was bis (trimethoxysilyl) ethane (abbreviated as “F” in the table), and the addition amount of the modifying agent was 0.0367 mmol / min. Other conditions were the same as those in [Comparative Example 1] to obtain a modified conjugated diene polymer (Sample 10). Table 1 shows the physical properties of Sample 10.
The modified conjugated diene polymer of Sample 10 does not have a nitrogen atom and has a 4-branched structure, and does not fall under any of the general formulas (1) and (2).

[Examples 9 to 16 and Comparative Examples 3 to 4]
Using samples 1 to 10 shown in Table 1 as raw rubbers, rubber compositions containing the raw rubbers were obtained according to the formulation shown below.
Modified conjugated diene polymer (samples 1 to 10): 100 parts by mass (excluding oil)
Silica (trade name “Ultrasil 7000GR” manufactured by Evonik Degussa, Inc., nitrogen adsorption specific surface area 170 m 2 / g): 75.0 parts by mass Carbon black (trade name “Seast KH (N339)” manufactured by Tokai Carbon Co., Ltd.): 5.0 mass Part Silane coupling agent (trade name “Si75” manufactured by Evonik Degussa, bis (triethoxysilylpropyl) disulfide): 6.0 parts by mass S-RAE oil (trade name “Process NC140 manufactured by JX Nippon Oil & Energy Corporation” )): 37.5 parts by mass Zinc flower: 2.5 parts by mass Stearic acid: 1.0 part by mass Anti-aging agent (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine): 2.0 parts by mass Sulfur: 2.2 parts by mass Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazylsulfinamide): 1.7 Part by weight Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by weight Total: 239.4 parts by weight

The above materials were kneaded by the following method to obtain a rubber composition.
Using a closed kneading machine (with an internal volume of 0.3 L) equipped with a temperature control device, as the first stage kneading, under the conditions of a filling rate of 65% and a rotor rotational speed of 30 to 50 rpm, raw rubber (samples 1 to 10), A filler (silica, carbon black), a silane coupling agent, process oil, zinc white, and stearic acid were kneaded. At this time, the temperature of the closed mixer was controlled, and each rubber composition (compound) was obtained at a discharge temperature of 155 to 160 ° C.

Next, as the second stage kneading, the blend obtained above was cooled to room temperature, an anti-aging agent was added, and kneaded again to improve silica dispersion. Also in this case, the discharge temperature of the blend was adjusted to 155 to 160 ° C. by controlling the temperature of the mixer.
After cooling, as a third stage kneading, sulfur and vulcanization accelerators 1 and 2 were added and kneaded with an open roll set at 70 ° C.
Then, it shape | molded and vulcanized with the vulcanization press for 20 minutes at 160 degreeC.
The rubber composition before vulcanization and the rubber composition after vulcanization were evaluated.
Specifically, the evaluation was performed by the following method. The results are shown in Table 2.

[Evaluation 1] Compound Mooney Viscosity Using the Mooney viscometer after the second-stage kneading obtained above and before the third-stage kneading as a sample, according to JIS K6300-1, After preheating at 130 ° C. for 1 minute, the viscosity after rotating the rotor at 2 revolutions per minute for 4 minutes was measured.
The result of Comparative Example 3 was indexed as 100.
The smaller the index, the better the workability.

[Evaluation 2] Viscoelastic Parameters Viscoelastic parameters were measured in a torsion mode using a viscoelasticity tester “ARES” manufactured by Rheometrics Scientific.
Each measured value was indexed with the result for the rubber composition of Comparative Example 3 as 100.
Tan δ measured at 0 ° C. with a frequency of 10 Hz and a strain of 1% was used as an index of wet grip properties.
It shows that wet grip property is so favorable that an index | exponent is large.
Further, tan δ measured at 50 ° C. with a frequency of 10 Hz and a strain of 3% was used as an indicator of low hysteresis loss.
It shows that low hysteresis loss property is so favorable that an index | exponent is small.

[Evaluation 3] Tensile Strength and Tensile Elongation In accordance with the tensile test method of JIS K6251, the tensile strength and tensile elongation were measured, and the result of Comparative Example 3 was indexed as 100.
The larger the index, the better the tensile strength and tensile elongation.

[Evaluation 4] Wear resistance Using an Akron abrasion tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.), the amount of wear at a load of 44.4 N and 1000 revolutions was measured according to JIS K6264-2. Was indexed as 100.
A larger index indicates better wear resistance.

As shown in Table 2, the samples 1 to 3 and 5 to 8 of the examples are the samples 1 to 3 and 5 to 8 of the examples although the Mooney viscosity is higher than that of the sample 9 of the comparative example. The rubber composition used had a low compound Mooney viscosity and showed excellent processability when compared with the rubber composition using Sample 9 of Comparative Example.
Further, the rubber compositions using the samples 1 to 8 of the examples were particularly excellent in low hysteresis loss and wetness when used as vulcanized products when compared with the rubber compositions using the samples 9 to 10 of the comparative examples. It was confirmed that it has a balance with skid resistance and wear resistance, and also has practically sufficient fracture characteristics.

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

Claims (5)

The weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less,
A modified conjugated diene polymer represented by the following general formula (1).
(In formula (1), P ^{1 to} P ³ each independently represents a conjugated diene polymer chain, and R ³ , R ⁴ and R ⁷ each independently represents an alkylene group having 1 to 20 carbon atoms. R ² , R ⁵ and R ⁸ each independently represents an alkyl group having 1 to 20 carbon atoms, and R ¹ , R ⁶ and R ⁹ each independently represent a hydrogen atom or a carbon atom having 1 to 20 carbon atoms. Indicates an alkyl group.
x, y and z each independently represent an integer of 1 to 2, q, s and u represent an integer of 0 to 3, r represents an integer of 1 to 6, and a conjugated diene polymer. The number of chains (x + (y × r) + z) is an integer of 5 to 20. The number of alkoxysilyl groups (q + (s × r) + u) is 1 or more. ) The weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less,
A modified conjugated diene polymer represented by the following general formula (2).
(In formula (2), P ^{1 to} P ³ each independently represents a conjugated diene polymer chain, and R ³ , R ⁴ , R ⁷ , R ¹² , and R ¹³ each independently represents 1 carbon atom. Represents an alkylene group having ˜20, R ² , R ⁵ and R ⁸ each independently represents an alkyl group having 1 to 20 carbon atoms, and R ¹ , R ⁶ and R ⁹ are each independently a hydrogen atom or R ¹⁰ and R ¹¹ each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, x, y and z each independently represent 1 to 2 carbon atoms. Q, s and u are integers of 0 to 3, r is an integer of 0 to 6, p and t are integers of 1 to 2, and a conjugated diene polymer chain ((X × p) + (y × r) + (z × t)) is an integer of 7 to 20. This is the number of alkoxysilyl groups ((q × p) + (s × r) + (u × t)) is Or more.) 100 parts by mass of the modified conjugated diene polymer according to claim 1 or 2,
1 to 60 parts by mass of extension oil,
An oil-extended modified conjugated diene polymer. A rubber component, and 5.0 parts by weight or more and 150 parts by weight of a filler with respect to 100 parts by weight of the rubber component,
The rubber composition, wherein the rubber component contains 10% by mass or more of the modified conjugated diene polymer according to any one of claims 1 to 3 with respect to the total amount of the rubber component.   A tire containing the rubber composition according to claim 4.