JP2020033546A - Modified conjugated diene-based polymer composition, rubber composition and method for producing rubber composition - Google Patents

Abstract

To produce a modified conjugated diene-based polymer composition that can provide in a short time a rubber composition excellent in processability, particularly exhibiting good dispersibility of a filler or the like because a torque of a mixer can be well applied to the polymer composition when kneaded with a filler, and excellent in abrasion resistance and fracture characteristics.SOLUTION: The modified conjugated diene-based polymer composition contains: 100 pts.mass of (A) a modified conjugated diene-based polymer, which has a Mw of 20×10to 300×10, a Mw/Mn of 1.6 to 4.0, and a modification ratio of 50 mass% or more based on the total amount of a conjugated diene-based polymer, and in which a modification ratio of a component, which has a molecular weight equal to 1/2 of a molecular weight of a peak top in a gel permeation chromatography (GPC) curve or, when there are a plurality of peak tops, of a peak top having a minimum molecular weight, is 1/2 or more of the above-mentioned modification ratio based on the total amount of the conjugated diene-based polymer; and 10 to 80 pts.mass of (B) polybutadiene having a cis 1,4-bond content in a microstructure analysis of 80.0 mol% or more.SELECTED DRAWING: None

Description

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

In recent years, there has been an increasing demand for low fuel consumption of automobiles, and there has been a demand for improvements in materials used for automobile tires, particularly tire treads in contact with the ground. Development is being sought.
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 having higher wear resistance is also required.
On the other hand, materials used for tire treads are required to be excellent in wet skid resistance and have practically sufficient breaking characteristics from the viewpoint of safety.

As a material meeting such a demand, there is a material containing a rubbery polymer and a reinforcing filler such as carbon black and silica.
For example, when a material containing silica is used, the balance between low hysteresis loss and wet skid resistance can be improved.
Further, by introducing a functional group having affinity or reactivity with silica to the molecular terminal of the rubbery polymer having high mobility, the dispersibility of silica in the rubber material is improved, and further, Attempts have been made to reduce hysteresis loss by reducing the mobility of the rubber-like polymer molecule terminal by bonding with silica particles.

For example, Patent Literatures 1 and 2 propose polymers modified by reacting a cyclic azasilacycle compound with a polymer active terminal.
Patent Document 3 proposes a diene rubber obtained by performing a coupling reaction between a polymer active terminal and a polyfunctional silane compound.

On the other hand, conventionally, polybutadiene has been widely used in various fields as a rubber material excellent in heat and mechanical properties. However, with the recent sophistication of resource and energy saving needs, polybutadiene has durability (breakage). Further improvements are required for properties and wear resistance) and energy loss (low loss property).
In order to solve such problems, the molecular structure of polybutadiene has a narrow molecular weight distribution, a small degree of molecular chain branching, and a large cis-1,4 bond content. It is being studied energetically through such means.
For example, Patent Document 4 discloses production of highly active polybutadiene having excellent stereoregularity using a catalyst obtained from a cobalt compound, an ionic compound of a non-coordinating anion and a cation, an organoaluminum compound, and water. A method is disclosed.

Japanese Patent Publication No. 2008-527150 International Publication No. 2011/129425 pamphlet WO 2007/114203 pamphlet JP-A-2006-148015

However, since silica has a hydrophilic surface with respect to carbon black having a hydrophobic surface, silica has a low affinity for a conjugated diene-based rubber, and thus silica is contained in a conjugated diene-based rubber material as compared with carbon black. Has the disadvantage that the dispersibility is poor.
Therefore, the conjugated diene rubber material containing silica needs to separately contain a silane coupling agent or the like in order to provide a bond between silica and the rubber and improve dispersibility.
On the other hand, a conjugated diene rubber material in which a functional group highly reactive with silica is introduced at the molecular end of the rubber, the reaction with the silica particles proceeds during the kneading step, but if the reaction progresses slowly, the torque increases. Or the kneading becomes insufficient because of the time required, or the sheet tends to be roughened or cut when the sheet is kneaded after kneading. I have.
Furthermore, when such a conjugated diene rubber material is used as a vulcanized product, particularly when used as a vulcanized product containing an inorganic filler such as silica, the balance between low hysteresis loss and wet skid resistance and abrasion resistance are obtained. However, there is a problem that there is room for improvement in the properties and the breaking characteristics.

  Therefore, in the present invention, a rubber composition having good workability, especially a high torque of a mixer when kneading with a filler, good dispersibility of the filler in a short time, and excellent abrasion resistance and breaking characteristics. It is an object of the present invention to provide a modified conjugated diene-based polymer composition from which is obtained.

The present inventors have conducted intensive studies in order to solve the above-mentioned problems of the prior art, and as a result, a modified conjugated diene-based polymer in which a functional group having affinity or reactivity with a filler is introduced into a molecule of a conjugated diene-based polymer. A modified conjugated diene-based polymer composition containing a polymer and polybutadiene, wherein the modified conjugated diene-based polymer has a weight average molecular weight and a molecular weight distribution in a specific range, and a molecular weight curve by GPC (gel permeation chromatography). In the above, the modification rate of the component having a molecular weight that is の of the molecular weight at the peak top is not less than a predetermined value as compared with the overall modification rate of the modified conjugated diene-based polymer, and The present inventors have found that a modified conjugated diene-based polymer composition having a 1,4 bond content of a specific amount or more can solve the above-mentioned problems of the prior art, and completed the present invention. This has led to the.
That is, the present invention is as follows.

[1]
(A) the weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less;
A modified conjugated diene-based polymer having a molecular weight distribution Mw / Mn of 1.6 or more and 4.0 or less,
The modification ratio to the total amount of the conjugated diene-based polymer is 50% by mass or more;
In a gel permeation chromatography (GPC) curve, the denaturation rate of a peak having a molecular weight which is の of the molecular weight of a peak having a minimum molecular weight when a plurality of peaks are present, or the conjugated diene, 100% by mass of a modified conjugated diene-based polymer, which is １ ／ or more of the modification ratio based on the total amount of the system-based polymer,
(B) 10 to 80 parts by mass of polybutadiene having a cis 1,4 bond content of 80.0 mol% or more in microstructure analysis;
And a modified conjugated diene-based polymer composition.
[2]
The (A) modified conjugated diene polymer is
The contraction factor (g ′) by 3D-GPC is 0.86 or more and 1.0 or less;
The modified conjugated diene-based polymer composition according to the above [1].
[3]
The (A) modified conjugated diene polymer is
The contraction factor (g ′) by 3D-GPC is 0.30 or more and less than 0.86;
The modified conjugated diene-based polymer composition according to the above [1].
[4]
The (A) modified conjugated diene polymer is
The contraction factor (g ′) by 3D-GPC is 0.30 or more and 0.70 or less;
The modified conjugated diene-based polymer composition according to the above [1].
[5]
The (B) polybutadiene comprises:
The cis-1,4 bond content in microstructure analysis is 90.0 mol% or more;
The modified conjugated diene-based polymer composition according to any one of the above [1] to [4].
[6]
(A) the modified conjugated diene-based polymer contains nitrogen and silicon in an amount of 3 ppm by mass or more,
The molar ratio of nitrogen to silicon is 1.1 or more and less than 10;
The modified conjugated diene-based polymer composition according to any one of the above [1] to [5].
[7]
(A) the modified conjugated diene-based polymer contains nitrogen and silicon in an amount of 3 ppm by mass or more,
The molar ratio of nitrogen to silicon is 0.1 or more and less than 0.9,
The modified conjugated diene-based polymer composition according to any one of the above [1] to [5].
[8]
(A) the modified conjugated diene polymer has a glass transition temperature of −20 ° C. or more and 0 ° C. or less;
The modified conjugated diene-based polymer composition according to any one of the above [1] to [7].
[9]
(A) The modified conjugated diene-based polymer composition according to any one of the above [1] to [7], wherein the modified conjugated diene-based polymer has a glass transition temperature of −50 ° C. or more and less than −20 ° C.
[10]
(A) The modified conjugated diene-based polymer composition according to any one of [1] to [7], wherein the modified conjugated diene-based polymer has a glass transition temperature of −70 ° C. or more and less than −50 ° C.
[11]
(A) The modified conjugated diene-based polymer composition according to any one of [1] to [10], wherein the polymerization initiator residue of the modified conjugated diene-based polymer does not contain nitrogen.
[12]
A polymer composition containing the modified conjugated diene-based polymer composition according to any one of the above [1] to [11] in an amount of 10% by mass or more.
[13]
100 parts by mass of a rubber-like polymer containing 10% by mass or more of the modified conjugated diene-based polymer composition according to any one of the above [1] to [11];
5 to 150 parts by mass of a filler,
And a rubber composition comprising:
[14]
The method for producing a rubber composition according to the above [13],
(A) 100 parts by mass of a modified conjugated diene-based polymer,
(B) 10 to 80 parts by mass of polybutadiene;
5 to 150 parts by mass of a filler containing (C) silica as the filler,
And a method for producing a rubber composition.
[15]
(A) the modified conjugated diene-based polymer,
The method for producing a rubber composition according to [14], wherein after kneading (C) the filler containing silica, kneading the obtained kneaded material and (B) polybutadiene.

  According to the present invention, a rubber composition having good workability, especially a high torque of a mixer when kneading with a filler, good dispersibility of the filler and the like in a short time, and excellent abrasion resistance and fracture characteristics. And a modified conjugated diene-based polymer composition can be provided.

Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail.
The following embodiment is an exemplification for describing the present invention, and is not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist.

(Modified conjugated diene polymer composition)
The modified conjugated diene-based polymer composition of the present embodiment includes:
(A) a modified conjugated diene-based polymer having a weight average molecular weight of 20 × 10 ⁴ or more and 300 × 10 ⁴ or less and a molecular weight distribution Mw / Mn of 1.6 or more and 4.0 or less; The denaturation rate with respect to the total amount of the polymer is 50% by mass or more, and the peak weight in the gel permeation chromatography (GPC) curve, or 1 in the case of a plurality of the peak peaks, the molecular weight of the peak peak having the smallest molecular weight. 100 parts by mass of a modified conjugated diene-based polymer, wherein the modification ratio of the component having a molecular weight of / 2 is 1/2 or more of the modification ratio based on the total amount of the conjugated diene-based polymer;
(B) 10 to 80 parts by mass of polybutadiene having a cis 1,4 bond content of 80.0 mol% or more in microstructure analysis;
Is contained.

((A) Modified conjugated diene polymer)
The (A) modified conjugated diene polymer is
The weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less;
The molecular weight distribution Mw / Mn is 1.6 or more and 4.0 or less;
(A) the modification ratio to the total amount of the conjugated diene polymer is 50% by mass or more;
In a gel permeation chromatography (GPC) curve, the denaturation rate of a component having a molecular weight that is の of the molecular weight of the peak top or, when there are a plurality of peaks, the minimum molecular weight, is determined by the conjugated diene system weight. It is 1/2 or more of the modification rate with respect to the total amount of the union.

<Modification rate>
(A) The modified conjugated diene-based polymer has a modification rate of 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more based on the total amount of the conjugated diene-based polymer.
When the modification ratio is 50% by mass or more, when a vulcanized product is obtained, the balance between low hysteresis loss and wet skid resistance is excellent.
The modification rate is a percentage by mass of the content of the polymer component having a specific functional group having affinity or binding reactivity with the filler in the polymer molecule, based on the total amount of the conjugated diene-based polymer.

  As the polymer component having a specific functional group having affinity or binding reactivity with the filler in the polymer molecule, a polymer having a functional group containing a nitrogen atom, a silicon atom and an oxygen atom is preferably exemplified. More preferably, it is a modified conjugated diene polymer having the functional group at the terminal of the polymer. For example, a polymer in which a functional group having a nitrogen atom is bonded to a polymerization start terminal and / or a modified conjugated diene system which is modified by a functional group having a functional group containing a nitrogen atom, a silicon atom, and an oxygen atom at an end terminal Polymers.

(A) The modification rate of the modified conjugated diene-based polymer can be measured by chromatography that can separate a functional group-containing modified component and a non-modified component. As a method using this chromatography, a column for gel permeation chromatography using a polar substance such as silica that adsorbs a specific functional group as a filler is used, and quantification is performed using an internal standard of a non-adsorbed component for comparison. Method.
More specifically, the denaturation rate is calculated by calculating the difference between the chromatogram measured with a polystyrene-based gel column and the chromatogram measured with a silica-based column of the sample solution containing the measurement sample and the low-molecular-weight internal standard polystyrene, It can be calculated by measuring the amount of adsorption to. The denaturation rate can be measured by the method described in Examples described later.
(A) The modification rate of the modified conjugated diene-based polymer can be controlled within the above numerical range by adjusting the amount of the modifying agent added.

<Modification rate of low molecular weight component>
The inventor of the present invention has found that, depending on the polymer, the modification ratio differs for each molecular weight region by measuring the modification ratio in each molecular weight region in the molecular weight curve by GPC.
Further, the modification ratio of a component having a molecular weight that is １ ／ of the molecular weight at the peak top of the GPC curve (hereinafter sometimes referred to as a low molecular weight component) is １ ／ of the modification ratio of the entire modified conjugated diene-based polymer. The modified conjugated diene-based polymer described above has a non-uniform modification rate, and in particular, a modified conjugated diene-based polymer in which the modification rate of components in the low molecular weight region is lower than １ ／ of the modification rate of the entire modified conjugated diene-based polymer. It has been found that the specific performance is superior to that of the diene polymer.

(A) The modified conjugated diene-based polymer has one peak in the GPC curve when one peak is present, and 1/1 of the molecular weight of the peak top having the smallest molecular weight when there are a plurality of peaks. The modification ratio of the component having a molecular weight of 2 (low molecular weight component) is 以上 or more of the modification ratio based on the total amount of the conjugated diene-based polymer. It is preferably at least 0.55, more preferably at least 0.57.
As a result, a rubber composition having excellent processability, particularly a high torque of the mixer when kneading with the filler, is obtained in a shorter time than the conventional rubber composition having a good dispersibility of the filler (A) Modified conjugate A diene polymer can be obtained.
Further, when the modified conjugated diene-based polymer composition of the present embodiment is a vulcanized composition, the balance between low hysteresis loss and wet skid resistance, and excellent breakage characteristics and wear resistance, especially tires As a result, a rubber composition having excellent low hysteresis loss properties can be obtained.

As described above, in addition to the fact that the present inventors have found that the modification ratio differs for each molecular weight region depending on the polymer, the following method is used as a method of transmitting torque during kneading with the polymer and the filler. The present invention has been completed by finding a mechanism.
That is, first, focusing on the modification rate of the modified conjugated diene-based polymer with respect to the total amount of the conjugated diene-based polymer, the Mooney viscosity of the polymer, the microstructure, the used modifier, the kneading conditions, and the like were the same. In this case, a polymer having a high modification rate (modification rate of 50% or more) based on the total amount of the conjugated diene-based polymer has a higher rate of increase in torque when kneading with the filler than a polymer having a low modification rate. Is fast, but on the other hand, the maximum value reached by the torque is also high, so that even if the denaturation rate as a whole changes, the time required to reach the maximum value of the torque is almost the same. In other words, the modification rate of the polymer as a whole affects both the maximum value of the torque and the rate of increase of the torque. As a result, even if the modification rate as a whole increases or decreases, the time required to reach the maximum value of the torque is obtained. It does not seem to have much effect on the length.
On the other hand, when attention is paid to the modification rate of the low molecular weight component, that is, the modification rate of the molecular weight component that is の of the peak top molecular weight, the modification rate of the low molecular weight component is modified relative to the total amount of the conjugated diene polymer. The lower the ratio, the lower the rate of increase in the torque when kneading the polymer with the filler, and the higher the modification ratio of the low molecular weight component with respect to the modification ratio relative to the total amount of the conjugated diene polymer, the higher the torque. Rises faster.

As described above, the rate of increase in torque also has an effect on the modification rate with respect to the total amount of the conjugated diene-based polymer. However, when the “modification rate with respect to the total amount of the conjugated diene-based polymer” is high, low, or “low”. The higher the "denaturation rate of the molecular weight component", the faster the torque rise rate.
That is, according to the study by the present inventor, the influence of the height of the "modification rate of low molecular weight components" on the "modification rate with respect to the total amount of the conjugated diene polymer" on the torque increasing speed is as follows. It is constant irrespective of the "modification ratio with respect to the total amount of the polymer".
On the other hand, since the maximum value of the torque is determined depending on the modification rate of the entire modified conjugated diene-based polymer, it does not change depending on the modification rate of the low molecular weight component, that is, does not depend on the modification rate of the low molecular weight component. The higher the denaturation rate, the shorter the time required to reach the maximum value of the torque. For this reason, regardless of the modification rate with respect to the total amount of the conjugated diene-based polymer, the time required to reach the maximum value of the torque depends on the modification rate of the low molecular weight component with respect to the modification rate with respect to the total amount of the conjugated diene-based polymer. Can be controlled.
Specifically, by setting the modification ratio of the low molecular weight component to be at least half the modification ratio relative to the total amount of the conjugated diene polymer, the processability, particularly the torque of the mixer when kneading with the filler, is increased. And the dispersibility of the filler becomes better in a shorter time than in the past. As a result, it is possible to minimize the thermal deterioration that occurs in the polymer during kneading, and it is possible to reduce the amount of the heat stabilizer to be compounded because it is difficult to thermally deteriorate.

Further, when the modification ratio of the low molecular weight component is １ ／ or more of the modification ratio based on the total amount of the conjugated diene polymer, when the modified conjugated diene polymer (A) is used in the vulcanized composition, The degree of freedom in designing a composition for obtaining a rubber composition having excellent balance between hysteresis loss property and wet skid resistance, excellent in breaking property and wear resistance, and particularly excellent in low hysteresis loss property for tires is increased. .
When producing a rubber composition for tires, it is effective to use a modified conjugated diene polymer having a higher degree of branching and / or a high molecular weight in order to improve low hysteresis loss. On the other hand, processing problems such as difficulty in kneading with a filler or the like may occur. In order to solve such a problem, kneading is performed by employing a technique for improving the processability of the modified conjugated diene-based polymer, by using a modified conjugated diene-based polymer having a higher degree of branching and / or high molecular weight. This prevents problems in the process and the like, and as a result, makes it easier to adjust a composition more suitable for a tire.
From such a viewpoint, in the modified conjugated diene-based polymer (A), the modification rate of the component having a molecular weight that is 1/2 of the molecular weight at the peak top in the GPC curve is 1/1 of the modification rate with respect to the total amount of the conjugated diene-based polymer. It is assumed to be 2 or more.
(A) The modified conjugated diene-based polymer can be obtained by a polymerization method in which the growth reaction is stopped or the chain transfer is extremely small. Therefore, the monomer and the solvent to be introduced into the polymerization reactor are subjected to ultra-high purification, low-temperature polymerization and 99 mass % Monomer conversion can be achieved.

The modification ratio for each molecular weight component can be measured by chromatography that can separate a modified component having a functional group and a non-modified component. As a method using this chromatography, a column for gel permeation chromatography using a polar substance such as silica that adsorbs a specific functional group as a filler is used, and quantification is performed using an internal standard of a non-adsorbed component for comparison. Method.
More specifically, the denaturation rate for each molecular weight component is determined by measuring the molecular weight components of a sample solution containing a measurement sample and a low-molecular weight internal standard polystyrene, a chromatogram measured with a polystyrene gel column and a chromatogram measured with a silica column. The difference can be obtained by measuring the amount of adsorption on the silica column from each difference. Further, the denaturation rate can be measured by the method described in Examples described later.
In order to make the modification rate of the component having a molecular weight that is の of the molecular weight at the peak top in the GPC curve to be 以上 or more of the modification rate with respect to the total amount of the conjugated diene polymer, as described above, It is effective to increase the purity of the monomer and the solvent introduced into the reactor to reduce the amount of the terminal deactivated during the polymerization.

<Weight average molecular weight>
(A) The modified conjugated diene polymer has a weight average molecular weight of 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, preferably 30 × 10 ⁴ or more and 270 × 10 ⁴ or less, more preferably 40 × 10 ⁴ or less. It is 250 × 10 ⁴ or less, and even more preferably 50 × 10 ^{4 or} more and 250 × 10 ⁴ or less.
If the weight average molecular weight is larger than 50 × 10 ^{4, the} amount of the polymerization initiator to be used is small, so that the termination or chain transfer of the growth reaction is caused by a component having a molecular weight of の of the molecular weight at the peak top in the GPC curve ( The influence on the modification rate of the low molecular weight component) is increased. For this reason, it is necessary to achieve ultra-high purity, low-temperature polymerization, and a monomer conversion of less than 99% by mass of a monomer and a solvent to be introduced into the polymerization reactor to obtain a modified conjugated diene-based polymer having a desired modification rate. Will be difficult.
(A) The modified conjugated diene-based polymer is preferably larger than 50 × 10 ⁴ . Thus, by performing the above operation, the modification ratio of the low molecular weight component can be controlled to a desired value.
When the weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, the vulcanized product is excellent in balance between low hysteresis loss and wet skid resistance and excellent in abrasion resistance. The greater the weight-average molecular weight, the greater the effect of improving the abrasion resistance, especially when the weight-average molecular weight is greater than 50 × 10 ⁴ .
Further, when the weight average molecular weight is 300 × 10 ⁴ or less, the filler has excellent dispersibility when it is formed into a vulcanized product, and excellent breaking characteristics can be obtained.
(A) The weight average molecular weight of the modified conjugated diene-based polymer can be measured by the method described in Examples described later.
(A) The weight average molecular weight of the modified conjugated diene-based polymer can be controlled within the above numerical range by adjusting the amount of the polymerization initiator added, for example.

<Molecular weight distribution>
(A) The modified conjugated diene-based polymer has a molecular weight distribution Mw / Mn represented by a ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 1.6 or more and 4.0 or less. The modified conjugated diene-based polymer (A) having a molecular weight distribution in this range tends to be more excellent in processability when forming a vulcanizate than a polymer having the same molecular weight and modification rate. Preferably it is 1.8 or more and 3.0 or less, more preferably 1.9 or more and 2.5 or less.
The (A) modified conjugated diene-based polymer having such a molecular weight distribution can be preferably obtained by continuous polymerization.
The molecular weight distribution is preferably a single peak (monomodal) molecular weight curve by GPC, or a trapezoidal or multi-peaked shape in the case of a plurality of peaks. The continuous peak type means that the height of the lowest part between the peaks is 50% or more of the height of the peaks on both sides. The (A) modified conjugated diene-based polymer having such a molecular weight distribution tends to be more excellent in processability when vulcanized.

Further, the modified conjugated diene-based polymer (A) is 0.3% by mass or more of a modified conjugated diene-based polymer having a molecular weight of 2,000,000 or more and 5,000,000 or less (hereinafter also referred to as "specific high molecular weight component"). Preferably, the content is 20% by mass or less. Thereby, when it is made into a vulcanized product, it tends to be more excellent in balance between low hysteresis loss property and wet skid resistance and abrasion resistance.
The content of the specific high molecular weight component is more preferably from 1.0% by mass to 18% by mass, and further preferably from 2.0% by mass to 15% by mass.
In order to obtain the (A) modified conjugated diene-based polymer in which the content of the specific high molecular weight component is within such a range, for example, the amount of the organic monolithium compound described later as a polymerization initiator is adjusted. In the polymerization step described below, it is preferable to select a method having a residence time distribution, that is, a method of broadening the time distribution of the growth reaction, in any of a continuous polymerization mode and a batch polymerization mode.
As a specific method in the continuous type, a method of using a tank type reactor with a stirrer to form a backmix reactor of a type in which mixing is performed vigorously with a stirrer, preferably a method of using as a complete mixing type reactor, in a tube type reactor, A method of partially recirculating, a method of providing an inlet in the middle of a polymerization reactor in addition to a monomer inlet at or near a monomer inlet, and a method of using a tank type and a tube type reactor in combination Is mentioned.
According to these methods, the residence time distribution can be enlarged, and the polymer component having a long residence time can be used as a high molecular weight component.
Further, as a specific method in the batch system, for example, the feed method of the polymerization initiator may be set to be continuous or intermittent during the period from the start of the polymerization to the middle of the polymerization, continuously at the start of the polymerization, and / or continuously during the polymerization. Alternatively, a method of intermittent feed may be used.
In this method, a polymer that has been polymerized from the start of polymerization when a polymerization initiator is first fed becomes a high molecular weight component, and a difference in molecular weight occurs between the polymer and a polymer that has started polymerization later. More specifically, if the amount of the polymerization initiator corresponding to the target molecular weight is continuously fed to the monomer, for example, at a conversion of 0% by mass to 95% by mass, the expanded molecular weight distribution can be increased. Polymer.
By using the above-mentioned method, the activity ratio of the living terminal of the conjugated diene-based polymer before the reaction step tends to be high, and the coupling rate after coupling, that is, the modified conjugated diene-based polymer having a high modification rate Tends to be obtained. Among these methods, a backmix reactor of a type in which a tank type reactor with a stirrer is used, and mixing is performed vigorously with a stirrer, is more preferable.
In addition, in this specification, a "molecular weight" is a standard polystyrene equivalent molecular weight obtained by GPC (gel permeation chromatography).
The number average molecular weight, the weight average molecular weight, and the content of the molecular weight distribution can be measured by the methods described in Examples described later.

<Shrink factor>
As the modified conjugated diene-based polymer (A) used in the modified conjugated diene-based composition of the present embodiment, the shrinkage factor (g ′) measured using 3D-GPC is 0.86 or more and 1.0 or less. A modified conjugated diene-based polymer is a preferred embodiment.
(A) When the shrinkage factor (g ′) of the modified conjugated diene polymer is in the above range, the strength at high temperatures tends to be excellent.
The shrinkage factor (g ′) is an index of the branched structure of the (A) modified conjugated diene copolymer, and the modified conjugated diene polymer having a shrinkage factor (g ′) of 0.86 or more and 1.0 or less is It is a modified conjugated diene polymer in which the number of branches in one molecule of the modified diene polymer is 3 or less. In such a case, the shrinkage factor (g ′) is more preferably 0.88 or more and 0.99 or less, and even more preferably 0.90 or more and 0.98 or less.
In order to obtain the modified (A) modified conjugated diene copolymer, for example, a modifier having three or less reaction points with a living active terminal is added to one-third of the total number of moles of the polymerization initiator. It is effective to obtain the modified conjugated diene-based copolymer (A) having three or less branches by adding it in the above molar number.

Further, as the modified conjugated diene-based polymer (A), those having a shrinkage factor (g ′) of at least 0.30 and less than 0.86 as measured using 3D-GPC are preferred.
In such a modified conjugated diene polymer (A), the viscosity of the composition to which the filler is added is significantly reduced, and the processability is extremely excellent.
The shrinkage factor (g ′) is an index of the branched structure of the (A) modified conjugated diene-based copolymer, and the (A) modified conjugated diene-based polymer having a shrinkage factor (g ′) of 0.30 or more and less than 0.86. The union is a modified conjugated diene polymer in which the number of branches in one molecule of the modified diene polymer is four or more.
In order to obtain the (A) modified conjugated diene-based copolymer, for example, a modifier having four or more reaction points with a living active terminal is added to a quarter of the total number of moles of the polymerization initiator. An effective method is to obtain the (A) modified conjugated diene copolymer having four or more branches by adding the following moles.

Further, the modified conjugated diene-based polymer (A) preferably has a shrinkage factor (g ′) of not less than 0.30 and not more than 0.70 measured using 3D-GPC.
In such a modified conjugated diene polymer (A), the viscosity of the composition to which the filler is added is lower, and the processability is further improved.
The shrinkage factor (g ′) is an index of the branched structure of the (A) modified conjugated diene copolymer, and the (A) modified conjugated diene system having a shrinkage factor (g ′) of 0.30 or more and 0.70 or less. The polymer is (A) a modified conjugated diene polymer in which the number of branches in one molecule of the modified diene polymer is 5 or more.
In order to obtain the (A) modified conjugated diene-based copolymer, for example, a modifier having five or more reaction points with a living active terminal is added to a one-fifth of the total number of moles of the polymerization initiator. It is effective to obtain a modified conjugated diene-based copolymer having five or more branches by adding the following moles.

The shrinkage factor (g ′) measured by GPC with a viscosity detector-light scattering method measurement (hereinafter also simply referred to as “GPC with a viscosity detector-light scattering method measurement” or “3D-GPC measurement”) is as follows. It also serves as an index of the number of branches of the modified conjugated diene polymer. For example, as the shrinkage factor (g ′) decreases, (A) the number of branches of the modified conjugated diene-based polymer (for example, the number of branches of a star polymer (also referred to as the “number of arms of a star polymer”)) Tend to increase.
When comparing modified conjugated diene-based polymers having the same absolute molecular weight, the shrinkage factor (g ') becomes smaller as the number of branches of the modified conjugated diene-based polymer (A) increases, so that the shrinkage factor (g') ) Can be used as an index of the degree of branching.
Contractile factor (g ') is measured using a 3D-GPC measurement. Assuming that constants (K, α) in a relational expression between intrinsic viscosity and molecular weight ([η] = KMα ([η]: intrinsic viscosity, M: molecular weight) are log K = −3.883, α = 0.772, molecular weight The range of M is input from 1000 to 20000000, and the relationship between the standard intrinsic viscosity [η] ₀ and the molecular weight M is created.
With respect to the standard intrinsic viscosity [η] ₀ , the intrinsic viscosity [η] at each molecular weight M of the sample obtained by the 3D-GPC measurement is defined as a relationship of the intrinsic viscosity [η] to the standard intrinsic viscosity [η] ₀ [ η] / [η] ₀ is calculated for each molecular weight M, and the average value is defined as a shrinkage factor (g ′).
More specifically, it can be measured by the method described in Examples described later.

<(A) Configuration of modified conjugated diene polymer>
(A) The modified conjugated diene-based polymer may have a branched structure.
The number of branch points may be one or more than one in one polymer.
(A) The modified conjugated diene-based polymer is preferably a modified conjugated diene-based polymer having a polymerization initiator residue and / or a modifying agent residue having a functional group having affinity or reactivity with a filler.
That is, (A) the modified conjugated diene-based polymer preferably comprises a polymerization initiator residue and / or a modifier residue having a functional group, and a conjugated diene-based polymer chain.
The terminal having the polymerization initiation residue preferably does not contain nitrogen. When nitrogen is contained, even if the final processability when the vulcanized product is the same, the reaction with the filler is fast, and the sheet processability tends to deteriorate in the initial stage of multi-stage kneading. It is in. On the other hand, when the terminal does not contain nitrogen, it reacts with the filler at an appropriate rate, so that the sheet processability is good even in the initial stage of multi-stage kneading.

<Modifier residue>
The modifier residue in the (A) modified conjugated diene-based polymer is a structural unit of the (A) modified conjugated diene-based polymer bonded to the conjugated diene-based polymer chain. It is a structural unit derived from a modifier, which is generated by reacting a polymer with a modifier.
The denaturant residue has a specific functional group having affinity or binding reactivity with the filler.
When the modified conjugated diene-based polymer (A) is a modified conjugated diene-based polymer in which a functional group is bonded to the polymerization initiation terminal, the (A) modified conjugated diene-based polymer is a polymerized conjugated diene-based polymer having a functional group. It can be obtained by performing a polymerization reaction using an agent.

<Terminal>
When (A) the modified conjugated diene-based polymer does not have a branched structure, (A) the modified conjugated diene-based polymer has a linear structure, and “terminal” means both ends of the linear chain. One is bound to a modifier residue and the other is bound to a polymerization initiator residue.
When (A) the modified conjugated diene-based polymer has a branched structure and at least one of the branch points is a modifier residue, the “terminal” in (A) the modified conjugated diene-based polymer is A point, for example, a terminal of a conjugated diene-based polymer chain that is not bonded to a “modifier residue” .First, a monomer is polymerized by using a polymerization initiator, and then, a polymerization is terminated to a polymerization end. When an agent is bonded to form a branch point, the modified conjugated diene-based polymer has a polymerization initiator residue at the end of the polymer chain not bonded to the modifier residue. In the case where (A) the modified conjugated diene-based polymer has a branched structure and does not have a branch point due to a modifying agent residue, the “terminal” in (A) the modified conjugated diene-based polymer means that It is the terminal of the conjugated diene-based polymer chain that is not bonded, and has a modifier residue or a polymerization initiator residue.

<Preferred embodiment regarding functional group>
Specific examples of the specific functional group having affinity or binding reactivity with the filler include a functional group containing a nitrogen atom and a silicon atom.
The ratio of the number of moles of nitrogen atoms to the number of moles of silicon atoms, that is, the mole ratio of N / Si is preferably 0.1 to 10.0, and more preferably 0.2 to 7.0.
In this range, the affinity with the silica filler is particularly good, the hysteresis loss of the rubber composition using the silica filler is small, and the rubber composition for a fuel-efficient tire exhibits good performance.
In particular, as will be described later, from the viewpoint that silica can be dispersed in a short time during kneading, the N / Si molar ratio is preferably 1.1 or more and less than 10, and abrasion resistance when a vulcanized product is obtained. Therefore, the N / Si molar ratio is preferably 0.1 or more and less than 0.9.
Examples of the functional group containing a silicon atom include, but are not limited to, a methoxysilyl group, an ethoxysilyl group, and a propoxysilyl group.
The functional group containing a nitrogen atom is not limited to the following, but includes, for example, a secondary amino group and a tertiary amino group.

Further, the modified conjugated diene-based polymer (A) is preferably a modified conjugated diene-based polymer having a functional group containing a nitrogen atom in a polymer molecule. In such a case, as the functional group containing a nitrogen atom, it is particularly preferable that the nitrogen atom contains at least a -NH- type secondary amine. In that case, the rubber composition using a silica-based filler and carbon black as the filler has a low hysteresis loss and exhibits good performance as a composition for a fuel-efficient tire.
When the modifier residue has a silicon atom, at least one of the silicon atoms preferably forms an alkoxysilyl group or a silanol group having 1 to 20 carbon atoms. These tend to improve the dispersibility of the filler when formed into a blend, thereby improving the low hysteresis loss property.
(A) In the modified conjugated diene-based polymer, the ends of a plurality of conjugated diene-based polymer chains may be bonded to one silicon atom. Further, the terminal of the conjugated diene polymer chain and the alkoxy group or the hydroxyl group may be bonded to one silicon atom, and as a result, the one silicon atom may constitute an alkoxysilyl group or a silanol group.

<Monomer Constituting Conjugated Diene Polymer>
(A) The conjugated diene-based polymer before modification of the modified conjugated diene-based polymer is obtained by polymerizing at least a conjugated diene compound, and if necessary, copolymerizes both the conjugated diene compound and the vinyl-substituted aromatic compound. Is obtained.
The conjugated diene compound is not particularly limited as long as it is a polymerizable monomer, but is preferably a conjugated diene compound having 4 to 12 carbon atoms per molecule, more preferably a conjugated diene compound having 4 to 8 carbon atoms. Compound. Such conjugated diene compounds are not limited to the following, but include, for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1 , 3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene. Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of industrial availability. These may be used alone or in combination of two or more.
The vinyl-substituted aromatic compound is not particularly limited as long as it is a monomer copolymerizable with the conjugated diene compound, but 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 preferred from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

<Preferred embodiment in case of SBR>
(A) When the modified conjugated diene-based polymer is a butadiene-styrene random copolymer (SBR), the amount of bound styrene is preferably 5% by mass to 50% by mass, and the vinyl content is 10% by mass to 75% by mass. Is preferred. Within this range, SBR that can be used for tires and other various applications can be obtained industrially.
In particular, when the amount of bound styrene is 25% by mass to 45% by mass and the vinyl content is 18% by mass to 30% by mass, a rubber composition having small hysteresis loss and excellent wear resistance can be obtained.
When the amount of bound styrene is from 18% by mass to 28% by mass and the vinyl content is from 45% by mass to 65% by mass, the rubber composition blended with natural rubber has a small hysteresis loss and excellent strength in fuel economy. A rubber composition for a tire is obtained.
The amount of bound styrene is the mass% of styrene in all the monomer components, and the vinyl content is the mass% of the vinyl binding component in the butadiene component.

<Glass transition temperature>
(A) The glass transition temperature of the modified conjugated diene-based polymer, that is, Tg, is the temperature at which the molecular chain of the modified conjugated diene-based polymer starts rotating, and greatly affects the low hysteresis loss property and the wet grip property. .
When Tg is low, the low hysteresis loss property is good, and when Tg is high, the wet grip property is improved.

  As the modified conjugated diene-based polymer (A), those having a Tg of -20 ° C or more and 0 ° C or less are preferred. Thereby, the wet grip property and the rigidity are extremely excellent. This modified conjugated diene polymer is extremely useful for high performance tires and ultra high performance tires.

  As the modified conjugated diene-based polymer (A), those having a Tg of -50 ° C or more and less than -20 ° C are mentioned as other preferable embodiments. Thereby, the balance between the low hysteresis loss property and the wet grip property is extremely excellent. This modified conjugated diene polymer is extremely useful for summer tires and all-season tires.

Further, as the modified conjugated diene-based polymer (A), those having a Tg of −70 ° C. or more and less than −50 ° C. are mentioned as other preferable embodiments. Thereby, low-temperature performance and abrasion resistance become extremely good.
This modified conjugated diene polymer is extremely useful for winter tires.
Further, it is used for compounding various tire treads to improve abrasion resistance.
The Tg of the modified conjugated diene-based polymer can be measured according to ISO 22768: 2006.
(A) The Tg of the modified conjugated diene-based polymer can be controlled to each of the numerical ranges described above by adjusting the amount of bound styrene and the content of vinyl.

<Preferred form of random SBR>
When the modified conjugated diene-based polymer (A) is a butadiene-styrene random copolymer (SBR), it is preferred that the proportion of styrene units present alone is high, and that the number of long chains is small.
Specifically, when the modified conjugated diene-based polymer is a butadiene-styrene copolymer, the copolymer is obtained by ozonolysis known as the method of 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 based on the total bound styrene amount, and the chain styrene structure having 8 or more styrene chains is 5% by mass or less. Preferably, there is. In this case, the obtained vulcanized rubber is a rubber composition for a fuel-efficient tire having particularly excellent hysteresis loss and excellent performance.

<Hydrogenated conjugated diene polymer>
(A) The modified conjugated diene-based polymer may be obtained by subjecting the modified conjugated diene-based polymer or the conjugated diene-based polymer before modification to a hydrogenation treatment in an inert solvent. Good. Thereby, all or a part of the double bond can be converted into a saturated hydrocarbon. In such a case, heat resistance and weather resistance are improved, and deterioration of the product when processed at a high temperature can be prevented, and the exercise performance as rubber tends to be improved. In addition, as a result, more excellent performance is exhibited in various uses such as automobile use.
The hydrogenation rate of the unsaturated double bond based on the conjugated diene compound can be arbitrarily selected according to the purpose, and is not particularly limited. When used as a vulcanizate, it is preferable that the double bond of the conjugated diene part partially remains. From such a viewpoint, the hydrogenation ratio of the conjugated diene part in the conjugated diene-based polymer is preferably from 3.0 mol% to 70 mol%, more preferably from 5.0 mol% to 65 mol%. Preferably, it is 10 mol% or more and 60 mol% or less. In particular, by selectively hydrogenating a vinyl group, heat resistance and exercise performance tend to be improved. The hydrogenation rate can be determined by a nuclear magnetic resonance apparatus (NMR).

<Oil-extended polymer / Mooney viscosity>
(A) The modified conjugated diene-based polymer may be an oil-extended polymer to which an extender oil has been added. (A) The modified conjugated diene-based polymer may be non-oil-extended or oil-extended.
In addition, from the viewpoint of processability when forming a rubber vulcanizate and abrasion resistance when forming a vulcanizate, the modified conjugated diene-based polymer (A) has a Mooney viscosity of 20 at 100 ° C. It is preferably at least 100 and at most 100, more preferably at least 30 and at most 80. The Mooney viscosity can be measured by the method described in Examples described later.

<Nitrogen / silicon content>
(A) In the modified conjugated diene-based copolymer, the content of nitrogen and silicon is preferably 3 mass ppm or more, more preferably 7 mass ppm or more, from the viewpoint of improving low hysteresis loss. And more preferably at least 10 ppm by mass.
(A) It is considered that the modified conjugated diene copolymer is physically adsorbed by nitrogen at the time of kneading with the filler and chemically bonded by silicon.

  (A) In the modified conjugated diene-based copolymer, the molar ratio of nitrogen to silicon contained is important, and the molar ratio of nitrogen to silicon (N / Si) is 1.1 or more and less than 10. From the viewpoint that silica can be dispersed in a short time at the time of kneading, it is preferably from 1.3 to 7, more preferably from 1.5 to 5, and still more preferably from 1.5 to 5. The reason why the molar ratio of N / Si is preferably within the above range is that the physical rate of physical adsorption by nitrogen on silica is faster than the chemical bond by silicon, so that the molar ratio of nitrogen to silicon is equimolar or more. Is presumed to be preferable.

Further, as the modified conjugated diene-based copolymer (A), those having a molar ratio of nitrogen to silicon (N / Si) of 0.1 or more and less than 0.9 are mentioned as another preferred embodiment. Thereby, it tends to be excellent in abrasion resistance when it is made into a vulcanized product. In such a case, it is more preferably 0.2 or more and 0.75 or less, and even more preferably 0.3 or more and 0.6 or less.
The reason why the molar ratio of nitrogen to silicon is preferably 0.1 or more and less than 0.9 is not clear at present, but since the chemical bond by silicon to silica is stronger than the physical adsorption by nitrogen, When the molar ratio of nitrogen to silicon is less than equimolar, it is estimated that the ratio of the modified conjugated diene-based polymer and silica linked by a chemical bond increases, and the bond between the modified conjugated diene-based polymer and silica increases. You. In this case, the content of silicon is preferably 7 ppm or more.

(A) The content of nitrogen and silicon in the modified conjugated diene-based copolymer and the molar ratio of nitrogen to silicon are controlled by appropriately selecting a modifier used in the modification reaction of the conjugated diene-based copolymer. It is possible to
For example, by selecting a modifier having a desired molar ratio of nitrogen to silicon, the content of nitrogen and silicon can be controlled, and by increasing the molar ratio of nitrogen to silicon, (A) the modified conjugated diene copolymer It is possible to increase the molar ratio of nitrogen to silicon.

<(A) Preferred structure of modified conjugated diene polymer>
(A) The modified conjugated diene-based polymer is preferably represented by the following general formula (I).

In the formula (I), D ₁ represents a diene polymer chain, R ^{1 to} R ³ each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms, and R ⁴ and R ⁷ each represent Independently represents an alkyl group having 1 to 20 carbon atoms, R ⁵ , R ⁸ , and R ⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁶ and R ¹⁰ are Each independently represents an alkylene group having 1 to 20 carbon atoms, and R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.
m and x represent an integer of 1 to 3, x ≦ m, p represents 1 or 2, y represents an integer of 1 to 3, y ≦ (p + 1), and z represents 1 Or an integer of 2.
When there are a plurality, D ₁ , R ^{1 to} R ¹¹ , m, p, x, y, and z are each independent.
i represents an integer of 0 to 6, j represents an integer of 0 to 6, k represents an integer of 0 to 6, (i + j + k) is an integer of 1 to 10, and ((x × i) + (Y × j) + (z × k)) is an integer of 1 to 30.
A has a hydrocarbon group having 1 to 20 carbon atoms, or at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom, and a phosphorus atom, and has an active hydrogen. Represents an organic group that is not used. However, when (i + j + k) is 1, A may be omitted. As a result, the modified conjugated diene polymer tends to be more excellent in a balance between low hysteresis loss and wet skid resistance and abrasion resistance when vulcanized.

  (A) In the modified conjugated diene-based polymer, preferably, in the formula (I), A represents any of the following general formulas (II) to (V).

In the formula (II), B ¹ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B ¹ , when two or more are present, each independently ing.

In the formula (III), B ² represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, B ³ represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10 , B ² and B ³ are independent of each other when there are a plurality of each.

In the formula (IV), B ⁴ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B ⁴ represents, when there are a plurality of them, each independently I have.

In the formula (V), B ⁵ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B ⁵ represents a plurality of groups independently when they exist in plurality. I have. Thereby, when it is made into a vulcanized product, it tends to be more excellent in balance between low hysteresis loss and wet skid resistance and abrasion resistance. In addition, it tends to be easily available in practical use.

(Production method of modified conjugated diene polymer)
(A) The method for producing a modified conjugated diene-based polymer preferably comprises the step of polymerizing at least a conjugated diene compound using an organic monolithium compound as a polymerization initiator to obtain a conjugated diene-based polymer; A polymer having a binding group that reacts with the active terminal of the conjugated diene polymer, and a modifier having a specific functional group having affinity or binding reactivity to the filler; and And

<Polymerization step>
(A) In the method for producing a modified diene-based polymer, preferably, in the polymerization step, at least a conjugated diene compound is polymerized using an organic monolithium compound as a polymerization initiator to obtain a conjugated diene-based polymer.
In the polymerization step, polymerization by a growth reaction by a living anionic polymerization reaction is preferable, whereby a conjugated diene-based polymer having an active terminal can be obtained, and a modified diene-based polymer having a high modification rate tends to be obtained. is there.

(A) In the modified conjugated diene-based polymer, the modification rate of a component having a molecular weight (low molecular weight component) that is の of the molecular weight at the peak top in the GPC curve is 1/1 of the modification rate with respect to the total amount of the conjugated diene-based polymer. 2 or more.
In order to obtain the modified (A) modified conjugated diene polymer, it is effective to obtain a conjugated diene polymer by a polymerization method in which the growth reaction is terminated or the chain transfer is extremely small.
For this reason, ultra-high purification of the monomer and the solvent introduced into the polymerization reactor requires a higher level than before.
Therefore, in the monomer components used, the total amount of impurities is preferably 30 ppm or less, and the content concentration (mass) of impurities such as allenes, acetylenes, primary and secondary amines is 20 ppm or less for allenes. Preferably, it is 10 ppm or less, more preferably, 20 ppm or less of acetylenes, and more preferably, 10 ppm or less, and the primary and secondary amines have a total nitrogen content of 4 ppm or less. And more preferably 2 ppm or less.
The allenes are not limited to the following, but include, for example, propadiene and 1,2-butadiene. Examples of acetylenes include, but are not limited to, ethyl acetylene and vinyl acetylene. Examples of the primary and secondary amines include, but are not limited to, methylamine and dimethylamine.

Ultra-high purity of the monomer and the solvent can be achieved by sufficiently purifying all the monomers and the solvent used for the polymerization.
In the purification of butadiene as a monomer, it is important to remove not only the polymerization inhibitor but also dimethylamine, N-methyl-γ-aminobutyric acid and the like which may adversely affect anionic polymerization. As a method for removing these, for example, 1,3-butadiene containing a polymerization inhibitor is washed with low-oxygen water having an oxygen concentration of less than 2 mg / L as washing water, and then 1,3-butadiene is washed with 1,3-butadiene. A method of removing the polymerization inhibitor from butadiene is exemplified.
In the purification of styrene as a monomer, it is important to remove phenylacetylenes and the like, which may adversely affect anionic polymerization. As a method of removing phenylacetylenes, for example, a method of performing a hydrogenation reaction using a palladium-supported alumina catalyst may be mentioned.
In the purification of normal hexane which is a polymerization solvent, it is important to remove water which may adversely affect anionic polymerization. As a method for removing this, for example, a method using γ-alumina, synthetic zeolite or the like can be mentioned. Among these, a method using a synthetic zeolite is preferable. As the synthetic zeolite, those having a large pore diameter are preferable, those having a pore diameter of 0.35 nm or more are more preferable, and those having a pore diameter of 0.42 nm or more are still more preferable.
Since the ultra-purification treatment required to obtain a preferable impurity concentration varies depending on the state before the treatment, the impurity concentration of the monomer and the solvent is measured before the polymerization reaction after the ultra-purification treatment of the monomer and the solvent. Is preferred.
If the desired impurity concentration of monomer and / or solvent could not be obtained, it is likely that either treatment was inadequate. When it is desired to reduce the amounts of the primary and secondary amines, butadiene is not sufficiently purified. preferable. When it is desired to reduce acetylenes, the purification of styrene is insufficient. For example, it is preferable to carry out a hydrogenation reaction again using a palladium-supported alumina catalyst. At this time, it is more preferable to perform a treatment such as increasing the amount of the palladium-supported alumina catalyst or increasing the contact time with the palladium-supported alumina catalyst.

Control of the polymerization temperature and control of the monomer addition rate are further effective as a polymerization method in which the growth reaction is stopped or the chain transfer is extremely small.
The polymerization temperature is preferably a temperature at which living anionic polymerization proceeds, and from the viewpoint of productivity, it is preferably 0 ° C or higher, and more preferably 80 ° C or lower. More preferably, it is 50 ° C. or more and 75 ° C. or less.
Further, the conversion of the entire monomer is preferably less than 99% by mass, and the reaction with the modifier is preferred. More preferably, the conversion is less than 98% by mass.

The conjugated diene-based polymer may be a random copolymer or a block copolymer. In order to make the conjugated diene-based polymer a rubbery polymer, the conjugated diene compound is preferably used in an amount of 40% by mass or more, and more preferably 55% by mass or more, based on the entire monomers of the conjugated diene-based polymer. More preferred.
Examples of the random copolymer include, but are not limited to, a random copolymer composed of two or more conjugated diene compounds such as a butadiene-isoprene random copolymer, a butadiene-styrene random copolymer, and an isoprene-styrene. Examples include a random copolymer and a random copolymer comprising a conjugated diene of 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 statistically random composition, or a tapered (gradient) random in which the composition is distributed in a tapered shape And copolymers. The bonding mode of the conjugated diene, that is, the composition such as 1,4-bond and 1,2-bond may be uniform or may have a distribution.
The block copolymer is not limited to the following, but, for example, a 2-type block copolymer composed of two blocks (diblock), a 3-type block copolymer composed of three blocks (triblock), 4 4 block copolymer (tetrablock). The polymer constituting one block may be a polymer composed of one kind of monomer or a copolymer composed of two or more kinds 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 / I”. Is represented by “B / S”, and the polymer block composed of styrene is represented by “S”, BB / I2-type block copolymer, BB / S2-type block copolymer, and S-B2-type block It is represented by a copolymer, a BB / SS3-type block copolymer, an S-B-S3-type block copolymer, an S-B-S-B4 type block copolymer, or the like.
In the above formula, the boundaries of each block do not necessarily need to be clearly distinguished. Further, when one polymer block is a copolymer composed of two types of monomers A and B, even if A and B in the block are uniformly distributed or tapered. Good.

<Polymerization initiator>
It is preferable to use at least an organic monolithium compound as the polymerization initiator.
Examples of the organic monolithium compound include, but are not limited to, low molecular compounds and solubilized oligomeric organic monolithium compounds. In addition, examples of the organic monolithium compound include compounds having a carbon-lithium bond, compounds having a nitrogen-lithium bond, and compounds having a tin-lithium bond in a bonding manner between the organic group and the lithium.
The amount of the organic monolithium compound used as the polymerization initiator is preferably determined according to the target molecular weight of the conjugated diene-based polymer or the modified conjugated diene-based polymer. The amount of the monomer such as the conjugated diene compound used relative to the amount of the polymerization initiator tends to be related to the degree of polymerization, that is, 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 the amount of the polymerization initiator to decrease, and to decrease the molecular weight, it is preferable to adjust the amount to increase the amount of the polymerization initiator.

Examples of the organic monolithium compound include an alkyllithium compound having a substituted amino group, and a dialkylaminolithium. In this case, a conjugated diene-based polymer having a nitrogen atom consisting 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. Examples of the alkyllithium compound having an amino group having no active hydrogen include, but are not limited to, the following: 3-dimethylaminopropyllithium, 3-diethylaminopropyllithium, 4- (methylpropylamino) butyllithium, Hexamethyleneiminobutyl lithium. Examples of the alkyllithium compound having an amino group having a structure in which active hydrogen is protected include, but are not limited to, the following: 3-bistrimethylsilylaminopropyllithium, 4-trimethylsilylmethylaminobutyllithium.
Examples of the dialkylamino lithium include, but are not limited to, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium dibutylamide, lithium di-n-hexylamide, lithium diheptylamide, lithium diisopropylamide, and lithium dioctylamide. , Lithium-di-2-ethylhexylamide, lithium didecylamide, lithium ethylpropylamide, lithium ethylbutylamide, lithium ethylbenzylamide, lithium methylphenethylamide, lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, Lithium heptamethyleneimide, lithium morpholide, 1-lithioazacyclooctane, 6-lithio-1,3,3-trimethyl-6-azabicik [3.2.1] octane, and 1-lithio-1,2,3,6-tetrahydropyridine.
These organic monolithium compounds having a substituted amino group are obtained by reacting a small amount of a polymerizable monomer, for example, a monomer such as 1,3-butadiene, isoprene, or styrene, to obtain an organic monolithium compound of an oligomer. It can also be used as a compound.

The organic monolithium compound is preferably an alkyl lithium compound. In this case, a conjugated diene-based polymer having an alkyl group at the polymerization start terminal is obtained. The alkyl lithium compound is not limited to the following, but examples include 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 preferred from the viewpoint of industrial availability and easy control of the polymerization reaction.
One of these organic monolithium compounds may be used alone, or two or more thereof may be used in combination.
Further, the organic monolithium compound may be used in combination with another organic metal compound. Examples of the organometallic compound include, but are not limited to, alkaline earth metal compounds, other alkali metal compounds, and other organometallic compounds. The alkaline earth metal compound is not limited to the following, but examples include an organic magnesium compound, an organic calcium compound, and an organic strontium compound. Further, compounds of alkoxides, sulfonates, carbonates, and amides of alkaline earth metals are also included. Examples of the organomagnesium compound include dibutylmagnesium and ethylbutylmagnesium. Other organic metal compounds include, for example, organic aluminum compounds.

In the polymerization step, the polymerization reaction mode is not limited to the following, and examples thereof include a batch type (also referred to as “batch type”) and a continuous type polymerization reaction mode.
In a continuous system, one 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 a polymer is obtained in the reactor. The coalescing solution is drained.
As the batch type reactor, for example, a tank type with a stirrer is used. In the batch system, preferably, the monomer, the inert solvent, and the polymerization initiator are fed, and if necessary, the monomer is continuously or intermittently added during the polymerization, and the polymer is added in the reactor. A polymer solution containing the polymer solution is obtained, and the polymer solution is discharged after completion of the polymerization.
In the production process of the modified conjugated diene-based polymer of the present embodiment, in order to obtain a conjugated diene-based polymer having a high proportion of active terminals, the polymer is continuously discharged and subjected to the next reaction in a short time. Preferably, a continuous type is possible.

The polymerization step is preferably performed 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; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane. Hydrocarbons composed of aromatic hydrocarbons such as benzene, toluene, xylene and mixtures thereof.

  Before being subjected to the polymerization reaction, by treating the allenes and acetylenes as impurities with an organometallic compound, a conjugated diene-based polymer having a high concentration of active terminals tends to be obtained, and a high modification rate of modification is obtained. This is preferable because a conjugated diene polymer tends to be obtained.

In the polymerization step, a polar compound may be added. As a result, the aromatic vinyl compound can be randomly copolymerized with the conjugated diene compound, and can be used as a vinylating agent for controlling the microstructure of the conjugated diene portion. Also, it tends to be effective in accelerating the polymerization reaction.
Examples of the polar compound include, but are not limited to, tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, 2,2-bis (2-oxolanyl) ) Ethers such as propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclidine; potassium-tert-amylate, potassium-tert-butyrate, sodium-tert-butyrate; Alkali metal alkoxide compounds such as sodium amylate; phosphine compounds such as triphenylphosphine; It is.
These polar compounds may be used alone or in combination of two or more.

The amount of the polar compound to be used is not particularly limited and can be selected according to the purpose and the like. Such a polar compound (vinylating agent) can be used as a regulator of the microstructure of the polymer conjugated diene portion in an appropriate amount depending on the desired amount of vinyl bonds. Many polar compounds have an effective randomizing effect at the same time in the copolymerization of the conjugated diene compound and the aromatic vinyl compound, and tend to be used as a regulator of the distribution of the aromatic vinyl compound and as a regulator of the styrene block amount. It is in.
As a method for randomizing a conjugated diene compound and an aromatic vinyl compound, for example, as described in JP-A-59-140221, the total amount of styrene and a part of 1,3-butadiene are used together. A method in which the polymerization reaction is started and the remaining 1,3-butadiene is added intermittently during the copolymerization reaction may be used.

The conjugated diene polymer obtained in the polymerization step before the reaction step described below 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 Is 20 or more and 60 or less.
When the Mooney viscosity is in the above range, the modified conjugated diene-based polymer composition of the present embodiment tends to have excellent workability and abrasion resistance.

The amount of the conjugated diene in the conjugated diene-based polymer or the modified conjugated diene-based polymer is not particularly limited, but is preferably 40% by mass or more and 100% by mass or less, and is 55% by mass or more and 80% by mass or less. Is more preferred.
Further, the amount of bound aromatic vinyl in the conjugated diene-based polymer or the modified conjugated diene-based polymer is not particularly limited, but is preferably from 0% by mass to 60% by mass, and is preferably from 20% by mass to 45% by mass. Is more preferable.
When the amount of the bonded conjugated diene and the amount of the bonded aromatic vinyl are in the above ranges, when a vulcanized product is obtained, the balance between the low hysteresis loss property and the wet skid resistance, and the breaking properties and abrasion resistance are more excellent. There is a tendency.
Here, the amount of the bonded aromatic vinyl can be measured by ultraviolet absorption of the phenyl group, and the amount of the bonded conjugated diene can also be determined therefrom. Specifically, it can be measured according to the method described in Examples described later.

In the conjugated diene-based polymer or the modified conjugated diene-based polymer, the vinyl bond amount in the conjugated diene bond unit is not particularly limited, but is preferably from 10 mol% to 75 mol%, and preferably from 20 mol% to 65 mol%. % Is more preferable.
When the vinyl bond amount is in the above range, when the vulcanized product is used, the balance between low hysteresis loss and wet skid resistance, and abrasion resistance and breaking strength tend to be more excellent.

  Here, when the modified conjugated diene polymer (A) is a branched modified diene polymer and a copolymer of butadiene and styrene, the method of Hampton (RR Hampton, Analytical Chemistry, 21) is used. , 923 (1949)), the vinyl bond amount (1,2-bond amount) in the butadiene bond unit can be determined. Specifically, it can be measured by the method described in Examples described later.

Regarding the microstructure of the modified conjugated diene-based polymer, (A) the amount of each bond in the modified conjugated diene-based polymer is within the above-mentioned numerical range, and (A) the glass transition temperature of the modified conjugated diene-based polymer is When the temperature is in the range of −50 ° C. or more and less than −20 ° C., there is a tendency that a more excellent vulcanizate can be obtained due to a balance between low hysteresis loss and wet skid resistance.
Regarding the glass transition temperature, in accordance with ISO 22768: 2006, a DSC curve is recorded while the temperature is raised in a predetermined temperature range, and the peak point (Inflection point) of the DSC differential curve is defined as the glass transition temperature. Specifically, it can be measured by the method described in Examples described later.

  (A) When the modified conjugated diene-based polymer is a conjugated diene-aromatic vinyl copolymer, the number of blocks in which 30 or more aromatic vinyl units are linked is preferably small or no. . More specifically, when the copolymer is a butadiene-styrene copolymer, the method of Kolthoff (the method described in IM KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946)). In a known method for decomposing a copolymer by the above method and analyzing the amount of polystyrene insoluble in methanol, a block in which 30 or more aromatic vinyl units are linked is preferably 5.0 to the total amount of the copolymer. % Or less, more preferably 3.0% by weight or less.

<Modification reaction step>
In the modification reaction step, the conjugated diene-based polymer obtained by the method described above has a binding group that reacts with the active terminal of the conjugated diene-based polymer, and further has an affinity or binding reactivity with the filler. With a modifying agent having a predetermined functional group.
In this case, a modifier having a predetermined functional group that also has an effect as a binding group may be used. Further, it is preferable to carry out the modification reaction step immediately after the polymerization step. In that case, a modified conjugated diene-based polymer having a high modification rate tends to be obtained.

When a compound having a monofunctional or bifunctional bonding group is used as a modifier, a linear terminal-modified diene polymer is obtained. A diene polymer is obtained.
Preferably, a monofunctional or polyfunctional compound containing at least one element of nitrogen, silicon, tin, phosphorus, oxygen, sulfur, and halogen is used as the modifier. In addition, an onium structure can be introduced into the modified conjugated diene-based polymer by adding and reacting a terminal modifier containing an onium generator. Further, a modifying agent containing a plurality of functional groups containing these elements in the molecule, or a modifying agent containing a functional group containing a plurality of these elements can also be used.
The modifier is preferably one having little or no active hydrogen, such as a hydroxyl group, a carboxyl group, a primary and secondary amino group. Active hydrogen tends to deactivate the active terminal of the conjugated diene polymer.

<Specific description of denaturing agent>
Examples of the nitrogen-containing compound include, but are not limited to, an isocyanate compound, an isothiocyanate compound, an isocyanuric acid derivative, a nitrogen-containing carbonyl compound, a nitrogen-containing vinyl compound, and a nitrogen-containing epoxy compound. Can be
Examples of the silicon-containing compound include, but are not limited to, silicon halide compounds, epoxidized silicon compounds, vinylated silicon compounds, alkoxysilicon compounds, and alkoxysilicon compounds containing a nitrogen-containing group.
Examples of the tin-containing compound include, but are not limited to, a tin halide compound and an organic tin carboxylate compound.
Examples of the phosphorus-containing compound include, but are not limited to, a phosphite compound and a phosphino compound.
Examples of the oxygen-containing compound include, but are not limited to, an epoxy compound, an ether compound, and an ester compound.
Examples of the sulfur-containing compound include, but are not limited to, a mercapto group derivative, a thiocarbonyl compound, and isothiocyanate.
Examples of the halogen-containing compound include, but are not limited to, the above-mentioned silicon halide compounds and tin halide compounds.
Examples of the onium-forming agent include a protected amine compound capable of forming a primary or secondary amine (forming ammonium), a protected phosphine compound capable of forming hydrophosphine (forming phosphonium), a hydroxyl group and a thiol. And a compound capable of forming an oxonium or a sulfonium, and the like, and it is preferable to use a terminal modifier having a functional group for bonding the onium generator and the modified conjugated diene polymer in the molecule.
Examples of the functional group for binding the modified conjugated diene polymer include a carbonyl group (ketone, ester, etc.), an unsaturated group such as a vinyl group, an epoxy group, a silicon halide group, and an alkoxysilicon group.

  The modifier preferably has a nitrogen-containing functional group, and the nitrogen-containing functional group is preferably an amine compound having no active hydrogen. For example, a tertiary amine compound, the above-mentioned active hydrogen is protected by a protecting group. Substituted protected amine compounds and imine compounds represented by the general formula -N = C are mentioned.

  Examples of the isocyanate compound of the nitrogen-containing compound as a modifier are not limited to the following, but include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, and polymeric. Diphenylmethane diisocyanate (C-MDI), phenyl isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, butyl isocyanate, 1,3,5-benzene triisocyanate and the like.

  Examples of the isocyanuric acid derivative which is a modifier include, but are not limited to, 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate and 1,3,5-tris (3- Triethoxysilylpropyl) isocyanurate, 1,3,5-tri (oxiran-2-yl) -1,3,5-triazinan-2,4,6-trione, 1,3,5-tris (isocyanatomethyl ) -1,3,5-Triazinan-2,4,6-trione, 1,3,5-trivinyl-1,3,5-triazinan-2,4,6-trione and the like.

  Examples of the nitrogen-containing carbonyl compound as a modifier include, but are not limited to, 1,3-dimethyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1-methyl-3- (2-methoxyethyl) -2-imidazolidinone, N-methyl-2-pyrrolidone, N-methyl-2-piperidone, N-methyl-2-quinolone, 4,4′-bis ( Diethylamino) benzophenone, 4,4'-bis (dimethylamino) benzophenone, methyl-2-pyridyl ketone, methyl-4-pyridyl ketone, propyl-2-pyridyl ketone, di-4-pyridyl ketone, 2-benzoylpyridine, N , N, N ', N'-tetramethylurea, N, N-dimethyl-N', N'-diphenylurea, methyl N, N-diethylcarbamate N, N-diethylacetamide, N, N-dimethyl -N ', N'-dimethylamino acetamide, N, N-dimethyl picolinic acid amide, N, N-dimethyl-isonicotinic acid amide.

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

  Examples of the nitrogen-containing epoxy compound as a modifier include, but are not limited to, an epoxy group-containing hydrocarbon compound bonded to an amino group, and further having an epoxy group bonded to an ether group. Is also good. For example, it is represented by the general formula (1).

In the formula (1), R is at least a divalent or higher valent hydrocarbon group, or at least one selected from oxygen such as ether, epoxy and ketone, sulfur such as thioether and thioketone, and nitrogen such as tertiary amino group and imino group. It is a divalent or higher organic group having one kind of polar group.
The divalent or higher valent hydrocarbon group is a saturated or unsaturated hydrocarbon group which may be linear, branched or cyclic, and includes an alkylene group, an alkenylene group, a phenylene group and the like. Preferably, it has 1 to 20 carbon atoms. Specific examples include, for example, methylene, ethylene, butylene, cyclohexylene, 1,3-bis (methylene) -cyclohexane, 1,3-bis (ethylene) -cyclohexane, o-, m-, p-phenylene, m- , P-xylene, bis (phenylene) -methane and the like.
In the formula (1), R ¹ and R ⁴ are a hydrocarbon group having 1 to 10 carbon atoms, and R ¹ and R ⁴ may be different from each other. R ² and R ⁵ are hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, and R ² and R ⁵ may be different from each other.
R ³ is a hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (2).
R ¹ , R ² and R ³ may be bonded to each other to form a cyclic structure.
Further, when R ³ is a hydrocarbon group, it may be bonded to R to form a cyclic structure, in which case N and R bonded to R ³ are directly bonded. Is also good.
In the above formula (1), n is an integer of 1 or more, and m is 0 or an integer of 1 or more.

In the formula (2), R ^1, R ² is R ^1, R ² the same definition in the formula (1), R ^1, R ² may be different from each other.

As the nitrogen group-containing epoxy compound used as the modifier, those having an epoxy group-containing hydrocarbon group are preferable, and those having a glycidyl group-containing hydrocarbon group are more preferable.
Examples of the epoxy group-containing hydrocarbon group bonded to an amino group or an ether group include a glycidylamino group, a diglycidylamino group, and a glycidoxy group. A more preferred molecular structure is an epoxy group-containing compound having a glycidylamino group or a diglycidylamino group, and a glycidoxy group, respectively, and is represented by the following general formula (3).

In the formula (3), R is defined in the same manner as R in the formula (1), and R ⁶ is a hydrocarbon group having 1 to 10 carbon atoms or a structure of the following formula (4).
When R ⁶ is a hydrocarbon group, it may be bonded to R to form a cyclic structure, in which case, N and R bonded to R ⁶ may be directly bonded. .
In the formula (3), n is an integer of 1 or more, and m is 0 or an integer of 1 or more.

The nitrogen-containing epoxy-containing compound as a modifier is most preferably a compound having at least one diglycidylamino group and at least one glycidoxy group in the molecule.
The nitrogen-containing epoxy compound as a modifying agent is not limited to the following compounds. For example, N, N-diglycidyl-4-glycidoxyaniline, 1-N, N-diglycidylaminomethyl-4-glycidoxy- Cyclohexane, 4- (4-glycidoxyphenyl)-(N, N-diglycidyl) aniline, 4- (4-glycidoxyphenoxy)-(N, N-diglycidyl) aniline, 4- (4-glycidoxy) Benzyl)-(N, N-diglycidyl) aniline, 4- (N, N′-diglycidyl-2-piperazinyl) -glycidoxybenzene, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N , N, N ', N'-tetraglycidyl-m-xylenediamine, 4,4-methylene-bis (N, N-diglycidylaniline), 1,4-bi (N, N-diglycidylamino) cyclohexane, N, N, N ′, N′-tetraglycidyl-p-phenylenediamine, 4,4′-bis (diglycidylamino) benzophenone, 4- (4-glycidylpiperazini) )-(N, N-diglycidyl) aniline, 2- [2- (N, N-diglycidylamino) ethyl] -1-glycidylpyrrolidine, N, N-diglycidylaniline, 4,4′-diglycidyl-di Examples include benzylmethylamine, N, N-diglycidylaniline, N, N-diglycidylorthotoluidine, N, N-diglycidylaminomethylcyclohexane, and the like.
Of these, particularly preferred are N, N-diglycidyl-4-glycidoxyaniline and 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane.

  Examples of the silicon halide compound as a modifier include, but are not limited to, dibutyldichlorosilane, methyltrichlorosilane, dimethyldichlorosilane, methyldichlorosilane, trimethylchlorosilane, tetrachlorosilane, and tris (trimethylsiloxy). Chlorosilane, tris (dimethylamino) chlorosilane, hexachlorodisilane, bis (trichlorosilyl) methane, 1,2-bis (trichlorosilyl) ethane, 1,2-bis (methyldichlorosilyl) ethane, 1,4-bis (trichlorosilyl) ) Butane, 1,4-bis (methyldichlorosilyl) butane and the like.

  Examples of the epoxidized silicon compound as a modifier include, but are not limited to, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyl. Examples include diethoxysilane and epoxy-modified silicone.

  Examples of the alkoxysilicon compound as a modifier include, but are not limited to, tetramethoxysilane, tetraethoxysilane, triphenoxymethylsilane, and methoxy-substituted polyorganosiloxane.

  Examples of the alkoxysilicon compound containing a nitrogen-containing group as a modifier include, but are not limited to, 3-dimethylaminopropyltrimethoxysilane, 3-dimethylaminopropylmethyldimethoxysilane, and 3-diethylaminopropyltrimethoxysilane. Ethoxysilane, 3-morpholinopropyltrimethoxysilane, 3-piperidinopropyltriethoxysilane, 3-hexamethyleneiminopropylmethyldiethoxysilane, 3- (4-methyl-1-piperazino) propyltriethoxysilane, 1- [3- (Triethoxysilyl) -propyl] -3-methylhexahydropyrimidine, 3- (4-trimethylsilyl-1-piperazino) propyltriethoxysilane, 3- (3-triethylsilyl-1-imidazolidinyl) propylmethyldie G Sisilane, 3- (3-trimethylsilyl-1-hexahydropyrimidinyl) propyltrimethoxysilane, 3-dimethylamino-2- (dimethylaminomethyl) propyltrimethoxysilane, bis (3-dimethoxymethylsilylpropyl) -N-methyl Amine, bis (3-trimethoxysilylpropyl) -N-methylamine, bis (3-triethoxysilylpropyl) methylamine, tris (trimethoxysilyl) amine, tris (3-trimethoxysilylpropyl) amine, N, N, N ', N'-tetra (3-trimethoxysilylpropyl) ethylenediamine, 3-isocyanatopropyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 2,2-dimethoxy-1- (3-trimethoxysilyl Propyl) -1-aza-2-si Cyclopentane, 2,2-diethoxy-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2,2-dimethoxy-1- (4-trimethoxysilylbutyl) -1-aza -2-silacyclohexane, 2,2-dimethoxy-1- (3-dimethoxymethylsilylpropyl) -1-aza-2-silacyclopentane, 2,2-dimethoxy-1-phenyl-1-aza-2-sila Cyclopentane, 2,2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-methyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-8 -(4-methylpiperazinyl) methyl-1,6-dioxa-2-silacyclooctane, 2,2-dimethoxy-8- (N, N-diethylamino) methyl-1,6- Dioxa-2-silacyclooctane and the like.

  As a protected amine compound capable of forming a primary or secondary amine as a modifier, a compound having an unsaturated bond and a protected amine in a molecule is not limited to the following. 4,4'-vinylidenebis [N, N-bis (trimethylsilyl) aniline], 4,4'-vinylidenebis [N, N-bis (triethylsilyl) aniline], 4,4'-vinylidenebis [N, N- Bis (t-butyldimethylsilyl) aniline], 4,4'-vinylidenebis [N-methyl-N- (trimethylsilyl) aniline], 4,4'-vinylidenebis [N-ethyl-N- (trimethylsilyl) aniline] 4,4'-vinylidenebis [N-methyl-N- (triethylsilyl) aniline], 4,4'-vinylidenebis [N-ethyl-N- (triethylsilyl) aniline 4,4'-vinylidenebis [N-methyl-N- (t-butyldimethylsilyl) aniline], 4,4'-vinylidenebis [N-ethyl-N- (t-butyldimethylsilyl) aniline], 1- [4-N, N-bis (trimethylsilyl) aminophenyl] -1- [4-N-methyl-N- (trimethylsilyl) aminophenyl] ethylene, 1- [4-N, N-bis (trimethylsilyl) amino Phenyl] -1- [4-N, N-dimethylaminophenyl] ethylene and the like.

  As a protected amine compound capable of forming a primary or secondary amine as a modifier, a compound having an alkoxysilane and a protected amine in a molecule is not limited to the following. N-bis (trimethylsilyl) aminopropyltrimethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-bis (trimethylsilyl) aminopropyltriethoxysilane, N, N-bis (trimethylsilyl) aminopropyl Methyldiethoxysilane, N, N-bis (trimethylsilyl) aminoethyltrimethoxysilane, N, N-bis (trimethylsilyl) aminoethylmethyldiethoxysilane, N, N-bis (triethylsilyl) aminopropylmethyldiethoxysilane, 3- (4-trimethyl Lyl-1-piperazino) propyltriethoxysilane, 3- (3-triethylsilyl-1-imidazolidinyl) propylmethyldiethoxysilane, 3- (3-trimethylsilyl-1-hexahydropyrimidinyl) propyltrimethoxysilane, 2,2 -Dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane, 2,2-diethoxy-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane 2,2-dimethoxy-1- (4-trimethoxysilylbutyl) -1-aza-2-silacyclohexane, 2,2-dimethoxy-1- (3-dimethoxymethylsilylpropyl) -1-aza-2- Silacyclopentane, 2,2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, , 2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-methyl-1-aza-2-silacyclopentane and the like.

  Examples of the tin halide compound as a modifier include, but are not limited to, tetrachlorotin, tetrabromotin, trichlorobutyltin, trichlorooctyltin, dibromodimethyltin, dichlorodibutyltin, chlorotributyltin, and chlorotrioctyl. Tin, chlorotriphenyltin, 1,2-bis (trichlorostannyl) ethane, 1,2-bis (methyldichlorostannyl) ethane, 1,4-bis (trichlorostannyl) butane, 1,4bis (methyl) Dichlorostannyl) butane and the like.

  Examples of the organotin carboxylate compound as a modifier include, but are not limited to, ethyltin tristearate, butyltin trioctanoate, butyltin tristearate, butyltin trilaurate, and dibutyltin bisoctanoate. Eat and the like.

  Examples of the phosphite compound as a modifier include, but are not limited to, trimethyl phosphite, tributyl phosphite, and triphenoxide phosphite.

  Examples of the phosphino compound as a denaturant include, but are not limited to, P, P-bis (trimethylsilyl) phosphinopropyltrimethoxysilane, P, P-bis (triethylsilyl) phosphinopropylmethyl Examples include a protected phosphino compound such as ethoxysilane, 3-dimethylphosphinopropyltrimethoxysilane, and 3-diphenylphosphinopropyltrimethoxysilane.

  Examples of the oxygen-containing compound as a denaturant include, but are not limited to, polyglycidyl ethers such as ethylene glycol diglycidyl ether and glycerin triglycidyl ether, 1,4-diglycidylbenzene, and 1,3. 5-triglycidylbenzene, polyepoxidized liquid polybutadiene, epoxidized soybean oil, polyepoxy compounds such as epoxidized linseed oil, dimethyl adipate, diethyl adipate, dimethyl terephthalate, ester compounds such as diethyl terephthalate, These generate a hydroxyl group at the terminal of the polymer.

  Examples of the sulfur-containing compound as a modifier include, but are not limited to, a protected thiol compound such as S-trimethylsilylthiopropyltrimethoxysilane, S-triethylsilylthiopropylmethyldiethylsilane, Methylthiopropyltrimethoxysilane, S-ethylthiopropylmethyldiethoxysilane, ethyl N, N-diethyldithiocarbamate, phenylisothiocyanate, phenyl-1,4-diisothiocyanate, hexamethylenediisothiocyanate, Butyl isothiocyanate and the like.

The modifier preferably has a silicon-containing functional group, and the silicon-containing functional group preferably has an alkoxysilyl group or a silanol group.
The alkoxysilyl group of the modifier is, for example, reacted with an active terminal of the conjugated diene-based polymer to dissociate the alkoxylithium, thereby forming a bond between the terminal of the conjugated diene-based polymer chain and silicon of the modifier residue. Tends to form. The value obtained by subtracting the number of SiORs reduced by the reaction from the total number of SiORs in one molecule of the modifying agent is the number of alkoxysilyl groups in the modifying agent residue. Further, the azasilacycle group of the modifier forms a> N-Li bond and a bond between the terminal of the conjugated diene polymer and silicon of the residue of the modifier. Note that the> N—Li bond tends to easily become> NH and LiOH due to water or the like at the time of finishing. In the modifier, unreacted remaining alkoxysilyl groups tend to easily become silanols (Si-OH groups) due to water or the like during finishing.

  In the modification reaction step, when a compound having three alkoxy groups is reacted with one silicon atom, that is, when 3 moles of an active terminal of a conjugated diene polymer are reacted with one mole of a trialkoxysilane group. A reaction with up to 2 mol of the conjugated diene polymer occurs, but 1 mol of the alkoxy group tends to remain unreacted. This is confirmed from the fact that 1 mol of the conjugated diene-based polymer remains as an unreacted polymer without reacting. It is to be noted that, by reacting a large number of alkoxy groups, there is a tendency that it is possible to suppress a large change in polymer viscosity due to a condensation reaction occurring during finishing and storage. Preferably, a modifier having one alkoxysilyl group per silicon atom is used.

The reaction temperature in the modification reaction step is preferably the same as the polymerization temperature of the conjugated diene polymer, and particularly preferably a temperature at which no heating is performed after the polymerization. The temperature is preferably from 0 ° C to 120 ° C, more preferably from 50 ° C to 100 ° C.
The reaction time in the denaturation reaction step is preferably at least 10 seconds, more preferably at least 30 seconds.
Mixing in the modification reaction step may be any of mechanical stirring, stirring with a static mixer, and the like.
When the polymerization step is of a continuous type, the modification reaction step is preferably of a continuous type.
As the reactor in the reaction step, for example, a tank type with a stirrer or a tube type is used. The modifier may be diluted with an inert solvent and continuously supplied to the reactor. When the polymerization step is a batch type, the reaction step may be performed by introducing a modifier into a polymerization reactor or by transferring the polymerization agent to another reactor.

  As the modifier, a compound represented by the following general formula (VI) is preferable.

In the above formula (VI), R ^{12 to} R ¹⁴ each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms, and R ^{15 to} R ¹⁸ and R ²⁰ each independently represent 1 carbon atom. Represents an alkyl group having from 20 to 20, R ¹⁹ and R ²² each independently represent an alkylene group having 1 to 20 carbon atoms, and R ²¹ represents an alkyl group having 1 to 20 carbon atoms or a trialkylsilyl group.
m represents an integer of 1 to 3, and p represents 1 or 2.
When a plurality of R ^{12 to} R ²² , m and p are present, each is independent.
i represents an integer of 0 to 6, j represents an integer of 0 to 6, k represents an integer of 0 to 6, and (i + j + k) represents an integer of 1 to 10.
A has a single bond, a hydrocarbon group having 1 to 20 carbon atoms, or at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom, and a phosphorus atom; Represents an organic group not having
The hydrocarbon group represented by A includes saturated, unsaturated, aliphatic, and aromatic hydrocarbon groups. The organic group having no active hydrogen is an organic group that inactivates the active terminal of the conjugated diene polymer. Examples of the organic group include a functional group having an active hydrogen such as a hydroxyl group (—OH), a secondary amino group (> NH), a primary amino group (—NH ₂ ), and a sulfhydryl group (—SH). Group. When (i + j + k) is 1, A may be omitted.

  In the formula (VI), A preferably represents any one of the following general formulas (II) to (V).

In the formula (II), B ¹ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B ¹ , when two or more are present, each independently ing.

In the formula (III), B ² represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, B ³ represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10 , B ² and B ³ are independent of each other when there are a plurality of each.

In the formula (IV), B ⁴ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B ⁴ represents, when there are a plurality of them, each independently I have.

In the formula (V), B ⁵ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B ⁵ represents a plurality of groups independently when they exist in plurality. I have.
Thereby, there is a tendency that a modified conjugated diene-based polymer having better performance of the present embodiment can be obtained.

  As the denaturing agent of the formula (VI), those having (i + j + k) of 1 to 2 are not limited to the following (including those overlapping with the above-mentioned denaturing agent), but for example, 3-dimethoxymethylsilylpropyl Dimethylamine (monofunctional), 3-trimethoxysilylpropyldimethylamine (bifunctional), bis (3-trimethoxysilylpropyl) methylamine (tetrafunctional), bis (3-dimethoxymethylsilylpropyl) methylamine (bifunctional) ), (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] ethylamine (tetrafunctional), [3- (2,2-dimethoxy-1) -Aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl) methylamine (tetrafunctional), bis [3- (2, -Dimethoxy-1-aza-2-silacyclopentane) propyl] methylamine (tetrafunctional), bis (3-triethoxysilylpropyl) ethylamine (tetrafunctional), 1- (3-triethoxysilylpropyl) -2, 2-diethoxy-1-aza-2-silacyclopentane (tetrafunctional), 1- (3-dimethoxymethylsilylpropyl) -2,2-dimethoxy-1-aza-2-silacyclopentane (trifunctional), [ 3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-diethoxyethylsilylpropyl) methylamine (trifunctional), bis [3- (2,2-diethoxy-1) -Aza-2-silacyclopentane) propyl] methylamine (tetrafunctional), (3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trimethyl Lil-sila-2-aza-cyclopentane) propyl] - and methyl amine (trifunctional) is.

  As the polyfunctional compound as the modifying agent of the formula (VI), (i + j + k) is 3 or more, and in the formula (VI), when A is represented by the formula (II), Is not limited to, for example, tris (3-trimethoxysilylpropyl) amine, bis (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-sila Cyclopentane) propyl] amine, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl) amine, tris [3- (2,2- Dimethoxy-1-aza-2-silacyclopentane) propyl] amine, tris (3-ethoxysilylpropyl) amine, bis (3-triethoxysilylpropyl)-[3- (2,2- Ethoxy-1-aza-2-silacyclopentane) propyl] amine, bis [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl) amine, Tris [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl] amine, tetrakis (3-trimethoxysilylpropyl) -1,3-propanediamine, tris (3-trimethoxysilylpropyl) )-[3- (2,2-Dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, bis (3-trimethoxysilylpropyl) -bis [3- (2,2 -Dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tris [3- (2,2-dimethoxy-1- The-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl) -1,3-propanediamine, tetrakis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tris (3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-propanediamine, Bis (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1-methoxy-2-trimethylsilyl-1-sila-2 -Azacyclopentane) propyl] -1,3-propanediamine, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) Propyl]-(3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-propanediamine, tris [3- (2 , 2-Dimethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-propanediamine, Tetrakis (3-triethoxysilylpropyl) -1,3-propanediamine, tris (3-triethoxysilylpropyl)-[3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]- 1,3-propanediamine, bis (3-triethoxysilylpropyl) -bis [3- (2,2-diethoxy-1-aza-2-silacy) Lopentane) propyl] -1,3-propanediamine, tris [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl) -1,3-propane Diamine, tetrakis [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tris (3-triethoxysilylpropyl)-[3- (1-ethoxy) -2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-propanediamine, bis (3-triethoxysilylpropyl)-[3- (2,2-diethoxy-1-aza-2) -Silacyclopentane) propyl]-[3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl]- , 3-propanediamine, bis [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl)-[3- (1-ethoxy-2-trimethylsilyl) -1-sila-2-azacyclopentane) propyl] -1,3-propanediamine, tris [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1 -Ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1,3-bisaminomethylcyclohexane, tris (3- Trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-bisa Minomethylcyclohexane, bis (3-trimethoxysilylpropyl) -bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tris [3 -(2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl) -1,3-bisaminomethylcyclohexane, tetrakis [3- (2,2-dimethoxy- 1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tris (3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclo) Pentane) propyl] -1,3-bisaminomethylcyclohexane, bis (3-trimethoxysilylpropyl)-[3 (2,2-Dimethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bis Aminomethylcyclohexane, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trimethylsilyl-1) -Sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tris [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1 -Methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tetrakis ( -Triethoxysilylpropyl) -1,3-propanediamine, tris (3-triethoxysilylpropyl)-[3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl] -1,3 -Bisaminomethylcyclohexane, bis (3-triethoxysilylpropyl) -bis [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tris [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl) -1,3-propanediamine, tetrakis [3- (2,2-diethoxy- 1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tris (3-triethoxysilylpropyl)- [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, bis (3-triethoxysilylpropyl)-[3- (2 2-diethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane , Bis [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl)-[3- (1-ethoxy-2-trimethylsilyl-1-sila-) 2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tris [3- (2,2-diethoxy-1-aza-2-) Lacyclopentane) propyl]-[3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tetrakis (3-trimethoxysilylpropyl) -1,6-hexamethylenediamine and pentakis (3-trimethoxysilylpropyl) -diethylenetriamine.

In the above formula (VI), the modifying agent when A is represented by the above formula (III) is not limited to the following, but for example, tris (3-trimethoxysilylpropyl) -methyl-1,3 -Propanediamine, bis (2-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -methyl-1,3-propanediamine, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl) -methyl-1,3-propanediamine, tris (3-triethoxysilylpropyl) -methyl- 1,3-propanediamine, bis (2-triethoxysilylpropyl)-[3- (2,2-diethoxy-1-aza-2-silacyclopentane) pro ] -Methyl-1,3-propanediamine, bis [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl) -methyl-1,3 - ^{propanediamine, N 1, N 1 '-} ( propane-1,3-diyl) bis (N ¹ - methyl -N ^3, N ³ - bis (3- (trimethoxysilyl) propyl) -1,3-propane diamine), N ¹ - (3- (bis (3- (trimethoxysilyl) propyl) amino) propyl) -N ¹ - methyl -N ³ - (3- (methyl (3- (trimethoxysilyl) propyl) amino ) propyl) -N ³ - (3- (trimethoxysilyl) propyl) -1,3-propane diamine.

  In the formula (VI), examples of the modifying agent when A is represented by the formula (IV) include, but are not limited to, for example, tetrakis [3- (2,2-dimethoxy-1-aza-2) -Silacyclopentane) propyl] silane, tris [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl) silane, tris [3- (2 2-dimethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] silane, bis (3-trimethoxysilyl) Propyl) -bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, (3-trimethoxysilyl)-[3- (1-methoxy 2-trimethylsilyl-1-sila-2-azacyclopentane) -bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, bis [3- (1-methoxy-2) -Trimethylsilyl-1-sila-2-azacyclopentane) -bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, tris (3-trimethoxysilylpropyl)-[ 3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, bis (3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trimethylsilyl-1-sila-2 -Azacyclopentane) propyl]-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, bis [3- (1-methoxy) -2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -bis (3-trimethoxysilylpropyl) silane, bis (3-trimethoxysilylpropyl) -bis [3- (1-methoxy-2- Methyl-1-sila-2-azacyclopentane) propyl] silane.

  In the formula (VI), examples of the modifying agent when A is represented by the formula (V) include, but are not limited to, the following: 3-tris [2- (2,2-dimethoxy-1-) Aza-2-silacyclopentane) ethoxy] silyl-1- (2,2-dimethoxy-1-aza-2-silacyclopentane) propane, 3-tris [2- (2,2-dimethoxy-1-aza-) 2-silacyclopentane) ethoxy] silyl-1-trimethoxysilylpropane.

  In the formula (VI), A represents an organic group having an oxygen atom and no active hydrogen, for example, as (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1). -Aza-2-silacyclopentane) propyl] ether (tetrafunctional), 3,4,5-tris (3-trimethoxysilylpropyl) -cyclohexyl- [3- (2,2-dimethoxy-1-aza-2) -Silacyclopentane) propyl] ether (8-functional).

  In the formula (VI), A represents a phosphorus atom and represents an organic group having no active hydrogen, but is not limited thereto. For example, (3-trimethoxysilylpropyl) phosphate, Bis (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] phosphate, bis [3- (2,2-dimethoxy-1-aza-2) -Silacyclopentane) propyl]-(3-trimethoxysilylpropyl) phosphate and tris [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] phosphate.

In the formula (VI), A preferably represents the formula (II) or the formula (III), and k represents 0. This tends to be a readily available modifier, and when the modified conjugated diene-based polymer (A) is a vulcanizate, the abrasion resistance and the low hysteresis loss tend to be more excellent. It is in.
Such a modifier is not limited to the following, but for example, bis (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] Amine, tris (3-trimethoxysilylpropyl) amine, tris (3-triethoxysilylpropyl) amine, tris (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-) Silacyclopentane) propyl] -1,3-propanediamine, tetrakis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tetrakis (3-tri Methoxysilylpropyl) -1,3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1,3-bisamino Tylcyclohexane, tris (3-trimethoxysilylpropyl) -methyl-1,3-propanediamine, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-tris (Methoxysilylpropyl) -methyl-1,3-propanediamine.

In the formula (VI), A more preferably represents the formula (II) or the formula (III), k represents 0, and in the formula (II) or the formula (III), a represents an integer of 2 to 10. Represent. Thereby, when vulcanized, abrasion resistance and low hysteresis loss performance tend to be more excellent.
Such modifiers are not limited to the following, but include, for example, tetrakis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1,3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1,3-bisaminomethylcyclohexane, N ^1- (3- (bis (3- (trimethoxysilyl) ) propyl) amino) propyl) -N ¹ - methyl -N ³ - (3- (methyl (3- (trimethoxysilyl) propyl) amino) propyl) -N ³ - (3- (trimethoxysilyl) propyl) - 1,3-propanediamine is exemplified.

The amount of the compound represented by the formula (VI) as a modifier can be adjusted so that the moles of the conjugated diene-based polymer to the moles of the modifier are reacted at a desired stoichiometric ratio. , Thereby achieving the desired degree of branching.
Specifically, the number of moles of the conjugated diene-based polymer, that is, the number of moles of the polymerization initiator is preferably at least 1.0 times, more preferably at least 2.0 times, the moles of the modifier. Is preferred. In this case, in Formula (VI), the number of functional groups ((m−1) × i + p × j + k) of the modifying agent is preferably an integer of 1 to 10, and more preferably an integer of 2 to 10.

<Hydrogenation process>
(A) The modified conjugated diene-based polymer may be one obtained by hydrogenating a conjugated diene portion. The method for hydrogenating the conjugated diene moiety is not particularly limited, and a known method can be used.
A preferred hydrogenation method includes a method in which gaseous hydrogen is blown into a polymer solution in the presence of a catalyst.
As the catalyst, for example, a heterogeneous catalyst such as a catalyst in which a precious metal is supported on a porous inorganic substance; a catalyst in which a salt such as nickel or cobalt is solubilized and reacted with an organic aluminum or the like; or a metallocene such as titanocene is used. A homogeneous catalyst such as a catalyst may be used. Among these, a titanocene catalyst is preferred from the viewpoint that mild hydrogenation conditions can be selected. The hydrogenation of the aromatic group can be performed by using a supported catalyst of a noble metal.
Specific examples of the hydrogenation catalyst are not limited to the following, but, for example, (1) a supported heterogeneous metal in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like; So-called Ziegler-type hydrogenation catalyst using (2) an organic acid salt such as Ni, Co, Fe, Cr or the like, or a transition metal salt such as acetylacetone salt and a reducing agent such as organoaluminum, (3) Ti And so-called organometallic complexes such as organometallic compounds such as Ru, Rh, and Zr. Further, as a hydrogenation catalyst, for example, JP-B-42-8704, JP-B-43-6636, JP-B-63-4841, JP-B1-37970, JP-B1-53851, Known hydrogenation catalysts described in JP-B-2-9041 and JP-A-8-109219 are also included. Preferred hydrogenation catalysts include a reaction mixture of a titanocene compound and a reducing organometallic compound.

<Addition of deactivator, neutralizer, etc.>
(A) In the step of producing the modified conjugated diene-based polymer, a deactivator, a neutralizing agent, or the like may be added to the modified conjugated diene-based polymer solution, if necessary, after the modification reaction step.
Examples of the deactivator include, but are not limited to, water and alcohols such as methanol, ethanol, and isopropanol. Examples of the neutralizing agent include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and versatic acid (a mixture of carboxylic acids having 9 to 11 carbon atoms and having mainly 10 and having many branches). Acids: aqueous solutions of inorganic acids and carbon dioxide.

<Addition of stabilizer for rubber and extension oil>
(A) It is preferable to add a rubber stabilizer to the modified conjugated diene-based polymer from the viewpoint of preventing gel formation after polymerization and improving the stability during processing. The stabilizer for rubber 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) propionate and 2-methyl-4,6-bis [(octylthio) methyl] phenol are preferred.
In order to further improve the processability of the (A) modified conjugated diene-based polymer, an extender oil can be added to the (A) modified conjugated diene-based copolymer as needed. The method of adding the extender oil to the modified conjugated diene-based polymer is not limited to the following, but the extender oil is added to the polymer solution and mixed to form an oil-extended copolymer solution, and the solvent is removed. Is preferred. Examples of the extending oil include aroma oil, naphthenic oil, paraffin oil and the like. Among these, an aroma substitute oil having a polycyclic aromatic (PCA) component of 3% by mass or less according to the IP346 method is preferred from the viewpoint of environmental safety, oil bleed prevention and wet grip characteristics. As aroma substitute oils, TDAE (Treated Distillate Aromatic Extracts) shown in Kautschuk Gummi Kunststoff 52 (12) 799 (1999), MES (Mild ExtractRatioRate, etc.) are also available. The amount of the extender oil is not particularly limited, but is preferably from 10 parts by mass to 60 parts by mass, more preferably from 20 parts by mass to 37.5 parts by mass, per 100 parts by mass of the modified conjugated diene polymer (A). preferable.

  As a method for obtaining the modified conjugated diene-based polymer (A) from the polymer solution, a known method can be used. As the method, for example, after separating the solvent by steam stripping or the like, the polymer is separated by filtration, further dehydrated and dried to obtain a polymer, concentrated in a flushing tank, further vented extruder, etc. And a method of devolatilizing directly with a drum dryer or the like.

((B) polybutadiene)
The modified conjugated diene-based polymer composition of the present embodiment contains (B) polybutadiene.
(B) The polybutadiene has a cis-1,4 bond content of 80.0 mol% or more in microstructure analysis.

<Cis 1,4 bond amount>
The cis 1,4 bond content in the microstructure is at least 80.0 mol%, preferably at least 90.0 mol%, more preferably at least 95.0 mol%. When the amount of cis 1,4 bond is in the above range, high abrasion resistance tends to be obtained.
(B) The cis-1,4 bond content of polybutadiene can be controlled in the above numerical range by polymerizing a combination of a transition metal compound such as yttrium, nickel, cobalt, neodymium, and titanium with an organic aluminum compound.

<Mooney viscosity>
(B) The Mooney viscosity (ML _{(1 + 4)} ) of the polybutadiene measured at 100 ° C. is preferably 20 or more and 120 or less, more preferably 30 or more and 100 or less, and 40 or more and 80 or less. Is even more preferred. When the Mooney viscosity is 120 or less, good processability tends to be obtained, and when it is 20 or more, high fracture characteristics tend to be obtained.

By containing (B) polybutadiene having a high cis-1,4 bond content, the abrasion resistance tends to be excellent, but at the same time, the workability tends to be poor.
(A) The modified conjugated diene-based polymer has a relatively high modification rate of low molecular weight components, so that the kneading with a filler or the like requires a good torque of a mixer, and the dispersibility of the filler in a short time. Since a good rubber composition tends to be obtained, by combining (A) the modified conjugated diene-based polymer and (B) polybutadiene, there is a tendency that the mixture is well kneaded and kneaded well, and the processability is improved. In addition, the excellent abrasion resistance characteristic of polybutadiene having a high cis 1,4 bond can be obtained.

  (B) polybutadiene includes (a-1) a cobalt compound, (b) an ionic compound of a non-coordinating anion and a cation, (c) an organometallic compound of an element in Groups I to III of the periodic table, and (d) water. Can be obtained by polymerizing 1,3-butadiene with a catalyst containing

<(A-1) component: cobalt compound>
As the cobalt compound as the component (a-1), a cobalt salt or complex is preferably used. Particularly preferred are cobalt salts such as cobalt chloride, cobalt bromide, cobalt nitrate, cobalt octylate, cobalt naphthenate, cobalt acetate, and cobalt malonate; cobalt bisacetylacetonate, trisacetylacetonate, and ethyl acetoacetate. Organic base complexes such as ester cobalt, cobalt pyridine complexes and picoline complexes, and ethyl alcohol complexes of cobalt.
As the cobalt compound, only one kind may be used alone, or two or more kinds may be used in combination.

<Component (b): an ionic compound of a non-coordinating anion and a cation>
The non-coordinating anion constituting the ionic compound of the non-coordinating anion and the cation of the component (b) is not limited to the following. Examples thereof include tetra (phenyl) borate and tetra (fluorophenyl). ) Borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis (tetrafluorophenyl) borate, tetrakis (pentafluorophenyl) borate, tetrakis (tetrafluoromethylphenyl) borate, tetrakis (3,5-bistri) Fluoromethylphenyl) borate, tetra (toluyl) borate, tetra (xylyl) borate, (triphenyl, pentafluorophenyl) borate, [tris (pentafluorophenyl), phenyl] borate, tridecahydra Such as de-7,8-dicarbaundecaborate deca borate, and the like.
On the other hand, examples of the cation include a carbenium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptatrienyl cation, and a ferrocenium cation having a transition metal.
Examples of the carbenium cation include a trisubstituted carbenium cation such as a triphenylcarbenium cation and a trisubstituted phenylcarbenium cation.
Examples of the tri-substituted phenylcarbenium cation include a tri (methylphenyl) carbenium cation and a tri (dimethylphenyl) carbenium cation.
Examples of the ammonium cation include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, tributylammonium cation, and tri (n-butyl) ammonium cation; N, N-dimethylanilinium cation; N, N-dialkylanilinium cations such as N-diethylanilinium cation and N, N-2,4,6-pentamethylanilinium cation; dialkylammonium cations such as di (i-propyl) ammonium cation and dicyclohexylammonium cation Is mentioned.
Examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tri (methylphenyl) phosphonium cation, and tri (dimethylphenyl) phosphonium cation.

As the ionic compound as the component (b), a combination of any of the non-coordinating anions and cations exemplified above can be preferably used. Among them, (b) ionic compounds include triphenylcarbenium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, and 1,1′-dimethylferrocenium tetrakis (pentane) Fluorophenyl) borate and the like are preferred.
(B) As the ionic compound, only one kind may be used alone, or two or more kinds may be used in combination.

<Component (c): Organometallic compound of an element in Groups I to III of the periodic table>
As the organometallic compound of the group I-III element of the periodic table as the component (c), organolithium, organomagnesium, organoaluminum and the like are used. Among them, as the organic metal compound, organic aluminum such as trialkylaluminum, dialkylaluminum chloride, dialkylaluminum bromide, alkylaluminum sesquichloride, and alkylaluminum sesquibromide are preferable. Specific examples of the organic aluminum compound include trialkylaluminums such as trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, and tridecylaluminum.
Further, organic aluminum includes organic aluminum halides such as dialkylaluminum chloride such as dimethylaluminum chloride and diethylaluminum chloride, sesquiethylaluminum chloride and ethylaluminum dichloride, and hydrogen such as diethylaluminum hydride, diisobutylaluminum hydride and sesquiethylaluminum hydride. Organic aluminum compounds are also included. The organometallic compounds may be used alone or in combination of two or more.

<Mole ratio of each component>
The mixing ratio of each component may be appropriately set according to various conditions. 10 is preferable, and 1: 0.2-5 is more preferable.
The molar ratio of component (a) to component (c) is preferably (a) :( c) = 1: 0.1-1000, more preferably 1: 1-500.
The molar ratio of the component (c) to the component (d) is preferably (c) :( d) = 1: 0.01 to 2, more preferably 1: 0.01 to 1.5, and more preferably 1: 0. 1 to 1.5 is more preferred.

<Addition order of each component>
The order of addition of each component is not particularly limited, but is preferably performed, for example, in the following order.
That is, in the presence of 1,3-butadiene to be polymerized, the component (d) is added, the component (c) is added, and then the components (a-1) and (b) are added in an arbitrary order. Is preferred.
The component (a-1) and the component (b) may be added simultaneously or may be added at intervals, but it is more preferable to add the component (b) after adding the component (a-1). .
By adding the component (d) and the component (c), a co-catalyst is formed, and thereafter, by contacting the component (a-1) with the co-catalyst, an effective and homogeneous active species is first formed. That is because
The components (a-1) and (b) are preferably added at the same time or at an interval of less than 3 minutes, more preferably at an interval of 2 minutes or less, more preferably 1 minute or less. More preferably, they are added at intervals.
If an interval of 3 minutes or more is provided, heterogeneous active species are formed, an ultrahigh molecular weight component is generated, and it becomes difficult to obtain polybutadiene having a desired Mz / Mw. Conversely, if the components (a-1) and (b) are added simultaneously or with an interval of less than 3 minutes, polybutadiene which can improve the balance between breaking strength, abrasion resistance and low loss can be easily obtained. Become.

<Mixing of components (c) and (d)>
It is preferable that the components (c) and (d) are mixed in the presence of 1,3-butadiene and then aged. The aging temperature is preferably from -50 to 80C, more preferably from -10 to 50C. The aging time is preferably 0.01 to 24 hours, more preferably 0.05 to 5 hours, and even more preferably 0.1 to 3 hours.
Further, each component can be used in a state of being supported on an inorganic compound or an organic polymer compound.

<Solvent>
At the time of polymerization of (B) polybutadiene, a solvent can be used.
Examples of the solvent include aromatic hydrocarbon solvents such as toluene, benzene, and xylene; saturated aliphatic hydrocarbon solvents such as n-hexane, butane, heptane, and pentane; alicyclic hydrocarbon solvents such as cyclopentane and cyclohexane; Olefin hydrocarbon solvents such as C4 fractions such as butene, cis-2-butene and trans-2-butene; petroleum hydrocarbon solvents such as mineral spirits, solvent naphtha and kerosene; and halogenated hydrocarbon solvents such as methylene chloride. And the like.
Further, 1,3-butadiene itself may be used as the polymerization solvent. Among them, benzene, cyclohexane, a mixture of cis-2-butene and trans-2-butene, and the like are preferably used.

<Molecular weight regulator>
(B) At the time of polymerization of polybutadiene, a molecular weight regulator can be used.
As the molecular weight regulator, non-conjugated dienes such as cyclooctadiene and arene, and α-olefins such as ethylene, propylene and butene-1 can be used. Particularly preferably, cyclooctadiene is used, and its use amount is preferably 30 mmol or less, more preferably 5 mmol or less per mole of 1,3-butadiene. If the molecular weight regulator is used in an amount exceeding this range, the problem of ML viscosity deviation may occur.

<Polymerization temperature and polymerization time>
(B) The polymerization temperature of the polybutadiene is preferably in the range of -30 to 100C, particularly preferably in the range of 30 to 80C. The polymerization time is preferably in the range of 10 minutes to 12 hours. The polymerization is carried out under normal pressure or under pressure up to about 10 atm (gauge pressure).

In the polymerization of (B) polybutadiene, for example, (a-2) a neodymium compound can be used instead of the (a-1) cobalt compound as a catalyst component.
(A-2) Examples of neodymium compounds include neodymium carboxylate, alkoxide, β-diketone complex, phosphate and phosphite, and among them, carboxylate or phosphate is preferable, and carboxylate is particularly preferable. Acid salts are preferred.
The neodymium carboxylate, the general formula (R4CO2) represented by ₃ M (M is a Group 3B metal periodic table), R4 is a hydrocarbon substituent having 1 to 20 carbon atoms, preferably It is a saturated or unsaturated alkyl group and is linear, branched or cyclic, and the carboxyl group is bonded to a primary, secondary or tertiary carbon atom.
Specifically, octanoic acid, 2-ethyl-hexanoic acid, oleic acid, stearic acid, benzoic acid, naphthenic acid, and versatic acid (trade names of Shell Chemical Co., Ltd., in which a carboxyl group is bonded to a tertiary carbon atom) And the like, and salts of 2-ethyl-hexanoic acid and versatic acid are preferred.

In the polymerization of (B) polybutadiene, for example, an (a-3) yttrium compound can be used as a catalyst component instead of the (a-1) cobalt compound.
(A-3) As the yttrium compound, for example, yttrium trichloride, yttrium tribromide, yttrium triiodide, yttrium nitrate, yttrium sulfate, yttrium trifluoromethanesulfonate, yttrium acetate, yttrium trifluoroacetate, yttrium malonate, Yttrium salts such as yttrium octylate (ethylhexanoate), yttrium naphthenate, yttrium versatate, yttrium neodecanoate, yttrium trimethoxide, yttrium triethoxide, yttrium triisopropoxide, yttrium tributoxide, yttrium triphenoxide, etc. Alkoxide, trisacetylacetonatoyttrium, tris (hexanedionato) yttrium, tris (heptanedionato Yttrium, tris (dimethylheptanedionato) yttrium, tris (tetramethylheptanedionato) yttrium, trisacetoacetaittrium, cyclopentadienyl yttrium dichloride, dicyclopentadienyl yttrium chloride, tricyclopentadienyl yttrium, etc. Organic base complexes such as organic yttrium compounds, yttrium salt pyridine complexes and yttrium salt picoline complexes, yttrium salt hydrates, yttrium salt alcohol complexes and the like can be mentioned.
Particularly, an yttrium complex represented by the following general formula (5) is preferable.

(In the formula (5), R1, R2, and R3 represent hydrogen or a substituent having 1 to 12 carbon atoms, O represents an oxygen atom, and Y represents an yttrium atom.)

Examples of the substituent having 1 to 12 carbon atoms include, but are not limited to, a methyl group, an ethyl group, a vinyl group, an n-propyl group, an isopropyl group, a 1-propenyl group, an allyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1,1-dimethylpropyl group, 1,2- Dimethylpropyl group, 2,2-dimethylpropyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, cyclohexyl group, methylcyclohexyl group, ethylcyclohexyl group, phenyl group, benzyl group, Examples include a toluyl group and a phenethyl group. Furthermore, those in which a hydroxyl group, a carboxyl group, a carbomethoxy group, a carboethoxy group, a phenoxy group, or the like is substituted at an arbitrary position are also included. R1 to R3 are preferably hydrogen or a hydrocarbon group having 1 to 12 carbon atoms.
Examples of the yttrium compound represented by the above general formula include tris (acetylacetonato) yttrium, tris (hexanedionato) yttrium, tris (heptanedionato) yttrium, tris (dimethylheptanedionato) yttrium, and tris (trimethylheptanedionate) ) Yttrium, tris (tetramethylheptanedionato) yttrium, tris (pentamethylheptanedionato) yttrium, tris (hexamethylheptanedionato) yttrium, trisacetoacetate yttrium and the like.

  Particularly, an yttrium complex represented by the following general formula (6) is preferable.

(In the formula (6), R1 to R6 represent hydrogen or a substituent having 1 to 12 carbon atoms, and Y represents an yttrium atom.)

Examples of the substituent having 1 to 12 carbon atoms include, but are not limited to, a methyl group, an ethyl group, a vinyl group, an n-propyl group, an isopropyl group, a 1-propenyl group, an allyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1,1-dimethylpropyl group, 1,2- Dimethylpropyl group, 2,2-dimethylpropyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, cyclohexyl group, methylcyclohexyl group, ethylcyclohexyl group, phenyl group, benzyl group, Examples include a toluyl group and a phenethyl group. Furthermore, those in which a hydroxyl group, a carboxyl group, a carbomethoxy group, a carboethoxy group, an amide group, an amino group, an alkoxy group, a phenoxy group, or the like is substituted at any position are also included.
In the formula (6), R1 to R6 are preferably hydrogen or a hydrocarbon group having 1 to 12 carbon atoms.

  Examples of the yttrium compound represented by the general formula (6) include tris [N, N-bis (trimethylsilyl) amide] yttrium, tris [N, N-bis (triethylsilyl) amide] yttrium, and tris [N , N-bis (dimethylphenylsilyl) amido] yttrium, tris [N, N-bis (t-butyl) amido] yttrium, tris [N, N-bis (dimethylphenylmethyl) amido] yttrium and the like.

In the production of polybutadiene (B), it is obtained by performing a modification reaction by adding a modifying agent at a stage where the terminal before the termination reaction (hereinafter sometimes referred to as a polymerization terminal) has reactivity. Modified polybutadiene to be obtained.
Examples of the modifier include carboxylic acid esters containing a silylated amino group, thiocarboxylic acid esters, epoxy group-containing alkoxysilane compounds, isocyanate group-containing alkoxysilane compounds, carboxyl group-containing alkoxysilane compounds, and imine group-containing hydrocarbyloxycyanide compounds. No.
The amount of the modifier added is not particularly limited, but is preferably 0.5 mol or more and 18 mol or less with respect to 1 mol of the polymerization terminal, from the viewpoint of increasing the modification rate of the resulting modified polybutadiene, but depending on the desired modification rate. Thus, the amount of the modifier added can be appropriately adjusted.

(Modified conjugated diene polymer composition)
The modified conjugated diene-based polymer composition of the present embodiment contains 100 parts by mass of the modified conjugated diene-based polymer (A) and 10 to 80 parts by mass of the polybutadiene (B). The component (A) preferably contains 15 to 60 parts by mass, more preferably 20 to 40 parts by mass.
By containing 10 to 80 parts by mass of the polybutadiene as the component (B), the abrasion resistance is improved.

(Rubber-like polymer)
The modified conjugated diene-based polymer composition of the present embodiment may contain other polymers other than (A) the modified conjugated diene-based polymer and (B) polybutadiene.
Examples of the other polymer include a rubber-like polymer (hereinafter, simply referred to as “rubber-like polymer”) and a resin-like polymer.
The rubbery polymer is not limited to the following, for example, a conjugated diene-based polymer or a hydrogenated product thereof, a random copolymer of a conjugated diene-based compound and a vinyl aromatic compound or a hydrogenated product thereof, conjugated Examples include a block copolymer of a diene compound and a vinyl aromatic compound or a hydrogenated product thereof, a non-diene polymer, and natural rubber. Specific rubbery polymers are not limited to the following, for example, butadiene rubber or its hydrogenated product, isoprene rubber or its hydrogenated product, styrene-butadiene rubber or its hydrogenated product, styrene-butadiene block Styrene-based elastomers such as a copolymer or a hydrogenated product thereof, a styrene-isoprene block copolymer or a hydrogenated product thereof, and acrylonitrile-butadiene rubber or a hydrogenated product thereof.
Examples of the non-diene polymer include, but are not limited to, olefins such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, and ethylene-octene rubber. System elastomer, butyl rubber, brominated butyl rubber, acrylic rubber, fluoro rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β-unsaturated nitrile-acrylate-conjugated diene copolymer rubber, urethane rubber, polysulfide rubber Is mentioned.
Examples of the natural rubber include, but are not limited to, the following: smoked sheets RSS Nos. 3 to 5, SMR, and epoxidized natural rubber.

In the case where the modified conjugated diene-based polymer composition of the present embodiment is mixed with another polymer other than the above (A) and (B), the mixing method may be a solution of the modified conjugated diene-based polymer. And a method of mechanically mixing a modified conjugated diene-based polymer with another polymer, and a method of mixing a solution of another polymer with a solution of another polymer.
The other polymer may be a modified rubber provided with a polar functional group such as a hydroxyl group or an amino group. When used for tires, butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber are preferably used.
When the other polymer is a rubbery polymer, its weight average molecular weight is preferably 2,000 or more and 2,000,000 or less, and 5,000 or more and 1,000,000 or less, from the viewpoint of a balance between performance and processing characteristics. , 500,000 or less. Further, a low molecular weight rubbery polymer, so-called liquid rubber, can also be used. These rubbery polymers may be used alone or in combination of two or more.

(Polymer composition)
The polymer composition of the present embodiment contains the above-described modified conjugated diene-based polymer composition of the present embodiment and other components.
In this case, from the viewpoint of processability, the content of the modified conjugated diene-based polymer composition is preferably at least 10% by mass, more preferably at least 30% by mass, and at least 50% by mass. Is more preferred.

(Rubber composition)
The rubber composition of the present embodiment contains 100 parts by mass of a rubbery polymer containing 10% by mass or more of the modified conjugated diene-based polymer composition of the present embodiment, and 5 to 150 parts by mass of a filler.
The content ratio (mass ratio) of the modified conjugated diene-based polymer composition to the other rubbery polymer is from 10/90 to 100/0 as (modified conjugated diene-based polymer composition / other rubbery polymer). The following is preferable, 20/80 or more and 90/10 or less are more preferable, and 50/50 or more and 80/20 or less are still more preferable.
Therefore, the rubber-like polymer component preferably contains the modified conjugated diene-based polymer composition with respect to the total amount of the rubber-like polymer component (100% by mass), more preferably 10% by mass or more and 100% by mass or less, more preferably. Is contained in an amount of 20% by mass to 90% by mass, more preferably 50% by mass to 80% by mass.
When the content ratio of the (modified conjugated diene-based polymer composition / rubber-like polymer) is within the above range, when a vulcanized product is obtained, the balance between low hysteresis loss and wet skid resistance is excellent, and wear resistance is improved. The properties and breaking strength are also satisfied.

The modified conjugated diene-based polymer composition of the present embodiment is suitably used as a vulcanized product.
Examples of the vulcanized product include tires, hoses, shoe soles, anti-vibration rubber, automobile parts, anti-vibration rubber, and rubber for resin reinforcement such as impact-resistant polystyrene and ABS resin.
In particular, the modified conjugated diene polymer composition is suitably used for a composition of a tread rubber for a tire. The vulcanized product is, for example, the modified conjugated diene-based polymer composition of the present embodiment, if necessary, a silica-based inorganic filler, an inorganic filler such as carbon black, a modified conjugated diene-based polymer of the present embodiment. After kneading with other rubbery polymer, silane coupling agent, rubber softener, vulcanizing agent, vulcanization accelerator, vulcanization aid, etc. And vulcanized.

As described above, the rubber composition of the present embodiment includes 100 parts by mass of the rubber-like polymer containing 10% by mass or more of the modified conjugated diene copolymer composition of the present embodiment, and 5 to 150 parts by mass of a filler. Including.
Further, the filler preferably contains a silica-based inorganic filler.
The rubber composition, by dispersing the silica-based inorganic filler, tends to be more excellent in processability when vulcanized, when the vulcanized, low hysteresis loss property and wet skid resistance It tends to be more excellent in balance, breaking strength and wear resistance.
Even when the rubber composition of the present embodiment is used for vulcanized rubber applications such as automobile parts such as tires and vibration-proof rubbers and shoes, it is preferable that the rubber composition contains a silica-based inorganic filler.

Examples of the filler include, but are not limited to, silica-based inorganic fillers, carbon black, metal oxides, and metal hydroxides. Among these, a silica-based 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 5.0 parts by mass or more and 150 parts by mass or less, and 10 parts by mass or more and 120 parts by mass with respect to 100 parts by mass of the rubber component containing the modified conjugated diene-based polymer composition. Parts by weight or less, more preferably 20 parts by weight or more and 100 parts by weight or less.
The content of the filler is 5.0 parts by mass or more from the viewpoint of exhibiting the effect of adding the filler, the filler is sufficiently dispersed, and the processability and mechanical strength of the rubber composition are practically sufficient. From the viewpoint of this, 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 preferred. Here, the main component refers to a component contained in the silica-based inorganic filler in an amount of 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more.
Specific examples of the silica-based inorganic filler include, but are not limited to, silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and inorganic fibrous substances such as glass fiber. . Further, a silica-based inorganic filler whose surface is hydrophobized, and a mixture of a silica-based inorganic filler and a non-silica-based inorganic filler may also be used. Among these, from the viewpoints of strength, abrasion resistance and the like, silica and glass fiber are preferred, and silica is more preferred. Examples of the silica include dry silica, wet silica, and synthetic silicate silica. Among these silicas, a wet silica is preferable from the viewpoint of improving the balance between the effect of improving the fracture characteristics and the wet skid resistance.

From the viewpoint of obtaining practically good abrasion resistance and breaking characteristics of the rubber composition, the nitrogen-adsorbed specific surface area of the silica-based inorganic filler determined by the BET adsorption method is 100 m ² / g or more and 300 m ² / g or less. And more preferably 170 m ² / g or more and 250 m ² / g or less. If necessary, a relatively small specific surface area (e.g., a specific surface area 200m of ² / g or less) and the silica-based inorganic filler, a relatively large specific surface area (e.g., greater than 200m ² / g) silica And an inorganic filler).
In the present 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, (A) the modified conjugated diene-based polymer improves the dispersibility of silica. In particular, it is effective in improving abrasion resistance, and tends to be able to highly balance good breaking characteristics and low hysteresis loss.

The content of the silica-based inorganic filler in the rubber composition is 5.0 parts by mass or more and 150 parts by mass with respect to 100 parts by mass of the rubber-like polymer component containing the modified conjugated diene-based polymer composition. More preferably, the amount is 20 parts by mass or more and 100 parts by mass or less.
The content of the silica-based inorganic filler 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 and mechanical strength of the composition are practically used. It is 150 parts by mass or less from the viewpoint of ensuring sufficient performance.

The carbon black is not limited to the following, but includes, for example, carbon black of each class such as SRF, FEF, HAF, ISAF, and SAF. Among them, 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 from 0.5 parts by mass to 100 parts by mass, and more preferably from 3.0 parts by mass to 100 parts by mass, based on 100 parts by mass of the rubbery polymer component containing the modified conjugated diene-based polymer composition. Or less, more preferably 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 exhibiting the performance required for applications such as tires such as dry grip performance and conductivity, and is preferably 100 parts by mass or more from the viewpoint of dispersibility. It is preferable to set the following.

The metal oxide refers to solid particles having a chemical formula of MxOy (M represents a metal atom, x and y each independently represent an integer of 1 to 6) as a main component of a structural unit. .
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 of the present embodiment may include a silane coupling agent.
The silane coupling agent has a function to tighten 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. And a compound having a sulfur bonding portion and an alkoxysilyl group or a silanol group portion in one molecule. Examples of such a compound include bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl] -disulfide, bis- [2- (triethoxysilyl) Silyl) -ethyl] -tetrasulfide.
The content of the silane coupling agent is preferably from 0.1 to 30 parts by mass, more preferably from 0.5 to 20 parts by mass, based on 100 parts by mass of the above-mentioned inorganic filler. The amount is more preferably 0 to 15 parts by mass. When the content of the silane coupling agent is in the above range, the effect of the addition by the silane coupling agent tends to be more remarkable.

The rubber composition of the present embodiment may include a rubber softener from the viewpoint of improving the 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 used for softening, increasing the volume of rubber, and improving processability are mixtures of aromatic rings, naphthene rings, and paraffin chains. Those whose carbon number of the paraffin chain accounts for 50% by mass or more of the total carbon are called paraffinic, and those whose naphthenic ring carbon number accounts for 30% to 45% by mass of the total carbon are naphthenic or aromatic carbon. Those whose number accounts for more than 30% by mass of the total carbon are called aromatic.
(A) When the modified conjugated diene-based polymer is a copolymer of a conjugated diene compound and a vinyl aromatic compound, a rubber softener having an appropriate aromatic content is suitable for the copolymer. Is preferable because it tends to be good.
The content of the rubber softener is preferably from 0 to 100 parts by mass, and more preferably from 10 to 90 parts by mass, based on 100 parts by mass of the rubbery polymer component (A) containing the modified conjugated diene-based polymer. Or less, more preferably 30 parts by mass or more and 90 parts by mass or less. When the content of the rubber softener is 100 parts by mass or less with respect to 100 parts by mass of the rubber component, bleed out tends to be suppressed, and stickiness on the surface of the rubber composition tends to be suppressed.

The modified conjugated diene-based polymer composition of the present embodiment is mixed with other rubber-like polymers, silica-based inorganic fillers, carbon black and other fillers, silane coupling agents, rubber softeners and other additives. The method is not limited to the following, but for example, melting using a general admixer such as an open roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, and a multi-screw extruder. A kneading method and a method of dissolving and mixing the respective components and then removing the solvent by heating may be used.
Among these, a melt kneading method using a roll, a Banbury mixer, a kneader, or an extruder is preferable from the viewpoint of productivity and good kneading. Further, any of a method of kneading the rubber component and the other filler, the silane coupling agent, and the additive at a time, and a method of mixing the rubber component in a plurality of times can be applied.

  The rubber composition of the present embodiment 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, high molecular weight polysulfur compounds, and the like. The content of the vulcanizing agent is preferably from 0.01 to 20 parts by mass, more preferably from 0.1 to 15 parts by mass, based on 100 parts by mass of the rubber component. As the vulcanization method, a conventionally known method can be applied, and the vulcanization temperature is preferably from 120 ° C to 200 ° C, more preferably from 140 ° C to 180 ° C.

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

In the rubber composition of the present embodiment, within a range that does not impair the purpose of the present embodiment, other softeners and fillers other than those described above, a heat stabilizer, an antistatic agent, a weather stabilizer, an antioxidant, Various additives such as a coloring agent and a lubricant may be used.
Known softeners can be used as other softeners. Specific examples of other fillers include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. Known materials can be used as the above-mentioned heat stabilizer, antistatic agent, weather stabilizer, antioxidant, coloring agent and lubricant.

(Method for producing rubber composition)
The method for producing a rubber composition according to the present embodiment comprises: (A) 100 parts by mass of a modified conjugated diene-based polymer, (B) 10 to 80 parts by mass of polybutadiene, and (C) a filler 5 containing silica as a filler. To 150 parts by mass.
(C) The filler contains silica as an essential component, and may contain an optional component together with silica as the essential component.
(C) Silica that is generally used as a filler can be used as the silica constituting the filler, but from the viewpoint of the rolling resistance and rebound resilience of a rubber elastic body obtained from a rubber composition, primary particles are used. Synthetic silicic acid having a diameter of 50 nm or less is preferred.
The content ratio of the silica constituting the filler (C) is 10 to 120 parts by mass with respect to 100 parts by mass of the rubbery polymer component containing the (A) modified conjugated diene polymer and (B) the polybutadiene. And more preferably 20 to 100 parts by mass.
(C) In any case where the content ratio of the filler is too small or too large, the balance between hardness and rolling resistance may be deteriorated in the rubber elastic body obtained from the rubber composition. .

  (C) The filler may contain an optional component in addition to silica, which is an essential component. Examples of the optional component include inorganic oxides such as aluminum oxide, titanium oxide, calcium oxide, and magnesium oxide, and water. Examples thereof include inorganic hydroxides such as aluminum oxide and magnesium hydroxide, and carbonates such as magnesium carbonate, and these can be used alone or in combination of two or more.

The rubber composition may contain the optional components described above, if necessary, in addition to the essential components (A) the modified conjugated diene-based polymer, (B) polybutadiene, and a filler.
Such a rubber composition is obtained by mixing and kneading optional components, if necessary, together with (A) a modified conjugated diene-based polymer, B) polybutadiene, and a filler, which are essential components, using, for example, a plastmill. Can be manufactured by

(A) The modified conjugated diene-based polymer acts to increase the dispersibility of silica, while (B) polybutadiene acts to decrease the dispersibility of silica. Can be controlled, so that the dispersibility of silica can be improved from the viewpoint of the balance between the rolling resistance and the rebound resilience of the rubber elastic body obtained from the rubber composition.
Therefore, according to the rubber composition of the present embodiment, a rubber elastic body having low rolling resistance and excellent rebound resilience can be obtained.

The method for producing the rubber composition is as follows: (A) 100 parts by mass of the modified conjugated diene-based polymer and (C) 5-150 parts by mass of the silica-containing filler are kneaded to obtain a kneaded product. It is preferable to knead the kneaded material with 10 to 80 parts by mass of the polybutadiene (B).
Specifically, first, (A) a modified conjugated diene-based polymer, (C) a filler containing silica, and optional components are kneaded as necessary to obtain a kneaded material, and then the kneaded material is mixed with polybutadiene ( B) is added and further kneaded.
After kneading (A) the modified conjugated diene-based polymer and (C) the filler, kneading the obtained kneaded product and (B) polybutadiene can improve the dispersibility of silica in the rubber composition. Since the rubber elastic body can be made even better, the obtained rubber elastic body has even lower rolling resistance and excellent rebound resilience.

The method for producing the rubber composition is not limited to a method in which (A) a modified conjugated diene-based polymer and (C) a filler are kneaded, and then the resulting kneaded product and (B) polybutadiene are kneaded. For example, a technique may be used in which optional components are simultaneously kneaded together with the (A) modified conjugated diene-based polymer, (B) polybutadiene, and (C) filler, which are essential components.
Modified conjugated diene-based polymer composition and other rubbery polymer, silica-based inorganic filler, carbon black and other fillers, a method of mixing additives such as silane coupling agent, rubber softener, Although not limited to the following, 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 kneader such as a multi-screw extruder, After dissolving and mixing the components, a method of removing the solvent by heating may be used. Among these, a melt kneading method using a roll, a Banbury mixer, a kneader, or an extruder is preferable from the viewpoint of productivity and good kneading.

〔tire〕
The rubber composition containing the modified conjugated diene polymer composition of the present embodiment is suitably used as a rubber composition for a tire.
The rubber composition for a tire according to the present embodiment is not limited to the following. For example, various tires such as a fuel-saving tire, an all-season tire, a high-performance tire, and a studless tire: a tread, a carcass, a sidewall, and a bead portion. It can be used for various parts of the tire such as. In particular, the rubber composition for a tire containing the modified conjugated diene-based polymer composition of the present embodiment is excellent in a balance between low hysteresis loss and wet skid resistance and abrasion resistance when vulcanized. Therefore, it is more suitably used as a tread for fuel-saving tires and high-performance tires.

Hereinafter, the present embodiment will be described in detail with reference to specific examples and comparative examples. However, the present embodiment is not limited to the following examples and comparative examples.
Various physical properties were measured by the following methods.

<Purification of 1,3-butadiene>
1,3-Butadiene used for the polymerization of the modified conjugated diene polymer was purified by the following steps.
(Washing process)
The operation was performed under the conditions of a circulating water amount of 1 m ³ / hr and a renewal (make-up) water amount of 0.1 m ³ / hr.
The 1,3-butadiene and the washing water were mixed using a static mixer (Static mixer N60 series manufactured by Noritake Co., Ltd.) and then transferred to a decanter, where the 1,3-butadiene was used. The phases were separated from the aqueous phase.
The operation was performed under the conditions of a liquid temperature of 30 ° C. and a decanter pressure of 1.0 MPaG.
The residence time of the 1,3-butadiene phase in the decanter was 30 minutes.
The aqueous phase separated by the decanter is introduced into a 1,3-butadiene removing tank, mixed with steam and heated to 89 ° C., and at the same time, the total pressure is set to 0.01 MPaG to convert 1,3-butadiene from the aqueous phase. separated.

(Oxygen removal process with oxygen scavenger)
Subsequently, a 10% aqueous solution of DAICLEAN F-504 (manufactured by Kurita Kogyo) was used as a deoxidizer at a circulation flow rate of 1 m ³ / hr, and the 1,3-butadiene after the above (water washing step) and the deaerator were used. An aqueous solution of an oxygen agent was mixed using a static mixer, and liquid-liquid extraction was performed. Thereafter, the mixture was moved to a decanter, and the 1,3-butadiene phase and the aqueous phase were separated by the decanter.
The residence time of the 1,3-butadiene phase in the decanter was 30 minutes. The operation was performed under the conditions of a liquid temperature of 30 ° C. and a decanter pressure of 1.0 MPaG.

(Polymerization inhibitor removal step)
Subsequently, a 10% aqueous solution of caustic soda was mixed with 1,3-butadiene after the above (oxygen removal step using an oxygen scavenger) at a circulation flow rate of 1 m ³ / hr using a packed tower containing pole rings, Liquid-liquid extraction was performed, and the liquid was further transferred to another decanter, where the 1,3-butadiene phase and the aqueous phase were separated.
The residence time of the 1,3-butadiene phase in the other decanter was 60 minutes. In the polymerization inhibitor removing step, the operation was performed under the conditions of a liquid temperature of 30 ° C. and a decanter pressure of 1.0 MPaG.

(Dehydration tower process)
Mixed hexane was added to the 1,3-butadiene phase separated by the other decanter to adjust the 1,3-butadiene concentration to 50% by mass, and then supplied to the dehydration tower.
After cooling and condensing the azeotropic mixture of 1,3-butadiene and water distilled from the top (top) in the dehydration tower, the condensate is transferred to a decanter, and the 1,3-butadiene phase and the aqueous phase are separated by the decanter. Was isolated.
The aqueous phase was removed, and the 1,3-butadiene phase was returned to the inlet of the dehydration tower, and the dehydration tower process was continuously performed.
A mixed solution of dehydrated 1,3-butadiene and hexane was taken out from the bottom (tower bottom) of the dehydration tower.

(Adsorption process)
The mixed solution of 1,3-butadiene and hexane is passed through a 500 L desiccant dryer containing activated alumina (a vertical cylindrical tank manufactured by Hitachi, Ltd.) to adsorb a small amount of residual impurities in 1,3-butadiene. Removed and purified 1,3-butadiene was obtained.

<Styrene purification>
Styrene used for the polymerization of the modified conjugated diene polymer was purified by the following steps.
Γ-alumina molded into a 3 mmφ × 3 mm cylindrical shape was impregnated with an aqueous solution of palladium chloride having a concentration of 0.6%, and dried at 100 ° C. for one day.
Next, the dried product was subjected to a reduction treatment under a hydrogen stream at a temperature of 400 ° C. for 16 hours to obtain a hydrogenation catalyst having a composition of Pd (0.3%) / γ-Al ₂ O ₃ .
The tubular reactor was charged with 2000 g of the obtained hydrogenation catalyst, and crude styrene was circulated for 8 hours while maintaining the temperature of the catalyst at 80 ° C. to obtain purified styrene.

<Purification of normal hexane>
Normal hexane used for the polymerization of the modified conjugated diene polymer was purified by the following steps.
2000 g of molecular sieve 13-X (Union Showa) was charged into a tubular reactor, and crude normal hexane was circulated at room temperature for 24 hours to obtain purified normal hexane.

<Raw material purity analysis (total impurities)>
Quantitative analysis of allenes, acetylenes and amines as impurities in the raw materials was performed.
Allenes and acetylenes were qualitatively and quantitatively determined by gas chromatography.
The column used was Rt-Alumina BOND / MAPD (Shimadzu Corporation).
Amines were extracted using boric acid, quantified by titration, and the total amount of impurities (ppm) was calculated.

<(Property 1) Amount of bound styrene>
Using the modified conjugated diene-based polymer as a sample, 100 mg of the sample was made up to 100 mL with chloroform and dissolved to obtain a measurement sample.
The amount of styrene bound (% by mass) with respect to 100% by mass of the modified conjugated diene-based polymer as a sample was measured based on the amount of absorption at an ultraviolet absorption wavelength (around 254 nm) by the phenyl group of styrene (Shimadzu Corporation). Photometer "UV-2450").

<(Physical property 2) Microstructure of butadiene portion (1,2-vinyl bond amount)>
Using a modified conjugated diene polymer as a sample, 50 mg of the sample was dissolved in 10 mL of carbon disulfide to obtain a measurement sample.
Using a solution cell, an infrared spectrum is measured in the range of 600 to 1000 cm ^-1 , and the absorbance at a predetermined wavenumber is used to determine the Hampton method (the method described in RR Hampton, Analytical Chemistry 21, 923 (1949)). The microstructure of the butadiene portion, that is, the amount of 1,2-vinyl bond (mol%) was determined (Fourier transform infrared spectrophotometer “FT-IR230” manufactured by JASCO Corporation) in accordance with the following calculation formula.

<(Physical property 3) Molecular weight>
Using a modified conjugated diene-based polymer as a sample, an RI detector (Tosoh Corporation) using a GPC measuring device (trade name “HLC-8320GPC” manufactured by Tosoh Corporation) in which three columns using a polystyrene-based gel as a filler are connected. Chromatogram was measured using a trade name “HLC8020” manufactured by the company, and based on a calibration curve obtained using standard polystyrene, the weight average molecular weight (Mw ₁ ), number average molecular weight (Mn ₁ ), and molecular weight distribution were measured. (Mw ₁ / Mn ₁ ), the peak top molecular weight (Mp ₁ ) of the modified conjugated diene-based polymer, and the ratio of the modified conjugated diene-based polymer having a molecular weight of 2,000,000 to 5,000,000.
The eluent used was THF (tetrahydrofuran).
As the column, three TSKgel SuperMultipore HZ-H manufactured by Tosoh Corporation were connected, and the guard column was connected to the trade name “TSKguardcolumn SuperMP (HZ) -H” manufactured by Tosoh Corporation as the guard column.
10 mg of a sample for measurement was dissolved in 20 mL of THF to prepare a measurement solution, 10 μL of the measurement solution was injected into a GPC measuring apparatus, and measurement was performed under the conditions of an oven temperature of 40 ° C. and a THF flow rate of 0.35 mL / min.
The peak top molecular weight (Mp ₁ ) was determined as follows.
In the GPC curve obtained by the measurement, the peak detected as the component having the highest molecular weight was selected. With respect to the selected peak, the molecular weight corresponding to the maximum value of the peak was calculated and defined as the peak top molecular weight.
Further, the ratio of the molecular weight of 2,000,000 to 5,000,000 was determined as the ratio of the mass of the molecular weight of 2,000,000 to 5,000,000 to the total mass of the polymer.

<(Property 4) Polymer Mooney viscosity>
Using the modified conjugated diene-based polymer as a sample, Mooney viscosity was measured using a Mooney viscometer (trade name “VR1132” manufactured by Kamishima Seisakusho) in accordance with JIS K6300 using an L-shaped rotor.
The measurement temperature was 100 ° C.
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 5) Glass transition temperature (Tg)>
Using a modified conjugated diene-based polymer as a sample, a differential scanning calorimeter “DSC3200S” manufactured by Mac Science Co., Ltd., in accordance with ISO 22768: 2006, under a flow rate of helium of 50 mL / min, from −100 ° C. to 20 ° C./min. The DSC curve was recorded while the temperature was raised in the above step, and the peak top (Inflection point) of the DSC differential curve was defined as the glass transition temperature.
Here, Tg is a value obtained by measuring a sample before adding oil.

<(Physical property 6) Modification ratio based on total amount of conjugated diene polymer>
Using the modified conjugated diene-based polymer as a measurement sample, a chromatogram was measured by applying the property of adsorbing the modified basic polymer component to a GPC column using a silica-based gel as a filler.
The amount of adsorption to the silica-based column is determined from the difference between the chromatogram measured by the polystyrene-based column and the chromatogram measured by the silica-based column of the measurement sample solution containing the measurement sample and the low-molecular-weight internal standard polystyrene. Then, the denaturation rate was determined.
Specifically, it is as shown below.
Preparation of sample solution for measurement:
10 mg of the measurement sample and 5 mg of standard polystyrene were dissolved in 20 mL of THF (tetrahydrofuran) to obtain a measurement sample solution.
GPC measurement conditions using polystyrene column:
Using Tosoh's trade name “HLC-8320GPC”, 10 μL of a sample solution for measurement was injected into the apparatus using THF as an eluent, and the conditions were as follows: column oven temperature 40 ° C., THF flow rate 0.35 mL / min. Chromatogram was obtained using an RI detector. As the column, three TSKgel SuperMultipore HZ-H manufactured by Tosoh Corporation were connected, and the guard column was connected to the trade name “TSKguardcolumn SuperMP (HZ) -H” manufactured by Tosoh Corporation as the guard column.
GPC measurement conditions using silica column:
Using Tosoh's trade name "HLC-8320GPC", 50 μL of a sample solution for measurement was injected into the apparatus using THF as an eluent, and the column oven temperature was 40 ° C. and the THF flow rate was 0.5 mL / min. Chromatogram was obtained using an RI detector. The column is used by connecting the product names “Zorbax PSM-1000S”, “PSM-300S”, and “PSM-60S”, and the product name “DIOL 4.6 × 12.5mm 5micron” as a guard column at the preceding stage. Connected and used.
Calculation method of denaturation rate:
With the total peak area of the chromatogram using the polystyrene column as 100, the peak area of the sample as P1, the peak area of the standard polystyrene as P2, and the total peak area of the chromatogram using the silica column as 100, the sample The peak area of P3 was defined as P3, and the peak area of standard polystyrene was defined as P4.
Denaturation rate (% by mass) = [1- (P2 × P3) / (P1 × P4)] × 100
(In the above equation, P1 + P2 = P3 + P4 = 100)

<(Physical property 7) Modification rate of low molecular weight component>
According to the measurement of (Physical Property 3), based on a calibration curve obtained using standard polystyrene, weight average molecular weight (Mw ₂ ), number average molecular weight (Mn ₂ ), molecular weight distribution (Mw ₂ / Mn ₂ ), The peak top molecular weight (Mp ₂ ) of the modified conjugated diene polymer was measured.
However, when there are a plurality of peak tops, the peak top molecular weight (Mp ₂ ) is the molecular weight of the peak top having the smallest molecular weight, and the peak top molecular weight (Mp ₂ ) is divided by 2. The height of the chart at the obtained molecular weight (the molecular weight of the low molecular weight component) was defined as L1.
The height at the molecular weight (the molecular weight of the low molecular weight component) obtained by dividing the peak top molecular weight (Mp ₂ ) by 2 in the chart measured according to the measurement of (physical property 6) using a silica column was defined as L2. .
The modification rate of the low molecular weight component was calculated by (1−L2 / L1) × 100.

[Modification degree of low molecular weight component]
The modification degree of the low-molecular-weight component was calculated by dividing the (physical property 7) modification rate (FL) of the low-molecular-weight component by the (physical property 6) modification rate (FT) with respect to the total amount of the conjugated diene-based polymer.
Degree of modification of low molecular weight component = (FL / FT) × 100

<(Physical property 8) Shrinkage factor (g ′)>
Using a modified conjugated diene-based polymer as a sample, a chromatogram was measured using a GPC-light scattering measurement device equipped with a viscosity detector in which three columns each containing a polystyrene-based gel as a filler were connected, and the solution viscosity and light intensity were measured. The molecular weight was determined based on the scattering method.
As an eluent, a mixed solution of tetrahydrofuran and triethylamine (THF in TEA: 5 mL of triethylamine was mixed with 1 L of tetrahydrofuran and adjusted) was used.
The columns were used by connecting a guard column: “TSKguardcolumn HHR-H” manufactured by Tosoh Corporation and a column: “TSKgel G6000HHR”, “TSKgel G5000HHR”, and “TSKgel G4000HHR” manufactured by Tosoh Corporation.
A GPC-light scattering measurement device equipped with a viscosity detector (trade name “Viscotek TDAmax” manufactured by Malvern) was used under the conditions of an oven temperature of 40 ° C. and a THF flow rate of 1.0 mL / min.
A molecular weight and an intrinsic viscosity were determined by dissolving 10 mg of a measurement sample in 20 mL of THF to prepare a measurement sample solution, injecting 200 μL of the measurement sample solution into a GPC measurement device, and performing measurement.
The shrinkage factor (g ′) was calculated using the intrinsic viscosity and molecular weight of the obtained sample solution for measurement.
The constant (K, α) in the relational expression between intrinsic viscosity and molecular weight ([η] = KMα ([η]: intrinsic viscosity, M: molecular weight)) is defined as log K = −3.883, α = 0.772, and With respect to the relationship between the standard intrinsic viscosity [η] ₀ and the molecular weight M created by inputting the range of M from 1000 to 20000000, the intrinsic viscosity [η] at each molecular weight M is calculated based on the intrinsic viscosity [η] ₀ for the standard intrinsic viscosity [η] ₀ . [Η] / [η] ₀ was calculated for each molecular weight M as a relationship of viscosity [η], and the average value was defined as a shrinkage factor (g ′).
The shrinkage factor (g ') is a value averaged when M is 1,000,000 or more and 2,000,000 or less.

<(Physical property 9) Silicon content>
The silicon content in the modified conjugated diene-based polymer was measured using an ICP mass spectrometer (Agilent Technology, Agilent 7700s).

<(Physical property 10) Nitrogen content>
The nitrogen content in the modified conjugated diene-based polymer was measured using a trace total nitrogen analyzer (TN-2100H manufactured by Mitsubishi Chemical Analytech).

[(Production Example 1) Synthesis of modified conjugated diene polymer (A-1)]
The internal volume is 10 L, the ratio (L / D) of the internal height (L) to the diameter (D) is 4.0, and the bottom has an inlet and the top has an outlet. A tank-type pressure vessel having a jacket was used as a polymerization reactor.
19.4 g / min of 1,3-butadiene, 10.6 g / min of styrene, and 150.0 g / min of n-hexane were mixed in advance by removing water. Allenes contained in this mixture were 9 ppm, acetylenes were 12 ppm, and amines were 1 ppm. The total amount of impurities was 22 ppm.
In a static mixer provided in the middle of a pipe for supplying this mixed solution to the inlet of the reaction group, n-butyllithium for inert impurity deactivation treatment was added at 0.104 mmol / min, mixed, and then added to the bottom of the reaction group. Feeded continuously. Further, 2,2-bis (2-oxolanyl) propane is used as a polar substance at a rate of 0.0216 g / min, and n-butyllithium is used as a polymerization initiator at a rate of 0.252 mmol / min. It was supplied to the bottom of the reactor to continuously continue the polymerization reaction. The temperature was controlled so that the temperature of the polymerization solution at the top outlet of the reactor was 75 ° C.
When the polymerization was sufficiently stabilized, bis (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-sila) was added as a modifier to the polymer solution flowing out of the outlet of the reactor. Cyclopentane) propyl] amine (abbreviated as “A” in the table) was continuously added at a rate of 0.043 mmol / min, and the polymer solution to which the modifier was added was mixed by passing through a static mixer. The denaturation reaction was performed.
An antioxidant (BHT) was continuously added to the polymer solution subjected to the modification reaction at a rate of 0.055 g / min (n-hexane solution) so as to be 0.2 g per 100 g of the polymer, thereby terminating the coupling reaction. . Simultaneously with the antioxidant, oil (JOMO process NC140 manufactured by JX Nippon Oil & Energy Corporation) was continuously added to 100 g of the polymer so as to become 37.5 g, and mixed with a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene-based polymer (Sample A-1). Table 1 shows the physical properties of Sample A-1.

[(Production Example 2) Modified conjugated diene-based polymer (sample A-2)]
The modifier was changed to tris (3-trimethoxysilylpropyl) amine (abbreviated as “B” in the table). Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene-based polymer (Sample A-2). Table 1 shows the physical properties of Sample A-2.

[(Production Example 3) Modified conjugated diene-based polymer (sample A-3)]
The modifier was N, N, N'-tris (3-trimethoxysilylpropyl) -N '-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3- Instead of propanediamine (abbreviated as "C" in the table), the amount of the polymerization initiator n-butyllithium was set to 0.317 mmol / min, the amount of the polar substance was set to 0.027 g / min, and the modifier was added. The addition amount was 0.041 mmol / min. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene-based polymer (sample A-3). Table 1 shows the physical properties of Sample A-3.

[(Production Example 4) Modified conjugated diene-based polymer (sample A-4)]
The modifying agent was N, N, N ', N'-tetrakis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine ("D" in the table) ), And the amount of the modifier added was 0.033 mmol / min. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene-based polymer (Sample A-4). Table 1 shows the physical properties of Sample A-4.

[(Production Example 5) Modified conjugated diene-based polymer (sample A-5)]
The addition amount of the polymerization initiator n-butyllithium was 0.15 mmol / min, the addition amount of the polar substance was 0.0131 g / min, and the modifier was N- (3-trimethoxysilylpropyl) -2,2-. Instead of dimethoxy-1-aza-2-silacyclopentane (abbreviated as “E” in the table), the amount of the modifier was 0.037 mmol / min. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene-based polymer (Sample A-5). Table 1 shows the physical properties of Sample A-5.

[(Production Example 6) Modified conjugated diene-based polymer (sample A-6)]
The addition amount of the polymerization initiator n-butyllithium was 0.08 mmol / min, the addition amount of the polar substance was 0.0076 g / min, and the modifier was N-3-trimethoxysilylpropyltriazole ("F" in the table). ). The modifier was added in an amount of 0.041 mmol / min. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene-based polymer (Sample A-6). Table 1 shows the physical properties of Sample A-6.

[(Production Example 7) Modified conjugated diene-based polymer (sample A-7)]
The addition amounts of butadiene and styrene were 23 g / min and 5 g / min, respectively, and the addition amount of the polar substance was 0.0155 g / min. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene-based polymer (sample A-7). Table 1 shows the physical properties of Sample A-7.

[(Production Example 8) Modified conjugated diene-based polymer (sample A-8)]
The addition amounts of butadiene and styrene were 16 g / min and 12 g / min, respectively, and the addition amount of the polar substance was 0.024 g / min. Other conditions were the same as in (Production Example 4) to obtain a modified conjugated diene-based polymer (Sample A-8). Table 1 shows the physical properties of Sample A-8.

[(Production Example 9) Modified conjugated diene-based polymer (sample A-9)]
N, N-dimethyl-phenyldimethoxysilylpropylamine (abbreviated as "G" in the table) as a modifier was continuously added at a rate of 0.03 mmol / min. Other conditions were the same as in (Production Example 6) to obtain a modified conjugated diene-based polymer (Sample A-9). Table 1 shows the physical properties of Sample A-9.

[(Production Example 10) Modified conjugated diene-based polymer (sample A-10)]
The amount of the modifier was 0.028 mmol / min. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene-based polymer (Sample A-10). Table 1 shows the physical properties of Sample A-10.

[(Production Example 11) Modified conjugated diene-based polymer (sample A-11)]
A sample (A-11) was obtained by kneading the sample A-4 and the sample A-9 at a mass ratio of (sample A-4) :( sample A-9) = 2: 1. Table 2 shows the physical properties of Sample A-11.

[(Production Example 12) Modified conjugated diene-based polymer (sample A-12)]
The internal volume is 10 L, the ratio (L / D) of the internal height (L) to the diameter (D) is 4.0, and the bottom has an inlet and the top has an outlet. Two tank-type pressure vessels having a jacket were connected to form a polymerization reactor.
1,3-butadiene, 22.3 g / min, styrene, 12.5 g / min, and n-hexane, 214.0 g / min, were mixed under the condition of removing water in advance. Allenes contained in this mixture were 8 ppm, acetylenes were 13 ppm, and amines were 1 ppm. The total amount of impurities was 21 ppm.
In a static mixer provided in the middle of a pipe for supplying this mixed solution to the inlet of the reaction group, n-butyllithium for inert impurity deactivation treatment was added at 0.130 mmol / min, mixed, and then added to the bottom of the reaction group. Feeded continuously.
Further, piperidinolithium prepared in advance as a polymerization initiator at a rate of 0.0347 g / min of 2,2-bis (2-oxolanyl) propane as a polar substance (abbreviated as "LA-1" in the table). And n-butyllithium (molar ratio piperidinolithium: n-butyllithium = 0.72: 0.28, piperidine and n-butyllithium in molar ratio piperidine: n-butyllithium = 0.72: 1.00). Of the first polymerization reactor at a rate of 0.336 mmol (lithium mole ratio) / min with the use of a stirrer to continuously feed the polymerization reaction. Was.
The temperature was controlled so that the temperature of the polymerization solution at the top outlet of the first reactor was 65 ° 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 such that the temperature of the polymer at the top outlet of the second reactor was 70 ° C.
Next, bis (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) was added as a modifier to the polymer solution flowing out of the outlet of the second reactor. )] Propyl] amine (abbreviated as “A” in the table) was continuously added at a rate of 0.0560 mmol / min, and the polymer solution to which the modifier was added was mixed by passing through a static mixer and denatured. did.
An antioxidant (BHT) was continuously added to the polymer solution subjected to the modification reaction at a rate of 0.055 g / min (n-hexane solution) so as to be 0.2 g per 100 g of the polymer, thereby terminating the coupling reaction. . Simultaneously with the antioxidant, oil (JOMO process NC140 manufactured by JX Nippon Oil & Energy Corporation) was continuously added to 100 g of the polymer so as to become 37.5 g, and mixed with a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene-based polymer (Sample A-12). Table 2 shows the physical properties of Sample A-12.

[(Production Comparative Example 1) Modified conjugated diene-based polymer (Sample A-13)]
In the purification of 1,3-butadiene, the residence time of the 1,3-butadiene phase in the decanter in the water washing step was adjusted to 10 minutes. The residence time of the 1,3-butadiene phase in the decanter in the polymerization inhibitor removing step was adjusted to 20 minutes. In the purification of styrene, a hydrogenation catalyst of Pd (0.3%) / γ-Al ₂ O ₃ was obtained. 2000 g of the obtained catalyst was charged into a tubular reactor, and styrene circulated and purified for 4 hours while maintaining the temperature of the catalyst at 80 ° C. was used. In the purification of normal hexane, the same purification as in the example was performed.
Allenes contained in the mixture of 1,3-butadiene, styrene and n-hexane were 25 ppm, acetylenes were 20 ppm, and amines were 9 ppm. The total amount of impurities was 54 ppm. Except that this was used, a modified conjugated diene-based polymer (sample A-13) was obtained in the same manner as in the above (Production Example 1). Table 2 shows the physical properties of Sample A-13.

[(Production Comparative Example 2) Modified conjugated diene-based polymer (sample A-14)]
The amount of the modifier added was 0.020 mmol / min. Other conditions were the same as in the above (Production Example 1) to obtain a modified conjugated diene-based polymer (Sample A-14). Table 2 shows the physical properties of Sample A-14.

[(Production Comparative Example 3) Modified conjugated diene-based polymer (Sample A-15)]
N, N-dimethyl-phenyldimethoxysilylpropylamine (abbreviated as "G" in the table) as a modifier was continuously added at a rate of 0.03 mmol / min. The other conditions were the same as in (Production Comparative Example 1) to obtain a modified conjugated diene-based polymer (Sample A-15). Table 2 shows the physical properties of Sample A-15.

[(Production Comparative Example 4) Modified conjugated diene-based polymer (Sample A-16)]
Using a stirrer having an inner volume of 10 liters and an autoclave equipped with a jacket and capable of controlling the temperature, 518 g of 1,3-butadiene, 282 g of styrene, 5600 g of normal hexane, and 5600 g of polar substance were purified in the same manner as in Production Example 1. After putting 53 g into the reactor and maintaining the internal temperature of the reactor at 55 ° C., 8.75 mmol of n-butyllithium was supplied to the reactor as a polymerization initiator.
After the start of the reaction, the temperature inside the reactor reached 83 ° C. due to the heat generated by the polymerization.
One minute after the temperature of the reactor began to drop, the polymerization reaction was determined to be completed.
When the temperature in the reactor was 83 ° C. after the completion of the polymerization reaction, 4.375 mmol of 3- (4-methylpiperazin-1-yl) propyltriethoxysilane (abbreviated as “H” in the table) was contained in the solution phase. Was added and stirred for 5 minutes to carry out a denaturation reaction. To the polymer solution subjected to the denaturation reaction, 0.2 g of an antioxidant (BHT) was added per 100 g of the polymer, and a modified conjugated diene-based polymer (sample A- 16) was obtained. No oil was added.
Table 2 shows the physical properties of Sample A-16.
Physical property 3 in Table 1 is an analysis value of a peak having the lowest molecular weight. In addition, g ′ could not be calculated because the amount of components having a molecular weight in the range of 1,000,000 to 2,000,000 was too small.

[(Production Example 13) Modified conjugated diene-based polymer (sample A-17)]
By mixing the polymer obtained in Production Comparative Example 1 and the polymer obtained in Production Comparative Example 4 at a mass ratio of (Production Comparative Example 1) :( Production Comparative Example 4) = 2: 1, A sample (A-17) was obtained. Table 2 shows the physical properties of Sample A-17.

[(Production Example 14) Modified conjugated diene-based polymer (sample A-18)]
By mixing the polymer obtained in Production Comparative Example 2 and the polymer obtained in Production Comparative Example 4 at a mass ratio of (Production Comparative Example 2) :( Production Comparative Example 4) = 2: 1, A sample (A-18) was obtained. Table 2 shows the physical properties of Sample A-18.

[(Production Example 15) Polybutadiene (Sample B-1)]
5.0 L of a polymerization solution (butadiene (BD): 34.2% by mass, cyclohexane (CH): 31.2% by mass) was placed in a 10-liter (L) stainless steel reactor equipped with a stirrer and purged with nitrogen gas. , The rest being 2-butenes).
Further, 7.5 mmol of water (H ₂ O), 10.4 mL of a 1 mol / L diethylaluminum chloride cyclohexane solution, 2.6 mL of a 1 mol / L triethylaluminum cyclohexane solution, (total aluminum / water = 1.73 (mixing molar ratio) )) 104.7 mL of a 1 mmol / L cobalt octoate cyclohexane solution and 31.3 mmol of cyclooctadiene (COD) were added, and the mixture was stirred at 70 ° C for 20 minutes to perform 1,4-cis polymerization.
Thereafter, ethanol containing 5% of 2,6-bis (t-butyl) -4-methylphenol (BHT) was added to terminate the polymerization, and unreacted butadiene and 2-butenes were removed by evaporation to obtain polybutadiene. (Sample B-1) was obtained. Table 3 shows the physical properties of the obtained polybutadiene (sample B-1).

<Microstructure analysis>
Using polybutadiene as a sample, 50 mg of the sample was dissolved in 10 mL of carbon disulfide to obtain a measurement sample.
Using a solution cell, an infrared spectrum is measured in the range of 600 to 1000 cm ^-1 , and the absorbance at a predetermined wavenumber is used to determine the Hampton method (the method described in RR Hampton, Analytical Chemistry 21, 923 (1949)). The microstructure of the butadiene moiety, that is, 1,4-cis bond content (mol%), 1,4-trans bond content (mol%), and 1,2-vinyl bond content (mol%) are determined according to the calculation formula (Fourier transform infrared spectrophotometer “FT-IR230” manufactured by JASCO Corporation).

<Mooney viscosity>
Using a polybutadiene as a sample, Mooney viscosity was measured using a Mooney viscometer (trade name “VR1132” manufactured by Kamishima Seisakusho) according to JIS K6300 using an L-shaped rotor.
The measurement temperature was 100 ° C.
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)} ).

[(Production Example 16) Polybutadiene 2 (Sample B-2)]
After replacing the flask with a capacity of 500 mL with nitrogen, at room temperature, 9 mL of a 1 mol / L diisobutylaluminum hydride cyclohexane solution, 1 mL of a 1 mol / L 1,3-butadienecyclohexane solution and 1 mmol / L of neodymium versatate (Shell Chemical Co., Ltd.) 100 mL of the versatile acid neodymium salt) cyclohexane solution was added in this order, and the mixture was aged at room temperature for 15 minutes with stirring.
Thereafter, 10 mL of a 0.1 mmol / L methylaluminoxane toluene solution was added, and the mixture was aged for 15 minutes. Then, 3 mL of a 0.1 mol / L diethylaluminum chloride cyclohexane solution was added and aged for 40 minutes to prepare a catalyst solution. did.
5.0 L of polymerization solution (butadiene (BD): 34.2% by mass, cyclohexane (CH): 65.8% by mass) was placed in a 10-liter (L) stainless steel reactor equipped with a stirrer and purged with nitrogen gas. ). The catalyst solution was added with an amount of 100 μmol of the neodymium complex and polymerized at 50 ° C. for 1 hour. After the polymerization, ethanol containing 5% of 2,6-bis (t-butyl) -4-methylphenol (BHT) was added to stop the polymerization, and unreacted butadiene and 2-butenes were removed by evaporation. Polybutadiene B-2 was obtained. Table 3 shows the physical properties of the obtained polybutadiene B-2.

[(Production Example 17) Polybutadiene 3 (Sample B-3)]
5.0 L (butadiene (BD): 35% by mass, toluene: 65% by mass) of the polymerization solution was charged into a 10-liter (L) stirrer and jacketed stainless steel reaction tank purged with nitrogen gas.
After adjusting the temperature of the solution to 30 ° C., 25 mL of a cyclohexane solution (1 mol / L) of triethylaluminum (TEA) was added. Next, 1.25 mL of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added, and the mixture was heated to 40 ° C. did. After stirring for 2 minutes, 10 mL of a toluene solution (0.012 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added, and polymerization was performed at 80 ° C. for 15 minutes.
After the polymerization, ethanol containing 5% of 2,6-bis (t-butyl) -4-methylphenol (BHT) was added to stop the polymerization, and unreacted butadiene and 2-butenes were removed by evaporation. Polybutadiene B-3 was obtained. Table 3 shows the physical properties of the obtained polybutadiene B-3.

[(Comparative Production Example 5) Polybutadiene 4 (Sample B-6)]
400 g of butadiene from which impurities were removed and 2800 g of cyclohexane were put into a reactor in a stainless steel reactor equipped with a stirrer and a jacket having a capacity of 10 liters and purged with nitrogen gas. 5.1 mmol of n-butyllithium was fed to the reactor as an initiator. After the polymerization, ethanol containing 5% of 2,6-bis (t-butyl) -4-methylphenol (BHT) was added to stop the polymerization, and unreacted butadiene and 2-butenes were removed by evaporation. Polybutadiene B-6 was obtained. Table 3 shows the physical properties of the obtained polybutadiene B-6.

[Examples 1 to 19 and Comparative Examples 1 to 7]
(Samples A-1 to A-18) shown in Tables 1 and 2 are (A) modified conjugated diene-based polymers, and (Samples B-1 to B-6) shown in Table 3 are (B) polybutadiene. In accordance with the following formulation and Tables 4 to 6, rubber compositions containing the respective raw rubbers were obtained.
(A) Component Modified conjugated diene polymer (Samples A-1 to A-18)
(B) Component Polybutadiene (B-1): Sample B-1
Polybutadiene (B-2): Sample B-2
Polybutadiene (B-3): Sample B-3
Polybutadiene (B-4): "BR150" Ube Industries
Polybutadiene (B-5): "CB24" Aranseo
Polybutadiene (B-6): Sample B-6

(A) Modified conjugated diene-based polymer (samples A-1 to A-18)
(B) Polybutadiene (B-1 to B-6)
Silica 1 (trade name “Ultrasil 7000GR” manufactured by Evonik Degussa Co., Ltd., nitrogen adsorption specific surface area 170 m 2 / g): 50.0 parts by mass Silica 2 (trade name “Zeosil Premium 200MP” manufactured by Rhodia Co., Ltd., nitrogen adsorption specific surface area 220 m 2 / g) : 25.0 parts by mass Carbon black (trade name “SEIST KH (N339)” manufactured by Tokai Carbon Co., Ltd.): 5.0 parts by mass Silane coupling agent (trade name “Si75” manufactured by Evonik Degussa, bis (triethoxy) Silylpropyl) disulfide): 6.0 parts by mass S-RAE oil (trade name “Process NC140” manufactured by JX Nippon Oil & Energy): 37.5 parts by mass Zinc white: 2.5 parts by mass Stearic acid: 1. 0 parts by mass Antioxidant (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylene Amine): 2.0 parts by mass Sulfur: 2.2 parts by mass Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazylsulfinamide): 1.7 parts by mass Vulcanization accelerator 2 (diphenylguanidine): 2 0.0 parts by mass in total: 234.9 parts by mass Tables 4 to 6 show the mixing results.

The above-mentioned materials were kneaded by the following method to obtain a rubber composition.
As a first-stage kneader, a raw rubber (samples A-1 to A-A) was used as a first-stage kneader at a filling rate of 65% and a rotor rotation speed of 30 to 50 rpm using a closed kneader equipped with a temperature controller. -18), filler (silica 1, silica 2, carbon black), silane coupling agent, process oil, zinc white, and stearic acid were kneaded.
At this time, the temperature of the closed mixer was controlled, and the discharge temperature was 155 to 160 ° C. to obtain each rubber composition (blend).

(Evaluation 1) Rise Time of Torque During the first stage of kneading, after the kneading of the hermetic kneader was started, the time required from when the torque started to rise to a constant value was measured.
Each measurement value was indexed with the result of Comparative Example 1 as 100.
A smaller index indicates shorter rise time and better moldability.

(Evaluation 2) Sheet processability Using the rubber composition (compound) obtained through the first-stage kneading as described above, a sheet-like composition was formed using an open roll set at 70 ° C. processed.
The state of the sheet of the obtained sheet-like composition was visually evaluated according to the following criteria, and evaluated in five steps.
A higher score indicates better sheet workability.
5: The unity during the roll operation is good, the sheet skin is smooth, and the sheet edge is not jagged.
4: The unity during the roll operation is good, but the sheet skin is slightly rough and the sheet edge is slightly jagged.
3: The unity during the roll operation is slightly poor, the sheet skin is slightly rough, and the sheet edge is slightly jagged.
2: The unity during the roll operation is slightly poor, the sheet skin is rough, and the sheet edges are also jagged.
1: The unity during the roll operation is poor, the sheet skin is rough, and the sheet edge is also jagged.

Using the compound obtained through the above-described first-stage kneading, the second-stage kneading was performed.
After cooling the mixture obtained above to room temperature, an antioxidant was added, and the mixture was kneaded again to improve the dispersion of silica. Also in this case, the discharge temperature of the mixture was adjusted to 155 to 160 ° C. by controlling the temperature of the mixer.
After cooling, sulfur and vulcanization accelerators 1 and 2 were added and kneaded with an open roll set at 70 ° C. as a third-stage kneading.
Thereafter, it was molded and vulcanized with a vulcanizing press at 160 ° C. for 20 minutes. The rubber composition before vulcanization and the rubber composition after vulcanization were evaluated. Specifically, evaluation was performed by the following method.
The evaluation results are shown in Tables 7 to 9.

(Evaluation 3) Compound Mooney Viscosity After kneading in the second stage, a Mooney viscometer (trade name “VR1132” manufactured by Ueshima Seisakusho Co., Ltd.) was used as a sample of the conjugated diene-based polymer or modified conjugated diene-based polymer before crosslinking. The Mooney viscosity was measured using an L-shaped rotor according to JIS K6300.
The measurement temperature was 100 ° C.
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)} ).
Each measurement value was indexed with the result of Comparative Example 1 as 100. A smaller index indicates better processability.

(Evaluation 4) Viscoelastic Parameter The viscoelastic parameter of the rubber composition after vulcanization was measured in a torsional mode using a viscoelasticity tester “ARES” manufactured by Rheometrics Scientific. Each measurement was indexed with the result for the rubber composition of Comparative Example 1 as 100. Tan δ measured at 0 ° C. at a frequency of 10 Hz and a strain of 1% was used as an index of wet grip properties. The higher the value, the better the wet grip property. In addition, tan δ measured at 50 ° C. at a frequency of 10 Hz and a strain of 3% was used as an index of low hysteresis loss. The larger the index, the better the low hysteresis loss property.

(Evaluation 5) Tensile Rupture Strength, Tensile Rupture Elongation, and Stretching Stress The vulcanized rubber composition was subjected to a tensile breaking strength, a tensile elongation at break, and a stress at 100% elongation (M100) in accordance with the tensile test method of JIS K6251. ) Was measured and the result of Comparative Example 1 was indexed as 100.

(Evaluation 6) Abrasion resistance The vulcanized rubber composition was subjected to an abrasion test using an Akron abrasion tester (manufactured by Yasuda Seiki Seisaku-Sho, Ltd.) in accordance with JIS K6264-2 at a load of 44.4 N and 1,000 rotations. Was measured, and the result of Comparative Example 1 was indexed as 100. The larger the index, the better the wear resistance.

As shown in Tables 7 to 9, the rubber compositions of the examples show a rapid increase in torque during kneading, a short torque increase time, and good workability as compared with the rubber compositions of the comparative examples. Was confirmed.
In addition, it was confirmed that when the vulcanized product was used, it was excellent in the balance between wet grip properties and low hysteresis loss, and also excellent in abrasion resistance. It was also confirmed that the vulcanized product had practically sufficient breaking strength.

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

Claims (15)

(A) the weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less;
A modified conjugated diene-based polymer having a molecular weight distribution Mw / Mn of 1.6 or more and 4.0 or less,
The modification ratio to the total amount of the conjugated diene-based polymer is 50% by mass or more;
In a gel permeation chromatography (GPC) curve, the denaturation rate of a peak having a molecular weight which is の of the molecular weight of a peak having a minimum molecular weight when a plurality of peaks are present, or the conjugated diene, 100% by mass of a modified conjugated diene-based polymer, which is １ ／ or more of the modification ratio based on the total amount of the system-based polymer,
(B) 10 to 80 parts by mass of polybutadiene having a cis 1,4 bond content of 80.0 mol% or more in microstructure analysis;
And a modified conjugated diene-based polymer composition. The (A) modified conjugated diene polymer is
The contraction factor (g ′) by 3D-GPC is 0.86 or more and 1.0 or less;
The modified conjugated diene-based polymer composition according to claim 1. The (A) modified conjugated diene polymer is
The contraction factor (g ′) by 3D-GPC is 0.30 or more and less than 0.86;
The modified conjugated diene-based polymer composition according to claim 1. The (A) modified conjugated diene polymer is
The contraction factor (g ′) by 3D-GPC is 0.30 or more and 0.70 or less;
The modified conjugated diene-based polymer composition according to claim 1. The (B) polybutadiene comprises:
The cis-1,4 bond content in microstructure analysis is 90.0 mol% or more;
The modified conjugated diene-based polymer composition according to claim 1. (A) the modified conjugated diene-based polymer contains nitrogen and silicon in an amount of 3 ppm by mass or more,
The molar ratio of nitrogen to silicon is 1.1 or more and less than 10;
The modified conjugated diene-based polymer composition according to claim 1. (A) the modified conjugated diene-based polymer contains nitrogen and silicon in an amount of 3 ppm by mass or more,
The molar ratio of nitrogen to silicon is 0.1 or more and less than 0.9,
The modified conjugated diene-based polymer composition according to claim 1. (A) the modified conjugated diene polymer has a glass transition temperature of −20 ° C. or more and 0 ° C. or less;
The modified conjugated diene-based polymer composition according to claim 1.   The modified conjugated diene-based polymer composition according to any one of claims 1 to 7, wherein the glass transition temperature of the (A) modified conjugated diene-based polymer is from -50C to less than -20C.   The modified conjugated diene-based polymer composition according to any one of claims 1 to 7, wherein the glass transition temperature of the (A) modified conjugated diene-based polymer is from -70 ° C to less than -50 ° C.   The modified conjugated diene-based polymer composition according to any one of claims 1 to 10, wherein the polymerization initiator residue of the (A) modified conjugated diene-based polymer does not contain nitrogen.   A polymer composition containing the modified conjugated diene-based polymer composition according to any one of claims 1 to 11 in an amount of 10% by mass or more. 20 parts by mass of a rubber-like polymer containing 10% by mass or more of the modified conjugated diene-based polymer composition according to any one of claims 1 to 11,
5 to 150 parts by mass of a filler,
And a rubber composition comprising: It is a manufacturing method of the rubber composition according to claim 13,
(A) 100 parts by mass of a modified conjugated diene-based polymer,
(B) 10 to 80 parts by mass of polybutadiene;
5 to 150 parts by mass of a filler containing (C) silica as the filler,
And a method for producing a rubber composition. (A) the modified conjugated diene-based polymer,
The method for producing a rubber composition according to claim 14, wherein after kneading the filler containing silica (C), the obtained kneaded product is kneaded with the polybutadiene (B).