JP7398901B2 - Modified conjugated diene polymer composition, rubber composition, and method for producing rubber composition - Google Patents

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, demands for lower fuel consumption for automobiles have increased, and there has been a demand for improvements in the materials used for automobile tires, especially tire treads that come in contact with the ground. Development is required.
Furthermore, in order to reduce the weight of tires, it is necessary to reduce the thickness of the tire tread, and there is also a need for materials with high wear resistance.
On the other hand, from the viewpoint of safety, materials used for tire treads are required to have excellent wet skid resistance and practically sufficient fracture characteristics.

Materials that meet these demands include materials containing rubber-like polymers and reinforcing fillers such as carbon black and silica.
For example, by using a material containing silica, it is possible to improve the balance between low hysteresis loss and wet skid resistance.
In addition, the dispersibility of silica in the material can be improved by introducing, in other words, modifying, a functional group that has affinity or reactivity with silica into the molecular end of a highly mobile conjugated diene polymer. Further, attempts have been made to reduce the hysteresis loss by reducing the mobility of the end portions of rubbery polymer molecules through bonding with silica particles.

For example, Patent Documents 1 and 2 propose modified conjugated diene polymers that are functionalized by reacting a cyclic azasilacycle compound with a polymer active end.
Further, Patent Document 3 proposes a modified conjugated diene polymer obtained by coupling a polymer active end with a polyfunctional silane compound.

In addition, conjugated diene polymer compositions blended with various tackifying resins have been proposed as rubber materials for tires for the purpose of imparting various properties (for example, Patent Documents 4 to 8), and the above-mentioned low hysteresis There is a need for a composition that can exhibit both loss resistance and various properties provided by the tackifying resin without any problems.

Special Publication No. 2008-527150 International Publication No. 2011/129425 pamphlet International Publication No. 2007/114203 pamphlet JP2016-022871A Japanese Patent Application Publication No. 2011-116819 Japanese Patent Application Publication No. 2016-037532 JP2013-028720A Japanese Patent Application Publication No. 2017-197715

Modified conjugated diene polymers, which have functional groups highly reactive with silica introduced at the molecular ends of the conjugated diene polymers, are produced by first dispersing silica particles during the kneading process and then reacting on the silica particle surfaces. , reduce hysteresis loss. However, there is a problem in that when a tackifying resin is blended, the density of the modified conjugated diene polymer decreases accordingly, and the function of reducing hysteresis loss decreases.

Therefore, an object of the present invention is to provide a modified conjugated diene polymer composition that exhibits a sufficient function of reducing hysteresis loss even when a tackifying resin is blended therein.

As a result of intensive studies to solve the problems of the prior art described above, the present inventors have discovered a modified conjugated diene polymer in which a functional group having affinity or reactivity with a filler is introduced into the molecule of a conjugated diene polymer. A modified conjugated diene polymer composition comprising a polymer and a tackifying resin, wherein the modified conjugated diene polymer has a weight average molecular weight and a molecular weight distribution within a specific range, and has a weight average molecular weight and a molecular weight distribution within a specific range, and is analyzed by GPC (gel permeation chromatography). A modified conjugated diene polymer, in which, in the molecular weight curve, the modification rate of a component with a molecular weight that is 1/2 of the peak top molecular weight is greater than or equal to a predetermined value compared to the overall modification rate of the modified conjugated diene polymer. The inventors have discovered that a modified conjugated diene polymer composition containing at least a tackifying resin can solve the problems of the prior art described above, and have completed the present invention.
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 polymer having a molecular weight distribution Mw/Mn of 1.6 or more and 4.0 or less,
The modification rate based on the total amount of the conjugated diene polymer is 50% by mass or more,
The modification rate of the component with a molecular weight that is 1/2 of the molecular weight of the peak top in the gel permeation chromatography (GPC) curve, or the molecular weight of the peak top with the minimum molecular weight when there are multiple peak tops, is the conjugated diene. 100 parts by mass of a modified conjugated diene polymer whose modification rate is 1/2 or more based on the total amount of the polymer;
(B) 2 to 30 parts by mass of tackifying resin;
A modified conjugated diene polymer composition containing.
[2]
(A) The 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 polymer composition described in [1] above.
[3]
(A) The 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 polymer composition described in [1] above.
[4]
(B) The tackifying resin is coumaron-indene resin, C5 resin, C9 resin, C5-C9 resin, dicyclopentane resin, terpene resin, terpene/phenol resin, rosin, modified rosin, alkylphenol resin, alkylphenol/formaldehyde. At least one selected from the group consisting of resin, and styrene-alpha methylstyrene resin,
The modified conjugated diene polymer composition according to any one of [1] to [3] above.
[5]
(A) The 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 polymer composition according to [3] or [4] above.
[6]
(A) the modified conjugated diene polymer contains nitrogen and silicon in an amount of 3 ppm or more by mass each;
The molar ratio of nitrogen to silicon is 1.1 or more and less than 10.
The modified conjugated diene polymer composition according to any one of [1] to [5] above.
[7]
(A) the modified conjugated diene polymer contains nitrogen and silicon in an amount of 3 ppm or more by mass each;
The molar ratio of nitrogen to silicon is 0.1 or more and less than 0.9.
The modified conjugated diene polymer composition according to any one of [1] to [5] above.
[8]
The glass transition temperature of the modified conjugated diene polymer (A) is -20°C or more and 0°C or less,
The modified conjugated diene polymer composition according to any one of [1] to [7] above.
[9]
The modified conjugated diene polymer composition according to any one of [1] to [7] above, wherein the modified conjugated diene polymer (A) has a glass transition temperature of -50°C or more and less than -20°C.
[10]
The modified conjugated diene polymer composition according to any one of [1] to [7] above, wherein the modified conjugated diene polymer (A) has a glass transition temperature of -70°C or more and less than -50°C.
[11]
The modified conjugated diene polymer composition according to any one of [1] to [10], wherein the polymerization initiator residue of the modified conjugated diene polymer (A) does not contain a nitrogen atom.
[12]
A polymer composition containing 10% by mass or more of the modified conjugated diene copolymer composition according to any one of [1] to [11] above.
[13]
100 parts by mass of a rubbery polymer containing 10% by mass or more of the modified conjugated diene copolymer composition according to any one of [1] to [11] above;
5 to 150 parts by mass of filler;
A rubber composition containing.
[14]
The method for producing the rubber composition according to [13] above,
(A) 100 parts by mass of a modified conjugated diene polymer;
(B) 2 to 30 parts by mass of tackifying resin;
(C) 5 to 150 parts by mass of a filler containing silica;
A method for producing a rubber composition, which comprises kneading.
[15]
After kneading 100 parts by mass of the modified conjugated diene polymer (A) and 5 to 150 parts by mass of the filler (C), the resulting kneaded product and 2 to 30 parts by mass of the tackifying resin (B) The method for producing a rubber composition according to [14] above, which comprises kneading the rubber composition.

According to the present invention, it is possible to provide a modified conjugated diene polymer composition that exhibits a sufficient function of reducing hysteresis loss even when a tackifying resin is blended.

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

[Modified conjugated diene polymer composition]
The modified conjugated diene polymer composition of this embodiment is
(A) the weight average molecular weight is 20×10 ⁴ or more and 300×10 ⁴ or less,
A modified conjugated diene polymer having a molecular weight distribution Mw/Mn of 1.6 or more and 4.0 or less,
The modification rate based on the total amount of the conjugated diene polymer is 50% by mass or more,
The modification rate of the component having a molecular weight that is 1/2 of the molecular weight of the peak top in the gel permeation chromatography (GPC) curve, or the molecular weight of the peak top with the minimum molecular weight when there are multiple peak tops, is the conjugated diene. 100 parts by mass of a modified conjugated diene polymer whose modification rate is 1/2 or more based on the total amount of the polymer;
(B) 2 to 30 parts by mass of tackifying resin;
Contains.

((A) Modified conjugated diene polymer)
The modified conjugated diene polymer (A) 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 rate based on the total amount of the conjugated diene polymer is 50% by mass or more,
A component with a molecular weight that is 1/2 of the molecular weight of the peak top in a gel permeation chromatography (GPC) curve, or if there are multiple peaks, the molecular weight of the peak top with the minimum molecular weight (hereinafter referred to as low molecular weight component) ) is 1/2 or more of the modification rate with respect to the total amount of the conjugated diene polymer.

<Denaturation rate>
(A) The modified conjugated diene polymer has a modification rate of 50% by mass or more, preferably 60% by mass or more, and more preferably 70% by mass or more based on the total amount of the conjugated diene polymer.
When the modification rate is 50% by mass or more, when it is made into a vulcanized product, it has an excellent balance between low hysteresis loss property and wet skid resistance.
The modification rate is the content of a polymer component having a specific functional group in the polymer molecule that has affinity or binding reactivity toward a filler, expressed in mass %, based on the total amount of the conjugated diene polymer.

Examples of the polymer component having a specific functional group in the polymer molecule that has an affinity or bonding reactivity to a filler include preferably polymers having a functional group containing a nitrogen atom, a silicon atom, or an oxygen atom. More preferably, it is a modified conjugated diene polymer having the functional group at the end of the polymer. For example, a polymer in which a functional group having a nitrogen atom is bonded to the polymerization initiation terminal and/or a modified conjugated diene system modified by a functional group having a functional group containing a nitrogen atom, silicon atom, or oxygen atom in the termination terminal. Examples include polymers.

(A) The modification rate of the modified conjugated diene polymer can be measured by chromatography that can separate modified components containing functional groups from unmodified components. This chromatography method uses a gel permeation chromatography column packed with a polar substance such as silica that adsorbs specific functional groups, and quantifies the non-adsorbed components using an internal standard for comparison. There are several methods.
More specifically, the denaturation rate is determined by calculating the difference between the chromatogram of a sample solution containing the measurement sample and a low molecular weight internal standard polystyrene using a polystyrene gel column and the chromatogram measured using a silica column. It can be calculated by measuring the amount of adsorption to. The modification rate can be measured by the method described in the Examples below.
(A) The modification rate of the modified conjugated diene polymer can be controlled within the above numerical range by adjusting the polymerization conditions. (A) Modified conjugated diene polymers are produced by living anionic polymerization, and the modifying groups are formed by chemically bonding a modifier to the terminal terminal side of the living polymer. Denaturation rate can be changed. Furthermore, since the reactivity between the modifier and the living polymer changes depending on the temperature conditions and stirring conditions within the polymerization machine, it can also be controlled using these factors.

<Modification rate of low molecular weight components>
By measuring the modification rate in each molecular weight region in a molecular weight curve by GPC, the present inventor found that the modification rate differs depending on the molecular weight region depending on the polymer.
In addition, a modified conjugated diene polymer in which the modification rate of a component with a molecular weight that is 1/2 of the molecular weight at the peak top of the GPC curve (low molecular weight component) is 1/2 or more of the modification rate of the entire modified conjugated diene polymer. Coalescence is more specific than modified conjugated diene polymers in which the modification rate is non-uniform and in particular the modification rate of components in the low molecular weight region is lower than 1/2 of the modification rate of the entire modified conjugated diene polymer. It was found that the performance was excellent.

(A) The modified conjugated diene polymer has a molecular weight of 1/1/2 of the molecular weight of the peak top of the peak in the GPC curve when there is one peak, and the molecular weight of the minimum peak top when there are multiple peaks. The modification rate of the component having a molecular weight of 2 (low molecular weight component) is 1/2 or more of the modification rate with respect to the total amount of the conjugated diene polymer. It is preferably 0.55 or more, more preferably 0.57 or more.
As a result, a rubber composition with excellent processability, especially the torque of the mixer is applied well when kneading with the filler, and a rubber composition with good dispersibility of the filler can be obtained in a shorter time than before. (A) Modified conjugate A diene polymer can be obtained.
Furthermore, when the modified conjugated diene polymer composition of the present embodiment is used as a vulcanized composition, it has excellent balance between low hysteresis loss property and wet skid resistance, as well as fracture properties and abrasion resistance, especially for tires. This increases the degree of freedom in designing the composition to obtain a rubber composition with excellent fuel efficiency for use.

As mentioned above, the present inventor found that the modification rate differs depending on the molecular weight range depending on the polymer. The present invention was completed by discovering the mechanism.
That is, first, focusing on the modification rate of the modified conjugated diene polymer relative to the total amount of the conjugated diene polymer, it was found that the Mooney viscosity, microstructure, modifier used, kneading conditions, etc. of the polymers were the same. In some cases, a polymer with a high modification rate based on the total amount of conjugated diene polymer (modification rate of 50% or more) has a higher torque increase rate when kneaded with a filler compared to a polymer with a lower modification rate. is fast, but on the other hand, the maximum value reached by the torque is also high, so even if the overall denaturation rate changes, the time it takes to reach the maximum value of the torque is approximately the same. In other words, the modification rate of the polymer as a whole affects both the maximum torque value and the rate of increase in torque. It is thought that the length will not be affected much.
On the other hand, when focusing on the modification rate of the low molecular weight component, that is, the modification rate of the molecular weight component that is 1/2 of the peak top molecular weight, the modification rate of the low molecular weight component with respect to the total amount of the conjugated diene polymer is The lower the ratio is, the slower the rate of increase in torque will be when kneading the polymer with the filler. will rise faster.

As mentioned above, the rate of increase in torque is also affected by the modification rate relative to the total amount of conjugated diene polymers, but whether the "modification ratio relative to the total amount of conjugated diene polymers" is high or low, The higher the denaturation rate of molecular weight components, the faster the torque increase speed.
In other words, according to the inventor's study, the influence of the "modification rate of low molecular weight components" relative to the "modification rate relative to the total amount of conjugated diene polymers" on the torque increase rate is It is constant regardless of the modification rate relative to the total amount of polymer.
On the other hand, the maximum value of torque is determined depending on the modification rate of the entire modified conjugated diene polymer, so it does not change depending on the modification rate of the low molecular weight components. The higher the rate of degeneration, the shorter the time it takes to reach the maximum torque value. Therefore, the time required to reach the maximum torque value is determined by the modification rate of the low molecular weight component relative to the total amount of conjugated diene polymer, regardless of the modification rate relative to the total amount of conjugated diene polymer. can be controlled.
Specifically, by setting the modification rate of the low molecular weight component to 1/2 or more of the total amount of conjugated diene polymer, processability, especially the torque of the mixer when kneading with the filler, can be improved. The dispersibility of the filler is improved in a shorter time than before. As a result, the thermal deterioration that occurs in the polymer during kneading can be minimized, and since thermal deterioration is difficult to occur, it is possible to reduce the amount of heat stabilizer to be blended.

In addition, by setting the modification rate of the low molecular weight component to 1/2 or more of the modification rate with respect to the total amount of the conjugated diene polymer, (A) when the modified conjugated diene polymer is used as a vulcanization composition, a low molecular weight component can be obtained. The degree of freedom in designing a composition is increased in order to obtain a rubber composition that has a good balance between hysteresis loss property and wet skid resistance, has excellent fracture properties and wear resistance, and has excellent fuel efficiency especially for use in tires.
When producing a rubber composition for tires, it is effective to use a modified conjugated diene polymer with a higher degree of branching and/or a higher molecular weight in order to improve fuel efficiency. On the other hand, processing problems may occur, such as difficulty in kneading with fillers and the like. To solve this problem, by adopting a technology that improves the processability of modified conjugated diene polymers, even if modified conjugated diene polymers (A) with a higher degree of branching and/or higher molecular weight are used, kneading is possible. This prevents problems from occurring during the process, and as a result, it becomes easier to prepare a composition that is more suitable for tires.
From this point of view, in (A) the modified conjugated diene polymer, the modification rate of the component with a molecular weight that is 1/2 of the molecular weight of the peak top in the GPC curve is 1/2 of the modification rate with respect to the total amount of the conjugated diene polymer. It shall be 2 or more.
(A) Modified conjugated diene polymers can be obtained by a polymerization method that causes very little termination of the growth reaction or chain transfer. Therefore, the monomers and solvent introduced into the polymerization reactor must be ultra-highly purified, low-temperature polymerization, and 99% mass can be achieved with monomer conversions of less than %.

The modification rate for each molecular weight component can be measured by chromatography, which can separate functional group-containing modified components and non-modified components. This chromatography method uses a gel permeation chromatography column packed with a polar substance such as silica that adsorbs specific functional groups, and quantifies the non-adsorbed components using an internal standard for comparison. There are several methods.
More specifically, the denaturation rate for each molecular weight component is the molecular weight component of the chromatogram measured using a polystyrene gel column and the chromatogram measured using a silica column for a sample solution containing a measurement sample and a low molecular weight internal standard polystyrene. It can be obtained by measuring the amount of adsorption onto the silica column from the difference between each time. Moreover, the modification rate can be measured by the method described in the Examples below.
In order to ensure that the modification rate of the component with a molecular weight that is 1/2 of the molecular weight of the peak top in the GPC curve is 1/2 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 monomers and solvents introduced into the reactor to reduce the amount of terminals that are deactivated during 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, and more preferably 40× It is 10 ⁴ or more and 250×10 ⁴ or less, and even more preferably larger than 50×10 ⁴ and 250×10 ⁴ or less.
When the weight average molecular weight is 20×10 ⁴ or more and 300×10 ⁴ or less, the balance between low hysteresis loss and wet skid resistance and abrasion resistance when made into a vulcanizate are excellent.
In addition, when the weight average molecular weight is 300×10 ⁴ or less, the filler has excellent dispersibility when it is made into a vulcanizate, and excellent fracture properties can be obtained. Furthermore, when the molecular weight is high, that is, the weight average molecular weight is larger than 50 × 10 ⁴ , the amount of polymerization initiator used is small, so that the termination of the growth reaction or chain transfer is less than 1% of the molecular weight at the top of the peak in the GPC curve. /2 has a large effect on the modification rate of components with a molecular weight of It is not possible to obtain a modified conjugated diene polymer with a certain modification rate.
The weight average molecular weight of the modified conjugated diene polymer (A) and the polybutadiene described later can be measured by the method described in the Examples described later.

<Molecular weight distribution Mw/Mn>
(A) The modified conjugated diene polymer has a molecular weight distribution Mw/Mn, expressed as a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn), of 1.6 or more and 4.0 or less. The modified conjugated diene polymer (A) having a molecular weight distribution in this range tends to have better processability when made into a vulcanizate compared to a polymer having a similar 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 modified conjugated diene polymer (A) having such a molecular weight distribution can preferably be obtained by continuous polymerization.
Regarding the molecular weight distribution, it is preferable that the molecular weight curve determined by GPC has a single peak (monomodal) shape, or a trapezoidal or mountain range shape in the case of multiple peaks. The mountain range type refers to a shape in which the height of the lowest point between the peaks is 50% or more of the height of the peaks on both sides. The modified conjugated diene polymer (A) having such a molecular weight distribution tends to have better processability when made into a vulcanizate.

In addition, (A) modified conjugated diene polymer contains 0.3% by mass or more of a modified conjugated diene polymer (hereinafter also referred to as "specific high molecular weight component") with a molecular weight of 2 million to 5 million. It is preferable that it contains 20% by mass or less. This allows it to exhibit superior toughness and wear resistance when made into a vulcanizate.
The content of the specific high molecular weight component is more preferably 1.0% by mass or more and 18% by mass or less, even more preferably 1.1% by mass or more and 18% by mass or less, even more preferably 2.0% by mass or more and 15% by mass or less. % by mass or less.
In order to obtain the modified conjugated diene polymer (A) 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 used as a polymerization initiator described below must be adjusted. In the polymerization process described below, in either continuous or batch polymerization mode, it is preferable to select a method that has a residence time distribution, that is, a method that widens the time distribution of the growth reaction.
Specific methods for the continuous type include a method of using a tank-type reactor with an agitator as a backmix reactor in which vigorous mixing is performed using a stirrer, preferably a method of using a complete mixing type reactor, and a method of using a tubular reactor A method of partially recirculating a part of the reactor, a method of feeding the polymerization initiator at or near the monomer inlet, or an inlet in the middle of the polymerization reactor, and a method of using a combination of a tank type reactor and a tubular reactor. can be mentioned.
According to these methods, it is possible to widen the residence time distribution and make the polymer component having a long residence time a high molecular weight component.
In addition, as specific methods for the batch method, for example, the method of feeding the polymerization initiator can be carried out continuously or intermittently from the start of polymerization to the middle of polymerization, or continuously at the start of polymerization and/or during the middle of polymerization. Alternatively, there is a method of feeding intermittently.
In this method, the polymer that is polymerized from the time when the polymerization initiator is first fed becomes a high molecular weight component, and a difference in molecular weight occurs between the polymer and the polymer that starts polymerization later. More specifically, if the amount of polymerization initiator corresponding to the target molecular weight is continuously fed to the monomer, for example, from 0% to 95% by mass at a conversion rate, an expanded molecular weight distribution can be obtained. There is a tendency that it can be made into a polymer with
By using the above-mentioned method, the activity ratio of the living end of the conjugated diene polymer before the reaction step tends to increase, and the coupling rate after coupling, that is, the modified conjugated diene polymer has a high modification rate. There is also a tendency to obtain Among these methods, a method using a tank-type reactor equipped with an agitator to create a backmix reactor in which vigorous mixing is performed using the agitator is more preferable.
In addition, in this specification, "molecular weight" is a standard polystyrene equivalent molecular weight obtained by GPC (gel permeation chromatography).
The number average molecular weight, weight average molecular weight, and molecular weight distribution content can be measured by the method described in the Examples described below.

<Contraction factor>
The modified conjugated diene polymer (A) used in the modified conjugated diene polymer composition of the present embodiment has a shrinkage factor (g') of 0.86 or more and 1.0 or less as measured using 3D-GPC. A preferred form of the modified conjugated diene polymer is
(A) When the shrinkage factor (g') of the modified conjugated diene polymer is within the above range, the strength at high temperatures tends to be excellent.
The shrinkage factor (g') is an indicator of the branched structure of the modified conjugated diene copolymer (A), and the modified conjugated diene polymer whose shrinkage factor (g') is 0.86 or more and 1.0 or less is This is a modified conjugated diene polymer in which the number of branches in one molecule of the modified conjugated diene polymer is three or less. In such a case, the contraction 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 conjugated diene copolymer (A), for example, the amount of the modifier having three or less reactive sites with the living active end is one-third of the total number of moles of the polymerization initiator. An effective method is to add the above mole number to obtain the (A) modified conjugated diene copolymer having three branches or less.

In addition, (A) the modified conjugated diene polymer has a shrinkage factor (g') measured using 3D-GPC of 0.30 or more and less than 0.86 as a preferable form.
Such a modified conjugated diene polymer (A) has significantly lower viscosity of a composition to which a filler is added, and has extremely excellent processability.
The shrinkage factor (g') is an index of the branched structure of the (A) modified conjugated diene copolymer, and the shrinkage factor (g') is 0.30 or more and less than 0.86. The polymer is a modified conjugated diene polymer in which the number of branches in one molecule of the modified conjugated diene polymer is 4 or more.
In order to obtain the modified conjugated diene copolymer (A), for example, the amount of the modifier having four or more reactive sites with the living active end is one-fourth of the total number of moles of the polymerization initiator. An effective method is to add the following molar numbers to obtain a modified conjugated diene copolymer (A) having four or more branches.

Furthermore, it is more preferable that the modified conjugated diene polymer (A) has a shrinkage factor (g') measured using 3D-GPC of 0.30 or more and 0.70 or less.
In such a modified conjugated diene polymer (A), the viscosity of the composition to which the filler is added becomes lower, and the processability becomes even more excellent.
The shrinkage factor (g') is an index of the branched structure of the (A) modified conjugated diene copolymer, and the (A) modified conjugated diene copolymer has 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 modified conjugated diene polymer (A), for example, the amount of the modifier having 5 or more reactive sites with the living active end is one-fifth or less of the total number of moles of the polymerization initiator. An effective method is to obtain a modified conjugated diene copolymer having 5 or more branches by adding it in a molar number of .

The contraction factor (g') measured by GPC-light scattering measurement with a viscosity detector (hereinafter also simply referred to as "GPC-light scattering measurement with a viscosity detector" or "3D-GPC measurement") is It also serves as an indicator of the number of branches in modified conjugated diene polymers. For example, as the shrinkage factor (g') decreases, the number of branches of (A) modified conjugated diene polymer (for example, the number of branches of star-shaped polymer (also referred to as "number of arms of star-shaped polymer")) is on the rise.
When comparing modified conjugated diene polymers with the same absolute molecular weight, the shrinkage factor (g') in this case is ) can be used as an index of the degree of branching.
Contraction factor (g') is measured using 3D-GPC measurements. The constants (K, α) in the relational expression between intrinsic viscosity and molecular weight ([η] = KMα ([η]: intrinsic viscosity, M: molecular weight) are set to logK = -3.883, α = 0.771, and the molecular weight Enter the range of M from 1,000 to 2,000,000 to create a relationship between standard intrinsic viscosity [η] ₀ and molecular weight M.
With respect to this standard intrinsic viscosity [η] ₀ , the intrinsic viscosity [η] at each molecular weight M of the sample obtained by 3D-GPC measurement is expressed as the relationship between the intrinsic viscosity [η] and the standard intrinsic viscosity [η] ₀ [ η]/[η] ₀ is calculated for each molecular weight M, and the average value is taken as the contraction factor (g').
More specifically, it can be measured by the method described in Examples below.

<(A) Structure of modified conjugated diene polymer>
(A) The modified conjugated diene polymer is preferably a modified conjugated diene polymer in which a modifying agent residue having a functional group having an affinity or reactivity with a filler is bonded to the polymerization start end and/or end end. It is.
That is, the modified conjugated diene polymer (A) preferably consists of a modifier residue having a functional group and a conjugated diene polymer chain.
(A) When the terminal of the modified conjugated diene polymer is a polymerization initiator residue, the polymerization initiator residue preferably does not contain a nitrogen atom. If the polymerization initiator residue contains a nitrogen atom, even if the final processability of the vulcanizate remains the same, the reaction with the filler will be faster, resulting in poor sheet processability in the early stages of multi-stage kneading. tends to get worse. On the other hand, when the polymerization initiator residue does not contain nitrogen, it reacts with the filler at an appropriate rate, so that sheet processability is also good even in the initial stage of multi-stage kneading.

<Modifier residue>
(A) The modifier residue in the modified conjugated diene polymer is a structural unit of the (A) modified conjugated diene polymer that is bonded to the conjugated diene polymer chain, such as the conjugated diene polymer described below. It is a structural unit derived from a modifier that is produced by reacting a polymer with a modifier.
The modifier residue has, for example, a specific functional group that has affinity or binding reactivity to the filler.
(A) When the modified conjugated diene polymer is a modified conjugated diene polymer in which a functional group is bonded to the polymerization initiation terminal, the modified conjugated diene polymer (A) is a polymerization initiation polymer having a functional group. It can be obtained by carrying out a polymerization reaction using an agent.

<Terminal>
(A) When the modified conjugated diene polymer does not have a branched structure, (A) the modified conjugated diene polymer has a linear structure, and "terminal" means both ends of the linear chain. , one is attached to the modifier residue and the other is attached to the polymerization initiator residue.
(A) When the modified conjugated diene polymer has a branched structure and at least one of the branch points is a modifier residue, the "end" in the modified conjugated diene polymer (A) refers to the branched structure. For example, the end of a conjugated diene polymer chain that is not bonded to a "modifier residue".First, the monomer is polymerized using a polymerization initiator, and then the end of the polymerization end is modified. When a branching point is formed by bonding the agent, the modified conjugated diene polymer has a polymerization initiator residue at the end of the polymer chain that is not bonded to the modifier residue. (A) When the modified conjugated diene polymer has a branched structure and does not have a branch point due to a modifier residue, the "terminal" in the modified conjugated diene polymer (A) refers to the branch point. The terminus of an unbonded conjugated diene polymer chain, which contains a modifier residue or a polymerization initiator residue.

<Preferred embodiments regarding functional groups>
The specific functional group having affinity or bonding reactivity with the filler is preferably a functional group containing a nitrogen atom or a silicon atom.
The ratio of the number of moles of nitrogen atoms to the number of moles of silicon atoms, ie, the N/Si molar ratio, is preferably from 0.1 to 10.0, more preferably from 0.2 to 7.0.
Within this range, the compatibility with the silica filler is particularly good, the hysteresis loss of the rubber composition using the silica filler is small, and the rubber composition exhibits good performance as a rubber composition for fuel-efficient tires.
Further, from the viewpoint of dispersing silica in a short time during kneading, the molar ratio of nitrogen atoms to silicon atoms is preferably 1.1 or more and less than 10, more preferably 1.3 to 7, and even more preferably 1. .5 to 5.
Furthermore, as another form, from the viewpoint of dispersing silica in a short time during kneading, the molar ratio of nitrogen atoms to silicon atoms is preferably 0.1 or more and less than 0.9, more preferably 0.2 to 0. .75, more preferably 0.3 to 0.6.
Examples of the functional group containing a silicon atom include, but are not limited to, a methoxysilyl group, an ethoxysilyl group, a propoxysilyl group, and the like.
In addition, examples of the functional group containing a nitrogen atom include, but are not limited to, secondary amino groups, tertiary amino groups, and the like.

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

<Monomer constituting the conjugated diene polymer>
(A) The conjugated diene polymer before modification of the modified conjugated diene polymer is obtained by polymerizing at least a conjugated diene compound, and if necessary, copolymerizing both the conjugated diene compound and a vinyl-substituted aromatic compound. It can be obtained by
The conjugated diene compound is not particularly limited as long as it is a polymerizable monomer, but conjugated diene compounds containing 4 to 12 carbon atoms per molecule are preferred, and conjugated diene compounds containing 4 to 8 carbon atoms are more preferred. It is a compound. Such conjugated diene compounds include, but are not limited to, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1 , 3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene. Among these, 1,3-butadiene and isoprene are 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 a conjugated diene compound, but monovinyl aromatic compounds are preferred. Examples of monovinyl aromatic compounds 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 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 is suitable for all kinds of uses other than tires 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 with excellent wear resistance can be obtained.
Further, when the amount of bound styrene is 18% by mass to 28% by mass and the vinyl content is 45% by mass to 65% by mass, a rubber composition for fuel-saving tires with excellent strength in a rubber composition blended with natural rubber can be obtained. is obtained.
Note that the amount of bound styrene is the mass % of styrene in all monomer components, and the vinyl content is the mass % of the vinyl bonded component in the butadiene component.

<Glass transition temperature>
(A) The glass transition temperature, ie, Tg, of the modified conjugated diene polymer is the temperature at which the molecular chains of the modified conjugated diene polymer begin rotational movement, and has a large effect on fuel efficiency and wet grip performance.
When Tg is low, fuel efficiency is improved, and when Tg is high, wet grip performance is improved.

Preferred forms of the modified conjugated diene polymer (A) include those having a Tg of -20°C or more and 0°C or less. This results in extremely good wet grip properties and rigidity. This modified conjugated diene polymer is extremely useful for high performance tires and ultra high performance tires.

Another preferable form of the modified conjugated diene polymer (A) is one having a Tg of -50°C or more and less than -20°C. This results in an extremely excellent balance between fuel efficiency and wet grip. This modified conjugated diene polymer is extremely useful for summer tires and all-season tires.

Another preferable form of the modified conjugated diene polymer (A) is one having a Tg of -70°C or more and less than -50°C. This results in extremely good low-temperature performance and wear resistance.
This modified conjugated diene polymer is extremely useful for winter tires.
It is also used in the formulation of various tire treads to improve wear resistance.
The Tg of the modified conjugated diene polymer can be measured in accordance with ISO 22768:2006.
(A) The Tg of the modified conjugated diene polymer can be controlled within the respective numerical ranges mentioned above by adjusting the amount of bound styrene and the vinyl content.

<Preferred form of random SBR>
When the modified conjugated diene polymer (A) is a butadiene-styrene random copolymer (SBR), it is preferable that the proportion of individual styrene units is high, and that the number of long chains is small.
Specifically, when the modified conjugated diene polymer is a butadiene-styrene copolymer, the copolymer is treated by an ozonolysis method known as the method of Tanaka et al. (Polymer, 22, 1721 (1981)). When the styrene chain distribution is analyzed by GPC, the amount of isolated styrene is 40% by mass or more, and the chain styrene structure with 8 or more styrene chains is 5% by mass or less with respect to the total amount of combined styrene. It is preferable that there be. In this case, the hysteresis loss of the resulting vulcanized rubber can be further reduced, and a rubber composition for fuel-efficient tires with excellent performance can be obtained.

<Hydrogenated conjugated diene polymer>
(A) The modified conjugated diene polymer may be one obtained by further hydrogenating the modified conjugated diene polymer or the conjugated diene polymer before modification in an inert solvent. good. This allows all or part of the double bonds to be converted into saturated hydrocarbons. In such a case, heat resistance and weather resistance are improved, product deterioration when processed at high temperatures can be prevented, and the movement performance as a rubber tends to be improved. Moreover, as a result, it exhibits even more excellent performance in various applications such as automotive applications.
The hydrogenation rate of the unsaturated double bond based on the conjugated diene compound can be arbitrarily selected depending on the purpose and is not particularly limited. When used as a vulcanizate, it is preferable that the double bond in the conjugated diene part remains partially. From this point of view, the hydrogenation rate of the conjugated diene moiety in the conjugated diene polymer is preferably 3.0 mol% or more and 70 mol% or less, and preferably 5.0 mol% or more and 65 mol% or less. More preferably, it is 10 mol% or more and 60 mol% or less. In particular, selective hydrogenation of vinyl groups tends to improve heat resistance and athletic performance. The hydrogenation rate can be determined using a nuclear magnetic resonance apparatus (NMR).

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

<Nitrogen/silicon content>
(A) The modified conjugated diene copolymer preferably has a nitrogen and silicon content of 3 mass ppm or more, and more preferably 7 mass ppm or more, from the viewpoint of improving fuel efficiency. More preferably, the content is 10 mass ppm or more.
(A) The modified conjugated diene copolymer is thought to be physically adsorbed by nitrogen during kneading with the filler and chemically bonded by silicon.

(A) In the modified conjugated diene copolymer, the molar ratio of nitrogen to silicon contained is important, and the molar ratio of nitrogen to silicon (N/Si) is preferably 1.1 or more and less than 10. is preferable from the viewpoint of dispersing silica in a short time during kneading, more preferably 1.3 or more and 7 or less, and even more preferably 1.5 or more and 5 or less. The reason why the N/Si molar ratio is preferably within the above range is that the reaction rate of physical adsorption by nitrogen is faster than chemical bonding by silicon, so the molar ratio of nitrogen to silicon is equal to or higher than equimolar. It is presumed that this is preferable.

Another preferable example of the modified conjugated diene copolymer (A) is one in which the molar ratio of nitrogen to silicon (N/Si) is 0.1 or more and less than 0.9. Thereby, silica can be dispersed in a short time during kneading. 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 it is preferable for the molar ratio of nitrogen to silicon to be 0.1 or more and less than 0.9 is not clear at present, but it is because the chemical bond due to silicon to the silica particles is stronger than the physical adsorption due to nitrogen. It is estimated that by making the molar ratio of nitrogen to silicon less than equimolar, the proportion of chemical bonds between the modified conjugated diene polymer and silica increases, and the bond between the modified conjugated diene polymer and silica becomes stronger. be done. In this case, the silicon content is preferably 7 ppm or more.

(A) The content of nitrogen and silicon in the modified conjugated diene copolymer and the molar ratio of nitrogen to silicon can be controlled by the modifier used in the modification reaction of the conjugated diene copolymer. .
For example, by increasing the molar ratio of nitrogen to silicon in the modifier, it is possible to increase the molar ratio of nitrogen to silicon in the modified conjugated diene copolymer.

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

In formula (I), D ₁ represents a diene polymer chain, R ¹ to R ³ each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms, and R ⁴ and R ⁷ each represent Each independently represents an alkyl group having 1 to 20 carbon atoms, R ⁵ , R ⁸ , and R ⁹ each independently represents 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 from 1 to 3, x≦m, p represents 1 or 2, y represents an integer from 1 to 3, y≦(p+1), and z is 1 or represents an integer of 2.
When a plurality of D ₁ , R ¹ to R ¹¹ , m, p, x, y, and z are each independent.
i represents an integer from 0 to 6, j represents an integer from 0 to 6, k represents an integer from 0 to 6, (i+j+k) represents an integer from 1 to 10, and ((x×i)+ (y×j)+(z×k)) is an integer from 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 oxygen atom, nitrogen atom, silicon atom, sulfur atom, and phosphorus atom, and has active hydrogen. Represents an organic group that does not. However, if (i+j+k) is 1, A may be omitted. As a result, when the modified conjugated diene polymer is made into a vulcanizate, it tends to have a better balance between low hysteresis loss and wet skid resistance, and a better abrasion resistance.

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

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

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

In 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 when multiple B ⁴ exist, each independently There is.

In 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 when multiple B ⁵ exist, each independently There is. As a result, when it is made into a vulcanized product, it tends to have a better balance between low hysteresis loss and wet skid resistance, and a better abrasion resistance. In addition, it tends to be easier to obtain in practical terms.

(Method for producing modified conjugated diene polymer)
(A) The method for producing a modified conjugated diene polymer preferably includes a polymerization step of polymerizing at least a conjugated diene compound using an organic monolithium compound as a polymerization initiator to obtain a conjugated diene polymer; A modification reaction step in which the polymer is reacted with a modifier having a binding group that reacts with the active end of the conjugated diene polymer and a specific functional group having affinity or binding reactivity to the filler. , has.

<Polymerization process>
(A) In the method for producing a modified diene 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 polymer.
The polymerization step is preferably a growth reaction based on a living anion polymerization reaction, which tends to yield a conjugated diene polymer having active terminals and a modified diene polymer with a high modification rate. be.

(A) In the modified conjugated diene polymer, the modification rate of a component (low molecular weight component) with a molecular weight that is 1/2 of the molecular weight at the top of the peak in the GPC curve is 1/2 of the modification rate with respect to the total amount of the conjugated diene polymer. It is 2 or more.
In order to obtain the modified conjugated diene polymer (A), it is effective to obtain the conjugated diene polymer using a polymerization method that causes very little termination of the growth reaction or chain transfer.
Therefore, it is necessary to achieve ultra-high purity of the monomers and solvents introduced into the polymerization reactor at a higher level than before.
Therefore, the total amount of impurities in the monomer components used is preferably 30 ppm or less, and the content concentration (mass) of impurities such as arenes, acetylenes, primary and secondary amines is 20 ppm or less. The nitrogen content of acetylenes is preferably 20 ppm or less, more preferably 10 ppm or less, and the total nitrogen content of primary and secondary amines is 4 ppm or less. The content is preferably 2 ppm or less, and more preferably 2 ppm or less.
Examples of arenes include, but are not limited to, propadiene and 1,2-butadiene. Examples of acetylenes include, but are not limited to, ethyl acetylene and vinyl acetylene. Examples of primary and secondary amines include, but are not limited to, methylamine and dimethylamine.

Ultra-high purification of monomers and solvents can be achieved by thoroughly purifying all monomers and solvents used in polymerization.
In purifying the monomer butadiene, it is important to remove not only polymerization inhibitors but also dimethylamine, N-methyl-γ-aminobutyric acid, etc. that may have an adverse effect on anionic polymerization. As a method for removing these, for example, 1,3-butadiene containing a polymerization inhibitor is washed with low-oxygen water with an oxygen concentration of less than 2 mg/L as washing water, and then 1,3-butadiene is A method for removing a polymerization inhibitor from butadiene may be mentioned.

In purifying the monomer styrene, it is important to remove phenylacetylenes and the like that may have an adverse effect on anionic polymerization. Examples of methods for removing phenylacetylenes include a method of carrying out a hydrogenation reaction using a palladium-supported alumina catalyst.

In purifying n-hexane, which is a polymerization solvent, it is important to remove water that may have an adverse effect on anionic polymerization. Examples of methods for removing this include methods using γ-alumina, synthetic zeolite, and the like. Among these, a method using a synthetic zeolite is preferred, and the synthetic zeolite preferably has a large pore diameter, more preferably a pore diameter of 0.35 nm or more, and even more preferably a pore diameter of 0.42 nm or more.
The ultra-high purification treatment required to achieve a desirable impurity concentration varies depending on the conditions before treatment, so after the ultra-high purification treatment of the monomer and solvent, and prior to the polymerization reaction, measure the impurity concentration of the monomer and solvent. is preferable.

If the monomer and/or solvent with the desired impurity concentration could not be obtained, it is considered that one of the treatments was insufficient. If you want to reduce the amount of primary and secondary amines, butadiene is insufficiently purified, so for example, it is necessary to wash again using low-oxygen water with an oxygen concentration of less than 2 mg/L as washing water. preferable. If it is desired to reduce the amount of acetylenes, it is preferable to carry out the hydrogenation reaction again using a palladium-supported alumina catalyst, for example, since the purification of styrene is insufficient. At this time, it is more preferable to perform treatments such as increasing the amount of the palladium-supported alumina catalyst or lengthening the contact time with the palladium-supported alumina catalyst.

As a polymerization method that causes very little termination of the growth reaction or chain transfer, it is further effective to control the polymerization temperature and the monomer addition rate.
Preferably, the polymerization temperature is a temperature at which living anion polymerization proceeds, and from the viewpoint of productivity, it is preferably 0°C or higher, and preferably 80°C or lower. More preferably, the temperature is 50°C or higher and 75°C or lower.
Further, it is preferable that the conversion rate of the entire monomer is less than 99% by mass when reacting with the modifier. More preferably, the conversion rate is less than 98% by mass.

The conjugated diene polymer may be a random copolymer or a block copolymer. In order to make the conjugated diene polymer into a rubber-like polymer, it is preferable to use the conjugated diene compound in an amount of 40% by mass or more, and preferably 55% by mass or more, based on the total monomers of the conjugated diene polymer. More preferred.

Examples of random copolymers include, but are not limited to, random copolymers made of two or more conjugated diene compounds such as butadiene-isoprene random copolymers, butadiene-styrene random copolymers, and isoprene-styrene random copolymers. Examples include random copolymers and random copolymers of butadiene-isoprene-styrene random copolymers consisting of a conjugated diene 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 with a composition close to statistically random, a tapered (gradient) random copolymer with a tapered composition distribution, etc. Examples include copolymers. The bonding mode of the conjugated diene, ie, the composition of 1,4-bonds, 1,2-bonds, etc., may be uniform or may be distributed.

The block copolymer is not limited to the following, but includes, for example, a type 2 block copolymer (diblock) consisting of two blocks, a type 3 block copolymer (triblock) consisting of three blocks, and a type 3 block copolymer consisting of three blocks (triblock). For example, a type 4 block copolymer (tetra block) consisting of: The polymer constituting one block may be a polymer made of one type of monomer or a copolymer made of two or more types of monomers. For example, a polymer block consisting 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 a polymer block made of styrene is represented by "S", then B-B/I2 type block copolymer, B-B/S2 type block copolymer, S-B2 type block Copolymer, BB/S-S3 type block copolymer, S-B-S3 type block copolymer, S-B-S-B4 type block copolymer, etc.
In the above formula, the boundaries of each block do not necessarily need to be clearly distinguished. In addition, when one polymer block is a copolymer consisting of two types of monomers A and B, A and B in the block may be uniformly distributed or tapered. good.

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

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

The organic monolithium compound is an alkyllithium compound having a substituted amino group or dialkylaminolithium. In this case, a conjugated diene polymer having a nitrogen atom consisting of an amino group at the polymerization initiation terminal is obtained.

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

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

These organic monolithium compounds having substituted amino groups are made by reacting a small amount of a polymerizable monomer, such as 1,3-butadiene, isoprene, or styrene, to form solubilized oligomeric organic monolithium compounds. It can also be used as a compound.
The organic monolithium compound is preferably an alkyllithium compound. In this case, a conjugated diene polymer having an alkyl group at the polymerization initiation terminal is obtained. Examples of the alkyllithium compound include, but are not limited to, n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and stilbenelithium. As the alkyllithium compound, n-butyllithium and sec-butyllithium are preferred from the viewpoint of industrial availability and ease of controlling the polymerization reaction.
These organic monolithium compounds may be used alone or in combination of two or more.

Moreover, the organomonolithium compound may be used in combination with other organometallic compounds. Examples of the organometallic compound include, but are not limited to, alkaline earth metal compounds, other alkali metal compounds, and other organometallic compounds. Examples of alkaline earth metal compounds include, but are not limited to, organic magnesium compounds, organic calcium compounds, and organic strontium compounds. Also included are alkaline earth metal alkoxide, sulfonate, carbonate, and amide compounds. Examples of the organic magnesium compound include dibutylmagnesium and ethylbutylmagnesium. Examples of other organometallic compounds include organoaluminum compounds.

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

The polymerization step is preferably carried out in an inert solvent.
Examples of the inert solvent include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons.
Specific hydrocarbon solvents include, but are not limited to, aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane. Examples include aromatic hydrocarbons such as benzene, toluene, and xylene, and hydrocarbons consisting of mixtures thereof.

By treating allenes and acetylenes, which are impurities, with an organometallic compound before subjecting them to the polymerization reaction, a conjugated diene polymer with a high concentration of active terminals tends to be obtained, resulting in a high modification rate. This is preferred because a conjugated diene polymer tends to be obtained.

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

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

The conjugated diene polymer obtained in the polymerization step and 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 even more preferably is 20 or more and 60 or less.
When the Mooney viscosity is within the above range, the modified conjugated diene polymer composition of this embodiment tends to have excellent processability and wear resistance.

The amount of bonded conjugated diene in the conjugated diene polymer or modified conjugated diene polymer is not particularly limited, but preferably 40% by mass or more and 100% by mass or less, and 55% by mass or more and 80% by mass or less. is more preferable.
Further, the amount of bonded aromatic vinyl in the conjugated diene polymer or modified conjugated diene polymer is not particularly limited, but is preferably 0% by mass or more and 60% by mass or less, and 20% by mass or more and 45% by mass or less. It is more preferable that
When the amount of bonded conjugated diene and the amount of bonded aromatic vinyl are within the above ranges, the vulcanizate tends to have better fracture properties and wear resistance.
Here, the amount of bonded aromatic vinyl can be measured by ultraviolet absorption of the phenyl group, and from this, the amount of bonded conjugated diene can also be determined. Specifically, it can be measured according to the method described in Examples described later.

In the conjugated diene polymer or modified conjugated diene polymer, the amount of vinyl bonds in the conjugated diene bond unit is not particularly limited, but is preferably 10 mol% or more and 75 mol% or less, and 20 mol% or more and 65 mol%. % or less is more preferable.
When the amount of vinyl bonds is within the above range, the balance between low hysteresis loss and wet skid resistance, abrasion resistance and fracture strength tend to be better when made into a vulcanized product.

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

Regarding the microstructure of the modified conjugated diene polymer, (A) the amount of each bond in the modified conjugated diene polymer is within the numerical range mentioned above, and (A) the glass transition temperature of the modified conjugated diene polymer is When the temperature is in the range of -50°C or more and less than -20°C, a more excellent vulcanizate tends to be obtained due to the balance between low hysteresis loss property and wet skid resistance.
Regarding the glass transition temperature, according to ISO 22768:2006, a DSC curve is recorded while increasing the temperature in a predetermined temperature range, and the peak top (inflection point) of the DSC differential curve is taken as the glass transition temperature. Specifically, it can be measured by the method described in Examples below.

(A) When the modified conjugated diene 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 nonexistent. . More specifically, when the copolymer is a butadiene-styrene copolymer, Kolthoff's method (method described in IM. KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946)) In a known method of decomposing a copolymer and analyzing the amount of polystyrene insoluble in methanol, the number of blocks in which 30 or more aromatic vinyl units are linked is preferably 5.0% based on the total amount of the copolymer. It is not more than 3.0% by mass, more preferably not more than 3.0% by mass.

<Modification reaction step>
In the modification reaction step, the conjugated diene polymer obtained by the method described above and a bonding group that reacts with the active end of the conjugated diene polymer and have affinity or binding reactivity to the filler are used. and a modifier having a predetermined functional group.
In this case, a modifier having a predetermined functional group that also has the effect of a binding group may be used. Moreover, it is preferable to carry out the modification reaction step immediately after the polymerization step. In that case, a modified conjugated diene polymer with a high modification rate tends to be obtained.

When a compound with a monofunctional or difunctional bonding group is used as a modifier, a linear terminal-modified diene polymer is obtained, and when a polyfunctional compound with a trifunctional or more bonding group is used, a branched modified diene polymer is obtained. A diene polymer is obtained.
Preferably, a monofunctional or polyfunctional compound containing at least one element selected from nitrogen, silicon, tin, phosphorus, oxygen, sulfur, and halogen is used as the modifier. Furthermore, an onium structure can be introduced into the modified conjugated diene polymer by adding and reacting a terminal modifier containing an onium generating agent. Furthermore, a modifier containing a plurality of functional groups containing these elements in a molecule, or a modifier containing a functional group containing a plurality of these elements can also be used.
The modifier preferably has little or no active hydrogen, such as hydroxyl groups, carboxyl groups, primary and secondary amino groups. Active hydrogen tends to deactivate the active end of the conjugated diene polymer.

<Specific description of modifier>
Examples of nitrogen-containing compounds include, but are not limited to, isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, nitrogen group-containing carbonyl compounds, nitrogen group-containing vinyl compounds, nitrogen group-containing epoxy compounds, etc. It will be done.
Examples of the silicon-containing compound include, but are not limited to, halogenated silicon compounds, epoxidized silicon compounds, vinylated silicon compounds, alkoxy silicon compounds, alkoxy silicon compounds containing a nitrogen-containing group, and the like.
Examples of the tin-containing compound include, but are not limited to, halogenated tin compounds, organic tin carboxylate compounds, and the like.
Examples of the phosphorus-containing compound include, but are not limited to, phosphite compounds, phosphino compounds, and the like.
Examples of the oxygen-containing compound include, but are not limited to, epoxy compounds, ether compounds, ester compounds, and the like.
Examples of the sulfur-containing compound include, but are not limited to, mercapto group derivatives, thiocarbonyl compounds, isothiocyanates, and the like.
Examples of the halogen-containing compound include, but are not limited to, the above-mentioned silicon halide compounds, tin halide compounds, and the like.
Onium-forming agents include protected amine compounds that can form primary or secondary amines (generating ammonium), protected phosphine compounds that can form hydrophosphine (generating phosphonium), hydroxyl groups, and thiols. Examples include compounds that can generate oxonium and sulfonium, and it is preferable to use terminal modifiers each having a functional group in its molecule for bonding the onium generator and the modified conjugated diene polymer.
Examples of the functional group for bonding the modified conjugated diene polymer include carbonyl groups (ketones, esters, etc.), unsaturated groups such as vinyl groups, epoxy groups, halogenated silicon groups, alkoxy silicon groups, and the like.

The modifier preferably has a nitrogen-containing functional group, and the nitrogen-containing functional group is preferably an amine compound that does not have active hydrogen. For example, a tertiary amine compound, the above active hydrogen is protected by a protecting group. Examples include substituted protected amine compounds and imine compounds represented by the general formula -N=C.

Isocyanate compounds of nitrogen-containing compounds that are modifiers include, but are not limited to, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, polymeric Examples include diphenylmethane diisocyanate (C-MDI), phenyl isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, butyl isocyanate, 1,3,5-benzene triisocyanate, and the like.

Examples of isocyanuric acid derivatives include, but are not limited to, 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate, 1,3,5-tris(3-triethoxysilylpropyl) ) isocyanurate, 1,3,5-tri(oxirane-2-yl)-1,3,5-triazinane-2,4,6-trione, 1,3,5-tris(isocyanatomethyl)-1, Examples include 3,5-triazinane-2,4,6-trione, 1,3,5-trivinyl-1,3,5-triazinane-2,4,6-trione, and the like.

Examples of nitrogen group-containing carbonyl compounds 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-pyridylketone, methyl-4-pyridylketone, propyl-2-pyridylketone, di-4-pyridylketone, 2-benzoylpyridine, N,N,N ',N'-tetramethylurea, N,N-dimethyl-N',N'-diphenylurea, N,N-methyl diethylcarbamate, N,N-diethylacetamide, N,N-dimethyl-N',N '-dimethylaminoacetamide, N,N-dimethylpicolinic acid amide, N,N-dimethylisonicotinic acid amide, and the like.

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

Examples of the nitrogen group-containing epoxy compound include, but are not limited to, hydrocarbon compounds containing an epoxy group bonded to an amino group, and may further have an epoxy group bonded to an ether group. For example, it is represented by general formula (1).

In the formula (1), R is at least one selected from a divalent or higher hydrocarbon group, oxygen such as ether, epoxy, ketone, sulfur such as thioether, thioketone, nitrogen such as tertiary amino group, imino group, etc. It is a divalent or higher organic group having one type of polar group.
The divalent or higher-valent hydrocarbon group is a saturated or unsaturated hydrocarbon group that may be linear, branched, or cyclic, and includes an alkylene group, an alkenylene group, a phenylene group, and the like. Preferably, the number of carbon atoms is 1 to 20. Specific examples include 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 hydrocarbon groups 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, and in that case, the N bonded to R ³ and R may be directly bonded. Good too.
In the 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 and R ² are defined in the same manner as R ¹ and R ² in the formula (1), and R ¹ and R ² may be different from each other.

The nitrogen group-containing epoxy compound used as a modifier preferably has an epoxy group-containing hydrocarbon group, more preferably a glycidyl group-containing hydrocarbon group.
Examples of the epoxy group-containing hydrocarbon group bonded to the amino group or 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, a diglycidylamino group, and a glycidoxy group, respectively, and is represented by the following general formula (3).

In the above formula (3), R is defined in the same manner as R in the above 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, and in that case, it may be in a form in which N bonded to R ⁶ and R are directly bonded. .
In 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 used as a modifier is most preferably a compound having one or more diglycidylamino groups and one or more glycidoxy groups in the molecule.
The nitrogen group-containing epoxy compound used as a modifier is not limited to the following, but includes, 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-xylene diamine, 4,4-methylene-bis(N,N-diglycidylaniline), 1,4-bis(N,N-diglycidylamino)cyclohexane, N,N,N',N'-tetraglycidyl-p-phenylenediamine, 4,4'-bis(diglycidylamino)benzophenone, 4-(4-glycidylpiperazinyl)-(N,N-diglycidyl)aniline , 2-[2-(N,N-diglycidylamino)ethyl]-1-glycidylpyrrolidine, N,N-diglycidylaniline, 4,4'-diglycidyl-dibenzylmethylamine, N,N-diglycidylaniline , N,N-diglycidyl orthotoluidine, N,N-diglycidylaminomethylcyclohexane, and the like.
Among these, particularly preferred are N,N-diglycidyl-4-glycidoxyaniline and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane.

Examples of the halogenated silicon 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, 3-glycidoxypropylmethyl Examples include diethoxysilane and epoxy-modified silicone.

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

Examples of the alkoxy silicon compound containing a nitrogen-containing group as a modifying agent include, but are not limited to, 3-dimethylaminopropyltrimethoxysilane, 3-dimethylaminopropylmethyldimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 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)propylmethyldi Ethoxysilane, 3-(3-trimethylsilyl-1-hexahydropyrimidinyl)propyltrimethoxysilane, 3-dimethylamino-2-(dimethylaminomethyl)propyltrimethoxysilane, Bis(3-dimethoxymethylsilylpropyl)-N- Methylamine, bis(3-trimethoxysilylpropyl)-N-methylamine, bis(3-triethoxysilylpropyl)methylamine, tris(trimethoxysilyl)amine, tris(3-trimethoxysilylpropyl)amine, N , N,N',N'-tetra(3-trimethoxysilylpropyl)ethylenediamine, 3-isocyanatopropyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 2,2-dimethoxy-1-(3-trimethoxy silylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-( 4-trimethoxysilylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy- 1-phenyl-1-aza-2-silacyclopentane, 2,2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-methyl-1-aza-2- silacyclopentane, 2,2-dimethoxy-8-(4-methylpiperazinyl)methyl-1,6-dioxa-2-silacyclooctane, 2,2-dimethoxy-8-(N,N-diethylamino)methyl -1,6-dioxa-2-silacyclooctane and the like.

Examples of protected amine compounds that can form a primary or secondary amine that is a modifier and which have an unsaturated bond and a protected amine in the molecule include, but are not limited to, 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)aminophenyl]-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, compounds having an alkoxysilane and a protected amine in the molecule include, but are not limited to, N, 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-trimethylsilyl-1-piperazino)propyltriethoxysilane, 3-(3-triethylsilyl-1-imidazolidinyl)propylmethyldiethoxysilane, 3-(3-trimethylsilyl-1-hexahydropyrimidinyl)propyltrimethoxy Silane, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza- 2-Silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1 -Aza-2-silacyclopentane, 2,2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, 2,2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2 , 2-dimethoxy-1-methyl-1-aza-2-silacyclopentane and the like.

Examples of tin halide compounds that are modifiers include, but are not limited to, tetrachlorotin, tetrabromtin, trichlorobutyltin, trichlorooctyltin, dibromdimethyltin, 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 organic tin carboxylate compounds as modifiers include, but are not limited to, ethyltin tristearate, butyltin trioctanoate, butyltin trisstearate, butyltin trilaurate, and dibutyltin bisoctanoate. Examples include et.

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

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

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

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

The modifier preferably has a silicon-containing functional group, and the silicon-containing functional group preferably has an alkoxysilyl group or a silanol group.
For example, the alkoxysilyl group of the modifier reacts with the active end of the conjugated diene polymer, dissociating the alkoxylithium, and causing the bond between the end of the conjugated diene polymer chain and the silicon of the modifier residue. tend to form. The value obtained by subtracting the number of SiORs reduced by the reaction from the total number of SiORs that one molecule of the modifier has is the number of alkoxysilyl groups that the modifier residue has. Further, the azasilacycle group possessed by the modifier forms a >N-Li bond and a bond between the terminal of the conjugated diene polymer and the silicon of the modifier residue. Note that >N—Li bonds tend to easily become >NH and LiOH due to water and the like during finishing. Furthermore, in the modifier, unreacted remaining alkoxysilyl groups tend to easily become silanol (Si--OH groups) due to water during finishing.

In the modification reaction step, when one silicon atom is reacted with a compound having three alkoxy groups, that is, when one mole of trialkoxysilane group is reacted with three moles of the active end of the conjugated diene polymer. , reaction with up to 2 moles of the conjugated diene polymer occurs, but 1 mole of the alkoxy group tends to remain unreacted. This is confirmed from the fact that 1 mole of the conjugated diene polymer did not react and remained as an unreacted polymer. Incidentally, by reacting a large amount of alkoxy groups, it tends to be possible to suppress large changes in polymer viscosity due to condensation reactions 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 temperature as the polymerization temperature of the conjugated diene polymer, particularly preferably a temperature at which no heating is performed after polymerization. The temperature is more preferably 0°C or more and 120°C or less, and even more preferably 50°C or more and 100°C or less.
The reaction time in the modification reaction step is preferably 10 seconds or more, more preferably 30 seconds or more.
Mixing in the modification reaction step may be performed by mechanical stirring, stirring using a static mixer, or the like.
When the polymerization step is continuous, it is preferable that the reaction step is also continuous.
The reactor used in the modification reaction step is, for example, a tank type or a tube type with a stirrer. The modifier may be diluted with an inert solvent and fed continuously to the reactor. When the polymerization process is a batch process, the modification reaction process may be carried out by charging the modifier into the polymerization reactor or by transferring it to another reactor.

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

In 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 a group having 1 to 20 carbon atoms. R ¹⁹ and R ²² each independently represent an alkylene group having 1 to 20 carbon atoms, and R ²¹ represents an alkyl group or trialkylsilyl group having 1 to 20 carbon atoms.
m represents an integer of 1 to 3, and p represents 1 or 2.
When a plurality of R ¹² to R ²² , m, and p are each independent.
i represents an integer from 0 to 6, j represents an integer from 0 to 6, k represents an integer from 0 to 6, and (i+j+k) represents an integer from 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 oxygen atom, nitrogen atom, silicon atom, sulfur atom, and phosphorus atom, and contains active hydrogen. Represents an organic group that does not have
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 end of the conjugated diene polymer. The organic groups include hydroxyl groups (-OH), secondary amino groups (>NH), primary amino groups (-NH ₂ ), and sulfhydryl groups (-SH), which do not have active hydrogen-containing functional groups. It is the basis. Note that if (i+j+k) is 1, A may be omitted.

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

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

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

In 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 when multiple B ⁴ exist, each independently There is.

In 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 when multiple B ⁵ exist, each independently There is.
This tends to make it possible to obtain a modified conjugated diene polymer having better performance than that of the present embodiment.

Modifiers of the formula (VI) with (i+j+k) of 1 to 2 are not limited to the following (including those that overlap with the above-mentioned modifiers), 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-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl] Methylamine (4 functional), bis(3-triethoxysilylpropyl)ethylamine (4 functional), 1-(3-triethoxysilylpropyl)-2,2-diethoxy-1-aza-2-silacyclopentane (4 functional), 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 (4 (3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-methylamine (trifunctional).

Hereinafter, as a polyfunctional compound, when (i+j+k) is 3 or more, and when A is represented by formula (II) in the above formula (VI), the modifier is not limited to the following, but for example, Tris(3-trimethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, bis[3-( 2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)amine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]amine, tris(3-ethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]amine, bis[ 3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)amine, tris[3-(2,2-diethoxy-1-aza-2-sila) cyclopentane)propyl]amine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2- silacyclopentane)propyl]-1,3-propanediamine, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1, 3-propanediamine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis[3-( 2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1- sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl] -[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis[3-(2,2-dimethoxy-1-aza-2-) silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tris[ 3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3 -Propanediamine, Tetrakis(3-triethoxysilylpropyl)-1,3-propanediamine, Tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane) ) propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propane diamine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-1,3-propanediamine, tetrakis[3-(2,2 -diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2) -azacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3 -(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane) )propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tris[3-( 2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine , tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-1,3-bisaminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3- Bisaminomethylcyclohexane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tetrakis[3 -(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl- 1-Sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclo pentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis[3-(2,2-dimethoxy- 1-Aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3 -bisaminomethylcyclohexane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclo) pentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis(3-triethoxysilylpropyl)-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy) -1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2- silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-1 ,3-propanediamine, tetrakis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy -1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis[ 3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-aza cyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl) -1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis(3-trimethoxysilylpropyl)-1,6-hexamethylenediamine, pentakis(3-trimethoxysilylpropyl) -Diethylenetriamine.

In the formula (VI), when A is represented by the formula (III), the modifier is not limited to the following, but for example, tris(3-trimethoxysilylpropyl)-methyl-1,3 -Propanediamine, bis(2-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propanediamine, bis[3- (2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tris(3-triethoxysilylpropyl)-methyl- 1,3-propanediamine, bis(2-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propanediamine, bis [3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-methyl-1,3-propanediamine, N ¹ ,N ^1' -(propane -1,3-diyl)bis(N ¹ -methyl-N ³ ,N ³ -bis(3-(trimethoxysilyl)propyl)-1,3-propanediamine), N ¹ -(3-(bis(3) -(trimethoxysilyl)propyl)amino)propyl) -N ¹ -methyl-N ³ -(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl) -N ³ -(3-(trimethoxy Examples include silyl)propyl)-1,3-propanediamine.

In formula (VI), the modifier when A is represented by formula (IV) is not limited to the following, but for example, tetrakis[3-(2,2-dimethoxy-1-aza-2 -silacyclopentane)propyl]silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)silane, tris[3-(2, 2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]silane, bis(3-trimethoxysilyl) propyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, (3-trimethoxysilyl)-[3-(1-methoxy-2-trimethylsilyl-1- sila-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis[3-(1-methoxy-2-trimethylsilyl-1-sila) -2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris(3-trimethoxysilylpropyl)-[3-(2,2 -dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl ]-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl ]-bis(3-trimethoxysilylpropyl)silane, bis(3-trimethoxysilylpropyl)-bis[3-(1-methoxy-2-methyl-1-sila-2-azacyclopentane)propyl]silane Can be mentioned.

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

In the formula (VI), examples of A representing an organic group having an oxygen atom and no active hydrogen include (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 (octafunctional).

In the formula (VI), A represents an organic group having a phosphorus atom and having no active hydrogen, but is not limited to the following, 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- Examples include 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. As a result, it tends to be a modifier that is easy to obtain, and when the (A) modified conjugated diene polymer is used as a vulcanizate, it tends to have better wear resistance and low hysteresis loss performance. It is in.
Such modifiers include, but are not limited to, the following, for example, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl] Amine, Tris(3-trimethoxysilylpropyl)amine, Tris(3-triethoxysilylpropyl)amine, Tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-) silacyclopentane)propyl]-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-tri methoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, Bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trismethoxysilylpropyl)-methyl-1,3-propanediamine is mentioned.

In the formula (VI), A more preferably represents formula (II) or formula (III), k represents 0, and in formula (II) or formula (III), a represents an integer of 2 to 10. represent. This tends to provide better wear resistance and low hysteresis loss performance when vulcanized.
Examples of such modifiers include, but are not limited to, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis (3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, N ¹ -(3-(bis(3-(trimethoxysilyl) )propyl)amino)propyl) ^-N1 -methyl- ^N3- (3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N3-( ^3- (trimethoxysilyl)propyl)- 1,3-propanediamine is mentioned.

The amount of the compound represented by formula (VI) as a modifier can be adjusted so that the number of moles of the conjugated diene polymer to the number of moles of the modifier is reacted in a desired stoichiometric ratio. , thereby achieving the desired degree of branching.
The specific number of moles of the conjugated diene polymer, that is, the number of moles of the polymerization initiator, is preferably 1.0 times or more, more preferably 2.0 times or more, relative to the number of moles of the modifier. It is preferable. In this case, in formula (VI), the number of functional groups ((m-1)×i+p×j+k) of the modifier is preferably an integer of 1 to 10, more preferably an integer of 2 to 10.

<Hydrogenation process>
(A) The modified conjugated diene polymer may be one in which the conjugated diene moiety is hydrogenated. The method of hydrogenating the conjugated diene moiety is not particularly limited, and any known method can be used.
A suitable hydrogenation method includes a hydrogenation method in which gaseous hydrogen is blown into the polymer solution in the presence of a catalyst.
As a catalyst, for example, a heterogeneous catalyst such as a catalyst in which a noble metal is supported on a porous inorganic substance; a catalyst in which a salt such as nickel or cobalt is solubilized and reacted with an organoaluminium, etc., or a metallocene such as titanocene is used. Examples include homogeneous catalysts such as catalysts. Among these, titanocene catalysts are preferred from the viewpoint of being able to select mild hydrogenation conditions. Further, hydrogenation of aromatic groups can be carried out by using a supported noble metal catalyst.
Specific examples of hydrogenation catalysts include, but are not limited to, the following: (1) Supported heterogeneous catalysts in which metals such as Ni, Pt, Pd, and Ru are supported on carbon, silica, alumina, diatomaceous earth, etc. (2) A so-called Ziegler type hydrogenation catalyst using an organic acid salt such as Ni, Co, Fe, or Cr or a transition metal salt such as an acetylacetone salt and a reducing agent such as an organic aluminum, (3) Ti , Ru, Rh, Zr, and other so-called organometallic complexes. Further, as a hydrogenation catalyst, for example, Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-37970, Japanese Patent Publication No. 1-53851, Also mentioned are known hydrogenation catalysts described in Hei 2-9041 and JP-A-8-109219. Preferred hydrogenation catalysts include reaction mixtures of titanocene compounds and reducing organometallic compounds.

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

<Addition of rubber stabilizer and extender oil>
(A) It is preferable to add a rubber stabilizer to the modified conjugated diene polymer from the viewpoint of preventing gel formation after polymerization and from the viewpoint of improving stability during processing. The stabilizer for rubber is not limited to the following, and any known stabilizer can be used, such as 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl-3 Antioxidants such as -(4'-hydroxy-3',5'-di-tert-butylphenol)propinate and 2-methyl-4,6-bis[(octylthio)methyl]phenol are preferred.
In order to further improve the processability of the modified conjugated diene copolymer (A), an extender oil can be added to the modified conjugated diene copolymer (A), if necessary.
Methods for adding the extender oil to the modified conjugated diene polymer include, but are not limited to, the following methods: adding the extender oil to the polymer solution and mixing to form an oil extended copolymer solution, which is then desolvated. A method of doing so is preferred. Examples of the extender oil include aroma oil, naphthenic oil, paraffin oil, and the like. Among these, from the viewpoint of environmental safety, oil bleed prevention and wet grip properties, aromatic alternative oils containing 3% by mass or less of polycyclic aromatic (PCA) components according to the IP346 method are preferred. As aroma substitute oils, TDAE (Treated Distillate Aromatic Extracts) and MES (Mild Extraction Solvate) shown in Kautschuk Gummi Kunststoffe 52 (12) 799 (1999) are used. ), as well as RAE (Residual Aromatic Extracts). The amount of extension oil added is not particularly limited, but is preferably 10 parts by mass or more and 60 parts by mass or less, more preferably 20 parts by mass or more and 37.5 parts by mass or less, per 100 parts by mass of (A) modified conjugated diene polymer. preferable.

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

((B) Tackifying resin)
The modified conjugated diene polymer composition of this embodiment contains (B) a tackifying resin.
(B) The tackifying resin is a resin commonly used for the purpose of imparting the following properties.
a) Adding tackiness b) Adjusting the Tg of the composition (adjusting the peak position of tan δ)
c) Adding rigidity

(B) Tackifying resins include, but are not limited to, coumaron-indene resins, C5 resins, C9 resins, C5-C9 resins, dicyclopentane resins, terpene resins, and terpene/phenol resins. , rosin, modified rosin, alkylphenol resin, alkylphenol formaldehyde resin, styrene-alphamethylstyrene resin, and the like.
C5 resin, C9 resin, and C5-C9 resin are petroleum-based resins. C5 resin is a resin made from a C5 fraction or its purified components, C9 resin is a resin made from a C9 fraction or its purified components, and C5-C9 resin is a resin made from a C5 fraction or its purified components and a C9 fraction or its purified components. It is a copolymer resin made from a mixture with purified components.
Each resin may exhibit only one of the above-mentioned properties, or may exhibit two or more of the above-mentioned properties.

Further, the solubility parameter (SP value) of the tackifying resin (B) is preferably in the range of 7.5 to 9.5. (A) The SP value of a modified conjugated diene polymer varies depending on the amount of styrene, which is a comonomer component, and the ratio of the amount of vinyl 1,4 bonds and 1,2 bonds in butadiene, which is also a comonomer component. , the SP value is approximately 8.5. It is known that the closer the SP value difference (ΔSP) is, the more compatible they become, and the farther apart they are, the more incompatible they become. However, if the SP value of (B) the tackifier resin is within the above range, (B) tackiness Even if the tackifier resin and (A) modified conjugated diene polymer are made compatibilized, partially compatibilized, or incompatible, the tackifier resin (B) can be finely dispersed to a microscopic degree, and the (A) modified conjugated diene polymer composition No peeling occurs when .

Note that the following are widely known as specific trade names of the tackifying resin (B).
(1) Kumaron-indene resin Kumaron V-120 manufactured by Nikuri Kagaku Co., Ltd.
Manufactured by Rutgers Chemicals, NOBARES C150, C160
(2) C5 resin Quinton A100 manufactured by Nippon Zeon Co., Ltd.
Manufactured by Tonen Chemical Co., Ltd., ESCOREZ1102
(3) C9 resin manufactured by Nippon Petrochemical Co., Ltd., Neopolymer L90, 140, 170S
(4) C5-C9 resin resin manufactured by ExxonMobil Chemical Company, ECR213
Quinton G100B manufactured by Nippon Zeon Co., Ltd.
(5) Dicyclopentane resin Alcon M90 manufactured by Arakawa Chemical Co., Ltd.
Alcon M135 manufactured by Arakawa Chemical Co., Ltd.
Idemitsu Kosan Co., Ltd., Imarb P140
Manufactured by Nippon Zeon Co., Ltd., product name: Quinton 1100, 1105
Manufactured by Maruzen Petrochemical Co., Ltd., Marukaretz M M-890A
(6) Terpene resin/terpene/phenol resin Manufactured by Yasuhara Chemical Co., Ltd., YS Polyster T100, T115, T145, T160
Manufactured by Yasuhara Chemical Co., Ltd., Clearon P125, P150
Manufactured by Yasuhara Chemical Co., Ltd., YS resin PX-1250, TO125
Sylvares TP115 manufactured by Arizona Chemical Co., Ltd.
(7) Rosin/modified rosin manufactured by Irec Co., Ltd., Hyrosin S
Harima Chemical Industry Co., Ltd., Haritac AQ-90A
(8) Alkylphenol resin manufactured by SI GROUP, R7510PJ
(9) Alkylphenol/formaldehyde resin manufactured by Sumitomo Bakelite Co., Ltd., Sumilite Resin PR-13349, PR-12686
Made by Nippon Shokubai Co., Ltd., SP1068
Manufactured by BASF, Koresin
(10) Styrene-alpha methylstyrene resin Neopolymer 170S manufactured by Nippon Petrochemical Co., Ltd.
Arizona Chemicals Sylvares SA85, SA140
Total Petrochemicals Norsolene W120

In addition, when these (B) tackifying resins are blended into ordinary modified conjugated diene polymers, in exchange for the effects of a) to c) above, the hysteresis loss becomes worse than when they are not blended, and as a result, the tire As a result, fuel efficiency performance deteriorates. Note that when the normal conjugated diene polymer is replaced with (A) the modified conjugated diene polymer that constitutes the modified conjugated diene polymer composition of the present embodiment described above, (B) the tackifying resin is blended. However, the function of reducing hysteresis loss can be achieved sufficiently. Although this mechanism has not yet been identified, the present inventor assumes the following two mechanisms.

Estimation mechanism 1):
It is presumed that the poor dispersibility of the tackifying resin (B) itself in the modified conjugated diene polymer composition is a contributing factor to the deterioration of hysteresis loss. (A) The modified conjugated diene polymer improves the dispersibility of the silica filler and exhibits the function of reducing hysteresis loss, but it also has the same function as (B) the dispersibility of the tackifying resin. By doing so, it is estimated that the hysteresis loss is sufficiently reduced even if the tackifying resin (B) is blended.

Estimation mechanism 2):
It is presumed that the tackifying resin (B) exerts its tackiness on the silica filler, resulting in deterioration of the dispersibility of the silica filler. In contrast, by replacing the known conjugated diene polymer with the above-mentioned (A) modified conjugated diene polymer, the dispersion ability of the modified conjugated diene polymer (A) for the silica filler can be improved by (B) It is presumed that the adhesive strength is superior to that of the tackifying resin, and as a result, the hysteresis loss is sufficiently reduced even when the tackifying resin (B) is blended.

[Modified conjugated diene polymer composition]
The modified conjugated diene polymer composition of the present embodiment contains 2 to 30 parts by mass of the tackifier resin, which is the component (B), per 100 parts by mass of the modified conjugated diene polymer, which is the component (A).
The amount of the tackifying resin (B) component is preferably 5 to 20 parts by weight, more preferably 5 to 10 parts by weight.
The reason why component (B) is required to be 2 parts by mass or more is because more than that is required to express the function as a tackifying resin, whereas the component (B) is required to be 30 parts by mass or less because the modified conjugated diene polymer This is because the hysteresis loss reduction effect can be fully exhibited.

(rubber-like polymer)
The modified conjugated diene polymer composition of the present embodiment may contain other polymers than (A) the modified conjugated diene polymer and (B) the tackifying resin.
Examples of polymers other than the other polymers include rubbery polymers (hereinafter simply referred to as "rubberlike polymers") and resinous polymers.
Rubbery polymers include, but are not limited to, conjugated diene polymers such as polybutadiene or hydrogenated products thereof, random copolymers of conjugated diene monomers and vinyl aromatic monomers, or hydrogenated products thereof. Examples include block copolymers of conjugated diene monomers and vinyl aromatic monomers or hydrogenated products thereof, non-diene polymers, and natural rubber. Specific rubber-like polymers include, but 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. Examples include copolymers or hydrogenated products thereof, styrenic elastomers such as styrene-isoprene block copolymers or hydrogenated products thereof, acrylonitrile-butadiene rubber or hydrogenated products thereof.
The non-diene polymers 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. elastomers, butyl rubber, brominated butyl rubber, acrylic rubber, fluororubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α,β-unsaturated nitrile-acrylic acid ester-conjugated diene copolymer rubber, urethane rubber, polysulfide rubber can be mentioned.
Examples of the natural rubber include, but are not limited to, smoked sheets RSS No. 3 to 5, SMR, and epoxidized natural rubber.

When the modified conjugated diene polymer composition of the present embodiment is mixed with other polymers other than the above-mentioned components (A) and (B), the mixing method is as follows: Various methods may be used, such as a method of mixing a solution with a solution of another polymer, and a method of mechanically mixing a modified conjugated diene polymer and another polymer.
The other polymer may be a modified rubber added 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 rubber-like polymer, its weight average molecular weight is preferably from 2,000 to 2,000,000, and from 5,000 to 1 ,500,000 or less. Furthermore, a low molecular weight rubbery polymer, a 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 this embodiment contains the modified conjugated diene polymer composition of this embodiment described above and other components.
In this case, from the viewpoint of processability, the content of the modified conjugated diene polymer composition is preferably 10% by mass or more, more preferably 30% by mass or more, and more preferably 50% by mass or more. is even more preferable.

[Rubber composition]
The rubber composition of this embodiment contains 100 parts by mass of a rubbery polymer containing 10% by mass or more of the modified conjugated diene polymer composition of this embodiment described above, and 5 to 150 parts by mass of a filler.
The content ratio (mass ratio) of the modified conjugated diene polymer composition to other rubbery polymers is 10/90 or more and 100/0 as (modified conjugated diene polymer composition/other rubbery polymer). The following are 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 rubbery polymer component preferably contains 10 parts by mass or more and 100 parts by mass or less, more preferably 10 parts by mass or more and 100 parts by mass or less of the modified conjugated diene polymer composition based on the total amount (100 parts by mass) of the rubbery polymer component. contains 20 parts by mass or more and 90 parts by mass or less, more preferably 50 parts by mass or more and 80 parts by mass or less.
When the content ratio of (modified conjugated diene polymer composition/other rubbery polymer) is within the above range, when it is made into a vulcanizate, it has an excellent balance between low hysteresis loss property and wet skid resistance, Abrasion resistance and fracture strength are also satisfactory.

The modified conjugated diene polymer composition of this embodiment is suitably used as a vulcanizate.
Examples of the vulcanizate include tires, hoses, shoe soles, anti-vibration rubber, automobile parts, and anti-vibration rubber, as well as rubbers for reinforcing resins such as impact-resistant polystyrene and ABS resin.
In particular, the modified conjugated diene polymer composition is suitably used in a tread rubber composition for tires. For example, the vulcanizate may include the modified conjugated diene polymer composition of the present embodiment, an inorganic filler such as a silica-based inorganic filler or carbon black, and the modified conjugated diene polymer of the present embodiment, if necessary. A modified conjugated diene polymer composition is obtained by kneading it with other rubbery polymers, silane coupling agents, rubber softeners, vulcanizing agents, vulcanization accelerators, vulcanization aids, etc., and then heating. It can be obtained by vulcanization.

As mentioned above, the rubber composition of this embodiment contains 100 parts by mass of a rubbery polymer containing 10% by mass or more of the modified conjugated diene copolymer composition of this embodiment, and 5 to 150 parts by mass of a filler. include.
Further, it is preferable that the filler includes a silica-based inorganic filler.
Rubber compositions tend to have better processability when made into vulcanizates by dispersing silica-based inorganic fillers, and when made into vulcanizates, they have low hysteresis loss properties and wet skid resistance. They tend to have better balance, fracture strength, and wear resistance.
Also when the rubber composition of this embodiment is used for vulcanized rubber applications such as tires, automobile parts such as anti-vibration rubber, and shoes, it is preferable that the rubber composition contains a silica-based inorganic filler.

Examples of fillers include, but are not limited to, silica-based inorganic fillers, carbon black, metal oxides, and metal hydroxides. Among these, silica-based inorganic fillers are preferred. 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, based on 100 parts by mass of the rubber component containing the modified conjugated diene polymer composition. It is preferably at most 20 parts by mass and at most 100 parts by mass.
The content of the filler is 5.0 parts by mass or more from the viewpoint of exhibiting the effect of adding the filler, and the filler is sufficiently dispersed to improve the processability and mechanical strength of the rubber composition to a practically sufficient level. From the viewpoint of achieving the desired content, the amount is 150 parts by mass or less.

The silica-based inorganic filler is not particularly limited and any known one can be used, but solid particles containing SiO ₂ or Si ₃ Al as a constituent unit are preferred, and SiO ₂ or Si ₃ Al is the main constituent unit. 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, and more preferably 80% by mass or more.
Specific silica-based inorganic fillers include, but are not limited to, inorganic fibrous substances such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber. . Also included are silica-based inorganic fillers whose surfaces have been made hydrophobic, and mixtures of silica-based inorganic fillers and inorganic fillers other than silica-based fillers. Among these, silica and glass fiber are preferred, and silica is more preferred, from the viewpoint of strength, abrasion resistance, and the like. Examples of silica include dry silica, wet silica, and synthetic silicate silica. Among these silicas, wet silica is preferred from the viewpoint of improving fracture properties and having an excellent balance of wet skid resistance.

From the viewpoint of obtaining practically good wear resistance and fracture characteristics of the rubber composition, the nitrogen adsorption specific surface area of the silica-based inorganic filler determined by the BET adsorption method should be 100 m ² /g or more and 300 m ² /g or less. is preferable, and more preferably 170 m ² /g or more and 250 m ² /g or less. In addition, if necessary, a silica-based inorganic filler with a relatively small specific surface area (for example, a specific surface area of 200 m ² /g or less) and a silica-based inorganic filler with a relatively large specific surface area (for example, a specific surface area of 200 m ² /g or more) may be used. (inorganic filler) can be used in combination.
In this embodiment, especially when using a silica-based inorganic filler with a relatively large specific surface area (for example, 200 m ² /g or more), (A) the modified conjugated diene-based polymer improves the dispersibility of silica. , is particularly effective in improving wear resistance, and tends to be able to achieve a high balance between good fracture properties and low hysteresis loss properties.

The content of the silica-based inorganic filler in the rubber composition may be 5.0 parts by mass or more and 150 parts by mass based on 100 parts by mass of the rubbery polymer component containing the modified conjugated diene polymer composition. It is preferably 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 in order to achieve the effect of adding the inorganic filler, and the inorganic filler is sufficiently dispersed to improve the processability and mechanical strength of the composition. From the viewpoint of ensuring sufficient performance, the amount is preferably 150 parts by mass or less.

Examples of carbon black include, but are not limited to, carbon blacks of various classes such as SRF, FEF, HAF, ISAF, and SAF. Among these, carbon black having a nitrogen adsorption specific surface area of 50 m ² /g or more and a dibutyl phthalate (DBP) oil absorption of 80 mL/100 g or less is preferred.
The content of carbon black is preferably 0.5 parts by mass or more and 100 parts by mass or less, and 3.0 parts by mass or more and 100 parts by mass, based on 100 parts by mass of the rubbery polymer component containing the modified conjugated diene polymer composition. Parts or less are more preferable, and 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 achieving the performance required for applications such as tires such as dry grip performance and conductivity, and from the viewpoint of dispersibility, it is preferably 100 parts by mass. The following is preferable.

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

The rubber composition may also include a silane coupling agent.
The silane coupling agent has the function of closely interacting the rubber component and the inorganic filler, and has groups that have affinity or binding properties for the rubber component and the silica-based inorganic filler. , a compound having a sulfur bonding moiety and an alkoxysilyl group or silanol group moiety in one molecule is preferred. Examples of such compounds include bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, bis-[2-(triethoxysilyl)-propyl]-tetrasulfide, and bis-[2-(triethoxysilyl)-propyl]-disulfide. silyl)-ethyl]-tetrasulfide.
The content of the silane coupling agent is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 0.5 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the above-mentioned inorganic filler. More preferably 0 parts by mass or more and 15 parts by mass or less. When the content of the silane coupling agent is within the above range, the effect of the addition of the silane coupling agent tends to be more pronounced.

The rubber composition of this embodiment may contain a rubber softener from the viewpoint of improving its 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, which are used to soften, increase volume, and improve processability of rubber, are a mixture of aromatic rings, naphthenic rings, and paraffin chains. Those in which the number of carbon atoms in the paraffin chain accounts for 50% by mass or more of all carbons are called paraffinic, and those in which the number of carbon atoms in the naphthene ring accounts for 30% by mass or more and 45% by mass or less of all carbons are called naphthenic and aromatic carbons. Carbons that account for more than 30% by mass of all carbons are called aromatic carbons.
(A) When the modified conjugated diene polymer is a copolymer of a conjugated diene compound and a vinyl aromatic compound, the rubber softener to be used should have an appropriate aromatic content. This is preferable because it tends to be familiar.
The content of the rubber softener is preferably 0 parts by mass or more and 100 parts by mass or less, and 10 parts by mass or more and 90 parts by mass, based on 100 parts by mass of the rubbery polymer component containing the modified conjugated diene polymer (A). Parts or less are more preferable, and 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 based on 100 parts by mass of the rubbery polymer component, bleed-out tends to be suppressed and stickiness on the surface of the rubber composition is suppressed.

The modified conjugated diene polymer composition of this embodiment and other rubber-like polymers, silica-based inorganic fillers, carbon black and other fillers, silane coupling agents, rubber softeners, and other additives are mixed. Methods include, but are not limited to, melting using common mixing machines such as open rolls, Banbury mixers, kneaders, single-screw extruders, twin-screw extruders, and multi-screw extruders. Examples include a kneading method and a method of dissolving and mixing each component and then removing the solvent by heating.
Among these, melt-kneading methods using rolls, Banbury mixers, kneaders, and extruders are preferred from the viewpoint of productivity and good kneading properties. Moreover, either a method of kneading the rubber component, other fillers, silane coupling agents, and additives at once, or a method of mixing them in a plurality of batches can be applied.

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

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

The rubber composition of the present embodiment may include other softeners and fillers other than those mentioned above, a heat stabilizer, an antistatic agent, a weather stabilizer, an anti-aging agent, within a range that does not impair the purpose of the present embodiment. Various additives such as colorants and lubricants may also be used.
As other softeners, known softeners can be used. Specific examples of other fillers include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. As the above-mentioned heat stabilizer, antistatic agent, weather stabilizer, anti-aging agent, colorant, and lubricant, known materials can be used.

(Method for producing rubber composition)
The method for producing a rubber composition of the present embodiment includes (A) 100 parts by mass of a modified conjugated diene polymer, (B) 2 to 30 parts by mass of a tackifying resin, and (C) 5 to 30 parts by mass of a silica-containing filler. 150 parts by mass. This manufacturing method is a preferred embodiment of the method for preparing the composition.
The filler (C) contains silica as an essential component, and may contain optional components in addition to silica as an essential component.
(C) As the silica constituting the filler, silica that is generally used as a filler can be used, but from the viewpoint of rolling resistance and impact resilience of the rubber elastic body obtained from the rubber composition, primary particles Synthetic silicic acid having a diameter of 50 nm or less is preferred.
The content ratio of silica constituting the filler (C) is 10 to 120 parts by mass per 100 parts by mass of the rubbery polymer component containing (A) the modified conjugated diene polymer and (B) the tackifying resin. parts, more preferably 20 to 100 parts by mass.
(C) If the content ratio of the filler is too low or too low, the balance between hardness and rolling resistance may deteriorate in the rubber elastic body obtained from the rubber composition in either case. .

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

In the rubber composition, in addition to fillers containing (A) a modified conjugated diene polymer, (B) a tackifying resin (B), and (C) silica as a filler, which are essential components, Depending on the situation, the above-mentioned optional components may be included.
Such a rubber composition is produced using, for example, a plastomill, together with a filler containing the essential components (A) a modified conjugated diene polymer, (B) a tackifying resin, and (C) silica as a filler. It can be manufactured by mixing and kneading arbitrary components as needed.

(A) The modified conjugated diene polymer acts to increase the dispersibility of silica, while (B) the tackifying resin acts to decrease the dispersibility of silica. Since the dispersibility of silica can be controlled by the ratio, the dispersibility of silica can be made good from the viewpoint of the balance between rolling resistance and impact resilience in 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 impact resilience can be obtained.

The method for producing a rubber composition includes kneading (A) 100 parts by mass of a modified conjugated diene polymer and (C) 5 to 150 parts by mass of the filler containing silica, and then kneading the obtained kneaded product; It is preferable to knead with 2 to 30 parts by mass of the tackifying resin (B).
Specifically, first, (A) a modified conjugated diene polymer, (C) a filler, and optional components are kneaded, and then (B) a tackifying resin is added to the kneaded product. Knead.
After kneading (A) the modified conjugated diene polymer and (C) the filler, the resulting kneaded product and (B) the tackifying resin are kneaded to disperse silica in the rubber composition. Since the properties can be further improved, the resulting rubber elastic body has even lower rolling resistance and excellent impact resilience.

The method for producing the rubber composition is limited to a method of kneading (A) a modified conjugated diene polymer and (C) a filler, and then kneading the obtained kneaded product and (B) a tackifying resin. For example, even if it is a method of kneading optional components together with the essential components (A) modified conjugated diene polymer, (B) tackifier resin, and (C) filler, if necessary. good.
Regarding the method of mixing the modified conjugated diene polymer composition and other rubber-like polymers, silica-based inorganic fillers, carbon black and other fillers, silane coupling agents, rubber softeners, and other additives, Examples include, but are not limited to, melt-kneading methods using common mixing machines such as open rolls, Banbury mixers, kneaders, single-screw extruders, twin-screw extruders, and multi-screw extruders; An example of this method is to heat and remove the solvent after dissolving and mixing the components. Among these, melt-kneading methods using rolls, Banbury mixers, kneaders, and extruders are preferred from the viewpoint of productivity and good kneading properties.

〔tire〕
A rubber composition containing the modified conjugated diene polymer composition of this embodiment is suitably used as a rubber composition for tires.
The rubber composition for tires of this embodiment is not limited to the following, but includes, for example, various tires such as fuel-saving tires, all-season tires, high-performance tires, and studless tires: treads, carcass, sidewalls, and bead parts. It can be used for various parts of tires such as. In particular, the rubber composition for tires containing the modified conjugated diene polymer composition of the present embodiment has an excellent balance between low hysteresis loss and wet skid resistance and wear resistance when made into a vulcanized product. Therefore, it is more suitable for use in treads of fuel-saving tires and high-performance tires.

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

<Purification of 1,3-butadiene>
1,3-butadiene used for polymerization of a modified conjugated diene polymer was purified by the following steps.
(Washing process)
It was operated under conditions of a circulating water amount of 1 m ³ /hr and a renewal (make-up) water amount of 0.1 m ³ /hr.
1,3-butadiene and washing water are mixed using a static mixer (static mixer N60 series manufactured by Noritake Company Limited), and then transferred to a decanter, where the 1,3-butadiene is mixed. The phase and aqueous phase were separated.
The operation was carried out under 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 removal tank, mixed with steam and heated to 89°C, and at the same time, 1,3-butadiene is removed from the aqueous phase at a total pressure of 0.01 MPaG. separated.

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

(Polymerization inhibitor removal process)
Further, a 10% by mass aqueous solution of caustic soda was mixed with the 1,3-butadiene after the above (oxygen removal step using an oxygen scavenger) using a packed column with a Pall ring at a circulating flow rate of 1 m ³ /hr. , liquid-liquid extraction was performed, and the mixture 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 addition, in the polymerization inhibitor removal process, operation was performed under 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 in the other decanter to make the 1,3-butadiene concentration 50% by mass, and the mixture was supplied to the dehydration tower.
The azeotropic mixture of 1,3-butadiene and water distilled from the top of the dehydration tower is cooled and condensed, then transferred to a decanter, where it is separated into a 1,3-butadiene phase and an aqueous phase. was separated.
The aqueous phase was removed, and the 1,3-butadiene phase was returned to the inlet of the dehydration tower to carry out the dehydration tower process continuously.
A mixed solution of dehydrated 1,3-butadiene and hexane was taken out from the bottom of the dehydration tower.

(Adsorption process)
The mixed solution of 1,3-butadiene and hexane was passed through a 500L desiccant dryer containing activated alumina (vertical cylindrical tank manufactured by Hitachi, Ltd.) to adsorb trace amounts of residual impurities in the 1,3-butadiene. This was removed to obtain purified 1,3-butadiene.

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

<Purification of normal hexane>
Normal hexane used for polymerization of a modified conjugated diene polymer was purified through the following steps.
Purified normal hexane was obtained by filling a tubular reactor with 2000 g of Molecular Sieve 13-X (manufactured by Union Showa) and circulating crude normal hexane at room temperature for 24 hours.

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

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

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

<(Physical property 3) Molecular weight>
Using a modified conjugated diene polymer as a sample, an RI detector (Tosoh Co., Ltd., product name "HLC-8320GPC") was used. The weight average molecular weight (Mw ₁ ), number average molecular weight (Mn ₁ ), and molecular weight distribution were determined based on the calibration curve obtained using standard polystyrene. (Mw ₁ /Mn ₁ ), the peak top molecular weight (Mp ₁ ) of the modified conjugated diene polymer, and the ratio of the modified conjugated diene polymer having a molecular weight of 2 million to 5 million were determined.
THF (tetrahydrofuran) was used as the eluent.
Three columns, manufactured by Tosoh Corporation under the trade name "TSKgel SuperMultiporeHZ-H", were connected, and a guard column manufactured by Tosoh Corporation under the trade name "TSKguardcolumn SuperMP (HZ)-H" was connected in front of the column.
10 mg of a sample for measurement was dissolved in 20 mL of THF to obtain a measurement solution, and 10 μL of the measurement solution was injected into a GPC measuring device, and measurement was performed under the conditions of an oven temperature of 40° C. and a THF flow rate of 0.35 mL/min.
The peak top molecular weight (Mp ₁ ) was determined as follows.
In the GPC curve obtained by measurement, the peak detected as the highest molecular weight component was selected. For 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 above ratio of molecular weight of 2 million to 5 million was determined as the ratio of the mass of molecular weight of 2 million to 5 million to the total mass of the polymer.

<(Physical property 4) Polymer Mooney viscosity>
Using a modified conjugated diene polymer as a sample, Mooney viscosity was measured using a Mooney viscometer (trade name "VR1132" manufactured by Ueshima Seisakusho Co., Ltd.) in accordance with JIS K6300 and 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 and defined as Mooney viscosity (ML ₍₁₊₄₎ ).

<(Physical property 5) Glass transition temperature (Tg)>
Using a modified conjugated diene polymer as a sample, temperature was measured from -100°C to 20°C/min under helium flow of 50 mL/min using a differential scanning calorimeter "DSC3200S" manufactured by Mac Science in accordance with ISO 22768:2006. A DSC curve was recorded while the temperature was raised at , and the peak top (inflection point) of the DSC differential curve was taken as the glass transition temperature.
Note that Tg is a value measured for a sample before adding oil.

<(Physical property 6) Modification rate relative to the total amount of conjugated diene polymer>
Using a modified conjugated diene polymer as a measurement sample, a chromatogram was measured by applying the property of adsorption of modified polymer components to a GPC column using silica gel as a packing material.
Measure the adsorption amount on the silica column from the difference between the chromatogram measured on a polystyrene column and the chromatogram measured on a silica column of the measurement sample solution containing the measurement sample and 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 prepare a measurement sample solution.
GPC measurement conditions using polystyrene column:
Using Tosoh Corporation's product name "HLC-8320GPC," 10 μL of the measurement sample solution was injected into the device using THF as the eluent, and the column oven temperature was 40°C and the THF flow rate was 0.35 mL/min. , chromatograms were obtained using an RI detector. Three columns, manufactured by Tosoh Corporation under the trade name "TSKgel SuperMultiporeHZ-H", were connected, and a guard column manufactured by Tosoh Corporation under the trade name "TSKguardcolumn SuperMP (HZ)-H" was connected in front of the column.
GPC measurement conditions using silica column:
Using Tosoh Corporation's product name "HLC-8320GPC," 50 μL of the measurement sample solution was injected into the device using THF as the eluent, and the column oven temperature was 40°C and the THF flow rate was 0.5 mL/min. , chromatograms were obtained using an RI detector. Columns with the product name "Zorbax PSM-1000S", "PSM-300S", and "PSM-60S" are connected and used, and the product name "DIOL 4.6 x 12.5 mm 5 micron" is used as a guard column in the preceding stage. Connected and used.
How to calculate denaturation rate:
The peak area of the sample is P1, the peak area of the standard polystyrene is P2, the total peak area of the chromatogram using the silica column is 100, the total peak area of the chromatogram using the polystyrene column is 100, and the peak area of the sample is P1. The modification rate (mass %) was determined from the following formula, with the peak area of P3 as P3 and the peak area of standard polystyrene as P4.
Denaturation rate (mass%) = [1-(P2×P3)/(P1×P4)]×100
(In the above formula, P1+P2=P3+P4=100.)

<(Physical property 7) Modification rate of low molecular weight components>
According to the measurement of (physical property 3) above, based on the calibration curve obtained using standard polystyrene, weight average molecular weight (Mw ₂ ), number average molecular weight (Mn ₂ ), and molecular weight distribution (Mw ₂ /Mn ₂ ), The peak top molecular weight (Mp ₂ ) of the modified conjugated diene polymer was measured.
However, if there are multiple peak tops, the peak top molecular weight (Mp ₂ ) is the molecular weight of the peak top with the minimum molecular weight, and by dividing this peak top molecular weight (Mp ₂ ) by 2, The height of the chart at the obtained molecular weight (molecular weight of the low molecular weight component) was defined as L1.
The height at the molecular weight (molecular weight of low molecular weight component) obtained by dividing the peak top molecular weight (Mp ₂ ) by 2 of 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.

[Degree of modification of low molecular weight components]
The degree of modification of the low molecular weight component was calculated by dividing the modification rate (FL) of the low molecular weight component (Property 7) by the modification rate (FT) relative to the total amount of the conjugated diene polymer (Property 6).
Denaturation degree of low molecular weight component = (FL/FT) x 100

<(Property 8) Contraction factor (g')>
Using a modified conjugated diene polymer as a sample, a chromatogram was measured using a GPC-light scattering measuring device equipped with a viscosity detector that connected three columns with polystyrene gel as a packing material, and the solution viscosity and light were measured. Molecular weight was determined based on scattering method.
The eluent used was a mixed solution of tetrahydrofuran and triethylamine (THF in TEA: prepared by mixing 5 mL of triethylamine with 1 L of tetrahydrofuran).
The columns were used by connecting a guard column: "TSKguardcolumn HHR-H" manufactured by Tosoh Corporation, and columns: "TSKgel G6000HHR", "TSKgel G5000HHR", and "TSKgel G4000HHR" manufactured by Tosoh Corporation.
A GPC-light scattering measuring device 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.
10 mg of a sample for measurement was dissolved in 20 mL of THF to prepare a sample solution for measurement, and 200 μL of the sample solution for measurement was injected into a GPC measuring device for measurement.
The intrinsic viscosity and molecular weight of the obtained measurement sample solution are expressed as the constants (K, α) in the relational expression between intrinsic viscosity and molecular weight ([η]=KMα ([η]: intrinsic viscosity, M: molecular weight), logK= -3.883, α=0.771, and the standard intrinsic viscosity created by inputting the range of molecular weight M from 1000 to 20000000 [η] For the relationship between ₀ and molecular weight M, the intrinsic viscosity at each molecular weight M [η] is the relationship between the intrinsic viscosity [η] and the standard intrinsic viscosity [η] ₀ , and [η]/[η] ₀ is calculated for each molecular weight M, and the average value thereof is used as the shrinkage factor (g').
Note that g' is an average value when M is 1 million or more and 2 million or less.

<(Physical properties 9) Silicon content>
The silicon content in the modified conjugated diene polymer was measured using an ICP mass spectrometer (Agilent 7700s manufactured by Agilent Technologies).

<(Physical property 10) Nitrogen content>
The nitrogen content in the modified conjugated diene 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 10L, the ratio of internal height (L) to diameter (D) (L/D) is 4.0, and it has an inlet at the bottom and an outlet at the top, and is equipped with a stirrer and temperature control unit. A tank-type pressure vessel with a jacket was used as a polymerization reactor.
Water was removed in advance, and 1,3-butadiene was mixed at 19.4 g/min, styrene at 10.6 g/min, and n-hexane at 150.0 g/min. This mixture contained 9 ppm of arenes, 12 ppm of acetylenes, and 1 ppm of amines. Total impurities were 22 ppm.
In a static mixer installed in the middle of the piping that supplies this mixed solution to the inlet of the reaction group, n-butyllithium for inactivating residual impurities was added at a rate of 0.104 mmol/min and mixed, and then added to the bottom of the reaction group. Supplied continuously. Furthermore, 2,2-bis(2-oxolanyl)propane was added as a polar substance at a rate of 0.0231 g/min, and n-butyllithium (a polymerization initiator containing no nitrogen atom) was added as a polymerization initiator at a rate of 0.27 mmol/min. The mixture was fed to the bottom of the polymerization reactor where it was vigorously mixed with a stirrer at a speed of 100 to continue the polymerization reaction continuously. The temperature was controlled so that the temperature of the polymerization solution at the top outlet of the reactor was 75°C.
Next, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl] was added to the polymer solution flowing out from the outlet of the reactor as a modifier. Amine (abbreviated as "A" in the table) was continuously added at a rate of 0.046 mmol/min, and the polymer solution to which the modifier was added was mixed by passing through a static mixer to undergo a modification reaction.
An antioxidant (BHT) was continuously added to the modified polymer solution at a rate of 0.055 g/min (n-hexane solution) at a rate of 0.2 g per 100 g of polymer to complete the coupling reaction. . Simultaneously with the antioxidant, 37.5 g of oil (JOMO Process NC140, manufactured by JX Nippon Oil & Energy Corporation) was continuously added to 100 g of the polymer, and mixed using a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (sample A-1). Table 1 shows the physical properties of sample A-1.

[(Production Example 2) Modified conjugated diene 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 polymer (Sample A-2). Table 1 shows the physical properties of sample A-2.

[(Production Example 3) Modified conjugated diene 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 n-butyllithium as a polymerization initiator was changed to 0.34 mmol/min, the amount of polar substance added was changed to 0.0289 g/min, and the modifier was changed to 0.34 mmol/min. The amount added was 0.044 mmol/min. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene polymer (Sample A-3). Table 1 shows the physical properties of sample A-3.

[(Production Example 4) Modified conjugated diene polymer (Sample A-4)]
The modifier was N,N,N',N'-tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine ("D" in the table). ), the amount of polar substance added was set to 0.0266 g/min, and the amount of modifier added was set to 0.035 mmol/min. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene polymer (Sample A-4). Table 1 shows the physical properties of sample A-4.

[(Production Example 5) Modified conjugated diene polymer (Sample A-5)]
The amount of n-butyllithium added as a polymerization initiator was 0.161 mmol/min, the amount of polar substance added was 0.015 g/min, and the modifier was N-(3-trimethoxysilylpropyl)-2,2- Dimethoxy-1-aza-2-silacyclopentane (abbreviated as "E" in the table) was used, and the amount of the modifier added was 0.04 mmol/min. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene polymer (Sample A-5). Table 1 shows the physical properties of sample A-5.

[(Production Example 6) Modified conjugated diene polymer (Sample A-6)]
The amount of n-butyllithium added as a polymerization initiator was 0.086 mmol/min, the amount of polar substance added was 0.0081 g/min, and the modifier was N-3-trimethoxysilylpropyltriazole (in the table, "F ), and the amount of the modifier added was set to 0.044 mmol/min. The total amount of impurities was 23 ppm. Other conditions were the same as in (Production Example 1) to obtain a modified conjugated diene polymer (Sample A-6). Table 1 shows the physical properties of sample A-6.

[(Manufacturing Comparative Example 1) Modified conjugated diene polymer (Sample A-7)]
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. Further, the residence time of the 1,3-butadiene phase in the decanter in the polymerization inhibitor removal step was adjusted to 20 minutes.
In addition, a Pd (0.3%)/γ-Al ₂ O ₃ hydrogenation catalyst was obtained in the purification of styrene. A tubular reactor was filled with 2000 g of the obtained catalyst, and while the temperature of the catalyst was maintained at 80° C., the purified styrene was circulated for 4 hours. In the purification of n-hexane, the same purification as in the example was carried out.
The mixture of 1,3-butadiene, styrene, and n-hexane contained 25 ppm of arenes, 20 ppm of acetylenes, and 9 ppm of amines. Total impurities were 55 ppm. A modified conjugated diene polymer (sample A-7) was obtained in the same manner as described above (Production Example 1) except that this was used. Table 1 shows the physical properties of sample A-7.

[(Manufacturing Comparative Example 2) Modified conjugated diene polymer (Sample A-8)]
The amount of modifier added was 0.021 mmol/min. Total impurities were 23 ppm. A modified conjugated diene polymer (Sample A-8) was obtained under the same conditions as described above (Production Example 1). Table 1 shows the physical properties of sample A-8.

[(Manufacturing Comparative Example 3) Modified conjugated diene polymer (Sample A-9)]
As a modifier, N,N-dimethyl-phenyldimethoxysilylpropylamine (abbreviated as "G" in the table) was continuously added at a rate of 0.032 mmol/min. Other conditions were the same as in (Comparative Production Example 1) to obtain a modified conjugated diene polymer (Sample A-9). Table 1 shows the physical properties of sample A-9.

[(Examples 1 to 11) and (Comparative Examples 1 to 4)]
Rubber compositions using modified conjugated diene polymers as raw materials were prepared according to the formulations shown in Table 2.
The specific names of the raw materials used for blending are as follows.

(A) Modified conjugated diene polymer: Samples A-1 to A-9 listed in Table 1
(B) Tackifying resin:
Sample B-1: Styrene-alpha methylstyrene resin
Manufactured by Arizona Chemicals
Sylvares SA140
Sample B-2: Dicyclopentane resin
Alcon M135 manufactured by Arakawa Chemical Co., Ltd.
Sample B-3: C9 resin Neopolymer 140 manufactured by Nippon Petrochemical Co., Ltd.
Sample B-4: Terpene phenol resin
Manufactured by Yasuhara Chemical Co., Ltd., YS Polyster T145
Silica: Evonik Degussa Ultrasil 7000G
Carbon black: Seast KH (N339) manufactured by Tokai Carbon Co., Ltd.
Silane coupling agent: Evonik Degussa Si75
S-RAE oil: Process NC140 manufactured by JX Nippon Oil & Energy Corporation
Zinc white: Uses general reagent ZnO Stearic acid: Uses general reagent Anti-aging agent: N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine)
Sulfur: Use a general reagent Vulcanization accelerator 1: Use a general reagent N-cyclohexyl-2-benzothiazyl sulfinamide Vulcanization accelerator 2: Use a general reagent diphenylguanidine

A rubber composition was obtained by kneading the above-mentioned materials by the following method.
Using a closed kneader (inner capacity 0.3 L) equipped with a temperature control device, the (A) modified conjugated diene polymer was mixed at a filling rate of 65% and a rotor rotation speed of 30 to 50 rpm for the first stage of kneading. (A-1 to A-9), (B) tackifier resin, silica, carbon black, silane coupling agent, S-RAE 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 an unvulcanized rubber composition.
Subsequently, an anti-aging agent, sulfur, vulcanization accelerator 1, and vulcanization accelerator 2 are added to the unvulcanized rubber composition, and after kneading in the closed kneading machine equipped with a temperature control device, it is put into a press molding machine. The mixture was heated and molded while being vulcanized to prepare a sheet with a thickness of 3 mm. A test piece of a predetermined size was punched out from the sheet to be used in the next viscoelasticity test.

(Evaluation) Viscoelasticity Evaluation The viscoelastic parameters of the rubber composition after vulcanization were measured in torsion mode using a viscoelasticity tester "ARES" manufactured by Rheometrics Scientific. Each measurement value was expressed as an index, with the result for the rubber composition of Comparative Example 1 set as 100. Tan δ, which was measured at 0° C. at a frequency of 10 Hz and a strain of 1%, was used as an index of wet grip property. The larger the value, the better the wet grip property. Further, tan δ measured at 50° C., frequency of 10 Hz, and strain of 3% was used as an index of fuel efficiency. The smaller the value, the better the fuel efficiency. The results are shown in Table 2.

As shown in Table 2, compared to the rubber compositions of Comparative Examples 1 to 4, the rubber compositions of Examples 1 to 11 had an excellent balance of wet grip properties and fuel efficiency when made into vulcanizates, and It was confirmed that a sufficient hysteresis loss reduction function can be achieved even when a sex-imparting resin is blended.

The modified conjugated diene polymer and rubber composition according to the present invention can be used industrially in fields such as tire treads, interior and exterior parts of automobiles, anti-vibration rubber, belts, footwear, foams, and various industrial products. There is sex.

Claims (15)

(A) the weight average molecular weight is 20×10 ⁴ or more and 300×10 ⁴ or less,
A modified conjugated diene polymer having a molecular weight distribution Mw/Mn of 1.6 or more and 4.0 or less,
The modification rate based on the total amount of the conjugated diene polymer is 50% by mass or more,
The modification rate of the component with a molecular weight that is 1/2 of the molecular weight of the peak top in the gel permeation chromatography (GPC) curve, or the molecular weight of the peak top with the minimum molecular weight when there are multiple peak tops, is the conjugated diene. The modification rate is 1/2 or more with respect to the total amount of the system polymer,
100 parts by mass of a modified conjugated diene polymer containing 3 ppm or more by mass of each of nitrogen and silicon;
(B) 2 to 30 parts by mass of tackifying resin;
A modified conjugated diene polymer composition containing. (A) The 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 polymer composition according to claim 1. (A) The 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 polymer composition according to claim 1. (B) The tackifying resin is coumaron-indene resin, C5 resin, C9 resin, C5-C9 resin, dicyclopentane resin, terpene resin, terpene/phenol resin, rosin, modified rosin, alkylphenol resin, alkylphenol/formaldehyde resin. The modified conjugated diene polymer composition according to any one of claims 1 to 3, which is at least one selected from the group consisting of , and styrene-alpha methylstyrene resin. (A) The 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 polymer composition according to claim 3 or 4. The molar ratio of nitrogen to silicon is 1.1 or more and less than 10.
The modified conjugated diene polymer composition according to any one of claims 1 to 5. The molar ratio of nitrogen to silicon is 0.1 or more and less than 0.9.
The modified conjugated diene polymer composition according to any one of claims 1 to 5. The glass transition temperature of the modified conjugated diene polymer (A) is -20°C or more and 0°C or less,
The modified conjugated diene polymer composition according to any one of claims 1 to 7. The modified conjugated diene polymer composition according to any one of claims 1 to 7, wherein the modified conjugated diene polymer (A) has a glass transition temperature of -50°C or more and less than -20°C. The modified conjugated diene polymer composition according to any one of claims 1 to 7, wherein the modified conjugated diene polymer (A) has a glass transition temperature of -70°C or more and less than -50°C. The modified conjugated diene polymer composition according to any one of claims 1 to 10, wherein the polymerization initiator residue of the modified conjugated diene polymer (A) does not contain a nitrogen atom. A polymer composition containing 10% by mass or more of the modified conjugated diene polymer composition according to any one of claims 1 to 11. 100 parts by mass of a rubbery polymer containing 10% by mass or more of the modified conjugated diene polymer composition according to any one of claims 1 to 11;
5 to 150 parts by mass of filler;
A rubber composition containing. A method for producing a rubber composition according to claim 13, comprising:
(A) 100 parts by mass of a modified conjugated diene polymer;
(B) 2 to 30 parts by mass of tackifying resin;
(C) 5 to 150 parts by mass of a filler containing silica;
A method for producing a rubber composition, which comprises kneading. After kneading 100 parts by mass of the modified conjugated diene polymer (A) and 5 to 150 parts by mass of the filler (C), the resulting kneaded product and 2 to 30 parts by mass of the tackifier resin (B) 15. The method for producing a rubber composition according to claim 14, wherein the rubber composition is kneaded.