阅读说明：本技术 改性共轭二烯系聚合物组合物、橡胶组合物以及橡胶组合物的制造方法 (Modified conjugated diene polymer composition, rubber composition, and method for producing rubber composition ) 是由 近藤正昭 于 2019-08-22 设计创作，主要内容包括：本发明提供改性共轭二烯系聚合物组合物、橡胶组合物以及橡胶组合物的制造方法,即使混配粘合性赋予树脂也表现出充分的磁滞损耗降低的功能。该改性共轭二烯系聚合物组合物含有：(A)改性共轭二烯系聚合物100质量份,该改性共轭二烯系聚合物是重均分子量为20×10<Sup>4</Sup>以上300×10<Sup>4</Sup>以下、分子量分布Mw/Mn为1.6以上4.0以下的改性共轭二烯系聚合物,相对于共轭二烯系聚合物的总量的改性率为50质量％以上,分子量为凝胶渗透色谱法(GPC)曲线中的峰顶(存在两个以上上述峰顶的情况下为分子量最小的峰顶)的分子量的1/2的成分的改性率是上述相对于共轭二烯系聚合物的总量的改性率的1/2以上；以及(B)粘合性赋予树脂2～30质量份。(The invention provides a modified conjugated diene polymer composition, a rubber composition and a method for producing the rubber composition, which can show a sufficient function of reducing hysteresis loss even if a resin with adhesiveness is added. The modified conjugated diene polymer composition comprises: (A) 100 parts by mass of a modified conjugated diene polymer having a weight-average molecular weight of 20X 10 4 300X 10 above 4 A modified conjugated diene polymer having a molecular weight distribution Mw/Mn of 1.6 to 4.0, wherein the modification ratio of the modified conjugated diene polymer to the total amount of the conjugated diene polymer is 50% by mass or more, and the modification ratio of the 1/2 component having a molecular weight of a peak top (a peak top having a minimum molecular weight when two or more peak tops are present) in a Gel Permeation Chromatography (GPC) curve is 1/2 or more of the modification ratio to the total amount of the conjugated diene polymer; and (B) 2 to 30 parts by mass of an adhesion imparting resin.)

1. A modified conjugated diene polymer composition comprising:

(A) 100 parts by mass of a modified conjugated diene polymer,

the modified conjugated diene polymer has a weight average molecular weight of 20X 10⁴300X 10 above⁴A modified conjugated diene polymer having a molecular weight distribution Mw/Mn of 1.6 to 4.0,

the modification ratio based on the total amount of the conjugated diene polymer is 50% by mass or more,

a modification ratio of a component of 1/2 having a molecular weight of a peak top in a GPC curve as gel permeation chromatography is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer, or in the case where two or more of the peak tops are present, a modification ratio of a component of 1/2 having a molecular weight of a peak top having the smallest molecular weight is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer; and

(B) 2 to 30 parts by mass of a tackiness-imparting resin.

2. The modified conjugated diene polymer composition according to claim 1, wherein the shrinkage factor g' of the modified conjugated diene polymer (A) by 3D-GPC is 0.86 to 1.0.

3. The modified conjugated diene polymer composition according to claim 1, wherein the shrinkage factor g' of the modified conjugated diene polymer (A) by 3D-GPC is 0.30 or more and less than 0.86.

4. The modified conjugated diene polymer composition according to any one of claims 1 to 3, wherein the adhesion-imparting resin (B) is at least one selected from the group consisting of coumarone-indene resin, C5 resin, C9 resin, C5-C9 resin, dicyclopentane resin, terpene-phenol resin, rosin, modified rosin, alkylphenol resin, alkylphenol-formaldehyde resin and styrene- α -methylstyrene resin.

5. The modified conjugated diene polymer composition according to claim 3 or 4, wherein the shrinkage factor g' of the modified conjugated diene polymer (A) by 3D-GPC is 0.30 to 0.70.

6. The modified conjugated diene polymer composition according to any one of claims 1 to 5, wherein,

(A) the modified conjugated diene polymer contains nitrogen and silicon in an amount of 3ppm by mass or more,

the molar ratio of nitrogen to silicon is 1.1 or more and less than 10.

7. The modified conjugated diene polymer composition according to any one of claims 1 to 5, wherein,

(A) the modified conjugated diene polymer contains nitrogen and silicon in an amount of 3ppm by mass or more,

the molar ratio of nitrogen to silicon is 0.1 or more and less than 0.9.

8. The modified conjugated diene polymer composition according to any one of claims 1 to 7, wherein the glass transition temperature of the modified conjugated diene polymer (A) is from-20 ℃ to 0 ℃.

9. The modified conjugated diene polymer composition according to any one of claims 1 to 7, wherein the glass transition temperature of the modified conjugated diene polymer (A) is-50 ℃ or higher and less than-20 ℃.

10. The modified conjugated diene polymer composition according to any one of claims 1 to 7, wherein the glass transition temperature of the modified conjugated diene polymer (A) is-70 ℃ or higher and less than-50 ℃.

11. 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.

12. A polymer composition comprising 10% by mass or more of the modified conjugated diene copolymer composition according to any one of claims 1 to 11.

13. A rubber composition comprising:

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 claims 1 to 11; and

5 to 150 parts by mass of a filler.

14. A method for producing a rubber composition according to claim 13, wherein 100 parts by mass of the modified conjugated diene polymer (A), 2 to 30 parts by mass of the adhesion-imparting resin (B), and 5 to 150 parts by mass of the silica-containing filler (C) are kneaded.

15. The method for producing a rubber composition according to claim 14, wherein 100 parts by mass of the modified conjugated diene polymer (A) and 5 to 150 parts by mass of the filler (C) are kneaded, and then the obtained kneaded product and the adhesion-imparting resin (B) are kneaded together by 2 to 30 parts by mass.

Technical Field

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

Background

In recent years, there has been an increasing demand for fuel economy in automobiles, and there has been a demand for improvement in materials used for automobile tires, particularly tire treads that come into contact with the ground, and there has been a demand for development of materials having low rolling resistance, that is, low hysteresis loss.

In addition, in order to reduce the weight of the tire, the thickness of the tread portion of the tire needs to be reduced, and a material having high wear resistance is also required.

On the other hand, materials used for tire treads are required to have excellent wet skid resistance and practically sufficient fracture characteristics from the viewpoint of safety.

As a material for meeting such a demand, there is a material containing a rubbery polymer and a reinforcing filler such as carbon black or silica.

For example, when a material containing silica is used, the balance between the hysteresis loss resistance and the wet skid resistance can be improved.

In addition, the following attempts were made: the modification of the terminal part of the molecule of the conjugated diene polymer having high mobility by introducing a functional group having affinity or reactivity with silica improves the dispersibility of silica in the material, and further reduces the mobility of the terminal part of the molecule of the rubbery polymer by bonding to silica particles, thereby reducing hysteresis loss.

For example, patent documents 1 and 2 propose modified conjugated diene polymers in which a cyclic aza-silacycle compound is functionalized by reacting with the active end of the polymer.

Further, patent document 3 proposes a modified conjugated diene polymer obtained by a coupling reaction of a polyfunctional silane compound with a polymer active end.

Further, as a rubber material for a tire, a conjugated diene polymer composition blended with various adhesion-imparting resins for imparting various properties has been proposed (for example, patent documents 4 to 8), and there is a demand for a composition capable of simultaneously exhibiting the above-mentioned low hysteresis loss factor and various properties based on the adhesion-imparting resins without any problem.

Disclosure of Invention

Problems to be solved by the invention

In a modified conjugated diene polymer having a functional group highly reactive with silica introduced into a molecular terminal of the conjugated diene polymer, the hysteresis loss is reduced by first dispersing silica particles and then reacting the silica particles on the surface thereof in a kneading step. However, when a resin is provided with adhesiveness by compounding, there are problems such as a decrease in density of the modified conjugated diene polymer and a decrease in hysteresis loss.

Accordingly, an object of the present invention is to provide a modified conjugated diene polymer composition which exhibits a function of sufficiently reducing hysteresis loss even when an adhesion-imparting resin is compounded.

Means for solving the problems

The present inventors have intensively studied to solve the above problems of the prior art and as a result, have found that the following modified conjugated diene polymer composition comprising at least a modified conjugated diene polymer and a tackifier resin can solve the above problems of the prior art, the present invention has been completed based on the finding that a modified conjugated diene polymer composition comprising a modified conjugated diene polymer obtained by introducing a functional group having affinity or reactivity with a filler into a molecule of a conjugated diene polymer, and a tackifier resin, wherein the modified conjugated diene polymer has a weight average molecular weight and a molecular weight distribution within specific ranges, in a molecular weight curve by GPC (gel permeation chromatography), the modification ratio of the component having a molecular weight of 1/2 with a molecular weight of a peak top is a predetermined value or more as compared with the modification ratio of the entire modified conjugated diene polymer.

Namely, the present invention is as follows.

[1]

A modified conjugated diene polymer composition comprising:

(A) 100 parts by mass of a modified conjugated diene polymer,

the modified conjugated diene polymer has a weight average molecular weight of 20X 10⁴300X 10 above⁴A modified conjugated diene polymer having a molecular weight distribution Mw/Mn of 1.6 to 4.0,

the modification ratio based on the total amount of the conjugated diene polymer is 50% by mass or more,

a modification ratio of the 1/2 component having a molecular weight of a peak top in a Gel Permeation Chromatography (GPC) curve is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer, or in the case where two or more peak tops are present, a modification ratio of the 1/2 component having a molecular weight of a peak top having the smallest molecular weight is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer; and

(B) 2 to 30 parts by mass of a tackifier resin.

[2]

The modified conjugated diene polymer composition according to [1], wherein the shrinkage factor (g') of the modified conjugated diene polymer (A) by 3D-GPC is 0.86 or more and 1.0 or less.

[3]

The modified conjugated diene polymer composition according to [1], wherein the shrinkage factor (g') of the modified conjugated diene polymer (A) by 3D-GPC is 0.30 or more and less than 0.86.

[4]

The modified conjugated diene polymer composition according to any one of the above [1] to [3], wherein the adhesion-imparting resin (B) is at least one selected from the group consisting of a coumarone-indene resin, a C5 resin, a C9 resin, a C5-C9 resin, a dicyclopentane resin, a terpene-phenol resin, a rosin, a modified rosin, an alkylphenol resin, an alkylphenol-formaldehyde resin and a styrene- α -methylstyrene resin.

[5]

The modified conjugated diene polymer composition according to [3] or [4], wherein the shrinkage factor (g') of the modified conjugated diene polymer (A) by 3D-GPC is 0.30 to 0.70.

[6]

The modified conjugated diene polymer composition according to any one of the above [1] to [5], wherein,

(A) the modified conjugated diene polymer contains nitrogen and silicon in an amount of 3ppm by mass or more,

the molar ratio of nitrogen to silicon is 1.1 or more and less than 10.

[7]

The modified conjugated diene polymer composition according to any one of the above [1] to [5], wherein,

(A) the modified conjugated diene polymer contains nitrogen and silicon in an amount of 3ppm by mass or more,

the molar ratio of nitrogen to silicon is 0.1 or more and less than 0.9.

[8]

The modified conjugated diene polymer composition according to any one of [1] to [7], wherein the glass transition temperature of the modified conjugated diene polymer (A) is from-20 ℃ to 0 ℃.

[9]

The modified conjugated diene polymer composition according to any one of the above [1] to [7], wherein the glass transition temperature of the modified conjugated diene polymer (A) is-50 ℃ or higher and less than-20 ℃.

[10]

The modified conjugated diene polymer composition according to any one of the above [1] to [7], wherein the glass transition temperature of the modified conjugated diene polymer (A) is-70 ℃ or higher and less than-50 ℃.

[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 comprising 10% by mass or more of the modified conjugated diene copolymer composition according to any one of [1] to [11 ].

[13]

A rubber composition comprising:

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 the above [1] to [11 ]; and

5 to 150 parts by mass of a filler.

[14]

A method for producing a rubber composition as described in [13], comprising kneading 100 parts by mass of the modified conjugated diene polymer (A), 2 to 30 parts by mass of the adhesion-imparting resin (B), and 5 to 150 parts by mass of the silica-containing filler (C).

[15]

The method for producing a rubber composition as described in [14], wherein 100 parts by mass of the modified conjugated diene polymer (A) is kneaded with 5 to 150 parts by mass of the filler (C), and the resulting kneaded product is kneaded with 2 to 30 parts by mass of the tackiness-imparting resin (B).

Effects of the invention

According to the present invention, a modified conjugated diene polymer composition can be provided which exhibits a function of sufficiently reducing hysteresis loss even when an adhesion-imparting resin is compounded.

Detailed Description

The mode for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail.

The following embodiments are illustrative of the present invention, and are not intended to limit the present invention to the following. The present invention can be suitably modified and implemented within the scope of the gist thereof.

[ modified conjugated diene Polymer composition ]

The modified conjugated diene polymer composition of the present embodiment contains:

(A) 100 parts by mass of a modified conjugated diene polymer,

the modified conjugated diene polymer has a weight average molecular weight of 20X 10⁴300X 10 above⁴A modified conjugated diene polymer having a molecular weight distribution Mw/Mn of 1.6 to 4.0,

the modification ratio based on the total amount of the conjugated diene polymer is 50% by mass or more,

a modification ratio of the 1/2 component having a molecular weight of a peak top in a Gel Permeation Chromatography (GPC) curve is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer, or in the case where two or more peak tops are present, a modification ratio of the 1/2 component having a molecular weight of a peak top having the smallest molecular weight is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer; and

(B) 2 to 30 parts by mass of a tackifier resin.

((A) modified conjugated diene Polymer)

The modified conjugated diene polymer (A) is obtained by polymerizing a monomer having a hydroxyl group,

weight average molecular weight of 20X 10⁴300X 10 above⁴In the following, the following description is given,

a molecular weight distribution Mw/Mn of 1.6 to 4.0,

the modification ratio of the conjugated diene polymer (A) is 50% by mass or more,

the modification ratio of the 1/2 component having a molecular weight of 1/2 (hereinafter, sometimes referred to as a low molecular weight component) having a molecular weight of a peak top (peak top having the smallest molecular weight when two or more of the peaks are present) in a Gel Permeation Chromatography (GPC) curve is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer.

< modification ratio >

The modified conjugated diene polymer (a) has a modification ratio 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.

Since the modification ratio is 50% by mass or more, the balance between the hysteresis loss factor and the wet skid resistance is more excellent after the production of a sulfide.

The modification ratio is a numerical value represented by mass% of the content of the polymer component having a specific functional group having affinity or bonding reactivity with the filler in the polymer molecule with respect to the total amount of the conjugated diene polymer.

The polymer component having a specific functional group having affinity or bonding reactivity with the filler in a polymer molecule is preferably a polymer having a functional group containing a nitrogen atom, a silicon atom, and an oxygen atom. More preferably, the modified conjugated diene polymer has the functional group at the terminal of the polymer. Examples thereof include a polymer having a functional group having a nitrogen atom bonded to the polymerization initiation terminal and/or a modified conjugated diene polymer having a functional group containing a nitrogen atom, a silicon atom and an oxygen atom at the terminal and modified with a functional group.

(A) The modification ratio of the modified conjugated diene polymer can be measured by a chromatography method capable of separating a modified component containing a functional group from an unmodified component. As a method of using this chromatography, there is a method of using a column for gel permeation chromatography using a polar substance such as silica capable of adsorbing a specific functional group as a packing material, and quantifying by using an internal standard of a non-adsorbed component for comparison.

More specifically, the modification ratio was calculated by calculating the difference between the chromatogram obtained by measuring a sample solution containing a measurement sample and low-molecular-weight internal standard polystyrene using a polystyrene gel column and the chromatogram obtained by measuring a sample solution using a silica-based column, and measuring the amount of adsorption on the silica column. The modification ratio can be measured by the method described in the examples described later.

(A) The modification ratio of the modified conjugated diene polymer can be controlled within the above numerical range by adjusting the polymerization conditions. (A) The modified conjugated diene polymer is produced by living anionic polymerization, and the modification group is formed by chemically bonding a modifier to the terminal end side of the living polymer, and the modification ratio can be changed by changing the amount of the modifier to be mixed. In addition, the reactivity of the modifier with the living polymer can be changed by the temperature condition or the stirring condition in the polymerization machine, and therefore, the control can be performed by utilizing these conditions.

< modification ratio of Low molecular weight component >

The present inventors have found that the modification ratio differs depending on the polymer in each molecular weight region by measuring the modification ratio in each molecular weight region in a molecular weight curve based on GPC.

Further, it was found that a modified conjugated diene polymer having a modification ratio of 1/2 (low molecular weight component) having a molecular weight of the peak top of the GPC curve of 1/2 or more of the modification ratio of the whole modified conjugated diene polymer is superior to a modified conjugated diene polymer having a modification ratio of heterogeneous, particularly 1/2 in which the modification ratio of the component in the low molecular weight region is lower than the modification ratio of the whole modified conjugated diene polymer.

The modified conjugated diene polymer (a) has a modification ratio of 1/2 or more, which is a component (low-molecular-weight component) having a molecular weight of 1/2 in the GPC curve with the peak top (the peak top of the peak when one peak is present, and the peak top having the lowest molecular weight when two or more peaks are present), to the total amount of the conjugated diene polymer (a) of 1/2 or more. The modification ratio is preferably 0.55 or more, more preferably 0.57 or more.

Thus, a modified conjugated diene polymer (a) can be obtained, which is excellent in processability, and particularly, a rubber composition in which the torque of a mixer works well at the time of kneading with a filler and the dispersibility of the filler is good in a shorter time than in the conventional case.

Further, when the modified conjugated diene polymer composition of the present embodiment is prepared as a vulcanized composition, the composition has excellent balance between low hysteresis loss characteristics and wet skid resistance, and excellent fracture characteristics and abrasion resistance, and particularly, the composition has an improved degree of freedom in designing a composition for obtaining a rubber composition having excellent fuel economy for tire use.

As described above, the present inventors have found that the modification ratio differs depending on the polymer in each molecular weight region, and in addition, the following mechanism is found as a torque transmission mode in kneading the polymer and the filler, thereby completing the present invention.

That is, first, when focusing attention on the modification ratio of the modified conjugated diene polymer with respect to the total amount of the conjugated diene polymer, when the mooney viscosity, the microstructure, the modifier used, the kneading conditions, and the like of the polymer are the same, the rate of increase in torque at the time of kneading with the filler is higher for a polymer having a high modification ratio (modification ratio of 50% or more) with respect to the total amount of the conjugated diene polymer than for a polymer having a low modification ratio, and on the other hand, the maximum value reached by the torque is higher, so that the time taken to reach the maximum value of the torque is substantially the same even if the modification ratio as a whole changes. That is, it is considered that the modification ratio of the whole polymer affects both the maximum value of the torque and the rate of rise of the torque, and as a result, even if the modification ratio of the whole polymer increases or decreases, the length of time until the maximum value of the torque is reached is not greatly affected.

On the other hand, when attention is paid to the modification ratio of the low-molecular-weight component, that is, the modification ratio of the component having a molecular weight of 1/2 having a molecular weight of the peak top, the lower the modification ratio of the low-molecular-weight component is, the lower the rate of increase in torque at the time of kneading the polymer and the filler is, as compared with the modification ratio with respect to the total amount of the conjugated diene polymer, and the higher the modification ratio of the low-molecular-weight component is, the faster the rate of increase in torque is, as compared with the modification ratio with respect to the total amount of the conjugated diene polymer.

As described above, the modification ratio with respect to the total amount of the conjugated diene polymer also affects the torque increase rate, but the torque increase rate is faster when the "modification ratio with respect to the total amount of the conjugated diene polymer" is high or low and the "modification ratio of the low molecular weight component" is high.

That is, according to the study of the present inventors, the influence of the height of the "modification ratio of the low-molecular-weight component" as compared with the "modification ratio with respect to the total amount of the conjugated diene-based polymer" on the torque increase rate is constant regardless of the "modification ratio with respect to the total amount of the conjugated diene-based polymer".

On the other hand, since the maximum value of the torque is determined depending on the modification ratio of the whole modified conjugated diene polymer, the maximum value of the torque is not changed depending on the modification ratio of the low-molecular-weight component, that is, the time taken to reach the maximum value of the torque becomes shorter as the modification ratio of the low-molecular-weight component is higher, regardless of the modification ratio of the low-molecular-weight component. Therefore, the time until the maximum value of the torque is reached can be controlled by the height of the modification ratio of the low-molecular-weight component compared with the modification ratio of the conjugated diene polymer, not by the modification ratio of the conjugated diene polymer with respect to the total amount of the conjugated diene polymer.

Specifically, by setting the modification ratio of the low-molecular weight component to a level of 1/2 or more based on the modification ratio of the total amount of the conjugated diene polymer, the processability is good, and particularly, the torque of the mixer during kneading with the filler acts well, and the dispersibility of the filler is good in a shorter time than in the conventional case. As a result, thermal deterioration occurring in the polymer during kneading can be minimized, and thermal deterioration is less likely to occur, whereby the effect of reducing the amount of the thermal stabilizer to be blended can be obtained.

Further, by setting the modification ratio of the low-molecular-weight component to 1/2 or more based on the modification ratio of the total amount of the conjugated diene polymer, the rubber composition having excellent balance between low hysteresis loss properties and wet skid resistance, and excellent fracture characteristics and abrasion resistance, particularly excellent fuel economy for tire use, can be obtained after the modified conjugated diene polymer (a) is made into a vulcanized composition.

In the case of producing a rubber composition for a tire, it is effective to use a modified conjugated diene polymer having a higher branching degree and/or a higher molecular weight in order to improve fuel economy, but on the other hand, there is a possibility that a problem in processing such as difficulty in kneading with a filler or the like occurs. In view of this problem, by adopting a technique for improving the processability of the modified conjugated diene polymer, even when the modified conjugated diene polymer (a) having a higher branching degree and/or a higher molecular weight is used, the occurrence of problems in the kneading step and the like can be prevented, and as a result, a composition more suitable for a tire can be easily produced.

In view of this, in the modified conjugated diene polymer (a), the modification ratio of the component having a molecular weight of 1/2 at the peak top in the GPC curve is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer.

(A) The modified conjugated diene polymer can be obtained by a polymerization method in which the termination of the growth reaction or chain transfer rarely occurs, and therefore can be obtained by ultrahigh-purity, low-temperature polymerization, and a monomer conversion rate of less than 99 mass% of the monomers and the solvent introduced into the polymerization reactor.

The modification ratio of each molecular weight component can be measured by chromatography which can separate a modified component containing a functional group from an unmodified component. As a method of using this chromatography, there is a method of using a column for gel permeation chromatography using a polar substance such as silica capable of adsorbing a specific functional group as a packing material, and quantifying by using an internal standard of a non-adsorbed component for comparison.

More specifically, the modification ratio of each molecular weight component can be obtained as follows: the modification ratio of each molecular weight component was obtained by measuring the adsorption amount on a silica column from the difference between each molecular weight component in a chromatogram obtained by measuring a sample solution containing a sample for measurement and low-molecular-weight internal standard polystyrene with a polystyrene gel column and a chromatogram obtained by measuring with a silica column. The modification ratio can be measured by the method described in the examples below.

In order to adjust the modification ratio of the component 1/2 having a molecular weight of the peak top in the GPC curve to 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer, it is effective to increase the purity of the monomer and the solvent introduced into the reactor and to reduce the amount of the terminal deactivated during polymerization as described above.

< weight average molecular weight >

(A) The weight-average molecular weight of the modified conjugated diene polymer was 20X 10⁴300X 10 above⁴Hereinafter, preferably 30 × 10⁴Above 270X 10⁴Hereinafter, more preferably 40 × 10⁴Above 250X 10⁴Hereinafter, more preferably more than 50X 10⁴And is 250X 10⁴The following.

By making the weight average molecular weight 20X 10⁴300X 10 above⁴Hereinafter, the vulcanizate obtained is excellent in the balance between the hysteresis loss resistance and the wet skid resistance and in the wear resistance.

In addition, the weight average molecular weight was 300X 10⁴Hereinafter, the filler is excellent in dispersibility in producing the sulfide, and excellent fracture characteristics can be obtained. In addition, the molecular weight is higher than 50X 10⁴In the case of the method, since the amount of the polymerization initiator to be used is reduced, the effect of the termination of the growth reaction and the chain transfer on the modification ratio of the 1/2 component having a molecular weight of the peak top in the GPC curve is increased, and therefore, if ultrahigh purity and low-temperature polymerization of the monomer and the solvent introduced into the polymerization reactor and less than 99 mass% of the monomer are not achievedThe modified conjugated diene polymer having a desired modification ratio cannot be obtained at a high conversion ratio.

(A) The weight average molecular weights of the modified conjugated diene polymer and polybutadiene described below can be measured by the methods described in the examples described below.

< molecular weight distribution Mw/Mn >

The modified conjugated diene polymer (A) has a molecular weight distribution Mw/Mn, expressed as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), of 1.6 to 4.0. The modified conjugated diene polymer (a) having a molecular weight distribution within this range tends to have better processability in producing a vulcanizate than a polymer having the same molecular weight and modification ratio. The Mw/Mn is preferably 1.8 to 3.0, more preferably 1.9 to 2.5.

The modified conjugated diene polymer (a) having such a molecular weight distribution is preferably obtained by continuous polymerization.

For the molecular weight distribution, the molecular weight curve based on GPC is preferably in the shape of one peak (single peak), or in the case of two or more peaks, a trapezoidal or continuous peak type. The continuous peak type is a shape in which the height of the lowermost part between 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 more excellent processability in producing a sulfide.

The modified conjugated diene polymer (a) preferably contains 0.3 to 20 mass% of a modified conjugated diene polymer having a molecular weight of 200 to 500 ten thousand (hereinafter also referred to as "specific high molecular weight component"). Thereby being capable of exhibiting more excellent toughness and wear resistance after sulfide formation.

The content of the specific high-molecular weight component is more preferably 1.0 mass% to 18 mass%, still more preferably 1.1 mass% to 18 mass%, and still more preferably 2.0 mass% to 15 mass%.

In order to obtain the modified conjugated diene polymer (a) having the content of the specific high molecular weight component in such a range, for example, the amount of the organic monolithium compound as a polymerization initiator to be described later may be adjusted, and in the polymerization step to be described later, a method having a residence time distribution, that is, a method of widening a time distribution of a growth reaction, may be preferably selected in either of a continuous type and a batch type.

Specific methods in the continuous formula include: a method of using a tank-type reactor with a stirrer as a back-mixed flow reactor in a form of intensive mixing with a stirrer, preferably as a complete mixing type reactor; a method of recycling a part in a tubular reactor; a method in which the position of the filler as the polymerization initiator is provided with an inlet in the middle of the polymerization vessel in addition to the inlet of the monomer or the vicinity thereof; and a method of using a combination of a vessel type and a tube type reactor.

These methods are methods capable of increasing the residence time distribution and converting a polymer component having a long residence time into a high molecular weight component.

Further, as a specific method in the batch system, for example, a method of continuously or intermittently feeding the polymerization initiator from the time of initiating polymerization to the time of the middle of polymerization, or a method of continuously or intermittently feeding the polymerization initiator at the time of initiating polymerization and/or the time of the middle of polymerization can be cited.

This method is a method in which a polymer polymerized from the initiation of polymerization when a polymerization initiator is initially charged forms a high molecular weight component and a molecular weight difference is generated between the polymer whose polymerization is initiated later. More specifically, if the amount of the polymerization initiator corresponding to the target molecular weight is continuously charged into the monomer so that the conversion is, for example, between 0% and 95%, a polymer having an expanded molecular weight distribution tends to be produced.

By using the above method, the active ratio of the active terminal of the conjugated diene polymer before the reaction step tends to be high, and a modified conjugated diene polymer having a high coupling ratio after coupling, that is, a high modification ratio tends to be obtained. Among these methods, a tank-type reactor with a stirrer is more preferably used as a method of using the reactor as a back-mixed flow reactor in a form of intensive mixing with a stirrer.

The "molecular weight" in the present specification is a molecular weight in terms of standard polystyrene obtained by GPC (gel permeation chromatography).

The number average molecular weight, weight average molecular weight, and content of molecular weight distribution can be measured by the methods described in the examples below.

< shrinkage factor >

Among the modified conjugated diene polymers (a) used in the modified conjugated diene polymer composition of the present embodiment, preferred examples thereof include modified conjugated diene polymers having a shrinkage factor (g') of 0.86 or more and 1.0 or less as measured by 3D-GPC.

When the shrinkage factor (g') of the modified conjugated diene polymer (a) is in the above range, the strength at high temperature tends to be excellent.

The shrinkage factor (g ') is an index of the branched structure of the modified conjugated diene copolymer (a), and the modified conjugated diene polymer having a shrinkage factor (g') of 0.86 to 1.0 is a modified conjugated diene polymer having 3 or less branches in 1 molecule of the modified conjugated diene polymer. In this case, the shrinkage factor (g') is more preferably 0.88 to 0.99, and still more preferably 0.90 to 0.98.

In order to obtain the modified conjugated diene copolymer (a), for example, the following methods are effective: the modifier having 3 or less reaction sites with the active end is added in a molar amount of at least one third relative to the total molar amount of the polymerization initiator to obtain the (a) modified conjugated diene copolymer having 3 or less branches.

Among the modified conjugated diene polymers (A), preferred is one having a shrinkage factor (g') of 0.30 or more and less than 0.86 as measured by 3D-GPC.

The modified conjugated diene polymer (a) can greatly reduce the viscosity of a composition to which a filler is added, and can provide extremely excellent processability.

The shrinkage factor (g ') is an index of the branched structure of the modified conjugated diene copolymer (a), and the modified conjugated diene polymer (a) having a shrinkage factor (g') of 0.30 or more and less than 0.86 is a modified conjugated diene polymer having 4 or more branches in the number of branches in 1 molecule of the modified conjugated diene polymer.

In order to obtain the modified conjugated diene copolymer (a), for example, the following methods are effective: the modifier having 4 or more reaction sites with the living active terminal is added in a molar amount of one-fourth or less based on the total molar amount of the polymerization initiator to obtain the (a) modified conjugated diene copolymer having 4 or more branches.

In the modified conjugated diene polymer (A), the shrinkage factor (g') as measured by 3D-GPC is more preferably 0.30 to 0.70.

The modified conjugated diene polymer (a) can significantly reduce the viscosity of a composition to which a filler is added, and can improve the processability.

The shrinkage factor (g ') is an index of the branched structure of the modified conjugated diene copolymer (a), and is a modified conjugated diene polymer (a) having a shrinkage factor (g') of 0.30 to 0.70 inclusive, in which the number of branches in 1 molecule of the modified diene polymer is 5 or more.

In order to obtain the modified conjugated diene polymer (a), for example, the following methods are effective: the modifier having 5 or more reaction sites with the active end is added in a mole number of one fifth or less relative to the total mole number of the polymerization initiator to obtain a modified conjugated diene copolymer having 5 or more branches.

The shrinkage factor (g') measured by GPC-light scattering measurement with a viscosity detector (hereinafter also referred to simply as "GPC-light scattering measurement with a viscosity detector" or "3D-GPC measurement") is an index of the number of branches of the modified conjugated diene polymer. For example, as the shrinkage factor (g') decreases, the number of branches of the (a) modified conjugated diene polymer (for example, the number of branches of the star polymer (also referred to as "the number of arms of the star polymer")) tends to increase.

In the case of comparing modified conjugated diene polymers having the same absolute molecular weight, the shrinkage factor (g ') is smaller as the number of branches of the modified conjugated diene polymer (a) is larger, and thus the shrinkage factor (g') in this case can be used as an index of the degree of branching.

The shrinkage factor (g') was measured by 3D-GPC measurement, and the relation between intrinsic viscosity and molecular weight ([ η ]]＝KMα([η]Intrinsic viscosity and M: molecular weight) is set to logK-3.883 and α -0.771, the range of input molecular weight M is 1000 to 20000000, and a standard intrinsic viscosity [ η ] is prepared]₀Relationship to molecular weight M.

As intrinsic viscosity [ η]Relative to standard intrinsic viscosity [ η]₀At each molecular weight M, the intrinsic viscosity of the sample at each molecular weight M as measured by 3D-GPC was calculated [ η]Relative to this standard intrinsic viscosity [ η]₀[ η ]]/[η]₀The average value thereof was taken as the shrinkage factor (g').

More specifically, the measurement can be carried out by the method described in the examples below.

[ constitution of modified conjugated diene Polymer (A) >

(A) The modified conjugated diene polymer is preferably a modified conjugated diene polymer in which a modifier residue having a functional group having affinity or reactivity with the filler is bonded to the polymerization initiation terminal and/or the termination terminal.

That is, the modified conjugated diene polymer (a) is preferably composed of a functional group-containing modifier residue and a conjugated diene polymer chain.

(A) When the modified conjugated diene polymer has a polymerization initiator residue at the terminal, the polymerization initiator residue preferably does not contain a nitrogen atom. When the polymerization initiator residue contains a nitrogen atom, the reaction with the filler is accelerated even if the final processability after production of the sulfide is the same, and the sheet processability tends to be deteriorated in the initial stage of the multistage kneading. On the other hand, when the polymerization initiator residue does not contain nitrogen, the polymerization initiator residue reacts with the filler at an appropriate rate, and therefore, the sheet processability is good even in the initial stage of the multistage kneading.

< modifier residue >

(A) The modifier residue in the modified conjugated diene polymer is a structural unit of the modified conjugated diene polymer (a) bonded to the conjugated diene polymer chain, and is, for example, a structural unit derived from a modifier generated by a reaction between the conjugated diene polymer and the modifier described later.

The modifier residue has, for example, a specific functional group having affinity or bonding reactivity with the filler.

(A) When the modified conjugated diene polymer is a modified conjugated diene polymer having a functional group bonded to a polymerization initiation terminal, the modified conjugated diene polymer (a) can be obtained by a polymerization reaction using a polymerization initiator having a functional group.

< end >

(A) When the modified conjugated diene polymer has no branched structure, (a) the modified conjugated diene polymer has a linear structure, and "terminal" means both ends of the linear structure, one end of the linear structure is bonded to the modifier residue, and the other end of the linear structure is bonded to the polymerization initiator residue.

(A) In the case where the modified conjugated diene polymer has a branched structure and at least one branching point is a modifier residue, (a) the "terminal end" of the modified conjugated diene polymer is the terminal end of a conjugated diene polymer chain to which the branching point, for example, the "modifier residue" is not bonded, and in the case where a monomer is first polymerized using a polymerization initiator and then the modifier is bonded to a polymerization terminating terminal end to form the branching point, the terminal end of the polymer chain to which the modifier residue is not bonded in the modified conjugated diene polymer has a polymerization initiator residue. (A) When the modified conjugated diene polymer (a) has a branched structure and does not have a branching point by a modifier residue, the "end" of the modified conjugated diene polymer (a) is the end of a conjugated diene polymer chain not bonded to the branching point, and has a modifier residue or a polymerization initiator residue.

< preferred embodiment regarding functional group >

The specific functional group having affinity or bonding reactivity with the filler is preferably a functional group having 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, i.e., the molar ratio of N/Si, is preferably 0.1 to 10.0, more preferably 0.2 to 7.0.

When N/Si is in this range, the affinity with the silica-based filler is particularly good, and the rubber composition using the silica-based filler has a small hysteresis loss, and exhibits good performance as a rubber composition for a low fuel consumption tire.

Further, 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, from the viewpoint that silica can be dispersed in a short time during kneading.

In another aspect, 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, and even more preferably 0.3 to 0.6, in view of dispersing silica in a short time during kneading.

Examples of the functional group containing a silicon atom include, but are not limited to, a methoxysilyl group, an ethoxysilyl group, and a propoxysilyl group.

Examples of the functional group containing a nitrogen atom include, but are not limited to, a secondary amino group, a tertiary amino group, 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 a polymer molecule. In this case, as the functional group containing a nitrogen atom, a functional group containing a secondary amine having a nitrogen atom of at least-NH-type is particularly preferable. In this case, the hysteresis loss of the rubber composition using the silica-based filler and the carbon black as the filler can be reduced, and the rubber composition exhibits good performance as a composition for a low fuel consumption tire.

When the modifier residue has a silicon atom, it is preferable that at least 1 of the silicon atoms constitutes an alkoxysilyl group or silanol group having 1 to 20 carbon atoms. This tends to improve the dispersibility of the filler when the composition is prepared into a compound and to improve fuel economy.

In the modified conjugated diene polymer (a), one silicon atom may be bonded to the end of 2 or more conjugated diene polymer chains. In addition, the terminal of the conjugated diene polymer chain is bonded to one silicon atom with an alkoxy group or a hydroxyl group, and as a result, the one silicon atom may constitute an alkoxysilyl group or a silanol group.

< monomers 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.

The conjugated diene compound is not particularly limited as long as it is a monomer capable of polymerization, and is preferably a conjugated diene compound having 4 to12 carbon atoms per 1 molecule, and more preferably a conjugated diene compound having 4 to 8 carbon atoms per 1 molecule. Examples of such conjugated diene compounds include, but are not limited to, 1, 3-butadiene, isoprene, 2, 3-dimethyl-1, 3-butadiene, 1, 3-pentadiene, 3-methyl-1, 3-pentadiene, 1, 3-hexadiene, and 1, 3-heptadiene. Among these, 1, 3-butadiene and isoprene are preferable in terms of ease of industrial availability. These may be used alone or in combination of two or more.

The monovinyl aromatic compound is not particularly limited as long as it is a monomer copolymerizable with the conjugated diene compound, and is preferably a monovinyl aromatic compound.

< preferred embodiment in the case of SBR >

(A) When the modified conjugated diene polymer is a butadiene-styrene random copolymer (SBR), the amount of the bonded styrene is preferably 5 to 50 mass%, and the vinyl content is preferably 10 to 75 mass%. Within this range, an SBR that is applicable to all uses other than tire uses can be obtained industrially.

In particular, when the amount of the bonded styrene is 25 to 45% by mass and the vinyl content is 18 to 30% by mass, a rubber composition having excellent abrasion resistance can be obtained.

When the amount of the bonded styrene is 18 to 28% by mass and the vinyl group content is 45 to 65% by mass, a rubber composition blended with a natural rubber can provide a fuel-efficient tire rubber composition having excellent strength.

The amount of the bonded styrene is the mass% of styrene in the entire monomer components, and the vinyl content is the mass% of the vinyl bonding component in the butadiene component.

< glass transition temperature >

(A) The glass transition temperature, Tg, of the modified conjugated diene polymer is a temperature at which the molecular chain of the modified conjugated diene polymer starts to rotate, and has a large influence on fuel economy and wet grip performance.

When Tg is low, fuel economy is good; when Tg is high, wet grip performance is improved.

The modified conjugated diene polymer (A) preferably has a Tg of-20 ℃ to 0 ℃. This provides excellent wet grip and rigidity. The modified conjugated diene polymer is extremely useful for high-performance tires and ultrahigh-performance tires.

Further, as another preferable embodiment, the modified conjugated diene polymer (A) may be a modified conjugated diene polymer having a Tg of-50 ℃ or higher and less than-20 ℃. This provides an extremely excellent balance between fuel economy and wet grip performance. The modified conjugated diene polymer is extremely useful for summer tires and all season tires.

Further, as another preferable embodiment, the modified conjugated diene polymer (A) may be a modified conjugated diene polymer having a Tg of-70 ℃ or higher and less than-50 ℃. Thereby making the low temperature performance and wear resistance extremely good.

The modified conjugated diene polymer is extremely useful for winter tires.

In addition, the rubber composition can be used for improving the wear resistance in the compounding of various tire treads.

The Tg of the modified conjugated diene polymer may be according to ISO 22768: 2006 for measurement.

(A) The Tg of the modified conjugated diene polymer can be controlled within the above numerical ranges by adjusting the amount of bound styrene and the vinyl content.

< preferred embodiment of random SBR >

(A) When the modified conjugated diene polymer is a butadiene-styrene random copolymer (SBR), the styrene unit is preferably present in a large proportion alone, and the long chain is preferably small.

Specifically, when the modified conjugated diene Polymer is a butadiene-styrene copolymer, it is preferable that the amount of separated styrene is 40 mass% or more and the number of styrene structures having 8 or more styrene chains is 5 mass% or less based on the total amount of bound styrene, when the copolymer is decomposed by a method known as a method by Tanskian et al (Polymer,22,1721(1981)) based on ozonolysis and the styrene chain distribution is analyzed by GPC. In this case, the hysteresis loss of the vulcanized rubber obtained can be further reduced, and a fuel-efficient rubber composition for a tire having excellent performance can be obtained.

< hydrogenated conjugated diene Polymer >

(A) The modified conjugated diene polymer may be a polymer obtained by subjecting the modified conjugated diene polymer or a conjugated diene polymer before modification to further hydrogenation treatment in an inert solvent. Thereby converting all or part of the double bonds into saturated hydrocarbons. In this case, the heat resistance and weather resistance are improved, and the deterioration of the product during processing at high temperature can be prevented, and the mobility as a rubber tends to be improved. As a result, the composition exhibits more excellent performance in various applications such as automobile applications.

The hydrogenation ratio of the unsaturated double bonds in the conjugated diene compound may be arbitrarily selected depending on the purpose, and is not particularly limited. When the sulfide is used, it is preferable that a part of the double bonds in the conjugated diene portion remain. From this viewpoint, the hydrogenation ratio of the conjugated diene portion in the conjugated diene polymer is preferably 3.0 mol% or more and 70 mol% or less, more preferably 5.0 mol% or more and 65 mol% or less, and still more preferably 10 mol% or more and 60 mol% or less. In particular, selective hydrogenation of vinyl groups tends to improve heat resistance and mobility. The hydrogenation rate can be determined by a nuclear magnetic resonance apparatus (NMR).

< oil extended Polymer, Mooney viscosity >

(A) The modified conjugated diene polymer may 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.

Further, the Mooney viscosity of the modified conjugated diene polymer (A) measured at 100 ℃ is preferably 20 to 100, more preferably 30 to 80, in view of processability in producing a rubber vulcanizate and abrasion resistance after producing a vulcanizate. The Mooney viscosity can be measured by the method described in examples below.

< content of Nitrogen and silicon >

(A) In the modified conjugated diene copolymer, the contents of nitrogen and silicon are preferably 3ppm by mass or more, more preferably 7ppm by mass or more, and still more preferably 10ppm by mass or more, respectively, from the viewpoint of improvement in fuel economy.

It is considered that the modified conjugated diene copolymer (a) is physically adsorbed by nitrogen and chemically bonded by silicon when kneaded with a filler.

(A) The molar ratio of nitrogen to silicon contained in the modified conjugated diene copolymer is important, and the molar ratio of nitrogen to silicon (N/Si) is preferably 1.1 or more and less than 10, more preferably 1.3 or more and 7 or less, and further preferably 1.5 or more and 5 or less, from the viewpoint that the silica can be dispersed in a short time during kneading. The reason why the molar ratio of N/Si is preferably in the above range is that it is estimated that the physical adsorption by nitrogen is faster than the reaction rate by chemical bonding of silicon, and therefore the molar ratio of nitrogen to silicon is preferably equal to or more than equimolar.

In addition, as another preferable embodiment, the modified conjugated diene copolymer (a) has a molar ratio of nitrogen to silicon (N/Si) of 0.1 or more and less than 0.9. This makes it possible to disperse silica in a short time during kneading. In this case, the molar ratio is more preferably 0.2 to 0.75, and still more preferably 0.3 to 0.6.

The reason why the molar ratio of nitrogen to silicon is preferably 0.1 or more and less than 0.9 is not clear at present, and it is presumed that the chemical bonding ratio to silica particles based on silicon is stronger than the physical absorption ratio based on nitrogen, and therefore, when the molar ratio of nitrogen to silicon is less than equimolar, the ratio of the modified conjugated diene polymer to silica by chemical bonding increases, and the bonding between the modified conjugated diene polymer and silica is enhanced. In this case, the content of silicon is preferably 7ppm or more.

(A) The contents of nitrogen and silicon and the molar ratio of nitrogen to silicon in the modified conjugated diene copolymer can be controlled by the modifier used in the modification reaction of the conjugated diene copolymer.

For example, the molar ratio of nitrogen to silicon in the modified conjugated diene copolymer can be increased by increasing the molar ratio of nitrogen to silicon in the modifier.

[ preferred Structure of modified conjugated diene Polymer (A) >

(A) The modified conjugated diene polymer is preferably represented by the following general formula (I).

[ solution 1]

In the formula (I), D₁Represents a diene polymer chain, R¹～R³Each independently represents a single bond or a carbon atomAlkylene of a number of 1 to 20, R⁴And R⁷Each independently represents an alkyl group having 1 to 20 carbon atoms, R⁵、R⁸And R⁹Each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R⁶And R¹⁰Each independently represents an alkylene group having 1 to 20 carbon atoms, R¹¹Represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

m and x represent an integer of 1 to 3, x ≦ m, p represents 1 or 2, y represents an integer of 1 to 3, y ≦ (p +1), and z represents an integer of 1 or 2.

D in case of two or more₁、R¹～R¹¹M, p, x, y and z are each independently.

i represents an integer of 0 to 6, j represents an integer of 0 to 6, k represents an integer of 0 to 6, (i + j + k) is an integer of 1 to 10, and ((x × i) + (y × j) + (z × k)) is an integer of 1 to 30.

A represents a hydrocarbon group having 1 to 20 carbon atoms or an organic group having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom and a phosphorus atom and having no active hydrogen. Where (i + j + k) is 1, A may not be present. Thus, the modified conjugated diene polymer tends to have a more excellent balance between low hysteresis loss properties and wet skid resistance and wear resistance after production of a vulcanizate.

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

[ solution 2]

In the formula (II), B¹B represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and two or more¹Each independently.

[ solution 3]

In the formula (III), B²Represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, B³B represents an alkyl group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B is present in the presence of two or more²And B³Each independently.

[ solution 4]

In the formula (IV), B⁴B represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and two or more⁴Each independently.

[ solution 5]

In the formula (V), B⁵B represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and two or more⁵Each independently. This tends to result in a more excellent balance between the hysteresis loss resistance and the wet skid resistance and the abrasion resistance after production of the vulcanizate. In addition, it tends to be easily available in practical use.

(method for producing modified conjugated diene Polymer)

(A) The method for producing the modified conjugated diene polymer preferably includes the steps of: 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; and a modification reaction step of reacting the conjugated diene polymer with a modifier having a linking group that reacts with the active end of the conjugated diene polymer and a specific functional group that has affinity or bonding reactivity with the filler.

< polymerization step >

(A) In the method for producing the modified diene polymer, it is preferable that at least the conjugated diene compound is polymerized using the organic monolithium compound as a polymerization initiator in the polymerization step to obtain the conjugated diene polymer.

In the polymerization step, it is preferable to carry out polymerization by a growth reaction based on a living anionic polymerization reaction, and thereby a conjugated diene polymer having a living terminal and a modified diene polymer having a high modification ratio tend to be obtained.

The modified conjugated diene polymer (a) has a modification ratio of 1/2 (low molecular weight component) having a molecular weight of 1/2 that is the peak of the GPC curve, that is 1/2 or more of the modification ratio of the total amount of the conjugated diene polymer.

In order to obtain the modified conjugated diene polymer (a), it is effective to obtain a conjugated diene polymer by a polymerization method in which termination of a growth reaction or chain transfer rarely occurs.

Therefore, ultrahigh purity of the monomer and the solvent introduced into the polymerization reactor needs to be at a level higher than that of the conventional one.

Therefore, the total amount of impurities in the monomer components used is preferably 30ppm or less, the content concentration (mass) of impurities such as propadienes, acetylenes, primary amines and secondary amines is preferably 20ppm or less, more preferably 10ppm or less, acetylenes is preferably 20ppm or less, more preferably 10ppm or less, and primary amines and secondary amines are preferably 4ppm or less, more preferably 2ppm or less in total nitrogen content.

Examples of the allenes include, but are not limited to, allenes and 1, 2-butadienes. Examples of the acetylene-based substance include, but are not limited to, ethyl acetylene and vinyl acetylene. Examples of the primary and secondary amines include, but are not limited to, methylamine and dimethylamine.

Ultra-high purity of the monomer and the solvent can be achieved by sufficiently purifying all of the monomer and the solvent used in the polymerization.

In the purification of butadiene as a monomer, it is not only necessary to remove the polymerization inhibitor but also important to remove dimethylamine, N-methyl- γ -aminobutyric acid, and the like, which may adversely affect the anionic polymerization. As a method for removing these components, for example, a method in which 1, 3-butadiene containing a polymerization inhibitor is washed with water using low-oxygen water having an oxygen concentration of less than 2mg/L as washing water, and then the polymerization inhibitor in 1, 3-butadiene is removed is given.

In the purification of styrene as a monomer, it is important to remove phenylacetylene and the like which may adversely affect anionic polymerization. Examples of the method for removing phenylacetylene compounds include a method of performing a hydrogenation reaction using a palladium-supported alumina catalyst.

In the purification of n-hexane as a polymerization solvent, it is important to remove moisture which may adversely affect anionic polymerization. Examples of the method for removing water include a method using γ -alumina, synthetic zeolite, or the like. Among these, a method of using synthetic zeolite is preferable, and synthetic zeolite having a large pore diameter is preferable, synthetic zeolite having a pore diameter of 0.35nm or more is more preferable, and synthetic zeolite having a pore diameter of 0.42nm or more is even more preferable.

Since the ultrahigh-purification treatment required to obtain a preferable impurity concentration varies depending on the state before the treatment, it is preferable to measure the impurity concentrations of the monomer and the solvent after the ultrahigh-purification treatment of the monomer and the solvent and before the polymerization reaction.

When the monomer and/or the solvent having a desired impurity concentration is not obtained, it is considered that some treatment is insufficient. In the case where it is desired to reduce the amount of primary and secondary amines, the purification of butadiene is insufficient, and therefore, for example, it is preferable to carry out water washing again using low-oxygen water having an oxygen concentration of less than 2mg/L as washing water. When it is desired to reduce acetylene-based substances, the purification of styrene is insufficient, and therefore, for example, it is preferable to perform the hydrogenation reaction again using a palladium-supported alumina catalyst. In this case, it is more preferable to perform treatments such as increasing the amount of the palladium-supported alumina catalyst or prolonging the contact time with the palladium-supported alumina catalyst.

Further, it is effective to control the polymerization temperature and the monomer addition rate as a polymerization method in which the growth reaction is stopped or chain transfer rarely occurs.

The polymerization temperature is preferably a temperature at which living anionic polymerization is carried out, and is preferably 0 ℃ or higher, and preferably 80 ℃ or lower, from the viewpoint of productivity. More preferably 50 ℃ to 75 ℃.

In addition, it is preferable to react with the modifier at a conversion of less than 99% by mass of the total monomers. More preferably, the conversion is less than 98 mass%.

The conjugated diene polymer may be a random copolymer or a block copolymer. In order to form the conjugated diene polymer into a rubbery polymer, the conjugated diene compound is used in an amount of preferably 40% by mass or more, more preferably 55% by mass or more, based on the total monomers of the conjugated diene polymer.

Examples of the random copolymer include, but are not limited to, random copolymers composed of two or more conjugated diene compounds such as a butadiene-isoprene random copolymer; random copolymers composed of a conjugated diene and a vinyl-substituted aromatic compound, such as a butadiene-styrene random copolymer, an isoprene-styrene random copolymer, and a butadiene-isoprene-styrene random copolymer.

The composition distribution of each monomer in the copolymer chain is not particularly limited, and examples thereof include a completely random copolymer having a nearly statistically random composition and a tapered (gradient) random copolymer having a composition distributed in a tapered shape. The composition of the conjugated diene in the form of a bond, i.e., a1, 4-bond, a1, 2-bond, etc., may be uniform or may have a distribution.

Examples of the block copolymer include, but are not limited to, a 2-type block copolymer (diblock) composed of 2 blocks, a 3-type block copolymer (triblock) composed of 3 blocks, and a 4-type block copolymer (tetrablock) composed of 4 blocks. The polymer constituting the 1 block may be a polymer composed of 1 kind of monomer, or a copolymer composed of 2 or more kinds of monomers. For example, when a polymer block composed of 1, 3-butadiene is represented by "B", a copolymer of 1, 3-butadiene and isoprene is represented by "B/I", a copolymer of 1, 3-butadiene and styrene is represented by "B/S", and a polymer block composed of styrene is represented by "S", the block copolymer is represented by B-B/I2 type block copolymer, B-B/S2 type block copolymer, S-B2 type block copolymer, B-B/S-S3 type block copolymer, S-B-S-B4 type block copolymer, or the like.

In the above formula, the boundaries of the blocks do not necessarily need to be clearly distinguished. In the case of a copolymer in which 1 polymer block is composed of two monomers A and B, A and B in the block may be uniformly distributed or may be distributed in a tapered shape.

< polymerization initiator >

As the polymerization initiator, at least an organic monolithium compound is preferably used.

Examples of the organic monolithium compound include, but are not limited to, low molecular weight compounds and soluble oligomer organic monolithium compounds. Examples of the organic monolithium compound include a compound having a carbon-lithium bond, a compound having a nitrogen-lithium bond, and a compound having a tin-lithium bond, in the form of a bond between an organic group and lithium.

The amount of the organic monolithium compound used as the polymerization initiator can be determined depending on the molecular weight of the target conjugated diene polymer or modified conjugated diene polymer. The amount of the monomer such as a conjugated diene compound used relative to the amount of the polymerization initiator used tends to be correlated with the degree of polymerization, that is, the number average molecular weight and/or the weight average molecular weight. Therefore, in order to increase the molecular weight, the polymerization initiator may be adjusted in a direction of decreasing the amount; in order to decrease the molecular weight, the amount of the polymerization initiator may be adjusted to be increased.

The organic monolithium compound is an alkyllithium compound having a substituted amino group or a lithium dialkylamide. In this case, a conjugated diene polymer having a nitrogen atom constituting an amino group at the polymerization initiation end can be obtained.

The substituted amino group is an amino group having no active hydrogen or a structure in which an active hydrogen is protected. Examples of the alkyllithium compound having an amino group not having an active hydrogen include, but are not limited to, 3-dimethylaminopropyllithium, 3-diethylaminopropyllithium, 4- (methylpropylamino) butyllithium, and 4-hexamethyleneiminobutyllithium. Examples of the alkyllithium compound having an amino group having a structure in which an active hydrogen is protected include, but are not limited to, 3-bistrimethylsilylaminopropyl lithium and 4-trimethylsilylmethylaminobutyl lithium.

Examples of the lithium dialkylamide include, but are not limited to, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium dibutylamide, lithium di-n-hexylamide, lithium diheptylamide, lithium diisopropylamide, lithium dioctylamide, lithium di-2-ethylhexylamide, lithium didecylamide, lithium ethylpropylamide, lithium ethylbutylamide, lithium ethylbenzylamino, lithium methylphenethylamide, lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, lithium morpholinyl, 1-lithium azacyclooctane, 6-lithium-1, 3, 3-trimethyl-6-azabicyclo [3.2.1] octane and 1-lithium-1, 2,3, 6-tetrahydropyridine.

These organic monolithium compounds having a substituted amino group may be used in the form of a solubilized oligomer organic monolithium compound by reacting a polymerizable monomer (for example, a monomer such as 1, 3-butadiene, isoprene or styrene) in a small amount.

The organic monolithium compound is preferably an alkyllithium compound. In this case, a conjugated diene polymer having an alkyl group at the polymerization initiation end can be obtained. Examples of the alkyllithium compound include, but are not limited to, n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and stilbene lithium. The alkyl lithium compound is preferably n-butyllithium or sec-butyllithium in view of easiness of industrial availability and easiness of control of polymerization reaction.

These organic monolithium compounds may be used alone or in combination of two or more.

In addition, the organic monolithium 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 the alkaline earth metal compound include, but are not limited to, organomagnesium compounds, organocalcium compounds, and organic strontium compounds. In addition, alkoxides, sulfonates, carbonates, and amides of alkaline earth metals can be cited. Examples of the organomagnesium compound include, but are not limited to, dibutylmagnesium and ethylbutylmagnesium. Examples of the other organometallic compounds include organoaluminum compounds.

Examples of the polymerization reaction form in the polymerization step include, but are not limited to, batch-type (also referred to as "batch-type") and continuous-type polymerization reaction forms.

In the continuous mode, 1 or 2 or more reactors may be connected. As the continuous reactor, for example, a tank type or a tubular type reactor with a stirrer is used. In the continuous type, it is preferable that the monomer, the inert solvent, and the polymerization initiator are continuously charged into a reactor, a polymer solution containing the polymer is obtained in the reactor, and the polymer solution is continuously discharged.

The batch reactor is, for example, a tank reactor with a stirrer. In the batch system, it is preferable to charge the monomer, the inert solvent and the polymerization initiator, add the monomer continuously or intermittently during the polymerization as needed, obtain a polymer solution containing the polymer in the reactor, and discharge the polymer solution after the polymerization is terminated.

In the production process of the modified conjugated diene polymer of the present embodiment, in order to obtain a conjugated diene polymer having an active terminal at a high ratio, a continuous type in which the polymer is continuously discharged and subjected to the next reaction in a short time is preferable.

In the polymerization step, the polymerization is preferably carried out in an inert solvent.

Examples of the inert solvent include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons.

Specific examples of the hydrocarbon solvent include, but are not limited to, aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene, and hydrocarbons composed of a mixture of these.

Before the polymerization reaction, the allene-based substance and the acetylene-based substance as impurities are treated with an organometallic compound, whereby a conjugated diene-based polymer having a high concentration of active terminals tends to be obtained, and a modified conjugated diene-based polymer having a high modification ratio tends to be obtained, which is preferable.

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

Examples of the polar compound include, but are not limited to, ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2, 2-bis (2-tetrahydrofuryl) propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, and quinuclidine; alkali metal alkoxide compounds such as potassium tert-butoxide, sodium tert-butoxide, and sodium pentoxide; 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 may be selected according to the purpose, etc., and is preferably 0.01 mol or more and 100 mol or less based on 1 mol of the polymerization initiator. Such a polar compound (vinylating agent) can be used as a regulator of the microstructure of the conjugated diene portion of the polymer in an appropriate amount depending on the desired vinyl bonding amount. Most polar compounds have the following tendency: the copolymer has an effective randomizing effect in the copolymerization of a conjugated diene compound and an aromatic vinyl compound, and can be used as a regulator for adjusting the distribution of the aromatic vinyl compound or the amount of styrene blocks.

As a method for randomizing the conjugated diene compound and the aromatic vinyl compound, for example, a method described in Japanese patent application laid-open No. 59-140211 is used in which a copolymerization reaction is initiated by a part of 1, 3-butadiene and the total amount of styrene, and the remaining 1, 3-butadiene is intermittently added in the middle of the copolymerization reaction.

The conjugated diene polymer obtained in the polymerization step before the reaction step described later preferably has a Mooney viscosity measured at 110 ℃ of 10 to 90, more preferably 15 to 85, and still more preferably 20 to 60.

When the mooney viscosity is within the above range, the modified conjugated diene polymer composition of the present embodiment tends to be excellent in processability and wear resistance.

The amount of the bonded conjugated diene in the conjugated diene polymer or modified conjugated diene polymer is not particularly limited, but is preferably 40 mass% to 100 mass%, more preferably 55 mass% to 80 mass%.

The amount of the bonded aromatic vinyl group in the conjugated diene polymer or the modified conjugated diene polymer is not particularly limited, but is preferably 0 mass% or more and 60 mass% or less, and more preferably 20 mass% or more and 45 mass% or less.

When the amount of the conjugated diene bonded and the amount of the aromatic vinyl group bonded are within the above ranges, the fracture characteristics and the abrasion resistance after the formation of the vulcanizate tend to be further excellent.

The amount of the bonded aromatic vinyl group can be measured by ultraviolet absorption of the phenyl group, and the amount of the bonded conjugated diene can be determined. Specifically, the measurement can be carried out by the method described in the examples below.

The vinyl bond amount in the conjugated diene bond unit in the conjugated diene polymer or modified conjugated diene polymer is not particularly limited, but is preferably 10 mol% or more and 75 mol% or less, and more preferably 20 mol% or more and 65 mol% or less.

When the vinyl bond content is in the above range, the balance between hysteresis loss resistance and wet skid resistance, and the wear resistance and breaking strength tend to be more excellent after the production of the vulcanizate.

Here, in the case where the modified conjugated diene polymer (a) is a branched modified diene polymer and is a copolymer of butadiene and styrene, the vinyl bond amount (1, 2-bond amount) in the butadiene bond unit can be determined by the Hampton method (r.r. Hampton, Analytical Chemistry,21,923 (1949)). Specifically, the measurement can be carried out by the method described in the examples below.

With respect to the microstructure of the modified conjugated diene polymer, when the amount of each bond in the modified conjugated diene polymer (a) is in the above numerical range and the glass transition temperature of the modified conjugated diene polymer (a) is in the range of-50 ℃ or more and less than-20 ℃, a sulfide having a further excellent balance between low hysteresis loss properties and wet skid resistance tends to be obtained.

With respect to the glass transition temperature, the glass transition temperature is determined according to ISO 22768: 2006, a DSC curve is recorded while raising the temperature in a predetermined temperature range, and the peak top (inflection point) of the DSC differential curve is set as the glass transition temperature. Specifically, the measurement can be carried out by the method described in the 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 none. More specifically, in the case where the copolymer is a butadiene-styrene copolymer, in a known method of decomposing the copolymer by Kolthoff (method described in i.m. Kolthoff, et al, j.polym.sci.1,429 (1946)), and analyzing the amount of polystyrene insoluble in methanol, a block segment in which 30 or more aromatic vinyl units are linked is preferably 5.0 mass% or less, more preferably 3.0 mass% or less, with respect to the total amount of the copolymer.

< modification reaction step >

In the modification reaction step, the conjugated diene polymer obtained by the above-described method is reacted with a modifier having a linking group that reacts with the active end of the conjugated diene polymer and a specific functional group that has affinity or bonding reactivity with the filler.

In this case, the modifier may have a specific functional group that also has an effect as a linking group. In addition, the modification reaction step is preferably performed immediately after the polymerization step. In this case, a modified conjugated diene polymer having a high modification ratio tends to be obtained.

When a compound having a monofunctional or 2-functional linking group is used as the modifier, a linear terminal-modified diene polymer can be obtained, and when a polyfunctional compound having a 3-or more-functional linking group is used, a branched modified diene polymer can be obtained.

As the modifier, a monofunctional or polyfunctional compound containing at least one element of nitrogen, silicon, tin, phosphorus, oxygen, sulfur, and halogen is preferably used. In addition, an onium structure can be introduced into the modified conjugated diene polymer by adding a terminal modifier containing an onium generating agent to carry out the reaction. Further, a modifier having two or more functional groups containing these elements in a molecule, or a modifier having two or more functional groups containing these elements may be used.

The modifier is preferably one having little or no active hydrogen such as hydroxyl, carboxyl, primary amino, or secondary amino. The active hydrogen tends to deactivate the active terminal of the conjugated diene polymer.

< description of specific modifying Agents >

Examples of the nitrogen-containing compound include, but are not limited to, isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, carbonyl compounds containing a nitrogen group, vinyl compounds containing a nitrogen group, epoxy compounds containing a nitrogen group, and the like.

Examples of the silicon-containing compound include, but are not limited to, halogenated silicon compounds, epoxidized silicon compounds, vinyl silicon compounds, alkoxysilicon compounds, and alkoxysilane compounds containing a nitrogen-containing group.

Examples of the tin-containing compound include, but are not limited to, a tin halide compound, an organotin carboxylate compound, and the like.

Examples of the phosphorus-containing compound include, but are not limited to, phosphite compounds and phosphine compounds.

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 derivatives, thiocarbonyl compounds, isothiocyanates, and the like.

Examples of the halogen-containing compound include, but are not limited to, the above-mentioned silicon halide compound and tin halide compound.

Examples of the onium generator include, but are not limited to, a protected amine compound (ammonium generator) capable of forming a primary or secondary amine, a protected phosphine compound (phosphonium generator) capable of forming a phosphine hydride, and a compound (oxonium or sulfonium generator) capable of forming a hydroxyl group or a thiol group, and it is preferable to use terminal modifiers each having a functional group for bonding the onium generator and the modified conjugated diene polymer in a molecule.

Examples of the functional group for bonding the modified conjugated diene polymer include carbonyl groups (such as ketones and esters), unsaturated groups such as vinyl groups, epoxy groups, silicon halide groups, and silicon alkoxide groups.

The modifier preferably has a nitrogen-containing functional group, and the nitrogen-containing functional group is preferably an amine compound having no active hydrogen, and examples thereof include a tertiary amine compound, a protected amine compound in which the active hydrogen is substituted with a protecting group, and an imine compound represented by the general formula — N ═ C.

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

Examples of the isocyanuric acid derivative include, but are not limited to, 1,3, 5-tris (3-trimethoxysilylpropyl) isocyanurate, 1,3, 5-tris (3-triethoxysilylpropyl) isocyanurate, 1,3, 5-tris (oxiranyl-2-yl) -1,3, 5-triazine-2, 4, 6-trione, 1,3, 5-tris (isocyanatomethyl) -1,3, 5-triazine-2, 4, 6-trione, and 1,3, 5-trivinyl-1, 3, 5-triazine-2, 4, 6-trione.

Examples of the nitrogen group-containing carbonyl compound 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 '-bis (diethylamino) benzophenone, 4' -bis (dimethylamino) benzophenone, methyl-2-pyridinone, methyl-4-pyridinone, propyl-2-pyridinone, di-4-pyridinone, 2-benzoylpyridine, methyl-2-imidazolidinone, methyl-2-pyridinone, methyl-2-pyrimidinone, methyl-2, N, N ' -tetramethylurea, N-dimethyl-N ', N ' -diphenylurea, N-diethylcarbamic acid methyl ester, N-diethylacetamide, N-dimethyl-N ', N ' -dimethylaminoacetamide, N-dimethylpyridinecarboxamide, N-dimethylisonicotinamide, and the like.

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

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

[ solution 6]

In the formula (1), R is a hydrocarbon group having a valence of 2 or more, or an organic group having a valence of 2 or more and containing at least one polar group selected from nitrogen such as oxygen such as ether, epoxy, ketone, sulfur such as thioether, thioketone, etc., a tertiary amino group, imino group, etc.

The hydrocarbon group having a valence of 2 or more is a saturated or unsaturated hydrocarbon group which may be linear, branched or cyclic, and includes an alkylene group, an alkenylene group, a phenylene group and the like. Preferably, the number of carbon atoms is 1 to 20. Specific examples thereof include methylene, ethylene, butylene, cyclohexylene, 1, 3-bis (methylene) -cyclohexane, 1, 3-bis (ethylene) -cyclohexane, o-phenylene, m-phenylene, p-phenylene, m-xylene, p-xylene, and bis (phenylene) -methane.

In the above formula (1), R¹、R⁴Is a hydrocarbon group having 1 to 10 carbon atoms, R¹、R⁴May be different from each other. R²、R⁵Is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, R²、R⁵May be different from each other.

R³Is a hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (2).

R¹、R²、R³Can be bonded to each other to form a ring structure.

In addition, R³In the case of a hydrocarbon group, R may be bonded to each other to form a cyclic structure, and in this case, R is bonded to R³The N and R in (A) can be directly bonded.

In the formula (1), n is an integer of 1 or more, and m is an integer of 0 or 1 or more.

[ solution 7]

In the above formula (2), R¹、R²With R of the above formula (1)¹、R²Are defined as such, R¹、R²May be different from each other.

The epoxy compound containing a nitrogen group used as the modifier preferably has a hydrocarbon group containing an epoxy group, and more preferably has a hydrocarbon group containing a glycidyl group.

Examples of the hydrocarbon group containing an epoxy group bonded to an amino group or an ether group include a glycidylamino group, a diglycidylamino group, and a glycidyloxy group. Further preferred molecular structures are compounds containing an epoxy group, each having a glycidylamino group, a diglycidylamino group, and a glycidyloxy group, and are represented by the following general formula (3).

[ solution 8]

In the above formula (3), R is as defined as R in the above formula (1), and R is⁶Is a hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (4).

R⁶When it is a hydrocarbon group, it may bond to R to form a cyclic structure, and in this case, it may bond to R⁶The direct bonding mode of bonded N and R.

In the formula (3), n is an integer of 1 or more, and m is an integer of 0 or 1 or more.

[ solution 9]

As the nitrogen group-containing epoxy compound used as the modifier, a compound having 1 or more diglycidylamino groups and 1 or more glycidyloxy groups in the molecule is most preferable.

Examples of the nitrogen group-containing epoxy compound used as the modifier include, but are not limited to, N-diglycidyl-4-glycidoxyaniline, 1-N, N-diglycidyl aminomethyl-4-glycidoxy-cyclohexane, 4- (4-glycidoxyphenyl) - (N, N-diglycidyl) aniline, 4- (4-glycidoxyphenoxy) - (N, N-diglycidyl) aniline, 4- (4-glycidoxybenzyl) - (N, N-diglycidyl) aniline, 4- (N, N' -diglycidyl-2-piperazinyl) -glycidoxybenzene, 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane, N-diglycidyl amino-4-glycidoxy-aniline, N-diglycidyl amino-4-glycidoxy-cyclohexane, N-diglycidyl amino-4-glycidoxy-phenyl-N, N-diglycidyl phenyl-4- (4-glycidoxypropyl) aniline, 1,3-, N, N, N ', N' -tetraglycidyl-m-xylylenediamine, 4-methylene-bis (N, N-diglycidylaniline), 1, 4-bis (N, N-diglycidylamino) cyclohexane, N, N, N ', N' -tetraglycidyl-p-phenylenediamine, 4 '-bis (diglycidylamino) benzophenone, 4- (4-glycidylpiperazinyl) - (N, N-diglycidylamino) aniline, 2- [2- (N, N-diglycidylamino) ethyl ] -1-glycidylpyrrolidine, N, N-diglycidylaniline, 4' -diglycidyldibenzylmethylamine, N, N-diglycidylaniline, N, N-diglycidyl o-toluidine, N-diglycidyl aminomethylcyclohexane, and the like.

Among these, N-diglycidyl-4-glycidoxyaniline and 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane are particularly preferable.

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

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

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

Examples of the alkoxysilane compound containing a nitrogen-containing group as the modifier include, but are not limited to, 3-dimethylaminopropyltrimethoxysilane, 3-dimethylaminopropylmethyldimethoxysilane, 3-diethylaminopropyltriethoxysilane, 3-morpholinopropyltrimethoxysilane, 3-piperidinylpropyltriethoxysilane, 3-hexamethyleneiminopropylmethyldiethoxysilane, 3- (4-methyl-1-piperazinyl) propyltriethoxysilane, 1- [3- (triethoxysilyl) -propyl ] -3-methylhexahydropyrimidine, 3- (4-trimethylsilyl-1-piperazinyl) propyltriethoxysilane, 3- (3-triethylsilyl-1-imidazolidinyl) propylmethyldiethoxysilane, N-phenyltrimethoxysilane, N-hydroxyiminopropylmethyldiethoxysilane, N-hydroxysilane, N-, 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' -tetrakis (3-trimethoxysilylpropyl) ethylenediamine, 3-isocyanatopropyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza Hetero-2-silacyclopentane, 2-diethoxy-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-dimethoxy-1- (4-trimethoxysilylbutyl) -1-aza-2-silacyclohexane, 2-dimethoxy-1- (3-dimethoxymethylsilylpropyl) -1-aza-2-silacyclopentane, 2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, 2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2-dimethyl-1-aza-2-silacyclopentane, 2-dimethyl-1-aza-2-silacyclopentane, 2, 2-dimethoxy-1-methyl-1-aza-2-silacyclopentane, 2-dimethoxy-8- (4-methylpiperazinyl) methyl-1, 6-dioxa-2-silacyclooctane, 2-dimethoxy-8- (N, N-diethylamino) methyl-1, 6-dioxa-2-silacyclooctane and the like.

Examples of the protected amine compound capable of forming a primary or secondary amine, which is a modifier, include, but are not limited to, 4 '-vinylidene bis [ N, N-bis (trimethylsilyl) aniline ], 4' -vinylidene bis [ N, N-bis (triethylsilyl) aniline ], 4 '-vinylidene bis [ N, N-bis (t-butyldimethylsilyl) aniline ], 4' -vinylidene bis [ N-methyl-N- (trimethylsilyl) aniline ], 4 '-vinylidene bis [ N-ethyl-N- (trimethylsilyl) aniline ], 4' -vinylidene bis [ N-methyl-N- (triethylsilyl) aniline ], (N-methyl-N- (triethylsilyl) aniline), 4,4 ' -vinylidene bis [ N-ethyl-N- (triethylsilyl) aniline ], 4 ' -vinylidene bis [ N-methyl-N- (t-butyldimethylsilyl) aniline ], 4 ' -vinylidene bis [ 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 the compound having an alkoxysilane and a protected amine in the molecule, which is a modifier, a protected amine compound capable of forming a primary or secondary amine, there may be mentioned, but not limited to, N-bis (trimethylsilyl) aminopropyltrimethoxysilane, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N-bis (trimethylsilyl) aminopropyltriethoxysilane, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, N-bis (trimethylsilyl) aminoethyltrimethoxysilane, N-bis (trimethylsilyl) aminoethylmethyldiethoxysilane, N-bis (triethylsilyl) aminopropylmethyldiethoxysilane, 3- (4-trimethylsilyl-1-piperazinyl) propyltriethoxysilane Alkyl, 3- (3-triethylsilyl-1-imidazolidinyl) propylmethyldiethoxysilane, 3- (3-trimethylsilyl-1-hexahydropyrimidinyl) propyltrimethoxysilane, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-diethoxy-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-dimethoxy-1- (4-trimethoxysilylbutyl) -1-aza-2-silacyclohexane, 2-dimethoxy-1- (3-dimethoxymethylsilylpropyl) -1-aza-2-silacyclohexane 2-silacyclopentane, 2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, 2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2-dimethoxy-1-methyl-1-aza-2-silacyclopentane, and the like.

Examples of tin halide compounds as modifiers include, but are not limited to, tetrachlorotin, tetrabromotin, trichlorobutyltin, trichlorooctyltin, dibromodimethyltin, dibutyltin dichloride, chlorotrifluorutyltin, chlorotriactyltin, chlorotriphenyltin, 1, 2-bis (trichlorostannyl) ethane, 1, 2-bis (methyldichlorosilyl) ethane, 1, 4-bis (trichlorostannyl) butane, 1, 4-bis (methyldichlorosilyl) butane, and the like.

Examples of organotin carboxylate compounds as modifiers include, but are not limited to, ethyltin tristearate, butyltin trioctoate, butyltin tristearate, butyltin trilaurate, dibutyltin dioctoate, and the like.

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

Examples of the phosphine-based compound as a modifier include, but are not limited to, protected phosphine-based compounds such as P, P-bis (trimethylsilyl) phosphinopropyltrimethoxysilane, P-bis (triethylsilyl) phosphinopropylmethylethoxysilane, and the like; 3-dimethylphosphinopropyltrimethoxysilane, 3-diphenylphosphinopropyltrimethoxysilane and the like.

Examples of the oxygen-containing compound as the modifier include, but are not limited to, polyglycidyl ethers such as ethylene glycol diglycidyl ether and glycerol triglycidyl ether; polyepoxy compounds such as 1, 4-diglycidylbenzene, 1,3, 5-triglycidylbenzene, poly-epoxidized liquid polybutadiene, epoxidized soybean oil, epoxidized linseed oil and the like; ester compounds such as dimethyl adipate, diethyl adipate, dimethyl terephthalate and diethyl terephthalate, which generate hydroxyl groups at the polymer terminals.

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

The modifier preferably has a silicon-containing functional group, and the silicon-containing functional group preferably has an alkoxysilyl group or a silanol group.

The alkoxysilyl group of the modifier, for example, has a tendency to react with the active terminal of the conjugated diene polymer to dissociate the lithium alkoxide, thereby forming a bond between the terminal of the conjugated diene polymer chain and the silicon of the modifier residue. The value obtained by subtracting the number of SiOR reduced by the reaction from the total number of SiOR possessed by 1 molecule of the modifier is the number of alkoxysilyl groups possessed by the modifier residue. The aza-silacyclic group of the modifier forms a bond of > N-Li and a bond between the terminal of the conjugated diene polymer and silicon of the modifier residue. The > N — Li bond tends to be > NH or LiOH, which is easily affected by water or the like during finishing. In addition, in the modifier, the unreacted and remaining alkoxysilyl group tends to be easily affected by water or the like during finishing to become silanol (Si — OH group).

In the modification reaction step, when a compound having 3 alkoxy groups per 1 silicon atom is reacted, that is, when 3 moles of active terminals of the conjugated diene polymer are reacted with 1 mole of trialkoxysilyl groups, the compound tends to react with at most 2 moles of the conjugated diene polymer, and 1 mole of alkoxy groups tends to remain unreacted. This was confirmed from the fact that 1 mole of the conjugated diene polymer was not reacted and remained as an unreacted polymer. By reacting the alkoxy group in a large part, the viscosity of the polymer tends to be prevented from being greatly changed by a condensation reaction during finishing or storage. It is preferred to use a modifier corresponding to1 alkoxysilyl group per 1 silicon atom.

The reaction temperature in the modification reaction step is preferably the same as the polymerization temperature of the conjugated diene polymer, and particularly preferably a temperature at which heating is not performed after the polymerization. More preferably 0 ℃ to 120 ℃ and even more preferably 50 ℃ to 100 ℃.

The reaction time in the modification reaction step is preferably 10 seconds or longer, more preferably 30 seconds or longer.

The mixing in the modification reaction step may be performed by any of mechanical stirring, stirring with a static mixer, and the like.

When the polymerization step is a continuous type, the reaction step is also preferably a continuous type.

The reactor used in the reforming reaction step is, for example, a tank-type or tubular reactor with a stirrer. The modifier may be diluted with an inert solvent and continuously supplied to the reactor. When the polymerization step is a batch-type polymerization step, a method of charging the modifier into a polymerization reactor may be employed, or the modifier may be transferred to another reactor to carry out the modification reaction step.

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

[ solution 10]

In the formula (VI), R¹²～R¹⁴Each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms, R¹⁵～R¹⁸And R²⁰Each independently represents an alkyl group having 1 to 20 carbon atoms, R¹⁹And R²²Each independently represents an alkylene group having 1 to 20 carbon atoms, R²¹Represents an alkyl group having 1 to 20 carbon atoms or a trialkylsilyl group.

m represents an integer of 1 to 3, and p represents 1 or 2.

R in the case where two or more¹²～R²²M and p are each independently.

i represents an integer of 0 to 6, j represents an integer of 0 to 6, k represents an integer of 0 to 6, and (i + j + k) represents an integer of 1 to 10.

A represents a single bond, a hydrocarbon group having 1 to 20 carbon atoms, or an organic group having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom, and a phosphorus atom and having no active hydrogen.

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 which deactivates an active terminal of the conjugated diene polymer. The organic group is a group having no hydroxyl group (-OH), a secondary amino group (- (OH)>NH), primary amino group (-NH)₂) Mercapto (-SH) and the like having active hydrogenOrganic group of the group. When (i + j + k) is 1, a may not be present.

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

[ solution 11]

In the formula (II), B¹B represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and two or more¹Each independently.

[ solution 12]

In the formula (III), B²Represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, B³B represents an alkyl group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B is present in the presence of two or more²And B³Each independently.

[ solution 13]

In the formula (IV), B⁴B represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and two or more⁴Each independently.

[ solution 14]

In the formula (V), B⁵B represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and two or more⁵Each independently.

This tends to make it possible to obtain a modified conjugated diene polymer having more excellent performance according to the present embodiment.

Examples of the modifier of the formula (VI) (including a modifier repeating with the modifier) in which (i + j + k) is 1 to 2 include, but are not limited to, 3-dimethoxymethylsilylpropyldimethylamine (1-functional), 3-trimethoxysilylpropyldimethylamine (2-functional), bis (3-trimethoxysilylpropyl) methylamine (4-functional), bis (3-dimethoxymethylsilylpropyl) methylamine (2-functional), (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] ethylamine (4-functional), and [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) silyl Amines (4 functional), 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 (3 functional), [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-diethoxyethylsilylpropyl) methylamine (3 functional), Bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] methylamine (4-functional), (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -methylamine (3-functional).

Hereinafter, examples of the modifier in the case where the polyfunctional compound (i + j + k) is 3 or more and A in the formula (VI) is represented by the formula (II) include, but are not limited to, 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, tris (VI) amine, tris (III) silylpropyl) amine, tris (III) amine, tris (3-methoxy-1-aza-2-silacyclopentane) amine, tris (III) 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-silacyclopentane) propyl ] amine, tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine, tris (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, bis (3-trimethoxysilylpropyl) -bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) -1, 3-propanediamine, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-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-propanediamine, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) -1, 3-propanediamine, tetrakis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, bis (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] ] -1, 3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tris (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-trimethoxysilylpropyl) -bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-methoxy-1-aza-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-methoxy-2-aza-2-sila-2-azacyclopentane) propyl ester, bis (3-methoxy-1-methoxy-, 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, tri (3-triethoxysilylpropyl) -1, 3-propanediamine, and mixtures thereof, Tetrakis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-ethoxysilylpropyl) - [1- (2-ethoxy-2-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-triethoxy-1-aza-2-sila-2-azacyclopentane) propyl ] -, Tetrakis (3-trimethoxysilylpropyl) -1, 6-hexanediamine, pentakis (3-trimethoxysilylpropyl) -diethylenetriamine.

Examples of the modifier in the case where A in the formula (VI) is represented by the formula (III) include, but are not limited to, tris (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine, bis (2-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl group]-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, N¹,N^1’- (propane-1, 3-diyl) bis (N)¹-methyl-N³,N³Bis (3- (trimethoxysilyl) propyl) -1, 3-propanediamine), N¹- (3- (bis (3- (trimethoxysilyl) propyl) amino) propyl) -N¹-methyl-N³- (3- (methyl (3- (trimethoxysilyl) propyl) amino) propyl) -N³- (3- (trimethoxysilyl) propyl) -1, 3-propanediamine.

Examples of the modifier in the case where A in the formula (VI) is represented by the formula (IV) include, but are not limited to, 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-trimethoxysilylpropyl) -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.

Examples of the modifier in the case where A in the formula (VI) is represented by the formula (V) include, but are not limited to, 3-tris [2- (2, 2-dimethoxy-1-aza-2-silacyclopentane) ethoxy ] silyl-1- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propane, 3-tris [2- (2, 2-dimethoxy-1-aza-2-silacyclopentane) ethoxy ] silyl-1-trimethoxysilylpropane.

Examples of the modifier in which A in the formula (VI) represents an organic group having an oxygen atom and no active hydrogen include (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] ether (4-functional), and 3,4, 5-tris (3-trimethoxysilylpropyl) -cyclohexyl- [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] ether (8-functional).

Examples of the modifier in which A in the formula (VI) represents an organic group having a phosphorus atom and no active hydrogen include, but are not limited to, (3-trimethoxysilylpropyl) phosphate, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] phosphate, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) phosphate, and tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] phosphate.

In the formula (VI), A preferably represents the formula (II) or the formula (III), and k preferably represents 0. This tends to make a modifier easily available, and also tends to be excellent in the wear resistance and hysteresis loss performance after the modified conjugated diene polymer (A) is made into a vulcanizate.

Examples of such modifiers include, but are not limited to, 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-trimethoxysilylpropyl) -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-trimethoxysilylpropyl) -methyl-1, 3-propanediamine.

In the formula (VI), A more preferably represents a formula (II) or a formula (III), k represents 0, and a in the formula (II) or the formula (III) represents an integer of 2 to 10. This tends to result in more excellent wear resistance and low hysteresis loss properties after production of the vulcanizate.

Examples of such a modifier include, but are not limited to, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl group]1, 3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, N¹- (3- (bis (3- (trimethoxysilyl) propyl) amino) propyl) -N¹-methyl-N³- (3- (methyl (3- (trimethoxysilyl) propyl) amino) propyl) -N³- (3- (trimethoxysilyl) propyl) -1, 3-propanediamine.

The amount of the compound represented by the formula (VI) added as the modifier can be adjusted so that the number of moles of the conjugated diene polymer is reacted with the number of moles of the modifier in a desired stoichiometric ratio, thereby achieving a desired degree of branching.

The specific mole number of the conjugated diene polymer, that is, the mole number of the polymerization initiator is preferably 1.0 time by mole or more, more preferably 2.0 times by mole or more, relative to the mole number of the modifier. In this case, in the formula (VI), the number of functional groups of the modifier ((m-1). times.i + p.times.j + k) is preferably an integer of 1 to 10, more preferably an integer of 2 to 10.

< hydrogenation step >

The modified conjugated diene polymer (a) may be one in which the conjugated diene portion has been hydrogenated. The method for hydrogenating the conjugated diene portion is not particularly limited, and a known method can be used.

A suitable hydrogenation method is a method in which hydrogenation is carried out by blowing gaseous hydrogen into a polymer solution in the presence of a catalyst.

Examples of the catalyst include heterogeneous catalysts such as a catalyst in which a noble metal is supported on a porous inorganic substance; a homogeneous catalyst such as a catalyst obtained by solubilizing a salt of nickel, cobalt or the like and reacting the solubilized salt with an organoaluminum or the like, and a catalyst using a metallocene such as titanocene. Among these, a titanocene catalyst is preferable in that mild hydrogenation conditions can be selected. In addition, the hydrogenation of the aromatic group can be carried out by using a supported catalyst of a noble metal.

Specific examples of the hydrogenation catalyst include, but are not limited to: (1) a supported heterogeneous hydrogenation catalyst in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, or diatomaceous earth; (2) so-called ziegler-type hydrogenation catalysts using organic acid salts such as Ni, Co, Fe, and Cr, transition metal salts such as acetylacetone salts, and reducing agents such as organic aluminum; (3) and so-called organometallic complexes such as organometallic compounds of Ti, Ru, Rh, Zr, etc. Further, as the hydrogenation catalyst, there may be mentioned, for example, known hydrogenation catalysts described in 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, Japanese patent publication No. 2-9041, and Japanese patent application laid-open No. 8-109219. As a preferred hydrogenation catalyst, a reaction mixture of a titanocene compound and a reducing organometallic compound can be mentioned.

< addition of deactivator, neutralizer, etc. >

In the step of producing the modified conjugated diene polymer (a), a deactivator, a neutralizer, or the like may be added to the modified conjugated diene polymer solution after the reaction step, as necessary.

Examples of the deactivator include, but are not limited to, water; alcohols such as methanol, ethanol, and isopropanol. Examples of the neutralizing agent include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and versatic acid (a multi-branched carboxylic acid mixture having 9 to 11 carbon atoms and 10 centers); aqueous solution of inorganic acid, carbon dioxide.

< addition of rubber stabilizer and extender oil >

The modified conjugated diene polymer (a) is preferably added with a rubber stabilizer in order to prevent gel formation after polymerization and to improve stability during processing. As the rubber stabilizer, known ones can be used, and preferred ones are, but not limited to, antioxidants such as 2, 6-di-t-butyl-4-hydroxytoluene (BHT), n-octadecyl-3- (4 ' -hydroxy-3 ', 5 ' -di-t-butylphenol) propionate, and 2-methyl-4, 6-bis [ (octylthio) methyl ] phenol.

In order to further improve the processability of the modified conjugated diene polymer (a), extender oil may be added to the modified conjugated diene copolymer (a) as required.

As a method of adding the extender oil to the modified conjugated diene polymer, the following methods are preferable, but not limited to: extender oil is added to the polymer solution, and the mixture is mixed to prepare an oil-extended copolymer solution, and then the solvent is removed. Examples of the extender oil include aromatic oil, naphthenic oil, and paraffin oil. Among these, in terms of environmental safety and performance for preventing oil leakage and wet grip, it is preferable that the polycyclic aromatic component (PCA) based on the IP346 method is a substitute aromatic oil having a content of 3 mass% or less. As alternative perfume oils, there may be mentioned TDAE (Treated distilled Aromatic Extracts), MES (Mild Extraction solvent), etc., shown in Kautschuk Gummi Kunststoffe 52(12)799(1999), and RAE (residual Aromatic Extracts). The amount of the extender oil is not particularly limited, and is preferably 10 parts by mass or more and 60 parts by mass or less, and more preferably 20 parts by mass or more and 37.5 parts by mass or less, per 100 parts by mass of the modified conjugated diene polymer (a).

As a method for obtaining the modified conjugated diene polymer (a) from the polymer solution, a known method can be used. Examples of the method include: a method in which a polymer is filtered out after separating a solvent by steam stripping or the like, and is further dehydrated and dried to obtain a polymer; a method of concentrating with a flash tank and further devolatilizing with an exhaust extruder or the like; a method of directly performing devolatilization using a rotary dryer or the like.

((B) adhesion imparting resin)

The modified conjugated diene polymer composition of the present embodiment contains (B) an adhesion imparting resin.

(B) The adhesion-imparting resin is a resin generally used for the purpose of imparting the following properties.

a) Imparting adhesion

b) Adjusting Tg of the composition (adjusting peak position of tan. delta.)

c) Imparting rigidity

Examples of the tackiness imparting resin (B) include, but are not limited to, coumarone-indene resins, C5 resins, C9 resins, C5-C9 resins, dicyclopentane resins, terpene-phenol resins, rosins, modified rosins, alkylphenol resins, alkylphenol-formaldehyde resins, styrene- α -methylstyrene resins, and the like.

The C5 resin, C9 resin and C5-C9 resin are petroleum resins. The C5 resin is a resin obtained by using a C5 fraction or a purified component thereof as a raw material, the C9 resin is a resin obtained by using a C9 fraction or a purified component thereof as a raw material, and the C5-C9 resin is a copolymer resin obtained by using a mixture of a C5 fraction or a purified component thereof and a C9 fraction or a purified component thereof as a raw material.

Each resin may exhibit only one of the above-described imparting properties, or may exhibit 2 or more.

The solubility parameter (SP value) of the tackiness imparting resin (B) is preferably in the range of 7.5 to 9.5. (A) The SP value of the modified conjugated diene polymer varies back and forth depending on the amount of styrene as a comonomer component thereof and the ratio of 1, 4-bonded vinyl groups to1, 2-bonded vinyl groups contained in butadiene as a comonomer component, but is approximately 8.5. It is known that the differences in SP values (Δ SP) are close to each other, and are compatible and incompatible as far as they are away from each other, but if the SP value of the adhesion-imparting resin (B) is within the above range, the adhesion-imparting resin (B) and the modified conjugated diene polymer (a) are compatible, partially compatible or incompatible, and the adhesion-imparting resin (B) is finely dispersible in a microscopic state, and is not peeled off when the modified conjugated diene polymer (a) is prepared.

Specific trade names of the (B) tackiness imparting resin include the following resins.

(1) Benzofuran-indene resins

Kumaron V-120, manufactured by Nissan chemical Co., Ltd

NOBARES C150 and C160 manufactured by Rutgers Chemicals

(2) C5 resin

QUINTON A100, manufactured by Zeon corporation of Japan

Manufactured by Toyobo chemical Co., Ltd., ESCOREZ1102

(3) C9 resin

Neopolymers L90, 140, 170S manufactured by New Japan petrochemical Co., Ltd

(4) C5-C9 resin grease

ECR213 manufactured by Exxon Mobil chemical Co., Ltd

QUINTON G100B, manufactured by Zeon corporation of Japan

(5) Dicyclopentane resin

Arkon M90, manufactured by Mitsuka chemical Co Ltd

Arkon M135, a chemical company of Mitsuga

I-Marv P140, manufactured by shingling products Co., Ltd

Manufactured by Zeon corporation of japan, trade name: QUINTON 1100, 1105

Marukarez M-890A, manufactured by Marukarez petrochemical Co

(6) Terpene resin and terpene-phenol resin

YS Polymer T100, T115, T145, T160, manufactured by YASUHARA CHEMICAL Co

Clearon P125, P150, manufactured by YASUHARA CHEMICAL Co., Ltd

YS Resin PX-1250, TO125, manufactured by YASUHARA CHEMICAL Co., Ltd

Sylvares TP115, manufactured by Arizona Chemical Co., Ltd

(7) Rosin and modified rosin

Hairojin (ハイロジン) S manufactured by Irec corporation

Haritack AQ-90A, manufactured by Harima Chemicals industries, Ltd

(8) Alkylphenol resin

R7510PJ manufactured by SI GROUP Corp

(9) Alkylphenol-formaldehyde resin

SUMITOMO BAKELITE, SUMITLIT RESIN PR-13349, PR-12686

Manufactured by Nippon catalyst, Inc., SP1068

Manufactured by BASF corporation, Koresin

(10) Styrene- α -methylstyrene resin

Neopoloxamer 170S manufactured by Nippon petrochemicals

Sylvares SA85, SA140, manufactured by Arizona Chemicals

Norsolene W120, manufactured by Total Petrochemicals

When these (B) adhesion-imparting resins are blended with a general modified conjugated diene polymer, hysteresis loss is inferior to that in the case of no blending, contrary to the effects of the above-mentioned a) to c), and as a result, fuel efficiency of the tire is deteriorated. When a general conjugated diene polymer is replaced with the modified conjugated diene polymer (a) constituting the modified conjugated diene polymer composition of the present embodiment, a sufficient function of reducing hysteresis loss can be exhibited even if the adhesion-imparting resin (B) is blended. The mechanism has not been determined, and the present inventors have assumed the following two mechanisms.

Presumption mechanism 1):

it is presumed that the deterioration of the dispersibility of the (B) adhesive property in the modified conjugated diene polymer composition to the resin itself is one of the causes of the deterioration of the hysteresis loss. (A) The modified conjugated diene polymer can improve the dispersibility of the silica filler and exhibit a function of reducing hysteresis loss, and can exert the same function as the modified conjugated diene polymer with respect to the dispersibility of the (B) adhesion-imparting resin, whereby it is presumed that hysteresis loss can be sufficiently reduced even if the (B) adhesion-imparting resin is compounded.

Putative mechanism 2):

it is presumed that the adhesiveness of the (B) adhesiveness imparting resin acts on the silica-based filler, and as a result, the dispersibility of the silica-based filler is deteriorated. On the other hand, by replacing the known conjugated diene polymer with the modified conjugated diene polymer (a) described above, it is presumed that the dispersibility of the modified conjugated diene polymer (a) in the silica filler is better than the adhesive force of the adhesion-imparting resin (B), and that the hysteresis loss can be sufficiently reduced even when the adhesion-imparting resin (B) is compounded.

[ modified conjugated diene Polymer composition ]

The modified conjugated diene polymer composition of the present embodiment contains 2 to 30 parts by mass of the adhesion imparting resin as the component (B) per 100 parts by mass of the modified conjugated diene polymer as the component (a).

(B) The amount of the component (b) is preferably 5 to 20 parts by mass, more preferably 5 to 10 parts by mass.

(B) The component needs to be 2 parts by mass or more because 2 parts by mass or more is required to exhibit a function as the adhesion-imparting resin; on the other hand, the reason why the amount of the component (B) is 30 parts by mass or less is that the hysteresis loss reducing effect of the modified conjugated diene polymer can be sufficiently exhibited by 30 parts by mass or less.

(rubbery Polymer)

The modified conjugated diene polymer composition of the present embodiment may further contain (a) a modified conjugated diene polymer and (B) a polymer other than the adhesion-imparting resin.

Examples of the polymer other than the above-mentioned polymer include a rubbery polymer (hereinafter, simply referred to as "rubbery polymer") and a resinous polymer.

Examples of the rubbery polymer include, but are not limited to, a conjugated diene polymer such as polybutadiene or a hydrogenated product thereof, a random copolymer of a conjugated diene monomer and a vinyl aromatic monomer or a hydrogenated product thereof, a block copolymer of a conjugated diene monomer and a vinyl aromatic monomer or a hydrogenated product thereof, a non-diene polymer, and natural rubber. Specific examples of the rubbery polymer include, but are not limited to, styrene-based elastomers such as butadiene rubber or a hydrogenated product thereof, isoprene rubber or a hydrogenated product thereof, styrene-butadiene block copolymer or a hydrogenated product thereof, and styrene-isoprene block copolymer or a hydrogenated product thereof, and nitrile rubber or a hydrogenated product thereof.

Examples of the non-diene polymer include, but are not limited to, olefin elastomers such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, and ethylene-octene rubber, butyl rubber, bromobutyl rubber, acrylic rubber, fluorine rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β -unsaturated nitrile-acrylate-conjugated diene copolymer rubber, urethane rubber, and polysulfide rubber.

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

Examples of the mixing method in the case where the modified conjugated diene polymer composition of the present embodiment is used by mixing with another polymer other than the above-mentioned component (a) and component (B) include a method of mixing a solution of the modified conjugated diene polymer with a solution of another polymer, a method of mechanically mixing the modified conjugated diene polymer with another polymer, and the like.

The other polymer may be a modified rubber to which a functional group having polarity such as a hydroxyl group or an amino group is added. In the case of use for tire applications, butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, butyl rubber are preferably used.

When the other polymer is a rubbery polymer, the weight average molecular weight thereof is preferably 2,000 to 2,000,000, more preferably 5,000 to1,500,000, from the viewpoint of balance between performance and processing characteristics. In addition, a low molecular weight rubbery polymer, so-called liquid rubber, can also be used. These rubbery polymers may be used alone or in combination of two or more.

[ Polymer composition ]

The polymer composition of the present embodiment contains the modified conjugated diene polymer composition of the present embodiment and other components.

In this case, the content of the modified conjugated diene polymer composition is preferably 10% by mass or more, more preferably 30% by mass or more, and further preferably 50% by mass or more, from the viewpoint of processability.

[ rubber composition ]

The rubber composition of the present embodiment comprises 100 parts by mass of a rubbery polymer comprising 10% by mass or more of the modified conjugated diene polymer composition of the present embodiment and 5 to 150 parts by mass of a filler.

The content ratio (mass ratio) of the modified conjugated diene polymer composition to the other rubbery polymer in terms of (modified conjugated diene polymer composition/other rubbery polymer) is preferably from 10/90 to 100/0, more preferably from 20/80 to 90/10, and still more preferably from 50/50 to 80/20.

Therefore, the modified conjugated diene polymer composition is preferably contained in the rubbery polymer component in an amount of 10 parts by mass or more and 100 parts by mass or less, more preferably 20 parts by mass or more and 90 parts by mass or less, and still more preferably 50 parts by mass or more and 80 parts by mass or less, based on the total amount (100 parts by mass) of the rubbery polymer component.

When the content ratio of (modified conjugated diene polymer composition/other rubbery polymer) is in the above range, the vulcanizate produced has an excellent balance between hysteresis loss resistance and wet skid resistance, and satisfactory wear resistance and fracture strength.

The modified conjugated diene polymer composition of the present embodiment is suitably used as a sulfide.

Examples of the vulcanizate include, for example, tires, hoses, shoe soles, vibration-proof rubbers, automobile parts, vibration-free rubbers, and further, resin-reinforcing rubbers such as high impact polystyrene and ABS resins.

The modified conjugated diene polymer composition is particularly suitable for use in a tread rubber composition for a tire. The sulfide can be obtained, for example, as follows: the modified conjugated diene polymer composition of the present embodiment is kneaded with, if necessary, a silica-based inorganic filler, an inorganic filler such as carbon black, a rubber-like polymer other than the modified conjugated diene polymer of the present embodiment, a silane coupling agent, a rubber softener, a vulcanizing agent, a vulcanization accelerator, a vulcanization aid, and the like to prepare a modified conjugated diene polymer composition, and then heated and vulcanized to obtain a vulcanizate.

The rubber composition of the present embodiment comprises 100 parts by mass of the rubbery polymer and 5 to 150 parts by mass of the filler, and the rubbery polymer comprises 10% by mass or more of the modified conjugated diene copolymer composition of the present embodiment.

The filler preferably contains a silica-based inorganic filler.

In the rubber composition, the silica-based inorganic filler is dispersed, so that the processability in producing a vulcanizate tends to be more excellent, and the balance between the hysteresis loss resistance and the wet skid resistance, the breaking strength and the abrasion resistance after producing a vulcanizate tend to be more excellent.

The rubber composition of the present embodiment preferably contains a silica-based inorganic filler even when used for automobile parts such as tires and vibration-proof rubbers, and vulcanized rubber applications such as shoes.

Examples of the filler 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, preferably 10 parts by mass or more and 120 parts by mass or less, and more preferably 20 parts by mass or more and 100 parts by mass or less, relative to 100 parts by mass of the rubber component comprising the modified conjugated diene polymer composition.

The content of the filler is 5.0 parts by mass or more in order to exhibit the effect of adding the filler, and 150 parts by mass or less in order to sufficiently disperse the filler and practically satisfy the processability and mechanical strength of the rubber composition.

The silica-based inorganic filler is not particularly limited, and a known silica-based inorganic filler can be used, and preferably contains SiO₂Or Si₃Solid particles of Al as a structural unit, more preferably SiO₂Or Si₃Solid particles of Al as the main component of the structural unit. The main component is a component contained in the silica-based inorganic filler by 50 mass% or more, preferably 70 mass% or more, and more preferably 80 mass% or more.

Specific examples of the silica-based inorganic filler include, but are not limited to, inorganic fibrous materials such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber. Further, there may be mentioned a silica-based inorganic filler having a hydrophobic surface, and a mixture of a silica-based inorganic filler and an inorganic filler other than silica. Among these, silica and glass fiber are preferable, and silica is more preferable, from the viewpoint of strength, abrasion resistance and the like. Examples of the silica include dry silica, wet silica, and synthetic silicate silica. Among these silicas, wet silicas are preferred in that the effect of improving the fracture properties and the balance of wet skid resistance are excellent.

The nitrogen adsorption specific surface area of the silica-based inorganic filler determined by the BET adsorption method is preferably 100m in view of obtaining practically excellent wear resistance and fracture characteristics of the rubber composition²300m above g²A ratio of 170m or less²More than 250 m/g²The ratio of the carbon atoms to the carbon atoms is less than g. In addition, the specific surface area can be made relatively small (for example, 200 m) as required²A/g or less) silica-based inorganic filler and a relatively large specific surface area (e.g., 200 m)²/g or more) of a silica-based inorganic filler.

In the present embodiment, the specific surface area is relatively large (e.g., 200 m) in particular when used²In the case of a silica-based inorganic filler (a) or more), the modified conjugated diene-based polymer (a) has an effect of improving the dispersibility of silica, particularly the abrasion resistance, and tends to be capable of highly balancing good fracture characteristics and low hysteresis loss.

The content of the silica-based inorganic filler in the rubber composition is preferably 5.0 parts by mass or more and 150 parts by mass or less, and more preferably 20 parts by mass or more and 100 parts by mass or less, per 100 parts by mass of the rubber-like polymer component including the modified conjugated diene-based polymer composition.

The content of the silica-based inorganic filler is preferably 5.0 parts by mass or more in terms of exhibiting the effect of adding the inorganic filler; the amount of the inorganic filler is preferably 150 parts by mass or less in order to sufficiently disperse the inorganic filler and practically satisfy the processability and mechanical strength of the composition.

Examples of the carbon black include, but are not limited to, various grades of carbon black such as SRF, FEF, HAF, ISAF, and SAF. Of these, the nitrogen adsorption specific surface area is preferably 50m²A carbon black having a dibutyl phthalate (DBP) oil absorption of 80mL/100g or less.

The content of the carbon black is preferably 0.5 to 100 parts by mass, more preferably 3.0 to 100 parts by mass, and still more preferably 5.0 to 50 parts by mass, based on 100 parts by mass of the rubber-like polymer component containing the modified conjugated diene polymer composition. The content of carbon black is preferably 0.5 parts by mass or more in terms of performance required for applications such as tires exhibiting dry grip performance, conductivity, and the like, and is preferably 100 parts by mass or less in terms of dispersibility.

The metal oxide is solid particles having a chemical formula MxOy (M represents a metal atom, and x and y each independently represent an integer of 1 to 6) as a main component of a structural unit.

Examples of the metal oxide include, but are not limited to, aluminum oxide, titanium oxide, magnesium oxide, and zinc oxide. Examples of the metal hydroxide include, but are not limited to, aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

The rubber composition may contain a silane coupling agent.

The silane coupling agent has a function of making the interaction between the rubber component and the inorganic filler tight, and has groups having affinity or bonding properties with respect to the rubber component and the silica-based inorganic filler, respectively, and is preferably a compound having a sulfur-bonding portion and an alkoxysilyl group or silanol group portion in one molecule. Examples of such compounds include bis [3- (triethoxysilyl) -propyl ] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl ] -disulfide, and bis- [2- (triethoxysilyl) -ethyl ] -tetrasulfide.

The content of the silane coupling agent is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and still more preferably 1.0 to 15 parts by mass, based on 100 parts by mass of the inorganic filler. When the content of the silane coupling agent is within the above range, the above-mentioned effect of adding the silane coupling agent tends to be more remarkable.

The rubber composition of the present embodiment may contain a rubber softener in order to improve the processability thereof.

As the softener for rubber, mineral oil or a liquid or low molecular weight synthetic softener is suitable. A softening agent for mineral oil-based rubber, which is called process oil or extender oil and is used for softening, extending and improving the processability of rubber, is a mixture of aromatic rings, naphthenic rings and paraffinic chains, a substance having 50% or more of the total carbon atoms in the paraffinic chains is called paraffinic, a substance having 30% or more and 45% or less of the total carbon atoms in the naphthenic rings is called naphthenic, and a substance having more than 30% of the total carbon atoms in the aromatic rings is called aromatic.

(A) When the modified conjugated diene polymer is a copolymer of a conjugated diene compound and a vinyl aromatic compound, the softening agent for rubber used is preferably a softening agent for rubber having an appropriate aromatic content because the softening agent for rubber tends to have good fusibility with the copolymer.

The content of the rubber softener is preferably 0 to 100 parts by mass, more preferably 10 to 90 parts by mass, and still more preferably 30 to 90 parts by mass, based on 100 parts by mass of the rubber-like polymer component containing the modified conjugated diene polymer (a). When the content of the rubber softener is 100 parts by mass or less based on 100 parts by mass of the rubber-like polymer component, bleeding can be suppressed, and stickiness on the surface of the rubber composition can be suppressed.

The method of mixing the modified conjugated diene polymer composition of the present embodiment with additives such as other rubber-like polymers, silica-based inorganic fillers, carbon black, other fillers, silane coupling agents, and rubber softeners includes, but is not limited to, a melt-kneading method using a common mixer such as an open mill, a banbury mixer, a kneader, a single-screw extruder, a twin-screw extruder, and a multi-screw extruder; dissolving and mixing the components, and heating to remove the solvent.

Among these methods, a melt kneading method using a roll, a banbury mixer, a kneader, or an extruder is preferable from the viewpoint of productivity and good kneading property. Further, any of a method of kneading the rubber component with other fillers, silane coupling agents and additives at once and a method of mixing the components 2 or more times can be applied.

The rubber composition of the present embodiment can be vulcanized by a vulcanizing agent to prepare a vulcanized composition. Examples of the vulcanizing agent include, but are not limited to, radical initiators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur-containing compounds. The sulfur-containing compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, polymer polysulfide compounds, and the like. The content of the vulcanizing agent is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, per 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 ℃ to 200 ℃ and more preferably 140 ℃ to 180 ℃.

In the vulcanization, a vulcanization accelerator may be used as needed.

As the vulcanization accelerator, conventionally known materials can be used, and examples thereof include, but are not limited to, sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, thiourea-based, and dithiocarbamate-based vulcanization accelerators. Examples of the vulcanization aid include, but are not limited to, zinc white and stearic acid. The content of the vulcanization accelerator is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, per 100 parts by mass of the rubber component.

In the rubber composition of the present embodiment, various additives such as other softening agents and fillers, heat stabilizers, antistatic agents, weather stabilizers, antioxidants, colorants, lubricants and the like may be used within the range not to impair the object of the present embodiment.

As the other softener, a known softener can be used. Specific examples of the other fillers include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. As the heat stabilizer, antistatic agent, weather stabilizer, aging inhibitor, colorant and lubricant, known materials can be used.

(method for producing rubber composition)

The method for producing a rubber composition of the present embodiment comprises a step of kneading 100 parts by mass of the modified conjugated diene polymer (A), 2 to 30 parts by mass of the adhesion-imparting resin (B), and 5 to 150 parts by mass of the filler containing silica (C). This production method is a preferred embodiment of the method for producing the composition.

(C) The filler contains silica as an essential component, and may contain an arbitrary component together with silica as the essential component.

The silica constituting the filler (C) may be silica generally used as a filler, and is preferably synthetic silicic acid having a primary particle diameter of 50nm or less, from the viewpoint of rolling resistance and rebound resilience of a rubber elastomer obtained from the rubber composition.

The content ratio of silica constituting the filler (C) is preferably 10 to 120 parts by mass, more preferably 20 to 100 parts by mass, per 100 parts by mass of the rubber-like polymer component containing the modified conjugated diene polymer (a) and the tackiness-imparting resin (B).

In both cases where the content ratio of the filler (C) is too small and where it is too large, the balance between the hardness and the rolling resistance in the rubber elastomer obtained from the rubber composition may deteriorate.

The filler (C) may contain an arbitrary component in addition to the essential component of silica, and examples of the arbitrary component include inorganic oxides such as alumina, titanium oxide, calcium oxide, and magnesium oxide; inorganic hydroxides such as aluminum hydroxide and magnesium hydroxide; carbonates such as magnesium carbonate, etc., and they may be used alone or in combination of 2 or more.

The rubber composition may contain the above-mentioned optional components as needed, in addition to the modified conjugated diene polymer (a), the tackiness-imparting resin (B), and the filler containing silica (C) as fillers, which are essential components.

Such a rubber composition can be produced, for example, as follows: the rubber composition is produced by mixing and kneading (a) the modified conjugated diene polymer, (B) the tackiness imparting resin, (C) the silica-containing filler as the filler, and optional components as required, using plutomill as essential components.

(A) Since the modified conjugated diene polymer (B) functions to increase the dispersibility of silica and the tackiness-imparting resin (B) functions to decrease the dispersibility of silica, the dispersibility of silica can be controlled by the mixing ratio thereof, and thus the dispersibility of silica can be improved in terms of the balance between rolling resistance and rebound resilience in the rubber elastomer obtained from the rubber composition.

Therefore, according to the rubber composition of the present embodiment, a rubber elastic body having a small rolling resistance and an excellent rebound resilience can be obtained.

The method for producing a rubber composition preferably comprises kneading 100 parts by mass of the modified conjugated diene polymer (A) with 5 to 150 parts by mass of the silica-containing filler (C), and then kneading the resulting kneaded product with 2 to 30 parts by mass of the adhesion-imparting resin (B).

Specifically, the modified conjugated diene polymer (a), the filler (C) and, if necessary, optional components are kneaded, and then the adhesion-imparting resin (B) is added to the kneaded mixture, followed by further kneading.

When the modified conjugated diene polymer (a) and the filler (C) are kneaded and then the obtained kneaded product is kneaded with the adhesion-imparting resin (B), the dispersibility of silica in the rubber composition can be further improved, and therefore the obtained rubber elastomer has a further reduced rolling resistance and excellent rebound resilience.

The method for producing the rubber composition is not limited to the method of kneading the modified conjugated diene polymer (a) and the filler (C) and then kneading the obtained kneaded product and the adhesion-imparting resin (B) and kneading them, and for example, the method may be a method of simultaneously kneading the modified conjugated diene polymer (a), the adhesion-imparting resin (B), the filler (C) and, if necessary, optional components as essential components.

Examples of the method for mixing the modified conjugated diene polymer composition with additives such as other rubbery polymers, silica-based inorganic fillers, carbon black, other fillers, silane coupling agents, and rubber softeners include, but are not limited to, melt-kneading methods using common mixers such as open mills, banbury mixers, kneaders, single-screw extruders, twin-screw extruders, and multi-screw extruders; dissolving and mixing the components, and heating to remove the solvent. Among these, a melt kneading method using a roll, a banbury mixer, a kneader, or an extruder is preferable from the viewpoint of productivity and good kneading property.

[ tires ]

The rubber composition containing the modified conjugated diene polymer composition of the present embodiment is suitably used as a rubber composition for a tire.

The rubber composition for a tire of the present embodiment can be applied to, for example, but not limited to, various tire parts such as treads, tire carcasses, beads, and beads of various tires such as fuel-efficient tires, all season tires, high performance tires, and studless tires. In particular, the rubber composition for a tire containing the modified conjugated diene polymer composition of the present embodiment is excellent in the balance between low hysteresis loss properties and wet skid resistance and wear resistance after being vulcanized, and therefore is more suitable for use as a tread of a fuel-efficient tire or a high-performance tire.