JP2020026524A - Modified conjugated diene polymer composition, method for producing modified conjugated diene polymer composition, and tire - Google Patents

Abstract

To provide a modified conjugated diene polymer composition that makes it possible to obtain a rubber composition keeping a good balance between snow performance and wet performance at high levels and also having excellent wear resistance.SOLUTION: A modified conjugated diene polymer composition has a rubber component A that is a modified conjugated diene polymer with a glass transition temperature of -35°C or more, a rubber component B with a glass transition temperature of -55°C or less, and a filler. Relative to the total amount ot the rubber component A and the rubber component B, the rubber component A is 50 mass% or more and 95 mass% or less. The rubber component A has a weight average molecular weight of 20×10or more and 300×10or less and a molecular weight distribution Mw/Mn of 1.6 or more and 4.0 or less. The rubber component A has a denaturation rate of 50 mass% or more.SELECTED DRAWING: None

Description

  The present invention relates to a modified conjugated diene-based polymer composition, a method for producing the modified conjugated diene-based polymer composition, and a tire.

In recent years, in winter tires, in addition to running performance on snowy roads (snow performance), improvement in running performance on wet road surfaces (wet performance) has been required.
Furthermore, due to social demands for reducing the burden on the global environment, demands for extending the life of tires have increased, and there has been a strong demand for improvements in wear resistance of tire performance.

Conventionally, in order to improve snow performance, the elasticity at low temperatures has been reduced and the tread rubber has a high trackability on snowy roads. Methods such as increasing the amount have been proposed.
However, such a method has a problem that the wet performance and abrasion resistance tend to decrease.

On the other hand, in order to improve the wet performance, a method of increasing the glass transition temperature of the rubber composition or increasing the energy loss by increasing the amount of filler added has been proposed.
However, such a method has a problem that the elastic modulus at a low temperature is improved and the snow performance tends to be reduced.
Particularly in recent years, maintenance of road surface conditions in winter has been progressing, and in winter tires, improvement of performance not only on snowy roads but also on wet roads has become increasingly important.

  Patent Document 1 proposes a rubber composition in which both snow performance and wet performance are improved by blending rubber components having different glass transition temperatures.

JP 2005-154473 A

  However, the rubber composition described in Patent Document 1 does not have sufficient reactivity between the modified group of the terminal-modified styrene-butadiene rubber and silica, and there is room for further improvement in both the snow performance and the wet performance. There is a problem that there is.

  Thus, in the present invention, a modified conjugated diene-based polymer having a good dispersibility of silica as a filler, an excellent balance between snow performance and wet performance, and a rubber composition excellent in abrasion resistance is obtained. It is intended to provide a composition.

The present inventors have conducted intensive studies in order to solve the above-mentioned problems of the prior art, and as a result, a modified conjugated diene polymer composition containing two types of rubber components A and B having different glass transition temperatures and a filler. By specifying the content, weight average molecular weight, molecular weight distribution, and modification rate of the rubber component A having a higher glass transition temperature than the rubber component B in the product, the balance between the snow performance and the wet performance is improved. , And excellent abrasion resistance were obtained, and completed the present invention.
That is, the present invention is as follows.

[1]
A rubber component A which is a modified conjugated diene polymer having a glass transition temperature of -35 ° C or higher;
A rubber component B having a glass transition temperature of -55 ° C or less;
A filler,
Containing,
The rubber component A is 50% by mass or more and 95% by mass or less based on the total amount of the rubber component A and the rubber component B,
The rubber component A has a weight average molecular weight of 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, a molecular weight distribution Mw / Mn of 1.6 or more and 4.0 or less, and a modification rate of the rubber component A of 50 mass%. % Or more,
A modified conjugated diene polymer composition.
[2]
The rubber component A is a peak permeation in a gel permeation chromatography (GPC) curve, or a modification of a component having a molecular weight that is の the molecular weight of a peak top having a minimum molecular weight when a plurality of the peak tops are present. The modified conjugated diene-based polymer composition according to the above [1], wherein the ratio is at least の of the modification rate based on the total amount of the conjugated diene-based polymer.
[3]
The modification rate of the rubber component A is 75% by mass or more,
The nitrogen content is 25 mass ppm or more;
The modified conjugated diene-based polymer composition according to the above [1] or [2].
[4]
The shrinkage factor (g ′) of the rubber component A by 3D-GPC is 0.70 or less.
The modified conjugated diene-based polymer composition according to any one of the above [1] to [3].
[5]
The rubber component B is
The weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, the molecular weight distribution Mw / Mn is 1.6 or more and 4.0 or less, the denaturation rate is 50% by mass or more, and gel permeation chromatography ( GPC) curve, or the modification rate of a component having a molecular weight that is の of the molecular weight of the peak top having the minimum molecular weight when a plurality of the peak tops are present, is based on the total amount of the conjugated diene-based polymer. A modified conjugated diene-based polymer having a modification ratio of 1/2 or more,
The modified conjugated diene-based polymer composition according to any one of the above [1] to [4].
[6]
A method for producing a modified conjugated diene-based polymer composition according to any one of the above [1] to [5],
Kneading the rubber component B and the filler to obtain a kneaded material;
A step of kneading the kneaded product and the rubber component A,
A method for producing a modified conjugated diene-based polymer composition having:
[7]
A tire comprising the modified conjugated diene-based polymer composition according to any one of [1] to [5].

  ADVANTAGE OF THE INVENTION According to this invention, the balance of snow performance and wet performance is highly excellent, and the modified conjugated diene polymer composition from which the rubber composition excellent in abrasion resistance can be obtained can be provided.

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

(Modified conjugated diene polymer composition)
The modified conjugated diene-based polymer composition of the present embodiment,
A rubber component A which is a modified conjugated diene polymer having a glass transition temperature of -35 ° C or higher;
A rubber component B having a glass transition temperature of -55 ° C or less;
A filler,
Containing,
The rubber component A is 50% by mass or more and 95% by mass or less based on the total amount of the rubber component A and the rubber component B,
The rubber component A has a weight average molecular weight of 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, a molecular weight distribution Mw / Mn of 1.6 or more and 4.0 or less, and a modification rate of the rubber component A of 50 mass%. % Or more.

(Modified conjugated diene polymer (rubber component A))
The modified conjugated diene-based polymer composition of the present embodiment contains a rubber component A that is a modified conjugated diene-based polymer having a glass transition temperature of −35 ° C. or higher.
The rubber component A has a weight average molecular weight of 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, a molecular weight distribution Mw / Mn of 1.6 or more and 4.0 or less, and a modification rate with respect to the total amount of the conjugated diene polymer. It is 50% by mass or more.
From the viewpoint of improving the abrasion resistance, the rubber component A preferably has a weight average molecular weight of more than 50 × 10 ⁴ and 300 × 10 ⁴ or less. When the weight-average molecular weight is larger than 50 × 10 ^{4, the} amount of the polymerization initiator to be used is small, so that the termination or chain transfer of the growth reaction is a component having a molecular weight that is の of the molecular weight at the peak top in the GPC curve. Has a greater effect on the denaturation rate. For this reason, it is necessary to achieve ultra-high purity, low-temperature polymerization, and a monomer conversion of less than 99% by mass of a monomer and a solvent to be introduced into the polymerization reactor to obtain a modified conjugated diene-based polymer having a desired modification rate. Becomes difficult.
Since the rubber component A constituting the modified conjugated diene-based polymer composition of the present embodiment has a preferable form in which the modification rate of a predetermined low molecular weight component is specified as described later, the weight average of the rubber component A is used. Preferably, the molecular weight is greater than 50 × 10 ⁴ .

The modified conjugated diene-based polymer composition of the present embodiment contains the rubber component A in an amount of 50% by mass or more based on the total amount of the rubber component A and the rubber component B. Thereby, the glass transition temperature of the modified conjugated diene-based polymer composition of the present embodiment is improved, and the wet performance tends to be excellent. It is preferably at least 55% by mass, more preferably at least 60% by mass.
The upper limit is set to 95% by mass or less, preferably 90% by mass or less, and more preferably 80% by mass or less. When the content of the rubber component A is 95% by mass or less, when the vulcanized product is softened at a low temperature, it tends to have excellent snow performance.

(Method for producing modified conjugated diene polymer (rubber component A))
The modified conjugated diene polymer (rubber component A) is produced by a polymerization step and a modification step described below.
<Polymerization step>
In the polymerization step of the modified conjugated diene polymer (rubber component A), at least the conjugated diene compound is polymerized using an organolithium compound as a polymerization initiator to obtain a conjugated diene polymer.
The polymerization step is preferably polymerization by a growth reaction of a living anionic polymerization reaction, whereby a conjugated diene-based polymer having an active end can be obtained, and a modified conjugated diene-based polymer having a high modification rate tends to be obtained. It is in.

In the polymerization step, at least the conjugated diene compound is polymerized, and if necessary, both the conjugated diene compound and the vinyl-substituted aromatic compound are copolymerized to obtain a conjugated diene-based polymer.
The conjugated diene compound is not particularly limited as long as it is a polymerizable monomer, but is preferably a conjugated diene compound having 4 to 12 carbon atoms per molecule, more preferably a conjugated diene compound having 4 to 8 carbon atoms. Compound.
Such conjugated diene compounds are not limited to the following, but include, for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1 , 3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene.
Among them, 1,3-butadiene and isoprene are preferred from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

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

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

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

[Polymerization initiator]
As the polymerization initiator in the polymerization step, at least an organic lithium compound is used as described above.
Examples of the organolithium compound include, but are not limited to, low molecular weight compounds and solubilized oligomeric organolithium compounds.
In addition, examples of the organic lithium 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 a bonding mode of the organic group and the lithium.
The amount of the polymerization initiator used is preferably determined according to the target molecular weight of the conjugated diene-based polymer or the modified conjugated diene-based polymer. The amount of the monomer such as the conjugated diene compound relative to the amount of the polymerization initiator used is related to the degree of polymerization. That is, it tends to be related to the number average molecular weight and / or the weight average molecular weight. Therefore, in order to increase the molecular weight, it is preferable to adjust the amount of the polymerization initiator to decrease, and to decrease the molecular weight, it is preferable to adjust the amount to increase the amount of the polymerization initiator.
The organic lithium compound as the polymerization initiator is preferably an alkyl lithium compound from the viewpoint of industrial availability and easy control of the polymerization reaction. In this case, a conjugated diene-based polymer having an alkyl group at the polymerization start terminal is obtained.

The alkyl lithium compound as the polymerization initiator is not limited to the following, for example, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, n-hexyl lithium, benzyl lithium, phenyl lithium, and stilbene lithium Is mentioned.
As the alkyllithium compound, n-butyllithium and sec-butyllithium are preferable from the viewpoint of industrial availability and easy control of the polymerization reaction.

A method using a compound having a nitrogen-lithium bond as a polymerization initiator (hereinafter sometimes referred to as a lithium amide compound) is used as one method for introducing a nitrogen atom into a conjugated diene-based polymer. Examples of the lithium amide compound include an alkyllithium compound having a substituted amino group and a dialkylaminolithium compound. In this case, a conjugated diene-based polymer and a modified conjugated diene-based polymer having a functional group represented by, for example, the following general formula (1) and having a nitrogen atom composed of an amino group at the polymerization initiation terminal are obtained.
By introducing a nitrogen atom into a conjugated diene-based polymer, low hysteresis loss property and wet skid resistance tend to be improved.

In the general formula (1), R ¹ and R ² are selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, and an aryl group having 6 to 20 carbon atoms. And it may be the same or different. Here, R ¹ and R ² may combine to form a cyclic structure with an adjacent nitrogen atom, and in that case, R ¹ and R ² are a hydrocarbon group having a total carbon number of 4 to 12. It is. R ¹ and R ² may have an unsaturated bond or may have a branched structure.

  Examples of the alkyllithium compound having a substituted amino group or the dialkylaminolithium compound include a compound represented by the following general formula (2).

In the general formula (2), R ¹ and R ² are each selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, and an aryl group having 6 to 20 carbon atoms. And may be the same or different. Here, R ¹ and R ² may combine to form a cyclic structure with an adjacent nitrogen atom, and in that case, R ¹ and R ² are a hydrocarbon group having a total carbon number of 4 to 12. It is. R ¹ and R ² may have an unsaturated bond or may have a branched structure.

  Examples of the compound represented by the formula (2) include, but are not limited to, 1-lithiopyrrolidine, 1-lithiopiperidine, 1-lithioazacycloheptane, 1-lithioazacyclooctane, -Lithioazacycloundecane, lithium diethylamide, lithium dibutylamide, lithium dihexylamide, 6-lithio-1,3,3-trimethyl-6-azabicyclo [3.2.1] octane, lithium ethylbutylamide, lithium ethylhexylamide, Examples thereof include lithium butylhexylamide, lithium methylphenylamide, lithium benzylmethylamide, and 1-lithio-1,2,3,4-tetrahydropyridine. The compound represented by the formula (2) is not limited to these, but includes analogs thereof if the above conditions are satisfied.

From the viewpoint of reducing the hysteresis loss of the modified conjugated diene-based polymer composition of the present embodiment, as the compound represented by the formula (2), 1-lithiopyrrolidine, 1-lithiopiperidine, 1-lithioazacycloheptane, Preferred are lithium dibutylamide, 6-lithio-1,3,3-trimethyl-6-azabicyclo [3.2.1] octane, 1-lithio-1,2,3,4-tetrahydropyridine and the like.
More preferred are 1-lithiopyrrolidine, 1-lithiopiperidine, and 1-lithioazacycloheptane, and even more preferred are 1-lithiopiperidine and 1-lithioazacycloheptane.

The lithium amide compound as the polymerization initiator can be synthesized by a known method.
For example, it can be obtained by reacting a secondary amine with an organolithium compound in a hydrocarbon solvent.

Examples of the hydrocarbon solvent include, but are not limited to, hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specifically, 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; Hydrocarbons composed of a mixture thereof are exemplified.
Examples of the secondary amine include, but are not limited to, compounds represented by the following general formula (3).

In the formula (3), R ¹ and R ² are each selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, and an aryl group having 6 to 20 carbon atoms. And may be the same or different. R ¹ and R ² may combine to form a cyclic structure with an adjacent nitrogen atom, in which case R ¹ and R ² are a hydrocarbon group having a total of 4 to 12 carbon atoms. R ¹ and R ² may have an unsaturated bond or may have a branched structure.

Examples of the compound represented by the formula (3) include pyrrolidine, piperidine, azacycloheptane, azacyclooctane, azacycloundecane, diethylamine, dibutylamine, dihexylamine, 1,3,3-trimethyl-6-azabicyclo [3.2.1] Octane, ethylbutylamine, ethylhexylamine, butylhexylamine, methylphenylamine, benzylmethylamine, 1,2,3,4-tetrahydropyridine and the like. The compound represented by the formula (3) is not limited thereto, and includes analogs thereof if the above conditions are satisfied.
From the viewpoint of reducing the hysteresis loss of the modified conjugated diene polymer composition of the present embodiment, the compound represented by the formula (3) includes pyrrolidine, piperidine, azacycloheptane, dibutylamine, 1,3,3- Trimethyl-6-azabicyclo [3.2.1] octane and 1,2,3,4-tetrahydropyridine are preferred. More preferred are pyrrolidine, piperidine and azacycloheptane. More preferred are piperidine and azacycloheptane.

  These lithium amide compounds can also be used as a solubilized oligomeric organic monolithium compound by reacting a small amount of a polymerizable monomer, for example, a monomer such as 1,3-butadiene, isoprene, or styrene. .

The above-mentioned organic lithium compound as a polymerization initiator may be used alone or in combination of two or more.
Moreover, you may use together with another organometallic compound. Examples of the organic metal compound include an alkaline earth metal compound, another alkali metal compound, and another organic metal compound.
The alkaline earth metal compound is not limited to the following, but includes, for example, an organic magnesium compound, an organic calcium compound, and an organic strontium compound.
Also included are compounds of alkoxides, sulfonates, carbonates and amides of alkaline earth metals.
Examples of the organomagnesium compound include dibutylmagnesium and ethylbutylmagnesium.
Examples of other organometallic compounds include, for example, organoaluminum compounds.

As a polymerization reaction mode in the polymerization step, it is preferable to carry out a continuous polymerization reaction mode.
In a continuous system, the polymerization can be carried out using one or more connected reactors.
As the continuous reactor, for example, a tank type with a stirrer or a tube type is used.
In the continuous method, preferably, a monomer, an inert solvent, and a polymerization initiator are continuously fed to a reactor, and a polymer solution containing a polymer is obtained in the reactor. The solution is drained.

[Polymerization solvent]
In the polymerization step, an inert solvent is preferably used as a polymerization solvent, and the polymerization is preferably performed in the inert solvent.
Examples of the inert solvent include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. 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; Examples include aromatic hydrocarbons such as benzene, toluene, and xylene, and hydrocarbons composed of mixtures thereof.

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

[Polar compounds]
In the polymerization step, a polar compound may be added. By adding a polar compound, an aromatic vinyl compound can be randomly copolymerized with a conjugated diene compound, and tends to be used as a vinylating agent for controlling the microstructure of the conjugated diene portion. Also, it tends to be effective in accelerating the polymerization reaction.
Examples of the polar compound include, but are not limited to, tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, 2,2-bis (2-oxolanyl) ) Ethers such as propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclidine; potassium-tert-amylate, potassium-tert-butyrate, sodium-tert-butyrate; Alkali metal alkoxide compounds such as sodium amylate; phosphine compounds such as triphenylphosphine; It is.
These polar compounds may be used alone or in combination of two or more.
The amount of the polar compound to be used is not particularly limited and can be selected according to the purpose and the like. Such a polar compound (vinylating agent) can be used as a regulator of the microstructure of the conjugated diene portion of the polymer in an appropriate amount depending on the desired amount of vinyl bonds.
Many polar compounds have an effective randomizing effect at the same time in the copolymerization of the conjugated diene compound and the aromatic vinyl compound, and tend to be used as a regulator of the distribution of the aromatic vinyl compound and as a regulator of the styrene block amount. It is in. As a method for randomizing a conjugated diene compound and an aromatic vinyl compound, for example, as described in JP-A-59-140221, the total amount of styrene and a part of 1,3-butadiene are used together. A method in which the polymerization reaction is started and the remaining 1,3-butadiene is added intermittently during the copolymerization reaction may be used.

<Physical properties of the modified conjugated diene polymer>
The modified conjugated diene-based polymer (rubber component A) that constitutes the modified conjugated diene-based polymer composition of the present embodiment has a minimum molecular weight when a GPC curve has a plurality of peak tops. It is preferable that the modification ratio of the component having a molecular weight (low molecular weight component) that is の of the molecular weight of the peak top is not less than の of the modification ratio with respect to the total amount of the conjugated diene polymer.
Further, when the rubber component B described later is a modified conjugated diene-based polymer, the rubber component B similarly has a peak top in the GPC curve, or the molecular weight is minimum when a plurality of the peak tops are present. It is preferable that the modification ratio of a component having a molecular weight that is の of the molecular weight of a certain peak top, that is, the modification ratio of the low molecular weight component is １ ／ or more of the modification ratio based on the total amount of the conjugated diene polymer.
This is because the low molecular weight component in the whole polymer is considered to contribute to the processability of the polymer, but when it is in the above range, it tends to be excellent in processability when vulcanized. .

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

Ultra-high purity of the monomer and the solvent can be achieved by sufficiently purifying all the monomers and the solvent used for the polymerization.
In the purification of butadiene as a monomer, it is important to remove not only the polymerization inhibitor but also dimethylamine, N-methyl-γ-aminobutyric acid and the like which may adversely affect anionic polymerization. As a method for removing these, for example, 1,3-butadiene containing a polymerization inhibitor is washed with low-oxygen water having an oxygen concentration of less than 2 mg / L as washing water, and then 1,3-butadiene is washed with 1,3-butadiene. A method of removing the polymerization inhibitor from butadiene is exemplified.
In the purification of styrene as a monomer, it is important to remove phenylacetylenes and the like, which may adversely affect anionic polymerization. As a method of removing phenylacetylenes, for example, a method of performing a hydrogenation reaction using a palladium-supported alumina catalyst may be mentioned.
In the purification of normal hexane which is a polymerization solvent, it is important to remove water which may adversely affect anionic polymerization. As a method for removing this, for example, a method using γ-alumina, synthetic zeolite or the like can be mentioned. Among these, a method using a synthetic zeolite is preferable. As the synthetic zeolite, those having a large pore diameter are preferable, those having a pore diameter of 0.35 nm or more are more preferable, and those having a pore diameter of 0.42 nm or more are still more preferable.

As a polymerization method in which the growth reaction is stopped or the chain transfer is extremely small, in addition to the purification of the monomer and the solvent described above, a method of controlling the polymerization temperature and controlling the monomer conversion in the polymerization step is effective. .
From the viewpoint of stopping the growth reaction or suppressing chain transfer, the polymerization temperature is preferably lower, but from the viewpoint of productivity, the polymerization temperature is preferably a temperature at which living anionic polymerization proceeds sufficiently, and specifically, The temperature is preferably 0 ° C. or higher, and more preferably 80 ° C. or lower. More preferably, it is 50 ° C. or more and 75 ° C. or less.
Further, the conversion rate of the whole monomer is less than 99% by mass, and it is preferable to react with a modifier in a modification step described later. A modifier is added at the stage where the monomer remains in the polymerization vessel, and the growing polymer chain reacts with the modifier before the monomer has been consumed, so that the weight at which the terminal end is not modified is increased. Formation of coalescence and other side reactions can be suppressed. More preferably, the monomer conversion is less than 98% by weight.

When the modified conjugated diene-based polymer (rubber component A) constituting the modified conjugated diene-based polymer composition of the present embodiment and the rubber component B described later are modified conjugated diene-based polymers, these are included. The amount of the bonded conjugated diene in the modified conjugated diene-based polymer constituting the modified conjugated diene-based polymer composition of the present embodiment is preferably from 40% by mass to 100% by mass, and more preferably from 55% by mass to 90% by mass. % Is more preferable.
Further, the amount of bound aromatic vinyl in the conjugated diene-based polymer or the modified conjugated diene-based polymer is not particularly limited, but is preferably 0% by mass to 60% by mass, and is preferably 10% by mass to 45% by mass. Is more preferable.
When the amount of the bonded conjugated diene and the amount of the bonded aromatic vinyl are in the above ranges, the vulcanized product tends to be more excellent in balance between snow performance and wet performance and abrasion resistance. Here, the amount of the bound aromatic vinyl can be measured by the ultraviolet absorption of the phenyl group, and the amount of the bound conjugated diene can be determined therefrom. Specifically, it can be measured according to the method described in Examples described later.

When the rubber component A and the rubber component B described later are modified conjugated diene-based polymers, the conjugated diene-based polymer or the modified conjugated diene-based polymer has a vinyl bond content in the conjugated diene bond unit of 10 mol%. It is preferably at least 75 mol% and more preferably at least 20 mol% and at most 65 mol%. When the vinyl bond content is in the above range, the balance between snow performance and wet performance when the vulcanized product is obtained and the abrasion resistance tend to be more excellent.
Here, when the modified conjugated diene-based polymer is a copolymer of butadiene and styrene, the butadiene-bonded unit is obtained by the Hampton method (RR Hampton, Analytical Chemistry, 21, 923 (1949)). Of the vinyl bond (1,2-bond amount) can be determined. Specifically, it is measured by a method described in Examples described later.

<Modification step>
After the above-described polymerization step, a modification step is performed on the conjugated diene-based polymer to obtain a modified conjugated diene-based polymer.
When the rubber component B described below is a modified conjugated diene-based polymer, the modification reaction step can be performed by the same method.
In the modification step, the conjugated diene-based polymer obtained by the method described above has a binding group that reacts with the active terminal of the conjugated diene-based polymer, and further has an affinity or binding reactivity with the filler. Reaction with a predetermined modifier having a predetermined functional group.
Further, it is preferable to carry out the modification step immediately after the polymerization step. In that case, a modified conjugated diene-based polymer having a high modification rate tends to be obtained.

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

[Modifier]
The modifier will be specifically described below.
Examples of the nitrogen-containing compound include, but are not limited to, an isocyanate compound, an isothiocyanate compound, an isocyanuric acid derivative, a nitrogen-containing carbonyl compound, a nitrogen-containing vinyl compound, and a nitrogen-containing epoxy compound. Can be
Examples of the silicon-containing compound include, but are not limited to, silicon halide compounds, epoxidized silicon compounds, vinylated silicon compounds, alkoxysilicon compounds, and alkoxysilicon compounds containing a nitrogen-containing group.
The tin-containing compound is not limited to the following, but examples thereof include a tin halide compound and an organic tin carboxylate compound.
Examples of the phosphorus-containing compound include, but are not limited to, a phosphite compound and a phosphino compound.
Examples of the oxygen-containing compound include, but are not limited to, an epoxy compound, an ether compound, and an ester compound.
Examples of the sulfur-containing compound include, but are not limited to, a mercapto group derivative, a thiocarbonyl compound, and isothiocyanate.
Examples of the halogen-containing compound include, but are not limited to, the above-mentioned silicon halide compounds and tin halide compounds.
Examples of the onium generator include, but are not limited to, a protected amine compound capable of forming a primary or secondary amine (forming ammonium), and a protected amine compound capable of forming a hydrophosphine. Phosphine compounds (forming phosphonium), compounds capable of forming hydroxyl groups and thiols (forming oxonium and sulfonium), and the like. It is preferable to use a terminal modifying agent having in each molecule.
Examples of the functional group for binding the modified conjugated diene polymer include a carbonyl group (ketone, ester, etc.), an unsaturated group such as a vinyl group, an epoxy group, a silicon halide group, and an alkoxysilicon group.

  The modifier is preferably a compound having a nitrogen-containing functional group, and the compound having the nitrogen-containing functional group is preferably an amine compound having no active hydrogen, for example, a tertiary amine compound, Examples include a protected amine compound in which 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 a modifier are not limited to the following, but include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, and polymeric. Diphenylmethane diisocyanate (C-MDI), phenyl isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, butyl isocyanate, 1,3,5-benzene triisocyanate and the like.

  Examples of the nitrogen-containing isocyanuric acid derivative as a modifier include, but are not limited to, 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate and 1,3,5-tris (3-triethoxysilylpropyl) isocyanurate, 1,3,5-tri (oxiran-2-yl) -1,3,5-triazinan-2,4,6-trione, 1,3,5-tris ( (Isocyanatomethyl) -1,3,5-triazinan-2,4,6-trione, 1,3,5-trivinyl-1,3,5-triazinan-2,4,6-trione and the like.

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

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

  Examples of the nitrogen-containing epoxy compound as a modifier include, but are not limited to, an epoxy group-containing hydrocarbon compound bonded to an amino group, and further having an epoxy group bonded to an ether group. You may. For example, a compound represented by the general formula (4) is given.

In the above formula (4), R represents a divalent or higher valent hydrocarbon group, a polar group having oxygen such as ether, epoxy or ketone; a polar group having sulfur such as thioether or thioketone; a tertiary amino group; It is a divalent or higher organic group having at least one polar group selected from nitrogen-containing polar groups such as a group.
The divalent or higher valent hydrocarbon group is a saturated or unsaturated hydrocarbon group which may be linear, branched or cyclic, and includes an alkylene group, an alkenylene group, a phenylene group and the like. Preferably, it is a hydrocarbon group having 1 to 20 carbon atoms. For example, methylene, ethylene, butylene, cyclohexylene, 1,3-bis (methylene) -cyclohexane, 1,3-bis (ethylene) -cyclohexane, o-, m-, p-phenylene, m-, p-xylene, Bis (phenylene) -methane and the like can be mentioned.
In the formula (4), R ¹ and R ⁴ are a hydrocarbon group having 1 to 10 carbon atoms, and R ¹ and R ⁴ may be the same or different from each other.
R ² and R ⁵ are hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, and R ² and R ⁵ may be the same or different from each other.
R ³ is a hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (5).
R ¹ , R ² and R ³ may have a cyclic structure bonded to each other.
When R ³ is a hydrocarbon group, it may have a cyclic structure bonded to R. In the case of the above-mentioned cyclic structure, a form in which N and R bonded to R ³ are directly bonded may be used.
In the formula (4), n is an integer of 1 or more, and m is 0 or an integer of 1 or more.

In the formula (5), R ^1, R ² is R ^1, R ² the same definition in the formula (4), R ^1, R ² may be the being the same or different.

As the nitrogen group-containing epoxy compound as a modifier, those having an epoxy group-containing hydrocarbon group are preferable, and those having a glycidyl group-containing hydrocarbon group are more preferable.
Examples of the epoxy group-containing hydrocarbon group bonded to an amino group or an ether group include a glycidylamino group, a diglycidylamino group, and a glycidoxy group. A more preferred molecular structure is an epoxy group-containing compound having a glycidylamino group or diglycidylamino group, and a glycidoxy group, respectively, and examples thereof include a compound represented by the following general formula (6).

In the formula (6), R is defined in the same manner as R in the formula (4), and R ⁶ is a hydrocarbon group having 1 to 10 carbon atoms or a structure of the following formula (7).
When R ⁶ is a hydrocarbon group, it may be bonded to R to form a cyclic structure, in which case, N and R bonded to R ⁶ may be directly bonded. .
In the above formula (6), n is an integer of 1 or more, and m is 0 or an integer of 1 or more.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The reaction temperature in the modification step is preferably the same as the polymerization temperature of the conjugated diene-based polymer, and particularly preferably a temperature at which no heating is performed after the polymerization. The temperature is more preferably from 0 ° C to 120 ° C, even more preferably from 50 ° C to 100 ° C.
The reaction time in the denaturation step is preferably at least 10 seconds, more preferably at least 30 seconds.
The mixing of the conjugated diene polymer and the modifier in the modification step may be performed by any mixing method such as mechanical stirring or stirring by a static mixer. When the polymerization step is of a continuous type, the modification step is preferably of a continuous type. As the reactor in the denaturation step, for example, a tank type with a stirrer or a tube type is used. The modifier may be diluted with an inert solvent and continuously supplied to the reactor.
As the modifier, a compound represented by the following general formula (8) is preferable.

In the formula (8), R ^{12 to} R ¹⁴ each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms, and R ^{15 to} R ¹⁸ and R ²⁰ each independently represent a 1 to 1 carbon atom. 20 represents an alkyl group, R ¹⁹ and R ²² each independently represent an alkylene group having 1 to 20 carbon atoms, and R ²¹ represents an alkyl group having 1 to 20 carbon atoms or a trialkylsilyl group.
m represents an integer of 1 to 3, and p represents 1 or 2.
When a plurality of R ^{12 to} R ²² , m and p are present, each is independent.
i represents an integer of 0 to 6, j represents an integer of 0 to 6, k represents an integer of 0 to 6, and (i + j + k) represents an integer of 1 to 10.
A has a single bond, a hydrocarbon group having 1 to 20 carbon atoms, or at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom, and a phosphorus atom; Represents an organic group having no organic group.
The hydrocarbon group represented by A includes saturated, unsaturated, aliphatic, and aromatic hydrocarbon groups. The organic group having no active hydrogen is an organic group that inactivates the active terminal of the conjugated diene polymer. As the organic group, there is no functional group having an active hydrogen such as a hydroxyl group (—OH), a secondary amino group (> NH), a primary amino group (—NH ₂ ), and a sulfhydryl group (—SH). Group. When (i + j + k) is 1, A may be omitted.

  In the formula (8), A preferably represents any one of the following general formulas (9) to (12).

In the formula (9), B ¹ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B ¹ has a plurality of independent groups when there are a plurality of them. are doing.

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

In the formula (11), B ⁴ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B ⁴ , when two or more exist, is each independently ing.

In the above formula (12), B ⁵ represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and B ⁵ is independently formed when a plurality of B ⁵ are present. ing.
In the formula (8), when A represents any one of the formulas (9) to (12), a modified conjugated diene-based polymer having more excellent performance tends to be obtained.

  Examples of the denaturant of the formula (8) include those in which (i + j + k) is 1 to 2, including, but not limited to, those described above, for example, 3-dimethoxymethylsilyl Propyldimethylamine (monofunctional), 3-trimethoxysilylpropyldimethylamine (bifunctional), bis (3-trimethoxysilylpropyl) methylamine (tetrafunctional), bis (3-dimethoxymethylsilylpropyl) methylamine (2 (Functional), (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] ethylamine (tetrafunctional), [3- (2,2-dimethoxy-) 1-aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl) methylamine (tetrafunctional), bis [3- ( , 2-Dimethoxy-1-aza-2-silacyclopentane) propyl] methylamine (tetrafunctional), bis (3-triethoxysilylpropyl) ethylamine (tetrafunctional), 1- (3-triethoxysilylpropyl)- 2,2-diethoxy-1-aza-2-silacyclopentane (tetrafunctional), 1- (3-dimethoxymethylsilylpropyl) -2,2-dimethoxy-1-aza-2-silacyclopentane (trifunctional) , [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-diethoxyethylsilylpropyl) methylamine (trifunctional), bis [3- (2,2-diethoxy) -1-aza-2-silacyclopentane) propyl] methylamine (tetrafunctional), (3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trime Rushiriru 1-sila-2-aza-cyclopentane) propyl] - and methyl amine (trifunctional) is.

  As a polyfunctional compound which is a modifier of the formula (8), (i + j + k) is 3 or more, and in the formula (8), as a modifier when A is represented by the formula (9) Is not limited to, for example, tris (3-trimethoxysilylpropyl) amine, bis (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-sila Cyclopentane) propyl] amine, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl) amine, tris [3- (2,2- Dimethoxy-1-aza-2-silacyclopentane) propyl] amine, tris (3-ethoxysilylpropyl) amine, bis (3-triethoxysilylpropyl)-[3- (2,2-die Xy-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-aza) Cyclopentane) propyl] -1,3-propanediamine, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) pro Pill]-(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-silacyclo) Pentane) propyl] -1,3-propanediamine, tris [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl) -1,3-propane Diamine, tetrakis [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tris (3-triethoxysilylpropyl)-[3- (1-ethoxy) -2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-propanediamine, bis (3-triethoxysilylpropyl)-[3- (2,2-diethoxy-1-aza-2) -Silacyclopentane) propyl]-[3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1, -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-trimethoxy Silylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-bisamino Methylcyclohexane, 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-Dimethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bisaminomethyl Cyclohexane, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trimethylsilyl-1-sila) -2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tris [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1-methoxy -2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tetrakis (3- Liethoxysilylpropyl) -1,3-propanediamine, tris (3-triethoxysilylpropyl)-[3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl] -1,3- Bisaminomethylcyclohexane, bis (3-triethoxysilylpropyl) -bis [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tris [ 3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl) -1,3-propanediamine, tetrakis [3- (2,2-diethoxy-1) -Aza-2-silacyclopentane) propyl] -1,3-propanediamine, tris (3-triethoxysilylpropyl)-[3 -(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, bis (3-triethoxysilylpropyl)-[3- (2,2- Diethoxy-1-aza-2-silacyclopentane) propyl]-[3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, bis [3- (2,2-Diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl)-[3- (1-ethoxy-2-trimethylsilyl-1-sila-2- Azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tris [3- (2,2-diethoxy-1-aza-2-sila) Clopentane) propyl]-[3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -1,3-bisaminomethylcyclohexane, tetrakis (3-trimethoxysilylpropyl) -1 , 6-hexamethylenediamine, pentakis (3-trimethoxysilylpropyl) -diethylenetriamine.

In the above formula (8), the modifying agent when A is represented by the above formula (10) is not limited to the following, but for example, tris (3-trimethoxysilylpropyl) -methyl-1,3 -Propanediamine, bis (2-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -methyl-1,3-propanediamine, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-trimethoxysilylpropyl) -methyl-1,3-propanediamine, tris (3-triethoxysilylpropyl) -methyl- 1,3-propanediamine, bis (2-triethoxysilylpropyl)-[3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl -Methyl-1,3-propanediamine, bis [3- (2,2-diethoxy-1-aza-2-silacyclopentane) propyl]-(3-triethoxysilylpropyl) -methyl-1,3-propane ^{diamine, N 1, N 1 '-} ( propane-1,3-diyl) bis (N ¹ - methyl -N ^3, N ³ - bis (3- (trimethoxysilyl) propyl) -1,3-propanediamine) , N ¹ - (3- (bis (3- (trimethoxysilyl) propyl) amino) propyl) -N ¹ - methyl -N ³ - (3- (methyl (3- (trimethoxysilyl) propyl) amino) propyl ) -N ³ - (3- (trimethoxysilyl) propyl) -1,3-propane diamine.

  In the formula (8), examples of the modifying agent when A is represented by the formula (11) 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-trimethoxysilyl) Propyl) -bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, (3-trimethoxysilyl)-[3- (1-methoxy- -Trimethylsilyl-1-sila-2-azacyclopentane) -bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, bis [3- (1-methoxy-2-) Trimethylsilyl-1-sila-2-azacyclopentane) -bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, tris (3-trimethoxysilylpropyl)-[3 -(2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, bis (3-trimethoxysilylpropyl)-[3- (1-methoxy-2-trimethylsilyl-1-sila-2-) Azacyclopentane) propyl]-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] silane, bis [3- (1-methoxy) 2-trimethylsilyl-1-sila-2-azacyclopentane) propyl] -bis (3-trimethoxysilylpropyl) silane, bis (3-trimethoxysilylpropyl) -bis [3- (1-methoxy-2-methyl) -1-sila-2-azacyclopentane) propyl] silane.

  In the formula (8), the modifying agent when A is represented by the formula (12) is not limited to the following, but for example, 3-tris [2- (2,2-dimethoxy-1-) Aza-2-silacyclopentane) ethoxy] silyl-1- (2,2-dimethoxy-1-aza-2-silacyclopentane) propane, 3-tris [2- (2,2-dimethoxy-1-aza-) 2-silacyclopentane) ethoxy] silyl-1-trimethoxysilylpropane.

  In the formula (8), examples of the modifier in the case where A represents an organic group having an oxygen atom and having no active hydrogen include, but are not limited to, the following. Methoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] ether (tetrafunctional), 3,4,5-tris (3-trimethoxysilylpropyl) -cyclohexyl -[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] ether (8-functional).

  In the formula (8), examples of the modifier when A represents a phosphorus atom and an organic group having no active hydrogen include, but are not limited to, the following. Methoxysilylpropyl) 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. Can be

In the above formula (8), A preferably represents the above formula (9) or the above formula (10), and k represents 0. This tends to be a readily available modifier, and when the modified conjugated diene-based polymer is a vulcanizate, the abrasion resistance and the low hysteresis loss tend to be more excellent.
Such a modifier is not limited to the following, but for example, bis (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] Amine, tris (3-trimethoxysilylpropyl) amine, tris (3-triethoxysilylpropyl) amine, tris (3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2- Silacyclopentane) propyl] -1,3-propanediamine, tetrakis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tetrakis (3-tri Methoxysilylpropyl) -1,3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1,3-bisamino Tylcyclohexane, tris (3-trimethoxysilylpropyl) -methyl-1,3-propanediamine, bis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl]-(3-tris (Methoxysilylpropyl) -methyl-1,3-propanediamine.

In the formula (8), A more preferably represents the formula (9) or the formula (10), k represents 0, and in the formula (9) or the formula (10), a is an integer of 2 to 10. Represents By using a modified conjugated diene-based polymer produced using such a modifying agent, when vulcanized, abrasion resistance and low hysteresis loss tend to be more excellent.
Such modifiers are not limited to the following, but include, for example, tetrakis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1,3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1,3-bisaminomethylcyclohexane, N ^1- (3- (bis (3- (trimethoxysilyl) ) propyl) amino) propyl) -N ¹ - methyl -N ³ - (3- (methyl (3- (trimethoxysilyl) propyl) amino) propyl) -N ³ - (3- (trimethoxysilyl) propyl) - 1,3-propanediamine is exemplified.

The amount of the compound represented by the formula (8) as the modifier is preferably adjusted so that the mole number of the polymerization initiator to the mole number of the modifier has a desired stoichiometric ratio. Thereby, a desired degree of branching is achieved in the modified conjugated diene-based polymer.
Specifically, the number of moles of the polymerization initiator is preferably at least 1.0 times, more preferably at least 2.0 times the number of moles of the modifying agent. In this case, in Formula (8), the number of functional groups ((m−1) × i + p × j + k) of the modifier is preferably an integer of 1 to 10, and more preferably an integer of 2 to 10.

<Glass transition temperature of modified conjugated diene polymer (rubber component A)>
The modified conjugated diene-based polymer (rubber component A) has a glass transition temperature of −35 ° C. or higher. Preferably it is -30 ° C or higher, more preferably -25 ° C or higher.
The glass transition temperature of the modified conjugated diene-based polymer (rubber component A) can be adjusted by adjusting the above-mentioned microstructure, that is, by adjusting the amount of the aromatic vinyl compound and the amount of vinyl bond in the modified conjugated diene-based polymer. It can be controlled within the above numerical range.
When the glass transition temperature is in the above range, there is a tendency that a more excellent vulcanizate can be obtained by balancing snow performance and wet performance.
Regarding the glass transition temperature, according to ISO 22768: 2006, a DSC curve is recorded while the temperature is raised within a predetermined temperature range, and the peak top (Inflection point) of the DSC differential curve is defined as the glass transition temperature. Specifically, it can be measured by the method described in Examples described later. Although the upper limit of the glass transition temperature of the modified conjugated diene-based polymer (rubber component A) is not particularly limited, it is preferably −10 ° C. or lower. When it is in this range, the balance between the snow performance and the wet performance tends to be more excellent.

<Addition of rubber stabilizer, extender oil, etc.>
The modified conjugated diene-based polymer constituting the modified conjugated diene-based polymer composition of the present embodiment has a rubber stabilizer from the viewpoint of preventing gel formation after polymerization and improving stability during processing. Is preferably added.
In this case, the modified conjugated diene-based polymer contains a rubber component A, and when the rubber component B is a modified conjugated diene-based polymer, it also contains this.
Known rubber stabilizers can be used, and are not limited to the following. For example, 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl- Antioxidants such as 3- (4'-hydroxy-3 ', 5'-di-tert-butylphenol) propionate and 2-methyl-4,6-bis [(octylthio) methyl] phenol are exemplified.
In order to further improve the processability of the modified conjugated diene-based polymer, extender oil can be added to the modified conjugated diene-based copolymer as needed.
The method for adding the extender oil to the modified conjugated diene-based polymer is not limited to the following method, but the extender oil is added to the polymer solution, mixed, and the oil-extended copolymer solution is desolvated. The method is preferred.
The time at which the extender oil is added is not limited to the following, but after the modification step and before mixing the polymerization solution, that is, after the modification step of the modified conjugated diene-based polymer of the rubber component A (and the rubber component B), Before mixing the respective polymerization solutions of the rubber component A and the rubber component B, or after mixing both polymerization solutions, that is, after the modification step of the rubber component A (and the rubber component B), After mixing the solution. From the viewpoint that the viscosity of the polymerization solution decreases when the extender oil is mixed, and the polymer solution is easily mixed, it is preferable to mix both polymerization solutions after the modification step.
Examples of the extending oil include aroma oil, naphthenic oil, paraffin oil and the like. Among these, an aroma substitute oil having a polycyclic aromatic (PCA) component of 3% by mass or less according to the IP346 method is preferred from the viewpoint of environmental safety, oil bleed prevention and wet grip characteristics.
As aroma substitute oils, TDAE (Treated Distillate Aromatic Extracts) shown in Kautschuk Gummi Kunststoff 52 (12) 799 (1999), MES (Mild ExtractRatioRate, etc.) are also available.
The amount of the extender oil is not particularly limited, but is preferably 5 parts by mass or more and 60 parts by mass or less based on 100 parts by mass of the modified conjugated diene-based polymer.

<Modification rate>
The modified conjugated diene-based polymer (rubber component A) has a modification rate of 50% by mass or more, preferably 60% by mass or more, more preferably 75% by mass or more based on the total amount of the conjugated diene-based polymer.
When the modification rate is 50% by mass or more, the reactivity with silica as a filler when a vulcanized product is formed is improved, and the dispersibility of silica in the vulcanized product tends to be improved. As a result, the temperature dispersion peak of the viscoelasticity becomes sharp, and the wet performance tends to be excellent.

The modification rate is the content of the polymer component having a specific functional group having affinity or binding reactivity to silica as a filler in a polymer molecule with respect to the total amount of the conjugated diene polymer in mass%. It is a representation.
As the polymer component having a specific functional group having affinity or binding reactivity to silica as a filler in the polymer molecule, preferably a polymer having a functional group containing a nitrogen atom, a silicon atom, and an oxygen atom Is mentioned. More preferably, it is a modified conjugated diene-based polymer having the functional group at the terminal of the polymer. For example, a polymer in which a functional group having a nitrogen atom is bonded to a polymerization start terminal and / or a modified conjugated diene-based polymer in which a terminal group is modified with a functional group containing a nitrogen atom, a silicon atom, and an oxygen atom at the end terminal. Can be

The modification ratio can be measured by chromatography that can separate a modified component having a functional group and a non-modified component. As a method using this chromatography, a column for gel permeation chromatography using a polar substance such as silica that adsorbs a specific functional group as a packing material is used, and quantification is performed using an internal standard of a non-adsorbed component for comparison. Method.
More specifically, the denaturation rate is calculated by calculating the difference between the chromatogram measured with a polystyrene-based gel column and the chromatogram measured with a silica-based column for a sample solution containing a measurement sample and a low-molecular-weight internal standard polystyrene, It can be obtained by measuring the amount of adsorption on.
The denaturation rate can be measured by the method described in Examples described later.

Examples of a method for controlling the modification ratio of the modified conjugated diene polymer to 50% by mass or more include a method of adjusting the amount of a modifier added and the conditions of the reaction step.
Here, the modified conjugated diene-based polymer includes a rubber component A constituting the modified conjugated diene-based polymer composition of the present embodiment, and a rubber component B described later is a modified conjugated diene-based polymer. In such a case, the rubber component B is also included.
For example, a method of polymerizing using an organic lithium compound having at least one nitrogen atom in a molecule described later as a polymerization initiator, a method of copolymerizing a monomer having at least one nitrogen atom in a molecule, a chain transfer reaction To prevent polymerization from being excessively promoted, a method of controlling polymerization conditions such as lowering the polymerization temperature.
The upper limit of the modification rate is not particularly limited, but is preferably 95% by mass or less. When the content is within this range, aggregation of the filler when it is formed into a vulcanized product can be suppressed, and the workability tends to be excellent.
As a method of controlling the modification rate of the modified conjugated diene-based polymer to 95% by mass or less, the amount of the modifying agent to be added is reduced (the number of moles of the functional group to which the modifying agent binds is smaller than the number of moles of the polymer chain). Or the amount of an organic lithium compound having at least one nitrogen atom in the molecule described below as a polymerization initiator is reduced (an organic lithium having a nitrogen atom and an organic lithium compound having no nitrogen atom). Using lithium as a polymerization initiator).

<Weight average molecular weight>
The modified conjugated diene-based polymer (rubber component A) has a weight average molecular weight of 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, preferably 30 × 10 ⁴ or more and 270 × 10 ⁴ or less, more preferably It is 40 × 10 ⁴ or more and 250 × 10 ⁴ or less.
When the weight average molecular weight is 20 × 10 ⁴ or more, the entanglement density between molecular chains is improved, and the breaking strength tends to be excellent. Also, the vulcanized product tends to have excellent wear resistance.
Further, when the weight average molecular weight is 300 × 10 ⁴ or less, the filler has excellent dispersibility when it is formed into a vulcanized product, and excellent wet performance tends to be obtained.
The weight average molecular weight of the modified conjugated diene-based polymer can be adjusted by appropriately selecting the ratio between the amount of the polymerization initiator used and the amount of the monomer used to adjust the molecular weight of the conjugated diene-based polymer chain or the type of the modifying agent. It can also be controlled by adjusting the amount used.
In addition, in this specification, a "molecular weight" is a standard polystyrene equivalent molecular weight obtained by GPC (gel permeation chromatography). The number average molecular weight, the weight average molecular weight, and the content of the molecular weight distribution can be measured by the methods described in Examples described later.

<Molecular weight distribution>
The modified conjugated diene-based polymer (rubber component A) has a molecular weight distribution Mw / Mn represented by a ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 1.6 or more and 4.0 or less. A modified conjugated diene-based polymer having a molecular weight distribution in this range tends to be more excellent in processability when forming a vulcanizate than a polymer having a similar molecular weight and a modification ratio. Preferably it is 1.8 or more and 3.0 or less, more preferably 1.9 or more and 2.5 or less.
The modified conjugated diene-based polymer having such a molecular weight distribution can be preferably obtained by continuous polymerization.
The molecular weight distribution is preferably a single peak (monomodal) molecular weight curve by GPC, or a trapezoidal or multi-peaked shape in the case of a plurality of peaks. The continuous peak type means that the height of the lowest part between the peaks is 50% or more of the height of the peaks on both sides. Modified conjugated diene polymers having such a molecular weight distribution tend to be more excellent in processability when vulcanized.
The molecular weight distribution can be adjusted by appropriately selecting the ratio between the amount of the polymerization initiator used and the amount of the monomer used, to adjust the molecular weight of the conjugated diene polymer chain, or to adjust the type of the modifier and the amount used or the polymerization temperature. By doing so, it can be controlled within the above range.

<Modification rate of low molecular weight component>
The modified conjugated diene-based polymer (rubber component A) has a peak weight in the GPC curve, or a molecular weight component which is の of the molecular weight of the peak weight having the minimum molecular weight when a plurality of the peaks are present. It is preferable that the modification ratio of the (low molecular weight component) is 1/2 or more of the modification ratio based on the total amount of the conjugated diene polymer.
When the modification ratio of the low-molecular-weight component of the modified conjugated diene-based polymer (rubber component A) is within the above range, the processability is excellent, and particularly when kneading with the filler, the torque of the mixer is sufficiently increased. In addition, the mixing properties of the rubber component A, the rubber component B described later, and the filler tend to be good. As a result, the dispersibility of the filler is improved, and the wet performance tends to be improved. As a result, the balance between the snow performance and the wet performance of the modified conjugated diene-based polymer composition can be improved.
The present inventors have found that, in addition to the fact that the modification ratio differs for each molecular weight region depending on the polymer, the following mechanism has been found as a method of transmitting torque when kneading the polymer and the filler. .
First, focusing on the modification ratio with respect to the total amount of the conjugated diene-based polymer, when the Mooney viscosity, the microstructure, the modifier used, and the kneading conditions of the polymer are the same, the modification ratio is high (denaturation). The polymer has a higher rate of increase in torque when kneaded with a filler than a polymer having a low modification rate, but on the other hand, the maximum value reached by the torque is high. Even if the denaturation rate changes, the time required to reach the maximum value of the torque is almost the same. In other words, the modification rate of the polymer as a whole affects both the maximum value of the torque and the rate of increase of the torque. As a result, even if the modification rate as a whole increases or decreases, the time required to reach the maximum value of the torque is obtained. It does not seem to have much effect on the length.
On the other hand, when focusing on the modification rate of the low molecular weight component, when the modification rate of the low molecular weight component is lower than the modification rate relative to the total amount of the conjugated diene polymer, the polymer is kneaded with a filler. The rate of increase in torque is slower, and the higher the rate of modification of the low molecular weight component with respect to the rate of modification with respect to the total amount of the conjugated diene polymer, the faster the rate of rise in torque.
On the other hand, since the maximum value of the torque is determined depending on the modification rate of the total amount of the conjugated diene-based polymer, the maximum value of the torque does not change depending on the modification rate of the low molecular weight component. Time to reach is shorter. For this reason, regardless of the modification rate with respect to the total amount of the conjugated diene-based polymer, the time required to reach the maximum value of the torque depends on the modification rate of the low molecular weight component with respect to the modification rate with respect to the total amount of the conjugated diene-based polymer. Can be controlled.
Specifically, by setting the modification ratio of the low molecular weight component to be at least 1/2 of the modification ratio relative to the total amount of the conjugated diene polymer, processability, particularly of the mixer when kneading with the filler. The torque is applied well, and the mixing properties of the rubber component A, the rubber component B, and the filler tend to be better in a shorter time than in the conventional case. As a result, the processability is improved, and the dispersibility of the filler is improved, so that the wet performance tends to be improved.

<Nitrogen content>
The nitrogen content of the modified conjugated diene-based polymer that is the rubber component A is preferably 25 mass ppm or more, more preferably 40 mass ppm or more, based on the total amount of the modified conjugated diene-based polymer. , And more preferably 60 ppm by mass or more.
When the nitrogen content is within this range, when the modified conjugated diene-based polymer composition of the present embodiment is used as a vulcanized product, the balance between low hysteresis and wet skid resistance tends to be excellent. Further, from the viewpoint of processability and the dispersibility of the filler when the vulcanized product, it is preferably 250 mass ppm or less, more preferably 150 mass ppm or less, and preferably 100 mass ppm or less. More preferred.
The nitrogen atom content can be measured by an oxidative combustion-chemiluminescence method (JIS-2609: crude oil and crude oil product-nitrogen content test method). More specifically, the content of the nitrogen atom can be measured by the method described in Examples described later.
Examples of a method for controlling the nitrogen content of the modified conjugated diene-based polymer as the rubber component A to 25 ppm by mass or more include a method of adjusting the type and / or the amount of the polymerization initiator, the modifier, and the monomer. For example, it is obtained by a method of polymerizing using an organolithium compound having at least one nitrogen atom in a molecule as described below as a polymerization initiator, or a method of copolymerizing a monomer having at least one nitrogen atom in a molecule. A method of reacting a conjugated diene-based polymer having a nitrogen atom with a modifying agent having at least one nitrogen atom in the molecule.

<Shrink factor>
The shrinkage factor (g ′) measured by GPC with a viscosity detector-light scattering method measurement (hereinafter also simply referred to as “GPC with a viscosity detector-light scattering method measurement” or “3D-GPC measurement”) is as follows. It 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 modified conjugated diene-based polymer (for example, the number of branches of a star polymer (also referred to as “the number of arms of a star polymer”)) increases. There is a tendency.
When comparing modified conjugated diene-based polymers having the same molecular weight, the more the number of branches of the modified conjugated diene-based polymer is, the smaller the contraction factor (g ') becomes. It can be used as an index of the degree.
Contractile factor (g ') is measured using a 3D-GPC measurement.
The constant (K, α) in the relational expression between intrinsic viscosity and molecular weight ([η] = KMα ([η]: intrinsic viscosity, M: molecular weight) is defined as log K = −3.883, α = 0.772, A graph of the relationship between the intrinsic viscosity [η] ₀ and the molecular weight M is created.
With respect to the standard intrinsic viscosity [η] ₀ , the intrinsic viscosity [η] at each molecular weight M of the sample obtained by the 3D-GPC measurement is defined as a relation of the intrinsic viscosity [η] to the standard intrinsic viscosity [η] ₀ [ η] / [η] ₀ is calculated for each molecular weight M, and the average value is defined as a shrinkage factor (g ′).
More specifically, it can be measured by the method described in Examples described later.

Among the modified conjugated diene-based polymers that are the rubber component A, those having a shrinkage factor (g ′) of 0.70 or less as measured using 3D-GPC are preferred.
More preferably, it is 0.30 or more and 0.70 or less.
In such a modified conjugated diene-based polymer, the viscosity of the rubber composition to which the filler is added is significantly reduced, and the processability is extremely excellent.
The shrinkage factor (g ′) is an index of the branched structure of the modified conjugated diene-based copolymer. It is a modified conjugated diene-based polymer having four or more branches in one molecule of the polymer.
In order to obtain a modified conjugated diene-based copolymer in which the shrinkage factor (g ′) is in the above range, for example, a modifier having four or more reaction points with a living active terminal is added to the total number of moles of the polymerization initiator. On the other hand, a method of obtaining a modified conjugated diene copolymer having four or more branches by adding it in a mole number of 1/4 or less is effective.

(Rubber component B)
The modified conjugated diene-based polymer composition of the present embodiment contains a rubber component B having a glass transition temperature of −55 ° C. or less. Preferably it is -60C or less, more preferably -65C or less.
By including the rubber component B, rigidity at a low temperature when a vulcanized product is obtained is reduced, and snow performance is improved.
The lower limit of the glass transition temperature of the rubber component B is not particularly limited, but is preferably −100 ° C. or higher. When the glass transition temperature is -100 ° C or higher, the breaking strength tends to be improved, and the abrasion resistance tends to be excellent.
The Tg of the rubber component B can be controlled in the above numerical range by adjusting the microstructure of the polymer as the rubber component B, that is, by adjusting the amount of the aromatic vinyl compound or the amount of the vinyl bond. Further, natural rubber may be used as the rubber component B so as to be controlled in the above numerical range.

As the rubber component B, a modified conjugated diene-based polymer can be preferably used.
When the rubber component B is a modified conjugated diene-based polymer, the structure of the rubber component B is not particularly limited, but, for example, a conjugated diene-based polymer or a hydrogenated product thereof, or a random mixture of a conjugated diene-based compound and a vinyl aromatic compound. Examples include a copolymer or a hydrogenated product thereof, a block copolymer of a conjugated diene compound and a vinyl aromatic compound or a hydrogenated product thereof, a non-diene polymer, and a natural rubber.
Other examples of the rubber component B include butadiene rubber or a hydrogenated product thereof, isoprene rubber or a hydrogenated product thereof, styrene-butadiene rubber or a hydrogenated product thereof, a styrene-butadiene block copolymer or a hydrogenated product thereof, and styrene. Styrene elastomers such as isoprene block copolymers or hydrogenated products thereof, acrylonitrile-butadiene rubber or hydrogenated products thereof.
Examples of the non-diene polymer include, but are not limited to, olefins such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, and ethylene-octene rubber. System elastomer, butyl rubber, brominated butyl rubber, acrylic rubber, fluoro rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β-unsaturated nitrile-acrylate-conjugated diene copolymer rubber, urethane rubber, polysulfide rubber Is mentioned.
Examples of the natural rubber include, but are not limited to, the following: From the viewpoint of a large amount of high molecular weight components and excellent breaking strength, RSS3 to 5 of smoked sheet, SMR, and epoxidized natural rubber are exemplified.

From the viewpoint of improving the balance between snow performance and wet performance and improving wear resistance, the rubber component B has a weight average molecular weight of 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, and a molecular weight distribution Mw / Mn of 1.6 or more. It is preferably a modified conjugated diene polymer having a value of 0 or less.
Further, from the viewpoint of improving the balance between snow performance and wet performance, the rubber component B is preferably a modified conjugated diene-based polymer having a modification rate of 50% by mass or more based on the total amount of the conjugated diene-based polymer.
Furthermore, from the viewpoint of excellent processability when a vulcanized product is obtained, the rubber component B has a peak top in a gel permeation chromatography (GPC) curve, or has a minimum molecular weight when a plurality of the peak tops are present. It is preferable that the modified conjugated diene-based polymer is a modified conjugated diene-based polymer in which the modification ratio of a component having a molecular weight that is の of the molecular weight at a certain peak top is 以上 or more of the modification ratio with respect to the total amount of the conjugated diene-based polymer.
When the rubber component B is a modified conjugated diene-based polymer, the rubber component B can be produced by the same method as the rubber component A described above, and the weight average molecular weight, the molecular weight distribution, and the modification ratio of the rubber component B The modification ratio of the low molecular weight component and the low molecular weight component can be controlled by the same method as in the case of the rubber component A described above.

(filler)
The modified conjugated diene-based polymer composition of the present embodiment contains a filler.
The modified conjugated diene-based polymer composition preferably contains the rubber component A and the rubber component B in a total amount of 100 parts by mass and a filler of 5 to 150 parts by mass.
The filler preferably contains a silica-based inorganic filler.
The modified conjugated diene-based polymer composition of the present embodiment tends to be more excellent in processability when a vulcanized product is obtained by dispersing a silica-based inorganic filler, and when the vulcanized product is used, snow performance is improved. And the wet performance, and the abrasion resistance.
The content of the filler is preferably 5.0 parts by mass or more when the total amount of the rubber component A and the rubber component B is 100 parts by mass from the viewpoint of exhibiting the effect of adding the filler. The amount is preferably 150 parts by mass or less from the viewpoint of sufficiently dispersing the agent and making the processability and mechanical strength of the modified conjugated diene polymer composition practically sufficient.
Even when the modified conjugated diene-based polymer composition of the present embodiment is used for vulcanized rubber applications such as automobile parts such as tires and vibration-proof rubbers, shoes, etc., it is preferable to include a silica-based inorganic filler.
The filler is not limited to the following, but examples thereof include carbon black, metal oxides, and metal hydroxides in addition to the silica-based inorganic filler. These may be used alone or in combination of two or more.

The silica-based inorganic filler is not particularly limited, but may be a known, solid particles preferably comprise SiO ₂ or Si ₃ Al as a constituent unit, the main structural units of SiO ₂ or Si ₃ Al Solid particles contained as a component are more preferred. Here, the main component refers to a component contained in the silica-based inorganic filler in an amount of 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more.
Examples of the silica-based inorganic filler are not limited to the following, but include, for example, inorganic fibrous substances such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber. Further, a silica-based inorganic filler whose surface is hydrophobized, and a mixture of a silica-based inorganic filler and a non-silica-based inorganic filler can also be used. Among these, from the viewpoints of strength, abrasion resistance and the like, silica and glass fiber are preferred, and silica is more preferred. Examples of the silica include dry silica, wet silica, and synthetic silicate silica. Among these silicas, wet silica is preferable from the viewpoint of improving the balance between the effect of improving the breaking characteristics and the wet skid resistance.

In the modified conjugated diene-based polymer composition of the present embodiment, from the viewpoint of obtaining practically good abrasion resistance and breaking characteristics, the nitrogen-adsorbed specific surface area of the silica-based inorganic filler determined by the BET adsorption method is 100 m ² / g and 300 m ² / g or less, more preferably 170 m ² / g or more and 250 m ² / g or less. If necessary, a relatively small specific surface area (e.g., a specific surface area 200m of ² / g or less) and the silica-based inorganic filler, a relatively large specific surface area (e.g., greater than 200m ² / g) silica An inorganic filler can be used in combination.
In particular, when a silica-based inorganic filler having a relatively large specific surface area (for example, 200 m ² / g or more) is used, good dispersion of silica in the modified conjugated diene-based polymer that is the rubber component A and the rubber component B described above. This is particularly effective in improving abrasion resistance, and tends to achieve a high balance between good breaking characteristics and low hysteresis loss.

The carbon black is not limited to the following, but includes, for example, carbon black of each class such as SRF, FEF, HAF, ISAF, and SAF. Among them, carbon black having a nitrogen adsorption specific surface area of 50 m ² / g or more and a dibutyl phthalate (DBP) oil absorption of 80 mL / 100 g or less is preferable.
The content of carbon black is preferably 0.5 parts by mass or more and 100 parts by mass or less, more preferably 3.0 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the total of the rubber component A and the rubber component B. More preferably, it is 5.0 parts by mass or more and 50 parts by mass or less. The content of carbon black is preferably 0.5 parts by mass or more from the viewpoint of exhibiting performance required for applications such as tires such as dry grip performance and conductivity, and is preferably 100 parts by mass or more from the viewpoint of dispersibility. It is preferable to set the following.

The modified conjugated diene-based polymer composition of the present embodiment may include a silane coupling agent.
The silane coupling agent has a function of tightening the interaction between the rubber-like polymer and the filler, particularly the inorganic filler, and has an affinity or binding for each of the rubber-like polymer and the silica-based inorganic filler. Compounds which have an acidic group and have a sulfur-binding portion and an alkoxysilyl or silanol group portion in one molecule are preferred.
Such compounds include, for example, bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl] -disulfide, bis- [2- (triethoxysilyl) Silyl) -ethyl] -tetrasulfide.
The content of the silane coupling agent is preferably from 0.1 to 30 parts by mass, more preferably from 0.5 to 20 parts by mass, based on 100 parts by mass of the above-mentioned inorganic filler. The content is more preferably 0 to 15 parts by mass. When the content of the silane coupling agent is in the above range, the effect of adding the silane coupling agent tends to be more remarkable.

(Rubber softener)
The modified conjugated diene-based polymer composition of the present embodiment may contain a rubber softener from the viewpoint of improving the processability.
As the softener for rubber, mineral oil or a liquid or low molecular weight synthetic softener is suitable.
Mineral oil-based rubber softeners called process oils or extender oils used for softening, increasing the volume of rubber, and improving processability are mixtures of aromatic rings, naphthenic rings, and paraffin chains. Those in which the number of carbon atoms in the paraffin chain occupies 50% by mass or more of the total carbon are called paraffinic. Those whose number accounts for more than 30% by mass of the total carbon are called aromatic.
The content of the rubber softener is preferably from 0 to 100 parts by mass, more preferably from 10 to 90 parts by mass, based on 100 parts by mass of the rubbery polymer containing the rubber component A and the rubber component B. Is more preferably 30 parts by mass or more and 90 parts by mass or less. When the content of the rubber softener is 100 parts by mass or less with respect to 100 parts by mass of the rubber-like polymer, bleed-out tends to be suppressed, and stickiness on the surface of the rubber composition tends to be suppressed.

(Production method of modified conjugated diene polymer composition)
The modified conjugated diene-based polymer composition of the present embodiment can be produced by mixing the above-mentioned rubber component A, rubber component B, and filler, and if necessary, other rubber component A and rubber component B. Additives such as rubbery polymers, silica-based inorganic fillers, carbon black, other fillers, silane coupling agents, and rubber softeners may be mixed.
The mixing method is not limited to the following, but for example, a general mixer such as an open roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, or a multi-screw extruder was used. A melt kneading method, a method of dissolving and mixing each component, and then removing the solvent by heating are exemplified.
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.
In addition, any of a method of kneading the rubber component A, the rubber component B, the filler, and other various materials at a time, and a method of mixing the components in a plurality of times can be applied.

The procedure for kneading the materials is not particularly limited, but it is preferable to knead the rubber component B and the filler to obtain a kneaded product, and then knead the kneaded product with the rubber component A. It is preferable to mix various additives such as a coupling agent and a rubber softener.
According to this method, the filler can be localized in the rubber component B.
By localizing the filler in the rubber component B, it becomes possible to increase the sectional modulus of the modified conjugated diene-based polymer composition of the present embodiment, and the breaking strength tends to be improved.

The modified conjugated diene polymer composition of the present embodiment may be a vulcanized composition that has been vulcanized with a vulcanizing agent.
Examples of the vulcanizing agent include, but are not limited to, radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur compounds.
Sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, high molecular weight polysulfur compounds, and the like.
The content of the vulcanizing agent is preferably from 0.01 to 20 parts by mass, and more preferably from 0.1 to 15 parts by mass, based on 100 parts by mass of the rubbery polymer containing the rubber component A and the rubber component B. The following is more preferred. As the vulcanization method, a conventionally known method can be applied, and the vulcanization temperature is preferably from 120 ° C to 200 ° C, more preferably from 140 ° C to 180 ° C.

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

In the modified conjugated diene-based polymer composition of the present embodiment, other softeners and fillers other than those described above, a heat stabilizer, an antistatic agent, and a weather stabilizer, as long as the object of the present embodiment is not impaired. Various additives such as an antioxidant, a coloring agent, and a lubricant may be used.
Known softeners can be used as other softeners. Other fillers include, for example, calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. Known materials can be used as the above-mentioned heat stabilizer, antistatic agent, weather stabilizer, antioxidant, coloring agent, and lubricant, respectively.

〔tire〕
The modified conjugated diene-based polymer composition of the present embodiment is suitably used as a rubber composition for a tire.
The modified conjugated diene-based polymer composition of the present embodiment is not limited to the following. For example, various tires such as a fuel-saving tire, an all-season tire, a high-performance tire, and a winter tire: a tread, a carcass, a sidewall, It can be used for each part of the tire such as a bead part. In particular, the modified conjugated diene-based polymer composition of the present embodiment including the rubbery polymer for a tire composed of the modified conjugated diene-based polymer (rubber component A) and the rubber component B is used as a vulcanized product. Since it has excellent balance between snow performance and wet performance and excellent wear resistance, it is more suitably used for treads of winter tires.

Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples, but the present embodiment is not limited to the following examples.
The materials used in the examples and comparative examples and methods for evaluating various characteristics are shown below.

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

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

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

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

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

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

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

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

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

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

[(Property 3) Polymer Mooney viscosity]
Using the modified conjugated diene polymer as a sample, Mooney viscosity was measured using a Mooney viscometer (trade name “VR1132” manufactured by Ueshima Seisakusho Co., Ltd.) in accordance with JIS K6300 using an L-shaped rotor.
The measurement temperature was 100 ° C.
First, after preheating the sample at the test temperature for 1 minute, the rotor was rotated at 2 rpm, and the torque after 4 minutes was measured to obtain the Mooney viscosity (ML _{(1 + 4)} ).

[(Physical property 4) molecular weight]
Using a modified conjugated diene-based polymer as a sample, an RI detector (Tosoh Corp.) using a GPC measuring device (trade name “HLC-8320GPC” manufactured by Tosoh Corp.) in which three columns using polystyrene-based gel as a filler are connected. Chromatogram was measured using a trade name “HLC8020” manufactured by the company, and based on a calibration curve obtained using standard polystyrene, the weight average molecular weight (Mw ₁ ), number average molecular weight (Mn ₁ ), and molecular weight distribution were measured. (Mw ₁ / Mn ₁ ) and the peak top molecular weight (Mp ₁ ) of the modified conjugated diene polymer were determined.
The eluent used was THF (tetrahydrofuran).
As the column, three TSKgel SuperMultipore HZ-H (trade name, manufactured by Tosoh Corporation) were connected, and as a guard column, a column (trade name, TSKguardcolumn SuperMP (HZ) -H, manufactured by Tosoh Corporation) was connected as a guard column.
A measurement sample was dissolved by dissolving 10 mg of a measurement sample in 20 mL of THF, and 10 μL of the measurement solution was injected into a GPC measuring apparatus, and measurement was performed under the conditions of an oven temperature of 40 ° C. and a THF flow rate of 0.35 mL / min.
The peak top molecular weight (Mp ₁ ) was determined as follows.
In the GPC curve obtained by the measurement, the peak detected as the component having the highest molecular weight was selected. With respect to the selected peak, the molecular weight corresponding to the maximum value of the peak was calculated and defined as the peak top molecular weight.

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

[(Physical property 6) Modification rate of low molecular weight component]
According to the measurement of (Physical Property 4), based on a calibration curve obtained using standard polystyrene, weight average molecular weight (Mw ₂ ), number average molecular weight (Mn ₂ ), molecular weight distribution (Mw ₂ / Mn ₂ ), The peak top molecular weight (Mp ₂ ) of the modified conjugated diene polymer was measured.
Incidentally, the peak top molecular weight (Mp _2), the peak top in the molecular weight curve, or when the peak top there are a plurality of assumed molecular weight of the molecular weight of the peak top is minimal, the peak top molecular weight (Mp ₂₎ The height of the chart at a molecular weight (the molecular weight of the low molecular weight component) that is 1/2 of the above was defined as L1.
The height at the molecular weight (molecular weight of the low molecular weight component) obtained by dividing the peak top molecular weight (Mp ₂ ) by 2 in the chart measured according to the measurement of (physical property 5) using a silica column was defined as L2. .
A component having a molecular weight that is の of the peak top molecular weight (Mp ₂ ) is defined as a low molecular weight component.
The modification ratio of the low molecular weight component was calculated by (1-L2 / L1) × 100.

[(Physical property 7) Degree of modification of low molecular weight component]
The modification ratio (FL) of the low molecular weight component (the molecular weight of ピ ー ク the peak top) of the (physical property 6) is divided by the modification rate (FT) with respect to the total amount of the (physical property 5) conjugated diene polymer. Calculated.
Degree of modification of low molecular weight component = FL / FT

[(Physical property 8) Glass transition temperature]
Using a modified conjugated diene polymer as a sample, a differential scanning calorimeter “DSC3200S” manufactured by Mac Science Co., Ltd., in accordance with ISO 22768: 2006, and using helium at a flow rate of 50 mL / min, from −100 ° C. to 20 ° C./min. The DSC curve was recorded while the temperature was raised in step (1), and the peak top (Inflection point) of the DSC differential curve was defined as the glass transition temperature.

[(Physical property 9) Contraction factor (g ')]
Using a modified conjugated diene-based polymer as a sample, a chromatogram was measured using a GPC-light scattering measurement device equipped with a viscosity detector in which three columns each containing a polystyrene-based gel as a filler were connected, and the solution viscosity and light intensity were measured. The molecular weight was determined based on the scattering method.
As an eluent, a mixed solution of tetrahydrofuran and triethylamine (THF in TEA: 5 mL of triethylamine was mixed with 1 L of tetrahydrofuran and adjusted) was used.
The columns were used by connecting a guard column: “TSKguardcolumn HHR-H” manufactured by Tosoh Corporation and a column: “TSKgel G6000HHR”, “TSKgel G5000HHR”, and “TSKgel G4000HHR” manufactured by Tosoh Corporation.
A GPC-light scattering measurement device with a viscosity detector (trade name “Viscotek TDAmax” manufactured by Malvern) was used under the conditions of an oven temperature of 40 ° C. and a THF flow rate of 1.0 mL / min.
10 mg of the sample for measurement was dissolved in 20 mL of THF to prepare a sample solution for measurement, and 200 μL of the sample solution for measurement was injected into a GPC measuring apparatus to measure the intrinsic viscosity.
The shrinkage factor (g ′) was calculated using the intrinsic viscosity and the molecular weight of the obtained sample solution for measurement.
When the constant (K, α) in the relational expression between intrinsic viscosity and molecular weight ([η] = KMα ([η]: intrinsic viscosity, M: molecular weight) is log K = −3.883, α = 0.772, molecular weight M In the relationship between the standard intrinsic viscosity [η] ₀ and the molecular weight M prepared by inputting the range of 1000 to 20000000, the intrinsic viscosity [η] at each molecular weight M is calculated as the intrinsic viscosity relative to the standard intrinsic viscosity [η] ₀ . [Η] / [η] ₀ was calculated for each molecular weight M as a relationship of [η], and the average value was defined as a shrinkage factor (g ′).
The shrinkage factor (g ′) is an average value when M is 1,000,000 or more and 2,000,000 or less.

[(Physical property 10) Nitrogen content]
The nitrogen content was measured using a trace total nitrogen analyzer (TN-2100H manufactured by Mitsubishi Chemical Analytech).

[Modified conjugated diene polymer (sample 1)]
The internal volume is 10 L, the ratio (L / D) of the internal height (L) to the diameter (D) is 4.0, and the bottom has an inlet and the top has an outlet. A tank-type pressure vessel having a jacket was used as a polymerization reactor.
1,3-butadiene, which had been removed in advance, was mixed at 19 g / min, styrene at 10.3 g / min, and n-hexane at 143.9 g / min. Allenes contained in this mixture were 10 ppm, acetylenes were 12 ppm, and amines were 1 ppm. The total amount of impurities was 23 ppm.
In a static mixer provided in the middle of a pipe for supplying this mixed solution to the inlet of the reaction group, n-butyllithium for inert treatment of residual impurities was added at 0.08 mmol / min and mixed, and then mixed at the bottom of the reaction group. Feeded continuously. Furthermore, 2,2-bis (2-oxolanyl) propane is used as a polar substance at a rate of 0.02 g / min, and n-butyllithium is used as a polymerization initiator at a rate of 0.18 mmol / min. It was supplied to the bottom of the reactor to continuously continue the polymerization reaction. The temperature was controlled so that the temperature of the polymerization solution at the top outlet of the reactor was 75 ° C.
When the polymerization was sufficiently stabilized, a small amount of the polymer solution before the addition of the coupling agent was withdrawn from the top outlet of the reactor, and an antioxidant (BHT) was added so that the amount became 0.2 g per 100 g of the polymer. Removed.
Next, tetraglycidyl-1,3-bisaminomethylcyclohexane as a modifier was continuously added at a rate of 0.05 mmol / min to the polymer solution flowing out from the outlet of the reactor, and the modifier was added. The polymer solution was mixed by passing through a static mixer to undergo a denaturing reaction.
An antioxidant (BHT) was continuously added to the polymer solution subjected to the denaturation reaction with an n-hexane solution so as to be 0.2 g per 100 g of the polymer, and the coupling reaction was terminated. At the same time as the antioxidant, oil (Vivatec 500, manufactured by H & R Co.) was continuously added to 100 g of the polymer so as to be 25 g, and mixed with a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (Sample 1). Table 1 shows the physical properties of Sample 1.

[Modified conjugated diene polymer (sample 2)]
As a polymerization initiator, a mixed solution of piperidinolithium (also referred to as “1-lithiopiperidine”), which is a lithium amide prepared in advance, and n-butyllithium (the molar ratio of piperidinolithium to n-butyllithium is: A modified conjugated diene-based polymer (sample 2) was obtained in the same manner as (sample 1) except that piperidino lithium: n-butyl lithium = 0.75: 0.25.
Table 1 shows the physical properties of Sample 2.

[Modified conjugated diene polymer (sample 3)]
A modified conjugate was prepared in the same manner as in (Sample 1) except that the modifying agent was changed to 3-trimethoxysilylpropyl- [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] amine. A diene polymer (sample 3) was obtained.
Table 1 shows the physical properties of Sample 3.

[Modified conjugated diene polymer (Sample 4)]
As a polymerization initiator, a mixed solution of piperidinolithium (also referred to as “1-lithiopiperidine”), which is a lithium amide prepared in advance, and n-butyllithium (the molar ratio of piperidinolithium to n-butyllithium is: A modified conjugated diene-based polymer (Sample 4) was obtained in the same manner as in (Sample 3), except that piperidinolithium: n-butyllithium was changed to 0.75: 0.25.
Table 1 shows the physical properties of Sample 4.

[Modified conjugated diene polymer (Sample 5)]
A modified conjugated diene polymer (Sample 5) was obtained in the same manner as in (Sample 1) except that the modifier was tris (3-trimethoxysilylpropyl) amine and the supply amount was changed to 0.034 mmol / min. Was.
Table 1 shows the physical properties of Sample 5.

[Modified conjugated diene polymer (sample 6)]
As a polymerization initiator, a mixed solution of piperidinolithium (also referred to as “1-lithiopiperidine”), which is a lithium amide prepared in advance, and n-butyllithium (the molar ratio of piperidinolithium to n-butyllithium is: A modified conjugated diene-based polymer (sample 6) was obtained in the same manner as (sample 5), except that piperidino lithium: n-butyl lithium = 0.75: 0.25.
Table 1 shows the physical properties of Sample 6.

[Modified conjugated diene polymer (Sample 7)]
A modified conjugated diene polymer was prepared in the same manner as in (Sample 1) except that the modifier was tetrakis (3-trimethoxysilylpropyl) -1,3-propanediamine, and the supply amount was changed to 0.026 mmol / min. (Sample 7) was obtained.
Table 1 shows the physical properties of Sample 7.

[Modified conjugated diene polymer (sample 8)]
As a polymerization initiator, a mixed solution of piperidinolithium (also referred to as “1-lithiopiperidine”), which is a lithium amide prepared in advance, and n-butyllithium (the molar ratio of piperidinolithium to n-butyllithium is: A modified conjugated diene-based polymer (Sample 8) was obtained in the same manner as (Sample 7), except that piperidinolithium: n-butyllithium was changed to 0.75: 0.25.
Table 1 shows the physical properties of Sample 8.

[Modified conjugated diene polymer (Sample 9)]
The internal volume is 10 L, the ratio (L / D) of the internal height (L) to the diameter (D) is 4.0, and the bottom has an inlet and the top has an outlet. A tank-type pressure vessel having a jacket was used as a polymerization reactor.
1,3-Butadiene, 20.9 g / min, styrene, 8.4 g / min, and n-hexane, 143.9 g / min, were mixed under the condition of removing water in advance. Allenes contained in this mixture were 10 ppm, acetylenes were 12 ppm, and amines were 1 ppm. The total amount of impurities was 23 ppm.
In a static mixer provided in the middle of a pipe for supplying this mixed solution to the inlet of the reaction group, n-butyllithium for inert treatment of residual impurities was added at 0.08 mmol / min and mixed, and then mixed at the bottom of the reaction group. Feeded continuously. Furthermore, 2,2-bis (2-oxolanyl) propane is used as a polar substance at a rate of 0.02 g / min, and n-butyllithium is used as a polymerization initiator at a rate of 0.18 mmol / min. It was supplied to the bottom of the reactor to continuously continue the polymerization reaction. The temperature was controlled so that the temperature of the polymerization solution at the top outlet of the reactor was 75 ° C. When the polymerization was sufficiently stabilized, a small amount of the polymer solution before the addition of the coupling agent was withdrawn from the top outlet of the reactor, and an antioxidant (BHT) was added so that the amount became 0.2 g per 100 g of the polymer. Removed.
Next, 3-trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] amine as a modifier was added to the polymer solution flowing out from the outlet of the reactor. The polymer solution to which the modifier was continuously added at a rate of 0.05 mmol / min and to which the modifier was added was mixed by passing through a static mixer to carry out a denaturation reaction.
An antioxidant (BHT) was continuously added to the polymer solution subjected to the denaturation reaction with an n-hexane solution so as to be 0.2 g per 100 g of the polymer, and the coupling reaction was terminated. Simultaneously with the antioxidant, 5 g of oil (Vivatec 500, manufactured by H & R) was continuously added to 100 g of the polymer, and mixed with a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (Sample 9). Table 2 shows the physical properties of Sample 9.

[Modified conjugated diene polymer (sample 10)]
(Samples were prepared except that 1,3-butadiene was mixed at 21 g / min, styrene at 8.8 g / min, and n-hexane at 143.9 g / min, and the amount of the polar substance added was changed to 0.015 mmol. In the same manner as in 3), a modified conjugated diene-based polymer (sample 10) was obtained. Table 2 shows the physical properties of Sample 10.

[Modified conjugated diene polymer (Sample 11)]
The addition amount of n-butyllithium as a polymerization initiator was 0.24 mmol / min, the addition amount of 2,2-bis (2-oxolanyl) propane as a polar substance was 0.01 g / min, Same as (Sample 3) except that the addition amount of trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] amine was changed to 0.03 mmol / min. Thus, a modified conjugated diene-based polymer (sample 11) was obtained. Table 2 shows the physical properties of Sample 11.

[Modified conjugated diene polymer (sample 12)]
The addition amount of n-butyllithium as a polymerization initiator was 0.30 mmol / min, the addition amount of 2,2-bis (2-oxolanyl) propane as a polar substance was 0.03 g / min, Same as (Sample 3) except that the addition amount of trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] amine was changed to 0.08 mmol / min. Thus, a modified conjugated diene-based polymer (sample 12) was obtained. Table 2 shows the physical properties of Sample 12.

[Modified conjugated diene polymer (Sample 13)]
The addition amount of n-butyllithium as a polymerization initiator was 0.40 mmol / min, the addition amount of 2,2-bis (2-oxolanyl) propane as a polar substance was 0.04 g / min, Same as (Sample 3) except that the addition amount of trimethoxysilylpropyl)-[3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] amine was changed to 0.11 mmol / min. Thus, a modified conjugated diene-based polymer (sample 13) was obtained. Table 2 shows the physical properties of Sample 13.

[Modified conjugated diene polymer (Sample 14)]
Allenes contained in the mixture of 1,3-butadiene, styrene and n-hexane were 15 ppm, acetylenes were 13 ppm, and amines were 2 ppm. The total amount of impurities was 30 ppm. Except for using these, a modified conjugated diene-based polymer (sample 14) was obtained in the same manner as (sample 3). Table 2 shows the physical properties of Sample 14.

[Modified conjugated diene polymer (Sample 15)]
Except that the addition amount of 3-trimethoxysilylpropyl- [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] amine as a modifier was changed to 0.01 mmol / min, In the same manner as in Sample 3), a modified conjugated diene-based polymer (Sample 15) was obtained. Table 2 shows the physical properties of Sample 15.

[Modified conjugated diene polymer (sample 16)]
After washing and drying the autoclave with a stirrer and a jacket having an internal volume of 10 L and purging with nitrogen, 592 g of 1,3-butadiene, 208 g of styrene and 5 kg of cyclohexane, which were previously removed of impurities such as moisture, were added. 1.47 g of -bis (2-oxolanyl) propane was added, and as a previously prepared lithium amide, a mixed solution of piperidinolithium and n-butyllithium (the molar ratio of piperidinolithium to n-butyllithium was 0%). .75: 0.25) was added, and polymerization was initiated at 52 ° C. The polymerization was carried out by adiabatic polymerization and the maximum temperature reached 70 ° C. After the polymerization was further performed for 5 minutes from when the maximum temperature was reached, the obtained reaction solution, that is, a polymer solution containing a conjugated diene-based polymer composed of a conjugated diene compound and an aromatic vinyl compound was sampled, and the solvent was removed. Analysis.
Next, a cyclohexane solution containing 1.3 mmol of 3-trimethoxysilylpropyl- [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] amine was added to the sampled polymerization solution. After reacting for 15 minutes, 2 g of an antioxidant (BHT) was added to the obtained polymer solution, and then the solvent was removed to obtain a modified conjugated diene-based polymer (Sample 16). Table 2 shows the physical properties of Sample 16.

The meanings of the symbols in Tables 1 and 2 are shown below.
* 1 2,2-bis (2-oxolanyl) propane * 2 tetraglycidyl-1,3-bisaminomethylcyclohexane * 3 3-trimethoxysilylpropyl- [3- (2,2-dimethoxy-1-aza-2) -Silacyclopentane) propyl] amine * 4 Tris (3-trimethoxysilylpropyl) amine * 5 Tetrakis (3-trimethoxysilylpropyl) -1,3-propanediamine * 6 Process oil (Vivatec500 manufactured by H & R)

[Modified conjugated diene polymer composition (Examples 1 to 20, Comparative Examples 1 to 9)]
Using the modified conjugated diene-based polymers (Samples 1 to 16), SBR A, SBR B, natural rubber (NR), and polybutadiene (BR) shown in Tables 1 and 2 as raw rubbers, the following materials were used. The mixture was kneaded by the following method to produce an unvulcanized rubber composition and a vulcanized rubber composition.
Tables 3 to 5 show the respective formulations.
In Tables 3 to 5, numerical values in parentheses indicate the amount of process oil contained in the sample.

-Modified conjugated diene polymer: Samples 1 to 16
-SBR-A (Asahi Kasei Corporation, Toughden 4850, glass transition temperature: -12 ° C)
・ SBR ・ B (Tafden 1834, glass transition temperature: -70 ° C, manufactured by Asahi Kasei Corporation)
・ NR (natural rubber, glass transition temperature: -70 ° C)
・ BR (manufactured by Ube Industries, BR150, glass transition temperature: -105 ° C)
・ Extension oil (Vivatec 500, manufactured by H & R)
・ Silica (Evonik Japan, Ultrasil 7000 GR, nitrogen adsorption specific surface area: 175 m ² / g)
・ Silane coupling agent (Evonik Japan, Si75)
・ Carbon black (Toast Carbon Co., Ltd., Seast KH (N339))
・ Zinc flower (Zinc flower No.1 manufactured by Mitsui Kinzoku Mining Co., Ltd.)
・ Stearic acid ・ Wax: (Ouchi Shinko Chemical Co., Ltd., Sannok)
・ Antiaging agent (N-isopropyl-N′-phenyl-p-phenylenediamine)
・ Sulfur / vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazylsulfinamide)
・ Vulcanization accelerator 2 (diphenylguanidine)

(Examples 1 to 13, 15 to 20, Comparative Examples 1 to 9)
According to the formulations shown in Tables 3 to 5, kneading was carried out by the following method to obtain an unvulcanized rubber composition and its vulcanized rubber composition.
Using a kneader (content 0.5L) equipped with a temperature control device, the first stage kneading was performed under the conditions of a filling rate of 65% and a rotor rotation speed of 50 rpm, and raw rubber, silica, a silane coupling agent, and carbon black. , Zinc white, stearic acid, wax, and an antioxidant, and kneaded for 4 minutes. At this time, the discharge temperature was adjusted to 155 to 160 ° C. by controlling the temperature of the kneader to obtain a blend.
Next, as the second stage kneading, the mixture obtained above was cooled to room temperature, and then kneaded for 3.5 minutes in the above kneader. Also in this case, the discharge temperature was adjusted to 155 to 160 ° C. by controlling the temperature of the kneader. The discharge temperature was controlled by measuring the temperature of each compound discharged from the kneader after kneading.
Further, after cooling the above-obtained compound to room temperature, the unvulcanized rubber composition was heated in an oven at 70 ° C. for 30 minutes, and then kneaded in a third stage at 30 ° C. with a kneader set at 70 ° C. After kneading in seconds, sulfur and a vulcanization accelerator were added and kneaded for 1.5 minutes, and the mixture was discharged at 105 ° C to obtain an unvulcanized rubber composition.
The blend Mooney viscosity of the obtained unvulcanized rubber composition was evaluated by the following method.
Thereafter, the unvulcanized rubber composition was vulcanized and molded with a vulcanizing press at 160 ° C. for 20 minutes to obtain a vulcanized rubber sheet.
The snow performance, wet performance, wear resistance and breaking strength of the vulcanized rubber sheet were evaluated by the following methods.

(Example 14)
In the first stage of kneading, Sample 9 and silica as raw rubbers were kneaded for 1 minute at a rotor rotation speed of 50 rpm, and then Sample 7, silica, silane coupling agent, carbon black, zinc white, stearic acid, The mixture was kneaded for 4 minutes using a wax and an antioxidant. At this time, the discharge temperature was adjusted to 155 to 160 ° C. by controlling the temperature of the kneader to obtain a blend.
Next, as the second stage kneading, the mixture obtained above was cooled to room temperature, and then kneaded for 3.5 minutes in the above kneader. Also in this case, the discharge temperature was adjusted to 155 to 160 ° C. by controlling the temperature of the kneader. The discharge temperature was controlled by measuring the temperature of each compound discharged from the kneader after kneading.
Further, after cooling the above-obtained compound to room temperature, the unvulcanized rubber composition was heated in an oven at 70 ° C. for 30 minutes, and then kneaded in a third stage at 30 ° C. with a kneader set at 70 ° C. After kneading in seconds, sulfur and a vulcanization accelerator were added and kneaded for 1.5 minutes, and the mixture was discharged at 105 ° C to obtain an unvulcanized rubber composition.
The blend Mooney viscosity of the obtained unvulcanized rubber composition was evaluated by the following method.
Thereafter, the unvulcanized rubber composition was vulcanized and molded with a vulcanizing press at 160 ° C. for 20 minutes to obtain a vulcanized rubber sheet.
The snow performance, wet performance, wear resistance and breaking strength of the vulcanized rubber sheet were evaluated by the following methods.

(Physical property measurement method)
(Compound Mooney Viscosity (Compound Mooney Viscosity) (Physical Properties 11))
After kneading in the second stage, the rubber composition was used as a sample, and Mooney viscosity was measured using a Mooney viscometer (trade name “VR1132” manufactured by Kamishima Seisakusho) in accordance with JIS K6300 using an L-shaped rotor. .
The measurement temperature was 100 ° C.
First, after preheating the sample at the test temperature for 1 minute, the rotor was rotated at 2 rpm, and the torque after 4 minutes was measured to obtain the Mooney viscosity (ML _{(1 + 4)} ).
The result of Comparative Example 1 was indexed with 100 as an index of workability.
A larger index indicates better processability.

(Viscoelastic parameters (Physical properties 12, 13))
The viscoelastic parameters of the rubber composition after vulcanization were measured in a torsional mode using a viscoelasticity tester “ARES” manufactured by Rheometrics Scientific. Each measurement was indexed with the result for the rubber composition of Comparative Example 1 as 100.
Tan δ measured at 0 ° C. at a frequency of 10 Hz and a strain of 1% was used as an index of wet performance. The higher the value, the better the wet grip property.
The storage elastic modulus (G ′) measured at −20 ° C. at a frequency of 10 Hz and a strain of 1% was used as an index of the snow performance. The larger the value, the better the snow performance.

(Wear resistance (physical properties 14))
Using a Akron abrasion tester (manufactured by Yasuda Seiki Seisaku-sho, Ltd.), the amount of abrasion of the rubber composition after vulcanization was measured at a load of 44.4 N and 1000 revolutions in accordance with JIS K6264-2. The result of (1) was indexed as 100. The larger the index, the better the wear resistance.

(Tensile breaking strength (physical property 15))
For the rubber composition after vulcanization, the tensile strength at break was measured in accordance with the tensile test method of JIS K6251, and the result of Comparative Example 1 was indexed as 100.

(Sheet workability (physical properties 16))
Using the rubber composition obtained through the first-stage kneading, a sheet-like rubber composition was processed with an open roll set at 70 ° C.
The state of the sheet of the obtained sheet-like rubber composition was visually evaluated according to the following criteria and evaluated on a 5-point scale.
A higher score indicates better sheet workability.
5: The unity during the roll operation is good, the sheet skin is smooth, and the sheet edge is not jagged.
4: The unity during the roll operation is good, but the sheet skin is slightly rough and the sheet edge is slightly jagged.
3: The unity during the roll operation is slightly poor, the sheet skin is slightly rough, and the sheet edge is slightly jagged.
2: The unity during the roll operation is slightly poor, the sheet skin is rough, and the sheet edges are also jagged.
1: The unity during the roll operation is poor, the sheet skin is rough, and the sheet edge is also jagged.

  As shown in Tables 6 to 8, when the modified conjugated diene-based polymer compositions of Examples 1 to 20 were compared with the modified conjugated diene-based polymer compositions of Comparative Examples 1 to 9, when they were vulcanized In addition, it was confirmed that the balance between the snow performance and the wet performance was excellent and the wear resistance was also excellent.

  Industrial Applicability The modified conjugated diene-based polymer composition according to the present invention has industrial applicability in fields such as tire treads, interior and exterior parts of automobiles, vibration-isolating rubber, belts, footwear, foams, and various industrial article applications. is there.

Claims (7)

A rubber component A which is a modified conjugated diene polymer having a glass transition temperature of -35 ° C or higher;
A rubber component B having a glass transition temperature of -55 ° C or less;
A filler,
Containing,
The rubber component A is 50% by mass or more and 95% by mass or less based on the total amount of the rubber component A and the rubber component B,
The rubber component A has a weight average molecular weight of 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, a molecular weight distribution Mw / Mn of 1.6 or more and 4.0 or less, and a modification rate of the rubber component A of 50 mass%. % Or more,
A modified conjugated diene polymer composition. The rubber component A has a peak at a gel permeation chromatography (GPC) curve or, when there are a plurality of the peaks, a component having a molecular weight that is の of the molecular weight of the peak at which the molecular weight is the minimum. Rate is １ ／ or more of the modification rate with respect to the total amount of the conjugated diene-based polymer,
The modified conjugated diene-based polymer composition according to claim 1. The modification rate of the rubber component A is 75% by mass or more,
The nitrogen content is 25 mass ppm or more;
The modified conjugated diene-based polymer composition according to claim 1. The shrinkage factor (g ′) of the rubber component A by 3D-GPC is 0.70 or less.
The modified conjugated diene-based polymer composition according to any one of claims 1 to 3. The rubber component B is
The weight average molecular weight is 20 × 10 ⁴ or more and 300 × 10 ⁴ or less, the molecular weight distribution Mw / Mn is 1.6 or more and 4.0 or less, the denaturation rate is 50% by mass or more, and gel permeation chromatography ( GPC) curve, or the modification rate of a component having a molecular weight that is の of the molecular weight of the peak top having the minimum molecular weight when a plurality of the peak tops are present, is based on the total amount of the conjugated diene-based polymer. A modified conjugated diene-based polymer having a modification ratio of 1/2 or more,
The modified conjugated diene-based polymer composition according to claim 1. A method for producing the modified conjugated diene-based polymer composition according to any one of claims 1 to 5,
Kneading the rubber component B and the filler to obtain a kneaded material;
A step of kneading the kneaded product and the rubber component A,
A method for producing a modified conjugated diene-based polymer composition having:   A tire comprising the modified conjugated diene-based polymer composition according to any one of claims 1 to 5.