CN110818975B

CN110818975B - Modified conjugated diene polymer composition, method for producing modified conjugated diene polymer composition, and tire

Info

Publication number: CN110818975B
Application number: CN201910724604.3A
Authority: CN
Inventors: 角谷省吾
Original assignee: Asahi Kasei Corp
Current assignee: Asahi Kasei Corp
Priority date: 2018-08-10
Filing date: 2019-08-07
Publication date: 2022-04-01
Anticipated expiration: 2039-08-07
Also published as: CN110818975A; DE102019121267A1

Abstract

The present invention provides a modified conjugated diene polymer composition which can give a rubber composition having an excellent balance between snow performance and wet skid performance and having excellent wear resistance. The modified conjugated diene polymer composition comprises a rubber component A which is a modified conjugated diene polymer having a glass transition temperature of-35 ℃ or higher, a rubber component B having a glass transition temperature of-55 ℃ or lower, and a filler, wherein the rubber component A and the rubber component B are present in a total amountA is 50 to 95 mass%, and the weight average molecular weight of the rubber component A is 20X 10⁴300X 10 above⁴The molecular weight distribution Mw/Mn is 1.6 to 4.0, and the modification ratio of the rubber component A is 50 mass% or more.

Description

Modified conjugated diene polymer composition, method for producing modified conjugated diene polymer composition, and tire

Technical Field

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

Background

In recent years, in winter tires, in addition to running performance on snow roads (snow performance), improvement in running performance on wet road surfaces (wet road surface performance) has been demanded.

Further, due to social demands for reduction of global environmental load, there is an increasing demand for longer life of tires, and there is a strong demand for improvement of wear resistance of tire performance.

Conventionally, for the purpose of improving snow performance, reducing the elastic modulus at low temperatures and ensuring high conformability of tread rubber to snow road surfaces, methods such as reducing the amount of a filler added and increasing the amount of an oil added have been proposed.

However, such a method has the following problems: the wet road performance and wear resistance tend to be reduced.

On the other hand, in order to improve the wet road surface performance, there have been proposed methods of increasing the glass transition temperature of the rubber composition or increasing the energy loss by increasing the amount of the filler added.

However, such a method has the following problems: the elastic modulus at low temperatures tends to increase and snow performance tends to decrease.

In particular, in recent years, maintenance of the road surface condition in winter has been progressing, and it is becoming more and more important for winter tires to improve the performance on wet road surfaces in addition to snow roads.

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.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-154473

Disclosure of Invention

Problems to be solved by the invention

However, the rubber composition described in patent document 1 has the following problems: the reactivity between the modifying group of the terminal-modified styrene-butadiene rubber and silica is insufficient, and there is room for further improvement in terms of improvement of both the snow performance and the wet performance.

Accordingly, an object of the present invention is to provide a modified conjugated diene polymer composition having good dispersibility of silica as a filler, and capable of providing a rubber composition having an excellent balance between snow performance and wet road performance and also having excellent wear resistance.

Means for solving the problems

The present inventors have intensively studied to solve the above problems of the prior art, and as a result, they have found that a balance between snow performance and wet road performance can be improved and excellent abrasion resistance can be obtained by limiting the content, weight average molecular weight, molecular weight distribution and modification ratio of the rubber component a having a higher glass transition temperature than the rubber component B in a modified conjugated diene polymer composition containing two rubber components a and B having different glass transition temperatures and a filler, and have completed the present invention.

Namely, the present invention is as follows.

[1]

A modified conjugated diene polymer composition comprising:

a rubber component A which is a modified conjugated diene polymer having a glass transition temperature of-35 ℃ or higher;

a rubber component B having a glass transition temperature of-55 ℃ or lower; and

a filler, a filler and a filler,

the rubber component A is 50 to 95 mass% based on the total amount of the rubber component A and the rubber component B,

the weight average molecular weight of the rubber component A was 20X 10⁴300X 10 above⁴The molecular weight distribution Mw/Mn is 1.6 to 4.0, and the modification ratio of the rubber component A is 50 mass% or more.

[2]

The modified conjugated diene polymer composition according to the above [1], wherein,

the rubber component a has a modification ratio of a component having a molecular weight of 1/2 and having a molecular weight of a peak top in a Gel Permeation Chromatography (GPC) curve of 1/2 or more relative to the total amount of the conjugated diene polymer, or has a modification ratio of a component having a molecular weight of 1/2 and having a molecular weight of a peak top having the smallest molecular weight when a plurality of peak tops are present of 1/2 or more relative to the total amount of the conjugated diene polymer.

[3]

The modified conjugated diene polymer composition according to the above [1] or [2], wherein,

the modification ratio of the rubber component A is 75% by mass or more,

the nitrogen content is 25 mass ppm or more.

[4]

The modified conjugated diene polymer composition according to any one of the above [1] to [3], wherein,

the rubber component A has a shrinkage factor (g') of 0.70 or less by 3D-GPC.

[5]

The modified conjugated diene polymer composition according to any one of the above [1] to [4], wherein,

the rubber component B is a modified conjugated diene polymer having a weight average molecular weight of 20X 10⁴300X 10 above⁴Hereinafter, the molecular weight distribution Mw/Mn is 1.6 or more and 4.0 or less, the modification ratio is 50% by mass or more, the modification ratio of the component having a molecular weight of 1/2 of the peak top in the Gel Permeation Chromatography (GPC) curve is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer, or, in the case where a plurality of the peak tops are present, the modification ratio of the component having a molecular weight of 1/2 of the peak top having the smallest molecular weight is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer.

[6]

A method for producing a modified conjugated diene polymer composition according to any one of the above [1] to [5], comprising:

a step of kneading the rubber component B and the filler to obtain a kneaded product; and

and a step of kneading the kneaded product and the rubber component A.

[7]

A tire comprising the modified conjugated diene polymer composition according to any one of [1] to [5 ].

Effects of the invention

According to the present invention, a modified conjugated diene polymer composition can be provided which is capable of obtaining a rubber composition having a high balance between snow performance and wet road performance and excellent wear resistance.

Detailed Description

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

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

[ modified conjugated diene Polymer composition ]

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

a filler, a filler and a filler,

(modified conjugated diene Polymer (rubber component A))

The modified conjugated diene polymer composition of the present embodiment contains a rubber component a, and the rubber component a is a modified conjugated diene polymer having a glass transition temperature of-35 ℃ or higher.

The weight-average molecular weight of the rubber component A was 20X 10⁴300X 10 above⁴The molecular weight distribution Mw/Mn is 1.6 to 4.0, and the modification ratio with respect to the total amount of the conjugated diene polymer is 50 mass% or more.

From the viewpoint of improving the wear resistance, the weight average molecular weight of the rubber component A is preferably more than 50X 10⁴And is 300X 10⁴The following. Weight average molecular weight greater than 50X 10⁴In the case of this, since the amount of the polymerization initiator to be used is reduced, the rate of modification of 1/2 having a molecular weight of the peak top in the GPC curve is greatly affected by the termination of the growth reaction and chain transfer. Therefore, if ultra-high purification, low-temperature polymerization, and a monomer conversion of less than 99 mass% of the monomers and solvents introduced into the polymerization reactor are not achieved, it is difficult to obtain a modified conjugated diene polymer having a desired modification ratio.

The rubber component a constituting the modified conjugated diene polymer composition of the present embodiment is preferably a mode in which the low molecular weight component is limited to a predetermined modification ratio as described later, and therefore the weight average molecular weight of the rubber component a is preferably greater than 50 × 10⁴。

The modified conjugated diene polymer composition of the present embodiment contains the rubber component a in an amount of 50 mass% or more based on the total amount of the rubber component a and the rubber component B. As a result, the glass transition temperature of the modified conjugated diene polymer composition of the present embodiment tends to be high, and the wet road surface performance tends to be excellent. Preferably 55% by mass or more, and more preferably 60% by mass or more.

The upper limit is 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, the vulcanizate tends to be soft at low temperatures and 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 through a polymerization step and a modification step described later.

< 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 the conjugated diene polymer.

The polymerization step is preferably a polymerization based on a growth reaction of living anionic polymerization, and thus there is a tendency that a conjugated diene polymer having an active terminal and a modified conjugated diene polymer having a high modification ratio can be obtained.

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 polymer.

The conjugated diene compound is not particularly limited as long as it is a monomer capable of polymerization, and is preferably a conjugated diene compound having 4 to 12 carbon atoms per 1 molecule, and more preferably a conjugated diene compound having 4 to 8 carbon atoms per 1 molecule.

Examples of such conjugated diene compounds include, but are not limited to, 1, 3-butadiene, isoprene, 2, 3-dimethyl-1, 3-butadiene, 1, 3-pentadiene, 3-methyl-1, 3-pentadiene, 1, 3-hexadiene and 1, 3-heptadiene.

Among these, 1, 3-butadiene and isoprene are preferable in terms of ease of industrial availability. These substances may be used alone in 1 kind, or 2 or more kinds may be used in combination.

Ultra-high purity of monomers and solvents can be achieved by sufficiently refining all monomers and solvents used in the polymerization.

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

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

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

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

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

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

Examples of the monovinyl aromatic compound include, but are not limited to, styrene, p-methylstyrene, α -methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and diphenylethylene. Among these, styrene is preferred in view of easy industrial availability. These substances may be used alone in 1 kind, or 2 or more kinds may be used in combination.

The conjugated diene polymer obtained in the polymerization step may be a random copolymer or a block copolymer.

In order to make the conjugated diene polymer a rubbery polymer, the conjugated diene compound is preferably used in an amount of 40% by mass or more, more preferably 55% by mass or more, based on the total monomers of the conjugated diene polymer obtained in the polymerization step.

Examples of the random copolymer include, but are not limited to, random copolymers composed of 2 or more kinds of conjugated diene compounds such as a butadiene-isoprene random copolymer; random copolymers composed of a conjugated diene and a vinyl-substituted aromatic compound, such as a butadiene-styrene random copolymer, an isoprene-styrene random copolymer, and a butadiene-isoprene-styrene random copolymer.

The composition distribution of each monomer in the copolymer chain is not particularly limited, and examples thereof include a completely random copolymer having a statistically close random composition and a tapered (gradient) random copolymer having a tapered distribution of composition. The bonding form of the conjugated diene, i.e., the composition such as 1, 4-bonding or 1, 2-bonding, may be uniform or may have a distribution.

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

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

[ polymerization initiator ]

As the polymerization initiator in the polymerization step, at least an organic lithium compound is used as described above.

Examples of the organic lithium compound include, but are not limited to, low molecular weight compounds and soluble oligomer organic lithium compounds.

Examples of the organic lithium compound include compounds having a carbon-lithium bond, compounds having a nitrogen-lithium bond, and compounds having a tin-lithium bond, in the bonding form between the organic group and lithium.

The amount of the polymerization initiator to be used is preferably determined in accordance with the molecular weight of the target conjugated diene polymer or modified conjugated diene polymer. The amount of the monomer such as a conjugated diene compound used relative to the amount of the polymerization initiator used is related to the degree of polymerization. That is, there is a tendency to be related to the number average molecular weight and/or the weight average molecular weight. Therefore, in order to increase the molecular weight, the polymerization initiator may be adjusted in a direction of decreasing the amount of the polymerization initiator, and in order to decrease the molecular weight, the polymerization initiator may be adjusted in a direction of increasing the amount of the polymerization initiator.

From the viewpoint of ease of industrial availability and ease of control of the polymerization reaction, the organolithium compound as the polymerization initiator is preferably an alkyllithium compound. In this case, the obtained conjugated diene polymer has an alkyl group at the polymerization initiation terminal.

Examples of the alkyllithium compound as the polymerization initiator include, but are not limited to, n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and lithium stilbene.

The alkyllithium compound is preferably n-butyllithium or sec-butyllithium in view of the ease of industrial availability and the ease of control of the polymerization reaction.

A method of using a compound having a nitrogen-lithium bond (hereinafter, sometimes referred to as an aminolithium compound) as a polymerization initiator is used as one method of introducing a nitrogen atom into a conjugated diene polymer, and examples of the aminolithium compound include an alkyllithium compound having a substituted amino group, or a dialkylaminolithium compound. In this case, a conjugated diene polymer and a modified conjugated diene polymer having a functional group represented by, for example, the following general formula (1) at the polymerization initiation end and having a nitrogen atom of an amino group are obtained.

Introduction of a nitrogen atom into a conjugated diene polymer tends to improve hysteresis loss characteristics and wet skid resistance.

[ CHEM 1]

In the above general formula (1), R¹And R²Is any one 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, R¹And R²May be the same or different. Here, R¹And R²R in the case that R may be bonded to form a cyclic structure together with an adjacent nitrogen atom¹And R²Is a hydrocarbon group having 4 to 12 carbon atoms in total. R¹And R²May have an unsaturated bond, and may have a branched structure.

Examples of the lithium alkyl compound or lithium dialkylamide compound having a substituted amino group include compounds represented by the following general formula (2).

[ CHEM 2]

In the above general formula (2), R¹And R²Is any one 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, R¹And R²May be the same or different. Here, R¹And R²R in the case that R may be bonded to form a cyclic structure together with an adjacent nitrogen atom¹And R²Is a hydrocarbon group having 4 to 12 carbon atoms in total. R¹And R²May have an unsaturated bond, and may have a branched structure.

Examples of the compound represented by the above formula (2) include, but are not limited to, 1-lithium pyrrolidine, 1-lithium piperidine, 1-lithium azepane, 1-lithium azacyclooctane, 1-lithium azacycloundecane, lithium diethylamide, lithium dibutylamide, lithium dihexylamide, 6-lithium-1, 3, 3-trimethyl-6-azabicyclo [3.2.1] octane, lithium ethylbutylamide, lithium ethylhexylamide, lithium butylhexylamide, lithium methylphenylamide, lithium benzylamide, and 1-lithium-1, 2,3, 4-tetrahydropyridine. The compound represented by the above formula (2) is not limited to these substances, and may include their analogs as long as the above conditions are satisfied.

From the viewpoint of reducing hysteresis loss of the modified conjugated diene polymer composition of the present embodiment, the compound represented by the formula (2) is preferably 1-lithium pyrrolidine, 1-lithium piperidine, 1-lithium azepane, lithium dibutylamide, 6-lithium-1, 3, 3-trimethyl-6-azabicyclo [3.2.1] octane, 1-lithium-1, 2,3, 4-tetrahydropyridine, or the like.

More preferred are 1-lithium pyrrolidine, 1-lithium piperidine and 1-lithium azepane, and still more preferred are 1-lithium piperidine and 1-lithium azepane.

The lithium amide compound as the polymerization initiator can be synthesized by a known method.

For example 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. Specific examples thereof include aliphatic hydrocarbons such as butane, pentane, hexane and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; and hydrocarbons composed of mixtures thereof, and the like.

Examples of the secondary amine include, but are not limited to, the following compounds represented by the following general formula (3).

[ CHEM 3]

In the above formula (3), R¹And R²Is any one 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, R¹And R²May be the same or different. R¹And R²May be bonded to form a cyclic structure together with the adjacent nitrogen atom, in which case R¹And R²Is a hydrocarbon group having 4 to 12 carbon atoms in total. R¹And R²May have an unsaturated bond, and may have a branched structure.

Examples of the compound represented by the formula (3) include pyrrolidine, piperidine, azepane, azocane, 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 above formula (3) is not limited to these substances, and may include their analogs as long as the above conditions are satisfied.

The compound represented by the formula (3) is preferably pyrrolidine, piperidine, azepane, dibutylamine, 1,3, 3-trimethyl-6-azabicyclo [3.2.1] octane, or 1,2,3, 4-tetrahydropyridine, from the viewpoint of reducing hysteresis loss of the modified conjugated diene polymer composition of the present embodiment. More preferably pyrrolidine, piperidine, azepane. Piperidine and azepane are more preferable.

These lithium amide compounds may be used in the form of an organic monolithium compound which is a soluble oligomer by reacting a small amount of a polymerizable monomer (for example, a monomer such as 1, 3-butadiene, isoprene or styrene).

The organic lithium compound as the polymerization initiator may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

In addition, other organometallic compounds may be used in combination. Examples of the organometallic compound include alkaline earth metal compounds, other alkali metal compounds, and other organometallic compounds.

Examples of the alkaline earth metal compound include, but are not limited to, organomagnesium compounds, organocalcium compounds, and organic strontium compounds.

In addition, there may be mentioned compounds of alkoxides, sulfonates, carbonates and amides of alkaline earth metals.

Examples of the organomagnesium compound include dibutylmagnesium and ethylbutylmagnesium.

Examples of the other organometallic compounds include organoaluminum compounds.

The polymerization reaction in the polymerization step is preferably carried out in a continuous polymerization reaction.

In the continuous system, polymerization can be carried out using 1 or 2 or more reactors connected in series.

As the continuous reactor, for example, a vessel type or tube type reactor with a stirrer is used.

In the continuous type, it is preferable to continuously feed the monomer, the inert solvent and the polymerization initiator to the reactor, obtain a polymer solution containing the polymer in the reactor, and continuously discharge the polymer solution.

[ polymerization solvent ]

In the polymerization step, it is preferable to carry out polymerization in an inert solvent using the inert solvent as a polymerization 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; aromatic hydrocarbons such as benzene, toluene, and xylene; and hydrocarbons composed of mixtures thereof.

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

[ polar Compound ]

In the polymerization step, a polar compound may be added. The addition of the polar compound tends to allow the aromatic vinyl compound and the conjugated diene compound to be randomly copolymerized and also to be used as a vinylating agent for controlling the microstructure of the conjugated diene portion. Further, there is a tendency that the polymerization reaction is also effectively accelerated.

Examples of the polar compound include, but are not limited to, ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2, 2-bis (2-tetrahydrofuryl) propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, and quinuclidine; alkali metal alkoxide compounds such as potassium tert-butoxide, sodium tert-butoxide, and sodium pentoxide; phosphine compounds such as triphenylphosphine, and the like.

These polar compounds may be used alone in 1 kind, or in combination in 2 or more kinds.

The amount of the polar compound to be used is not particularly limited and may be selected according to the purpose, and is preferably 0.01 to 100 moles based on 1 mole of the polymerization initiator. Such a polar compound (vinylating agent) can be used in an appropriate amount according to the desired vinyl bonding amount as a regulator of the microstructure of the conjugated diene portion of the polymer.

Most polar compounds have the following tendency: the copolymer has an effective randomizing effect in the copolymerization of a conjugated diene compound and an aromatic vinyl compound, and can be used as a regulator for the distribution of the aromatic vinyl compound or the amount of styrene blocks. As a method for randomizing the conjugated diene compound and the aromatic vinyl compound, for example, a method described in Japanese patent application laid-open No. 59-140211 starts a copolymerization reaction using a total amount of styrene and a part of 1, 3-butadiene, and the remaining 1, 3-butadiene is intermittently added during the copolymerization reaction.

< Properties of modified conjugated diene Polymer >

The modified conjugated diene polymer (rubber component a) constituting the modified conjugated diene polymer composition of the present embodiment is preferably such that the modification ratio of the component (low molecular weight component) having a molecular weight of 1/2, which is the molecular weight of the peak top (when a plurality of peak tops are present, the peak top having the smallest molecular weight) in the GPC curve, is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer.

In the case where the rubber component B described later is a modified conjugated diene polymer, it is also preferable that the modification ratio of 1/2, which is a component having a molecular weight of a peak top (when a plurality of peak tops are present, a peak top having the smallest molecular weight) in the GPC curve, that is, the low-molecular-weight component, is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer in the rubber component B.

This is because, considering that the low molecular weight component contributes to the processability of the polymer in the whole polymer, the processability in the case of producing a vulcanizate tends to be excellent in the above range.

In order to obtain the modified conjugated diene polymer (rubber component a, rubber component B) having a low molecular weight component with a predetermined modification ratio as described above, it is effective to adopt the following method: the conjugated diene polymer is obtained by a polymerization method in which the growth reaction is stopped or chain transfer is extremely small in the polymerization step.

Therefore, it is necessary to achieve ultrahigh purity of the monomer and the solvent introduced into the polymerization reactor at a level as high as that of the conventional one.

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

Examples of the allenes include, but are not limited to, allenes and 1, 2-butadiene. Examples of the acetylene include, but are not limited to, ethyl acetylene and vinyl acetylene. Examples of the primary amine and the secondary amine include, but are not limited to, the following, for example, methylamine and dimethylamine.

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

As a polymerization method in which the growth reaction is stopped and the chain transfer is extremely small, a method of controlling the polymerization temperature and the monomer conversion rate in the polymerization step is effective in addition to the above-described high purification of the monomer and the solvent.

The polymerization temperature is preferably lower from the viewpoint of suppressing the stop of the growth reaction or chain transfer, but from the viewpoint of productivity, the polymerization temperature is preferably a temperature at which living anionic polymerization sufficiently proceeds, specifically, preferably 0 ℃ or higher, and preferably 80 ℃ or lower. More preferably 50 ℃ to 75 ℃.

The conversion of the whole monomer is preferably less than 99 mass% and the monomer is reacted with the modifier in the modification step described later. The modifier is added at a stage where the monomer remains in the polymerizer, and the growing polymer chain and the modifier are reacted while the monomer is not completely consumed, whereby the formation of a polymer whose end is not modified or the occurrence of other side reactions can be suppressed. More preferably, the monomer conversion is less than 98 mass%.

When the modified conjugated diene polymer (rubber component a) constituting the modified conjugated diene polymer composition of the present embodiment and the rubber component B described later are modified conjugated diene polymers, the amount of the bonded conjugated diene in the modified conjugated diene polymer constituting the modified conjugated diene polymer composition of the present embodiment including these is preferably 40% by mass or more and 100% by mass or less, and more preferably 55% by mass or more and 90% by mass or less.

The amount of the bonded aromatic vinyl group in the conjugated diene polymer or the modified conjugated diene polymer is not particularly limited, but is preferably 0 mass% or more and 60 mass% or less, and more preferably 10 mass% or more and 45 mass% or less.

When the amount of the conjugated diene bonded and the amount of the aromatic vinyl bonded are within the above ranges, the balance between snow performance and wet skid performance and wear resistance in producing a vulcanizate tend to be more excellent. The amount of the bonded aromatic vinyl group can be measured by ultraviolet absorption of the phenyl group, and the amount of the bonded conjugated diene can be determined therefrom. Specifically, the measurement can be carried out by the method described in the examples described later.

When the rubber component a and the rubber component B described later are modified conjugated diene polymers, the vinyl bond content in the conjugated diene polymer or the modified conjugated diene polymer is preferably 10 mol% or more and 75 mol% or less, and more preferably 20 mol% or more and 65 mol% or less, in the conjugated diene bond unit. When the vinyl bond amount is in the above range, the balance between snow performance and wet road performance in producing a vulcanizate tends to be more excellent, as well as wear resistance.

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

< modification step >

After the polymerization step, the conjugated diene polymer is subjected to a modification step to obtain a modified conjugated diene polymer.

When the rubber component B described later is a modified conjugated diene polymer, the modification reaction step can be carried out by the same method.

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

In addition, the modification step is preferably performed immediately after the polymerization step. In this case, a modified conjugated diene polymer having a high modification ratio tends to be obtained.

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

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

The modifier is preferably a modifier having a functional group with little or no active hydrogen, such as a hydroxyl group, a carboxyl group, a primary amino group, or a secondary amino group. The 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, isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, carbonyl compounds containing a nitrogen group, vinyl compounds containing a nitrogen group, epoxy compounds containing a nitrogen group, and the like.

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

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

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

Examples of the oxygen-containing compound include, but are not limited to, epoxy compounds, ether compounds, ester compounds, and the like.

Examples of the sulfur-containing compound include, but are not limited to, mercapto derivatives, thiocarbonyl compounds, isothiocyanates, and the like.

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

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

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

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

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

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

As the nitrogen group-containing carbonyl compound as the modifier, there may be mentioned, but not limited to, 1, 3-dimethyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1-methyl-3- (2-methoxyethyl) -2-imidazolidinone, N-methyl-2-pyrrolidone, N-methyl-2-piperidone, N-methyl-2-quinolone, 4 '-bis (diethylamino) benzophenone, 4' -bis (dimethylamino) benzophenone, methyl-2-pyridinone, methyl-4-pyridinone, propyl-2-pyridinone, di-4-pyridinone, di-3-ethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, N-methyl-2-piperidone, N-methyl-2-quinolone, N-methyl-2-pyrimidinone, N-methyl-2-pyrimidinone, N-methyl-2-pyrimidinone, N-methyl-2-pyrimidinone, N-methyl-2-pyrimidinone, N-methyl-pyrimidinone, N-p-methyl-p, 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' -dimethylaminoacetamide, N, N-dimethylpyridinecarboxamide, N, N-dimethylisonicotinamide, and the like.

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

Examples of the nitrogen group-containing epoxy compound as the modifier include, but are not limited to, hydrocarbon compounds containing an epoxy group bonded to an amino group, and epoxy groups bonded to an ether group. Examples thereof include compounds represented by the general formula (4).

[ CHEM 4]

In the formula (4), R is an organic group having a valence of 2 or more and having at least one polar group selected from a hydrocarbon group having a valence of 2 or more, a polar group having oxygen such as an ether, an epoxy, a ketone, a polar group having oxygen such as a thioether, a thioketone, a polar group having sulfur, a tertiary amino group, a polar group having nitrogen such as an imino group, and the like.

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

In the above formula (4), R¹、R⁴Is a hydrocarbon group having 1 to 10 carbon atoms, R¹、R⁴May be the same as or different from each other.

R²、R⁵Is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, R²、R⁵May be the same as or different from each other.

R³Is a hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (5).

R¹、R²、R³May be bonded ring structures.

In addition, R³When it is a hydrocarbon group, it may have a cyclic structure bonded to R. In the case of the above cyclic structure, R may be substituted with R³The bonded N and R are directly bonded.

In the formula (4), n is an integer of 1 or more, and m is an integer of 0 or 1 or more.

[ CHEM 5]

In the above formula (5), R¹、R²With R of the above formula (4)¹、R²Are defined as such, R¹、R²May be the same as or different from each other.

As the epoxy compound having a nitrogen-containing group as the modifier, an epoxy compound having an epoxy-containing hydrocarbon group is preferable, and an epoxy compound having a glycidyl-containing hydrocarbon group is more preferable.

Examples of the hydrocarbon group containing an epoxy group bonded to an amino group or an ether group include a glycidylamino group, a diglycidylamino group, and a glycidyloxy group. Further preferred molecular structures are epoxy group-containing compounds having glycidylamino group, diglycidylamino group and glycidyloxy group, respectively, and examples thereof include compounds represented by the following general formula (6).

[ CHEM 6 ]

In the above formula (6), R is as defined as R in the above formula (4), and R is⁶Is a hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (7).

R⁶When it is a hydrocarbon group, it may have a cyclic structure bonded to R, and in this case, it may have a cyclic structure bonded to R⁶The bonded N and R are directly bonded.

In the formula (6), n is an integer of 1 or more, and m is an integer of 0 or 1 or more.

[ CHEM 7 ]

The nitrogen group-containing epoxy compound as the modifier is more preferably a compound having 1 or more diglycidylamino groups and 1 or more glycidyloxy groups in the molecule.

Examples of the nitrogen group-containing epoxy compound as the modifier include, but are not limited to, N-diglycidyl-4-glycidoxyaniline, 1-N, N-diglycidyl aminomethyl-4-glycidoxy-cyclohexane, 4- (4-glycidoxyphenyl) - (N, N-diglycidyl) aniline, 4- (4-glycidoxyphenoxy) - (N, N-diglycidyl) aniline, 4- (4-glycidoxybenzyl) - (N, N-diglycidyl) aniline, 4- (N, N' -diglycidyl-2-piperazinyl) -glycidoxybenzene, 1, 3-bis (N, n-diglycidylaminomethyl) cyclohexane, N, N, N ', N' -tetraglycidyl-m-xylylenediamine, 4-methylene-bis (N, N-diglycidylaniline), 1, 4-bis (N, N-diglycidylamino) cyclohexane, N, N, N ', N' -tetraglycidyl-p-phenylenediamine, 4 '-bis (diglycidylamino) benzophenone, 4- (4-glycidylpiperazinyl) - (N, N-diglycidylamino) aniline, 2- [2- (N, N-diglycidylamino) ethyl ] -1-glycidylpyrrolidine, N, N-diglycidylaniline, 4' -diglycidyldibenzylmethylamine, N, N '-tetraglycidylamide, 4, N' -diglycidylamino-p-xylylenediamine, N, N, N '-diglycidylaniline, N, N, N' -diglycidylpiperazinyl-N, N, N, N '-diglycidylamino-p-xylylenediamine, N, N, N' -diglycidylpyrrolidine, N, N, N '-tetraglycidyl-diglycidylaniline, N, N, N' -tetraglycidyl-bis (N, N, N '-diglycidylaniline, N, N' -diglycidylpyrrolidylm, N, N, N, N, N-diglycidylaniline, N-diglycidylotoluidine, N-diglycidylaminomethylcyclohexane, and the like.

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

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

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

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

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

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

Examples of the compound having an alkoxysilane and a protected amine in the molecule, which is a protected amine compound capable of forming a primary or secondary amine as a modifier, include, but are not limited to, N-bis (trimethylsilyl) aminopropyltrimethoxysilane, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N-bis (trimethylsilyl) aminopropyltriethoxysilane, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, N-bis (trimethylsilyl) aminoethyltrimethoxysilane, N-bis (trimethylsilyl) aminoethylmethyldiethoxysilane, N-bis (triethylsilyl) aminopropylmethyldiethoxysilane, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, N-bis (triethylsilyl) aminopropylmethyldiethoxysilane, N-bis (trimethylsilyl) amide compounds, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, N-bis (trimethylsilyl) amide compounds, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, N-bis (trimethylsilyl) amino-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, N-bis (trimethylsilyl) amino-propyl) methyldiethoxysilane, N, and the like, N, and the like, 3- (4-trimethylsilyl-1-piperazinyl) propyltriethoxysilane, 3- (3-triethylsilyl-1-imidazolidinyl) propylmethyldiethoxysilane, 3- (3-trimethylsilyl-1-hexahydropyrimidinyl) propyltrimethoxysilane, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-diethoxy-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-dimethoxy-1- (4-trimethoxysilylbutyl) -1-aza-2-silacyclohexane, and mixtures thereof, 2, 2-dimethoxy-1- (3-dimethoxymethylsilylpropyl) -1-aza-2-silacyclopentane, 2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, 2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2-dimethoxy-1-methyl-1-aza-2-silacyclopentane and the like.

Examples of the tin halide compound as the modifier include, but are not limited to, tetrachlorotin, tetrabromotin, tributyltin trichloride, trioctyltin trichloride, dimethyltin dibromide, dibutyltin dichloride, chlorotrimethyltin, chlorotriectyltin trichloride, triphenyltin chloride, 1, 2-bis (trichlorostannyl) ethane, 1, 2-bis (methyldichlorosilyl) ethane, 1, 4-bis (trichlorostannyl) butane, 1, 4-bis (methyldichlorosilyl) butane and the like.

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

The phosphite compound as a modifier includes, but is not limited to, trimethyl phosphite, tributyl phosphite, triphenyl phosphite, and the like.

The phosphine-based compound as a modifier includes, but is not limited to, protected phosphine-based compounds such as P, P-bis (trimethylsilyl) phosphinopropyltrimethoxysilane, P-bis (triethylsilyl) phosphinopropylmethylethoxysilane, 3-dimethylphosphinopropyltrimethoxysilane, and 3-diphenylphosphinopropyltrimethoxysilane.

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

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

The modifier is preferably a compound having a silicon-containing functional group, which preferably has an alkoxysilyl group or a silanol group.

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

In the modification step, when a modifier having 3 alkoxy groups per 1 silicon atom is used, that is, when 3 moles of the active end of the conjugated diene polymer are reacted with 1 mole of the trialkoxysilyl group, at most 2 moles of the conjugated diene polymer tend to be reacted, and 1 mole of alkoxy groups tend to remain unreacted. This can be determined by the fact that 1 mole of the conjugated diene polymer is not reacted and remains as an unreacted polymer. Note that, the following tendency exists: the alkoxy group is mostly reacted, whereby an increase in the viscosity of the polymer due to a condensation reaction during finishing or storage can be suppressed. It is preferred to use a modifier corresponding to 1 alkoxysilyl group per 1 silicon atom.

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

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

The conjugated diene polymer and the modifier in the modification step may be mixed by any mixing method such as mechanical stirring and stirring with a static mixer. When the polymerization step is a continuous type, the modification step is preferably also a continuous type. As the reactor used in the modification step, for example, a tank type or tubular type reactor with a stirrer can be 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.

[ CHEM 8 ]

In the formula (8), R¹²～R¹⁴Each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms, R¹⁵～R¹⁸And R²⁰Each independently represents an alkyl group having 1 to 20 carbon atoms, R¹⁹And R²²Each independently represents an alkylene group having 1 to 20 carbon atoms, R²¹Represents an alkyl group having 1 to 20 carbon atoms or a trialkylsilyl group.

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

R in case of plural¹²～R²²M and p are each independently.

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

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

The hydrocarbon group represented by a includes saturated, unsaturated, aliphatic, and aromatic hydrocarbon groups. The organic group having no active hydrogen is an organic group which renders the active terminal of the conjugated diene polymer inactive. The organic group is a group having no hydroxyl group (-OH), a secondary amino group (- (OH)>NH), primary amino group (-NH)₂) And an organic group having an active hydrogen functional group such as a mercapto group (-SH). When (i + j + k) is 1, a substance having no a may be used.

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

[ CHEM 9 ]

In the above formula (9), B¹Represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, B¹When there are plural, they are independent of each other.

[ CHEM 10 ]

In the above formula (10), B²Represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, B³Represents an alkyl group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, B²And B³When there are plural ones, plural ones B²And B³Each independently.

[ CHEM 11 ]

In the above formula (11), B⁴Represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, B⁴When there are plural, they are independent of each other.

[ CHEM 12 ]

In the above formula (12), B⁵Represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, B⁵When there are plural, they are independent of each other.

In the formula (8), a represents any one of the formulae (9) to (12), and thus there is a tendency that a modified conjugated diene polymer having more excellent performance can be obtained.

The modifier of the formula (8) includes, as the modifier having (i + j + k) of 1 to 2, a substance that overlaps with the modifier, but is not limited to, for example, 3-dimethoxymethylsilylpropyldimethylamine (1-functional), 3-trimethoxysilylpropyldimethylamine (2-functional), bis (3-trimethoxysilylpropyl) methylamine (4-functional), bis (3-dimethoxymethylsilylpropyl) methylamine (2-functional), (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] ethylamine (4-functional), and [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropylethylamine (4-functional) Yl) methylamine (4 functional), bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] methylamine (4 functional), bis (3-triethoxysilylpropyl) ethylamine (4 functional), 1- (3-triethoxysilylpropyl) -2, 2-diethoxy-1-aza-2-silacyclopentane (4 functional), 1- (3-dimethoxymethylsilylpropyl) -2, 2-dimethoxy-1-aza-2-silacyclopentane (3 functional), [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-diethoxyethylsilylpropyl) methylamine (3 functional), Bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] methylamine (4-functional), (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -methylamine (3-functional).

In the case where (i + j + k) of the polyfunctional compound is 3 or more and A in the formula (8) is represented by the formula (9), examples of the modifier of the formula (8) include, but are not limited to, tris (3-trimethoxysilylpropyl) amine, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) amine, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine, Tris (3-ethoxysilylpropyl) amine, bis (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] amine, bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) amine, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] amine, tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine, tris (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, bis (3-trimethoxysilylpropyl) -bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) -1, 3-propanediamine, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, tetrakis (3-triethoxysilylpropyl) -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, bis (3-triethoxysilylpropyl) -bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) -1, 3-propanediamine, tetrakis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, bis (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] ] -1, 3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tris (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-trimethoxysilylpropyl) -bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-methoxy-1-aza-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-methoxy-2-aza-2-sila-2-azacyclopentane) propyl ester, bis (3-methoxy-1-methoxy-2-azacyclopentane) propyl ester, bis (3-methoxy-1-sila-2-azacyclopentane) propyl ester, bis (3-methyl) propyl ester, tris (3-amino-methyl) methyl ester, tris (2-methyl) ethyl ester, tris (meth) amide, bis (2-amino) methyl ester, tris (meth) methyl ester, bis (2-amino) methyl ester, and (meth) methyl ester, Tetrakis (3-triethoxysilylpropyl) -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-triethoxysilylpropyl) -bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) -1, 3-propanediamine, tri (3-triethoxysilylpropyl) -1, 3-propanediamine, and mixtures thereof, Tetrakis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-ethoxysilylpropyl) - [1- (2-ethoxy-2-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-triethoxy-1-aza-2-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-ethoxysilylpropyl) - [3- (2-ethoxysilylpropyl) -2-azacyclopentane, bis (3-ethyl) propyl ] -1, 3-sila-2-azacyclopentane, and (3-ethyl-2-sila-cyclopentane), Tetrakis (3-trimethoxysilylpropyl) -1, 6-hexanediamine, pentakis (3-trimethoxysilylpropyl) -diethylenetriamine.

Examples of the modifier in the case where A is represented by the formula (10) in the formula (8) include, but are not limited to, tris (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine, bis (2-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl]-methyl-1, 3-propanediamine, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclePentane) propyl group]- (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine, tris (3-triethoxysilylpropyl) -methyl-1, 3-propanediamine, bis (2-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl]-methyl-1, 3-propanediamine, bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl]- (3-triethoxysilylpropyl) -methyl-1, 3-propanediamine, N¹,N^1’- (propane-1, 3-diyl) bis (N)¹-methyl-N³,N³Bis (3- (trimethoxysilyl) propyl) -1, 3-propanediamine), N¹- (3- (bis (3- (trimethoxysilyl) propyl) amino) propyl) -N¹-methyl-N³- (3- (methyl (3- (trimethoxysilyl) propyl) amino) propyl) -N³- (3- (trimethoxysilyl) propyl) -1, 3-propanediamine.

Examples of the modifier in the case where A is represented by the formula (11) in the formula (8) include, but are not limited to, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] silane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) silane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] silane, bis (3-trimethoxysilylpropyl) -bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] silane, (3-trimethoxysilyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) -bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] silane, bis [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) -bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] silane, tris (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] silane, bis (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] silane, bis [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -bis (3-trimethoxysilylpropyl) silane, bis (3-trimethoxysilylpropyl) -bis [3- (1-methoxy-2-methyl-1-sila-2- Azacyclopentane) propyl ] silane.

Examples of the modifier in the case where A in the formula (8) is represented by the formula (12) include, but are not limited to, 3-tris [2- (2, 2-dimethoxy-1-aza-2-silacyclopentane) ethoxy ] silyl-1- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propane, 3-tris [2- (2, 2-dimethoxy-1-aza-2-silacyclopentane) ethoxy ] silyl-1-trimethoxysilylpropane.

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

Examples of the modifier in the case where a in the formula (8) represents an organic group having a phosphorus atom and no active hydrogen include, but are not limited to, (3-trimethoxysilylpropyl) phosphate, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] phosphate, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) phosphate, and tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] phosphate.

In the formula (8), a preferably represents the formula (9) or the formula (10), and k preferably represents 0. Therefore, the modifier tends to be easily obtained, and when the modified conjugated diene polymer is used as a sulfide, the wear resistance and the low hysteresis loss performance tend to be more excellent.

Examples of such modifiers include, but are not limited to, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine, tris (3-trimethoxysilylpropyl) amine, tris (3-triethoxysilylpropyl) amine, tris (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tris (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine.

In the formula (8), a more preferably represents a formula (9) or a formula (10), k represents 0, and a in the formula (9) or the formula (10) represents an integer of 2 to 10. By using the modified conjugated diene polymer produced by using such a modifier, the wear resistance and the hysteresis loss performance tend to be more excellent when vulcanization is performed.

Such a modifier includes, but is not limited to, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl group]1, 3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, N¹- (3- (bis (3- (trimethoxysilyl) propyl) amino) propyl) -N¹-methyl-N³- (3- (methyl (3- (trimethoxysilyl) propyl) amino) propyl) -N³- (3- (trimethoxysilyl) propyl) -1, 3-propanediamine.

The amount of the compound represented by formula (8) as the modifier is preferably adjusted so that the molar number of the polymerization initiator is in a desired stoichiometric ratio with respect to the molar number of the modifier, thereby achieving a desired degree of branching in the modified conjugated diene polymer.

Specifically, the number of moles of the polymerization initiator is preferably 1.0 time by mole or more, more preferably 2.0 times by mole or more, based on the number of moles of the modifier. In this case, in formula (8), the number of functional groups of the modifier ((m-1). times.i + p.times.j + k) is preferably an integer of 1 to 10, more preferably an integer of 2 to 10.

< glass transition temperature of modified conjugated diene Polymer (rubber component A) >

The glass transition temperature of the modified conjugated diene polymer (rubber component A) is-35 ℃ or higher. Preferably-30 ℃ or higher, more preferably-25 ℃ or higher.

The glass transition temperature of the modified conjugated diene polymer (rubber component a) can be controlled within the above numerical range by adjusting the above microstructure, that is, by adjusting the amount of the aromatic vinyl compound or the vinyl bonding amount in the modified conjugated diene polymer.

When the glass transition temperature is in the above range, a sulfide having a more excellent balance between snow performance and wet road performance tends to be obtained.

For the glass transition temperature, the glass transition temperature is determined in accordance with ISO 22768: 2006, a DSC curve is recorded while raising the temperature within a predetermined temperature range, and the peak top (reflection point) of the DSC differential curve is set as the glass transition temperature. Specifically, the measurement can be performed by the method described in the examples described later. The upper limit of the glass transition temperature of the modified conjugated diene polymer (rubber component A) is not particularly limited, but is preferably-10 ℃ or lower. When the amount is within this range, the balance between snow performance and wet road performance tends to be more excellent.

< addition of rubber stabilizer, filling oil, etc. >

From the viewpoint of preventing gel formation after polymerization and improving stability during processing, it is preferable to add a rubber stabilizer to the modified conjugated diene polymer constituting the modified conjugated diene polymer composition of the present embodiment.

In this case, the modified conjugated diene polymer includes the rubber component a, and the modified conjugated diene polymer includes the rubber component B.

As the rubber stabilizer, known ones can be used, and examples thereof include, but are not limited to, antioxidants such as 2, 6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl 3- (4 ' -hydroxy-3 ', 5 ' -di-tert-butylphenol) propionate, 2-methyl-4, 6-bis [ (octylthio) methyl ] phenol, and the like.

In order to further improve the processability of the modified conjugated diene polymer, an extender oil may be added to the modified conjugated diene copolymer as necessary.

As a method of adding the extender oil to the modified conjugated diene polymer, a method of adding the extender oil to a polymer solution, mixing the mixture to form an oil-extended copolymer solution, and then removing the solvent is preferable, but not limited to.

The timing of adding the extender oil includes, but is not limited to, a timing after the modification step before mixing the polymerization solutions, that is, after the modification step of the modified conjugated diene polymer of the rubber component a (and the rubber component B) and before mixing the polymerization solutions of the rubber component a and the rubber component B, or a timing after mixing both the polymerization solutions, that is, after the modification step of the rubber component a (and the rubber component B) and after mixing the polymerization solutions of the rubber component a and the rubber component B. When the extender oil is mixed, the extender oil is preferably added after the modification step before the two polymerization solutions are mixed, from the viewpoint that the viscosity of the polymerization solution is lowered and the polymer solution is easily mixed.

Examples of the extender oil include aromatic oil, naphthenic oil, and paraffin oil. Among these, in terms of environmental safety and oil leakage prevention and wet grip performance, a substituted aromatic oil having a polycyclic aromatic (PCA) component of 3 mass% or less by the IP346 method is preferable.

Examples of the alternative Aromatic oils include TDAE (treated dispersed Aromatic extracts), MES (Mill extract solvent) and RAE (residual Aromatic extracts) shown in Kautschuk Gummi Kunststoffe 52(12)799 (1999).

The amount of the extender oil to be added is not particularly limited, and is preferably 5 to 60 parts by mass per 100 parts by mass of the modified conjugated diene polymer.

< modification ratio >

The modified conjugated diene polymer (rubber component a) has a modification ratio of 50% by mass or more, preferably 60% by mass or more, and more preferably 75% by mass or more, based on the total amount of the conjugated diene polymer.

Since the modification ratio is 50% by mass or more, reactivity with silica as a filler is improved in producing a sulfide, and dispersibility of silica in the sulfide tends to be good. As a result, the viscoelastic temperature dispersion peak tends to be sharp, and the wet road surface performance tends to be excellent.

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

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

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

More specifically, the modification ratio was obtained by calculating the difference between the chromatogram obtained by measuring a sample solution containing the measurement sample and low-molecular-weight internal standard polystyrene using a polystyrene gel column and the chromatogram obtained by measuring using a silica-based column, and measuring the amount of adsorption on the silica column.

The modification ratio can be measured by the method described in the examples described later.

As a method for controlling the modification ratio of the modified conjugated diene polymer to 50% by mass or more, there can be mentioned a method of adjusting the amount of the modifier to be added and conditions of the reaction step.

Here, when the rubber component a constituting the modified conjugated diene polymer composition of the present embodiment is contained and the rubber component B described later is a modified conjugated diene polymer, the modified conjugated diene polymer also includes the rubber component B.

Examples thereof include: a method of performing polymerization using an organolithium compound having at least one nitrogen atom in the molecule as a polymerization initiator, which will be described later; a method of copolymerizing a monomer having at least one nitrogen atom in the molecule; a method of controlling the polymerization conditions such as lowering the polymerization temperature so as not to excessively promote the chain transfer reaction.

The upper limit of the modification rate is not particularly limited, but is preferably 95% by mass or less. When the amount is within this range, aggregation of the filler during production of a sulfide can be suppressed, and the processability tends to be excellent.

Examples of the method for controlling the modification ratio of the modified conjugated diene polymer to 95% by mass or less include: a method of reducing the amount of the modifier to be added (the amount is adjusted so that the number of moles of the functional groups bonded to the modifier is smaller than the number of moles of the polymer chain); a method of reducing the amount of an organolithium compound having at least one nitrogen atom in the molecule (a combination of organolithium having a nitrogen atom and organolithium having no nitrogen atom as a polymerization initiator) to be described later as a polymerization initiator.

< weight average molecular weight >

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

Weight average molecular weight of 20X 10⁴In the above case, the entanglement density between the molecular chains tends to be increased, and the fracture strength tends to be excellent, and the wear resistance tends to be excellent when the vulcanizate is produced.

In addition, weight average moleculesThe amount is 300X 10⁴When the filler is used as a sulfide, the dispersibility of the filler is excellent, and excellent wet road surface performance tends to be obtained.

The weight average molecular weight of the modified conjugated diene polymer can be controlled by adjusting the molecular weight of the conjugated diene polymer chain or the kind and amount of the modifier by appropriately selecting the ratio of the amount of the polymerization initiator to the amount of the monomer.

In the present specification, the term "molecular weight" refers to a molecular weight obtained by GPC (gel permeation chromatography) and converted to standard polystyrene. The number average molecular weight, weight average molecular weight, and content of molecular weight distribution can be measured by the methods described in the examples described later.

< molecular weight distribution >

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

The modified conjugated diene polymer having such a molecular weight distribution can be preferably obtained by continuous polymerization.

For the molecular weight distribution, the molecular weight curve based on GPC is preferably in the shape of one peak (single peak), or in the case of a plurality of peaks, preferably in the shape of a trapezoid or a continuous peak. The continuous peak type is a shape in which the height of the lowermost part between peaks is 50% or more of the height of the peaks on both sides. The modified conjugated diene polymer having such a molecular weight distribution tends to have more excellent processability when it is produced into a vulcanizate.

The molecular weight distribution can be controlled within the above range by adjusting the molecular weight of the conjugated diene polymer chain by appropriately selecting the ratio of the amount of the polymerization initiator to the amount of the monomer, or by adjusting the kind and amount of the modifier or the polymerization temperature.

< modification ratio of Low molecular weight component >

The modified conjugated diene polymer (rubber component a) is preferably such that the modification ratio of the component (low-molecular-weight component) of 1/2 having a molecular weight of the peak top (peak top having the smallest molecular weight in the case where a plurality of peak tops are present) in the GPC curve is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer.

When the modification ratio of the low-molecular-weight component of the modified conjugated diene polymer (rubber component a) is within the above range, the following tendency is observed: the rubber composition is excellent in processability, and particularly, the torque of a mixer works well when the rubber composition is kneaded with a filler, and the mixing property of the rubber composition A with a rubber composition B and a filler described later is good. As a result, the dispersibility of the filler tends to be improved, and the wet performance tends to be improved, and as a result, the balance between the snow performance and the wet performance of the modified conjugated diene polymer composition can be improved.

The present inventors have found that the following mechanism is found as a torque transmission method in kneading a polymer and a filler, in addition to the modification ratio being different for each molecular weight region of the polymer.

First, focusing on the modification ratio with respect to the total amount of the conjugated diene polymer, when the mooney viscosity, microstructure, modifier used, kneading conditions, and the like of the polymer are the same, a polymer having a high modification ratio (modification ratio of 50% or more) has a higher speed of torque rise during kneading with a filler than a polymer having a low modification ratio, but on the other hand, the maximum value of torque is high, and therefore, even if the modification ratio as a whole changes, the time taken until the torque reaches the maximum value is substantially the same. That is, it is considered that the modification ratio of the whole polymer affects both the maximum value of the torque and the rate of rise of the torque, and as a result, the length of time for which the torque reaches the maximum value is not much affected even if the modification ratio of the whole polymer increases or decreases.

On the other hand, focusing on the modification ratio of the low-molecular-weight component, the lower the modification ratio of the low-molecular-weight component is, the slower the rise rate of torque at the time of kneading the polymer and the filler is, as compared with the modification ratio with respect to the total amount of the conjugated diene polymer, and the higher the modification ratio of the low-molecular-weight component is, the faster the rise rate of torque is.

On the other hand, since the maximum value of the torque is determined depending on the modification ratio with respect to the total amount of the conjugated diene polymer, it does not vary depending on the modification ratio of the low-molecular-weight component, and the time until the torque reaches the maximum value becomes shorter as the modification ratio of the low-molecular-weight component is higher. Therefore, the time at which the torque reaches the maximum value is controlled by the height of the modification ratio of the low-molecular-weight component compared to the modification ratio with respect to the total amount of the conjugated diene polymer, not by the modification ratio with respect to the total amount of the conjugated diene polymer.

Specifically, when the modification ratio of the low-molecular weight component is set to a height of 1/2 or more relative to the modification ratio of the total amount of the conjugated diene polymer, the following tendency is observed: the workability, in particular, the torque of the mixer during kneading with the filler works well, and the mixing property of the rubber component A, the rubber component B and the filler becomes good in a shorter time than the conventional one. As a result, the workability becomes good, the dispersibility of the filler is improved, and the wet road surface performance tends to become good.

< Nitrogen content >

The nitrogen content of the modified conjugated diene polymer as the rubber component a is preferably 25 mass ppm or more, more preferably 40 mass ppm or more, and further preferably 60 mass ppm or more, relative to the total amount of the modified conjugated diene polymer.

When the nitrogen content is in this range, the modified conjugated diene polymer composition of the present embodiment tends to have an excellent balance between low hysteresis and wet skid resistance when formed into a vulcanizate. The nitrogen content is preferably 250 mass ppm or less, more preferably 150 mass ppm or less, and still more preferably 100 mass ppm or less, from the viewpoints of processability in producing a sulfide and dispersibility of a filler.

The content of nitrogen atoms can be measured by the oxidative combustion-chemiluminescence method (JIS-2609: crude oil and crude oil products-nitrogen component test method). More specifically, the content of nitrogen atoms can be measured by the method described in the examples described later.

As a method for controlling the nitrogen content of the modified conjugated diene polymer as the rubber component a to 25 mass ppm or more, there can be mentioned a method for adjusting the kind and/or the addition amount of the polymerization initiator, the modifier, and the monomer, and there can be mentioned, for example, the following methods: a method of performing polymerization using an organolithium compound having at least one nitrogen atom in the molecule as a polymerization initiator, which will be described later; a method of reacting a modifier having at least one nitrogen atom in a molecule with a conjugated diene polymer having a nitrogen atom obtained by a method of copolymerizing a monomer having at least one nitrogen atom in a molecule.

< shrinkage factor >

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

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

The shrinkage factor (g') was measured by 3D-GPC measurement.

The relation between intrinsic viscosity and molecular weight ([ eta. ])]＝KMα([η]: intrinsic viscosity, M: molecular weight) was set to logK-3.883 and α -0.771, and a standard intrinsic viscosity [. eta. ] was prepared]₀Graph relating to molecular weight M.

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

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

Among the modified conjugated diene polymers as the rubber component A, preferred examples thereof include those having a shrinkage factor (g') of 0.70 or less as measured by 3D-GPC.

The contraction factor (g') is more preferably 0.30 to 0.70.

The rubber composition containing such a modified conjugated diene polymer added with a filler has a greatly reduced viscosity and is extremely excellent in processability.

The shrinkage factor (g ') is an index of the branched structure of the modified conjugated diene copolymer, and the modified conjugated diene polymer having a shrinkage factor (g') of 0.30 to 0.70 is a modified conjugated diene polymer having 4 or more branches in 1 molecule of the modified diene polymer.

In order to obtain a modified conjugated diene copolymer having a shrinkage factor (g') within the above range, for example, the following method is effective: the modifier having 4 or more reaction sites with the active end is added in a mole number of one-fourth or less relative to the total mole number of the polymerization initiator to obtain a modified conjugated diene copolymer having 4 or more branches.

(rubber component B)

The modified conjugated diene polymer composition of the present embodiment contains a rubber component B having a glass transition temperature of-55 ℃ or lower. Preferably-60 ℃ or lower, more preferably-65 ℃ or lower.

By containing the rubber component B, the rigidity at low temperature when the vulcanizate is produced is lowered, and the 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 ℃ or higher. When the glass transition temperature is-100 ℃ or higher, the breaking strength tends to be improved and the wear resistance tends to be excellent.

The Tg of the rubber component B can be controlled to the above numerical range by adjusting the microstructure of the polymer as the rubber component B, that is, the amount of the aromatic vinyl compound or the vinyl bond amount. Further, natural rubber may be used as the rubber component B and controlled to the above numerical range.

As the rubber component B, a modified conjugated diene polymer can be preferably used.

When the rubber component B is a modified conjugated diene polymer, the structure of the rubber component B is not particularly limited, and examples thereof include a conjugated diene polymer or a hydrogenated product thereof, a random copolymer of a conjugated diene compound and a vinyl aromatic compound 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.

Examples of the rubber component B include styrene-based elastomers such as butadiene rubber or a hydrogenated product thereof, isoprene rubber or a hydrogenated product thereof, styrene-butadiene block copolymer or a hydrogenated product thereof, and styrene-isoprene block copolymer or a hydrogenated product thereof, and nitrile rubber or a hydrogenated product thereof.

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

The natural rubber is not limited to the following natural rubbers, for example, RSS 3-5, SMR, and epoxidized natural rubber, which are smoke films, because the natural rubber has a large amount of high molecular weight components and is excellent in breaking strength.

From improving balance of snow performance and wet road performance and wear resistanceIn view of this, the rubber component B preferably has a weight average molecular weight of 20X 10⁴300X 10 above⁴The modified conjugated diene polymer has a molecular weight distribution Mw/Mn of 1.6 to 4.0.

In addition, from the viewpoint of improving the balance between the snow performance and the wet road performance, the rubber component B is preferably a modified conjugated diene polymer having a modification ratio of 50 mass% or more with respect to the total amount of the conjugated diene polymer.

In addition, from the viewpoint of excellent processability in producing a vulcanizate, the rubber component B is preferably a modified conjugated diene polymer having a modification ratio of 1/2 or more, which is a molecular weight of a component having a molecular weight of 1/2 of a peak top (a peak top having a smallest molecular weight when a plurality of peak tops are present) in a Gel Permeation Chromatography (GPC) curve, of 1/2 or more relative to the modification ratio of the total amount of the conjugated diene polymer.

When the rubber component B is a modified conjugated diene polymer, the rubber component B can be produced by the same method as that for the rubber component a, and the weight average molecular weight, the molecular weight distribution, the modification ratio, and the modification ratio of the low molecular weight component of the rubber component B can be controlled by the same method as that for the rubber component a.

(Filler)

The modified conjugated diene polymer composition of the present embodiment contains a filler.

The modified conjugated diene polymer composition preferably contains 5 to 150 parts by mass of a filler per 100 parts by mass of the total amount of the rubber component A and the rubber component B.

The filler preferably contains a silica-based inorganic filler.

The modified conjugated diene polymer composition of the present embodiment has a tendency to have more excellent processability when formed into a vulcanizate, and to have an excellent balance between snow performance and wet skid performance and wear resistance when formed into a vulcanizate, by dispersing a silica inorganic filler.

The content of the filler is preferably 5.0 parts by mass or more per 100 parts by mass of the total amount of the rubber component a and the rubber component B from the viewpoint of exhibiting the effect of adding the filler, and is preferably 150 parts by mass or less from the viewpoint of sufficiently dispersing the filler and practically satisfying the processability and mechanical strength of the modified conjugated diene polymer composition.

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

Examples of the filler include, but are not limited to, carbon black, metal oxides, and metal hydroxides in addition to the silica-based inorganic filler. These substances may be used alone in 1 kind, or 2 or more kinds may be used in combination.

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

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

In the modified conjugated diene polymer composition of the present embodiment, the nitrogen adsorption specific surface area of the silica inorganic filler determined by the BET adsorption method is preferably 100m in view of obtaining practically good wear resistance and fracture characteristics²300m above g²A ratio of 170m or less per gram²More than 250 m/g²The ratio of the carbon atoms to the carbon atoms is less than g. The specific surface area may be relatively small as required (for example, 200 m)²A/g or less) silica-based inorganic filler and a relatively large specific surface area (e.g., 200 m)²/g or more) of a silica-based inorganic filler.

In particular, the specific surface area is relatively large (e.g. 200 m)²(iv)/g or more), the following tendency is present in the modified conjugated diene polymer as the rubber component a and the rubber component B: the silica has a good dispersibility, and is effective in improving the abrasion resistance, and the good fracture characteristics and the low hysteresis loss can be well balanced.

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

The content of carbon black is preferably 0.5 to 100 parts by mass, more preferably 3.0 to 100 parts by mass, and still more preferably 5.0 to 50 parts by mass, based on 100 parts by mass of the total amount of the rubber component a and the rubber component B. The content of carbon black is preferably 0.5 parts by mass or more in terms of exhibiting performance required for applications such as tires, including dry grip performance and conductivity, and is preferably 100 parts by mass or less in terms of dispersibility.

The modified conjugated diene polymer composition of the present embodiment may contain a silane coupling agent.

The silane coupling agent has a function of causing the rubbery polymer to interact with a filler, particularly an inorganic filler, and has groups having affinity or bonding properties with respect to the rubbery polymer and the silica-based inorganic filler, respectively, and is preferably a compound having a sulfur-bonding portion and an alkoxysilyl or silanol portion in one molecule.

Examples of such compounds include bis [3- (triethoxysilyl) -propyl ] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl ] -disulfide, and bis- [2- (triethoxysilyl) -ethyl ] -tetrasulfide.

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

(softener for rubber)

The modified conjugated diene polymer composition of the present embodiment may contain a softening agent for rubber in order to improve processability.

As the softener for rubber, mineral oil or a liquid or low molecular weight synthetic softener is preferable.

A softening agent for mineral oil-based rubber, which is called process oil or extender oil and is used for softening, extending and improving the processability of rubber, is a mixture of aromatic rings, naphthenic rings and paraffinic chains, a substance having 50 mass% or more of the total carbon number of paraffinic chains is called paraffinic, a substance having 30 mass% or more or 45 mass% or less of the total carbon number of naphthenic ring carbons is called naphthenic, and a substance having more than 30 mass% of the total carbon number of aromatic carbon numbers is called aromatic.

The content of the rubber softener is preferably 0 to 100 parts by mass, more preferably 10 to 90 parts by mass, and still more preferably 30 to 90 parts by mass, based on 100 parts by mass of the rubber-like polymer containing the rubber component a and the rubber component B. When the content of the rubber softener is 100 parts by mass or less based on 100 parts by mass of the rubber-like polymer, bleeding tends to be suppressed and surface tackiness of the rubber composition tends to be suppressed.

[ Process for producing modified conjugated diene Polymer composition ]

The modified conjugated diene polymer composition of the present embodiment can be produced by mixing the rubber component a, the rubber component B, and the filler, and if necessary, additives such as a rubbery polymer other than the rubber component a and the rubber component B, a silica-based inorganic filler, carbon black, other fillers, a silane coupling agent, and a rubber softener can be mixed.

Examples of the mixing method include, but are not limited to, melt-kneading methods using a usual mixer such as an open mill, a banbury mixer, a kneader, a single-screw extruder, a twin-screw extruder, or a multi-screw extruder; dissolving and mixing the components, and heating to remove the solvent.

Among these, a melt kneading method using a roll, a banbury mixer, a kneader, or an extruder is preferable in terms of productivity and good kneading property.

In addition, any of a method of kneading the rubber component a, the rubber component B, the filler and other various materials at once, and a method of mixing them divided into 2 or more times may be applied.

The procedure for kneading the above materials is not particularly limited, but it is preferable to knead the rubber component B and the filler to obtain a kneaded product, then knead the kneaded product and the rubber component a, and further, if necessary, to mix various additives such as a silane 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, the section modulus of the modified conjugated diene polymer composition of the present embodiment can be increased, and the breaking strength tends to be improved.

The modified conjugated diene polymer composition of the present embodiment may be vulcanized by a vulcanizing agent to prepare a vulcanized composition.

Examples of the vulcanizing agent include, but are not limited to, radical initiators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur-containing compounds.

The sulfur-containing compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, polymeric polysulfide compounds, and the like.

The content of the vulcanizing agent is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, per 100 parts by mass of the rubber-like polymer containing the rubber component a and the rubber component B. As the vulcanization method, conventionally known methods can be applied, and the vulcanization temperature is preferably 120 ℃ to 200 ℃ inclusive, more preferably 140 ℃ to 180 ℃ inclusive.

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

As the vulcanization accelerator, conventionally known materials can be used, and examples thereof include, but are not limited to, sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, thiourea-based, and dithiocarbamate-based vulcanization accelerators.

Examples of the vulcanization aid include, but are not limited to, zinc white and stearic acid.

The content of the vulcanization accelerator is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, per 100 parts by mass of the rubbery polymer containing the rubber component a and the rubber component B.

The modified conjugated diene polymer composition of the present embodiment may contain various additives such as a softening agent, a filler, a heat stabilizer, an antistatic agent, a weather stabilizer, an aging inhibitor, a colorant, and a lubricant, other than those described above, within a range not to impair the object of the present embodiment.

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

[ tires ]

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

The modified conjugated diene polymer composition of the present embodiment can be used for, but not limited to, various tire parts such as treads, tire carcasses, sidewalls, and bead portions of various tires such as fuel-efficient tires, all-season tires, high-performance tires, and winter tires. In particular, the modified conjugated diene polymer composition of the present embodiment, which contains a rubber-like polymer for a tire comprising the modified conjugated diene polymer (rubber component a) and rubber component B, is more preferably used as a tread of a winter tire because it is excellent in the balance between snow performance and wet performance and wear resistance when prepared into a vulcanizate.

Examples

The present embodiment will be described in more detail below by referring to specific examples and comparative examples, but the present embodiment is not limited to the following examples.

The materials used in examples and comparative examples and the evaluation methods of various characteristics are as follows.

[ purification of 1, 3-butadiene ]

1, 3-butadiene used for polymerization of the modified conjugated diene polymer was purified by the following procedure.

(washing step)

In the circulating water amount of 1m³Hr, 0.1m of water for renewal (supplement)³Run at/hr.

The 1, 3-butadiene and the washing water were mixed using a static mixer (NORITAKE CO., series of static mixers N60 manufactured by LIMITED Co., Ltd.), and then transferred to a decanter, by which the 1, 3-butadiene phase and the aqueous phase were separated.

The operation was carried out at a temperature of 30 ℃ 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 was introduced into a 1, 3-butadiene removal tank, mixed with steam and heated to 89 ℃ while the total pressure was adjusted to 0.01MPaG, and 1, 3-butadiene was separated from the aqueous phase.

(oxygen removal step by deoxidant)

Next, ダイクリーン F-504 (manufactured by Tantaki Kaisha industries) in a 10% aqueous solution was used as a deoxidizer, and a static mixer was used at a circulation flow rate of 1m³The 1, 3-butadiene after the washing step is mixed with the aqueous solution of the deoxidizer to carry out liquid-liquid extraction.

Then, 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 carried out at a temperature of 30 ℃ and a decanter pressure of 1.0 MPaG.

(polymerization inhibitor removing step)

Next, using a packed column to which a pall ring was added, a 10% aqueous sodium hydroxide solution was added at a circulation flow rate of 1m³The mixture was mixed with 1, 3-butadiene after the above-mentioned (oxygen removal step by a deoxidizer), liquid-liquid extraction was performed, and then the mixture was transferred to another decanter to separate the 1, 3-butadiene phase and the aqueous phase by the use of the decanter.

The residence time of the 1, 3-butadiene phase in the further decanter was 60 minutes. In the polymerization inhibitor removal step, the operation was carried out at a temperature of 30 ℃ and a decanter pressure of 1.0 MPaG.

(dehydration column Process)

Hexane was added to the 1, 3-butadiene phase separated by the other decanters described above so that the 1, 3-butadiene concentration was 50 mass%, and the mixture was supplied to the dehydration column.

In the dehydration column, the azeotropic mixture of 1, 3-butadiene and water distilled off from the top (overhead) is cooled and condensed, and then transferred to a decanter, whereby the 1, 3-butadiene phase and the aqueous phase are separated.

The aqueous phase was removed, and the 1, 3-butadiene phase was returned to the inlet of the dehydration column, thereby continuously conducting the dehydration column step.

The mixture of dehydrated 1, 3-butadiene and hexane was taken out from the bottom (bottom) of the dehydration column.

(adsorption step)

The mixed solution of 1, 3-butadiene and hexane was passed through a 500L dehumidifying dryer (vertical cylindrical tank, manufactured by Hitachi, Ltd.) containing activated alumina, to adsorb and remove a small amount of residual impurities in 1, 3-butadiene, thereby obtaining purified 1, 3-butadiene.

[ purification of styrene ]

Styrene used for polymerization of the modified conjugated diene polymer was purified by the following procedure.

Is formed into

The cylindrical gamma-alumina was immersed in a 0.6% aqueous solution of palladium chloride and dried at 100 ℃ for 1 day and night.

Then, the dried product was subjected to a reduction treatment at 400 ℃ for 16 hours under a hydrogen stream to obtain a composition of Pd (0.3%)/γ -Al₂O₃The hydrogenation catalyst of (1).

2000g of the obtained hydrogenation catalyst was packed in a tubular reactor, and styrene was added to the reactor while maintaining the temperature of the catalyst at 80 ℃ and circulated for 8 hours, thereby obtaining purified styrene.

[ refining of n-Hexane ]

N-hexane used for polymerization of the modified conjugated diene polymer was purified by the following procedure.

2000g of molecular sieve 13-X (UNION SHOWA) was charged in a tubular reactor, and n-hexane was added to the reactor and circulated at room temperature for 24 hours, whereby purified n-hexane was obtained.

[ analysis of purity of raw Material (calculation of Total amount of impurities) ]

Quantitative analysis was performed on allenes, acetylenes, and amines as impurities in the raw materials.

The allenes and the acetylenes are qualitatively and quantitatively determined by gas chromatography.

The column used was Rt-Alumina BOND/MAPD (Shimadzu corporation).

In addition, the amine-based substance was extracted with boric acid and quantified by titration, and the total amount of impurities (ppm) was calculated.

[ (Property 1) amount of bonded styrene ]

The modified conjugated diene polymer was used as a sample, and 100mg of the sample was dissolved in chloroform to 100mL to prepare a measurement sample.

The amount (mass%) of bound styrene relative to 100 mass% of the modified conjugated diene polymer as a sample was measured from the amount of styrene absorbed by the phenyl group at an ultraviolet absorption wavelength (around 254 nm) (spectrophotometer "UV-2450" manufactured by Shimadzu corporation).

[ (physical Property 2) microstructure of butadiene moiety (1, 2-vinyl bond amount) ]

The modified conjugated diene polymer was used as a sample, and 50mg of the sample was dissolved in 10mL of carbon disulfide to prepare a measurement sample.

Using a solution vessel at 600-1000 cm^-1The infrared spectrum was measured, and the microstructure of the butadiene portion, that is, the 1, 2-vinyl bond content (mol%) was determined by the absorbance at a predetermined wave number according to the calculation formula of the Hampton method (the method described in r. Hampton, Analytical Chemistry 21,923(1949)) (fourier transform infrared spectrophotometer "FT-IR 230" manufactured by japan spectrophotometer).

[ (Property 3) Mooney viscosity of Polymer ]

The Mooney viscosity was measured using an L-shaped rotor in accordance with JIS K6300 using a Mooney viscometer (trade name "VR 1132" manufactured by Shanghai Co., Ltd.) using the modified conjugated diene polymer as a sample.

The measurement temperature was 100 ℃.

First, after preheating the sample at the test temperature for 1 minute, the rotor was rotated at 2rpm, and the torque after 4 minutes was measured as the Mooney viscosity (ML)₍₁₊₄₎)。

[ (Property 4) molecular weight ]

The modified conjugated diene polymer was used as a sample, and a weight average molecular weight (Mw) was determined based on a calibration curve obtained using standard polystyrene by measuring a chromatogram using a GPC measurement apparatus (trade name "HLC-8320 GPC" manufactured by Tosoh corporation) to which 3 columns each containing a polystyrene gel as a filler were connected (trade name "HLC-8020 GPC" manufactured by Tosoh corporation) and an RI detector (trade name "HLC 8020" manufactured by Tosoh corporation)₁) Number average molecular weight (Mn)₁) Molecular weight distribution (Mw)₁/Mn₁) And peak molecular weight (Mp) of the modified conjugated diene polymer₁)。

THF (tetrahydrofuran) was used as eluent.

The column was used by connecting 3 columns of the column under the trade name "TSKgel SuperMultipolypore HZ-H" manufactured by Tosoh corporation and connecting the column to the front thereof under the trade name "TSKguardcolumn SuperMP (HZ) -H" manufactured by Tosoh corporation as a guard column.

10mg of a sample for measurement was dissolved in 20mL of THF to prepare a measurement solution, and 10. mu.L of the measurement solution was injected into a GPC measurement apparatus and measured at a furnace temperature of 40 ℃ and a THF flow rate of 0.35 mL/min.

The above peak molecular weight (Mp)₁) The results were obtained as follows.

In the GPC curve obtained by the measurement, a peak detected as a component having the highest molecular weight was selected. For the selected peak, the molecular weight corresponding to the maximum value of the peak was calculated as the peak molecular weight.

[ (Property 5) modification ratio ]

The chromatogram is determined by applying the modified conjugated diene polymer as a measurement sample to the property of adsorbing the modified basic polymer component in a GPC column using a silica gel as a filler.

The modification ratio was determined by measuring the adsorption amount on a silica-based column from the difference between the chromatogram obtained by measuring a sample solution for measurement containing the above-mentioned sample for measurement and low-molecular-weight internal standard polystyrene with a polystyrene-based column and the chromatogram obtained by measuring with a silica-based column.

Specifically, the following is shown.

Preparation of sample solution for measurement:

10mg of the above-mentioned measurement sample and 5mg of standard polystyrene were dissolved in 20mL of THF (tetrahydrofuran) to prepare a measurement sample solution.

GPC measurement conditions using polystyrene columns:

a10. mu.L of a sample solution for measurement was poured into the apparatus using "HLC-8320 GPC" manufactured by Tosoh corporation and THF as an eluent, and a chromatogram was obtained using an RI detector under conditions of a column temperature of 40 ℃ and a THF flow rate of 0.35 mL/min. The column was used by connecting 3 columns of the column under the trade name "TSKgel SuperMultipolypore HZ-H" manufactured by Tosoh corporation and connecting the column to the front thereof under the trade name "TSKguardcolumn SuperMP (HZ) -H" manufactured by Tosoh corporation as a guard column.

GPC measurement conditions using silica-based column:

a chromatogram was obtained by using a RI detector under the conditions of a column temperature of 40 ℃ and a THF flow rate of 0.5 mL/min, using THF as an eluent and 50. mu.L of a sample solution for measurement, which was prepared by Tosoh corporation under the trade name of "HLC-8320 GPC", and using a RI detector. The column was used by connecting the trade names "Zorbax PSM-1000S", "PSM-300S" and "PSM-60S" and connecting the trade name "DIOL 4.6X 12.5mm 5 micron" as a protective column to the front stage.

The calculation method of the modification rate comprises the following steps:

the modification ratio (mass%) was determined by the following equation, where the total peak area of the chromatogram using a polystyrene column was 100, the peak area of the sample was P1, the peak area of the standard polystyrene was P2, the total peak area of the chromatogram using a silica column was 100, the peak area of the sample was P3, and the peak area of the standard polystyrene was P4.

Modification rate (mass%) [1- (P2 × P3)/(P1 × P4) ] × 100

(in the above formula, P1+ P2 ═ P3+ P4 ═ 100)

[ (Property 6) modification ratio of Low molecular weight component ]

The weight average molecular weight (Mw) was determined based on a calibration curve obtained using standard polystyrene in accordance with the above (Property 4) measurement₂) Number average molecular weight (Mn)₂) Molecular weight distribution (Mw)₂/Mn₂) And the peak molecular weight (Mp) of the modified conjugated diene polymer₂)。

The peak molecular weight (Mp) is₂) The molecular weight at the peak top (peak top with the smallest molecular weight when a plurality of peak tops are present) in the molecular weight curve will be the peak molecular weight (Mp)₂) The height of the graph of the molecular weight of 1/2 (molecular weight of the low molecular weight component) is L1.

The peak molecular weight (Mp) of a graph measured in accordance with the measurement of (Property 5) using a silica column₂) The height of the molecular weight (molecular weight of the low molecular weight component) obtained by dividing the height by 2 was designated as L2.

Molecular weight is the above peak molecular weight (Mp)₂) 1/2 as a low molecular weight component.

The modification ratio of the low molecular weight component was calculated as (1-L2/L1). times.100.

[ (Property 7) modification degree of Low molecular weight component ]

The modification degree of the low-molecular-weight component was calculated by dividing the modification ratio (FL) of the low-molecular-weight (molecular weight of 1/2 at the peak top) component of the above (property 6) by the modification ratio (FT) of the above (property 5) with respect to the total amount of the conjugated diene polymer.

Degree of modification of Low molecular weight component (FL/FT)

[ (Property 8) glass transition temperature ]

The modified conjugated diene polymer was used as a sample in accordance with ISO 22768: 2006, a DSC curve was recorded using a differential scanning calorimeter "DSC 3200S" manufactured by MAC Science corporation under a helium flow of 50 mL/min while raising the temperature from-100 ℃ at 20 ℃/min, and the peak top (reflection point) of the DSC differential curve was set as the glass transition temperature.

[ (Property 9) shrinkage factor (g') ]

The modified conjugated diene polymer was used as a sample, and a GPC-light scattering measurement apparatus with a viscosity detector, to which 3 columns each containing a polystyrene gel as a filler were connected, was used to measure a chromatogram, and the molecular weight was determined based on the solution viscosity and the light scattering method.

A mixed solution of tetrahydrofuran and triethylamine (THF in TEA: 5mL of triethylamine was mixed in 1L of tetrahydrofuran) was used as an eluent.

The column was used by connecting a guard column (trade name "TSKguardcolumn HHR-H" manufactured by Tosoh corporation) and a column (trade name "TSKgel G6000 HHR", "TSKgel G5000 HHR" and "TSKgel G4000 HHR" manufactured by Tosoh corporation).

A GPC-light scattering measuring apparatus (trade name "Viscotek TDAmax" manufactured by Malvern) equipped with a viscosity detector was used under conditions of a furnace temperature of 40 ℃ and a THF flow rate of 1.0 mL/min.

A measurement sample solution was prepared by dissolving 10mg of the measurement sample in 20mL of THF, and 200. mu.L of the measurement sample solution was injected into a GPC measurement apparatus to measure the intrinsic viscosity.

The intrinsic viscosity and the molecular weight of the obtained measurement sample solution were used to calculate the shrinkage factor (g').

Relating the intrinsic viscosity to the molecular weight ([ eta ] eta)]＝KMα([η]: intrinsic viscosity, M: molecular weight) is set to logK-3.883 and α -0.771, the input molecular weight M is in the range of 1000 to 20000000, and the standard intrinsic viscosity [. eta. ] is prepared]₀Relation with molecular weight M, for the prepared standard intrinsic viscosity [. eta. ]]₀Relationship with molecular weight M, and intrinsic viscosity [ eta ] at each molecular weight M]Relative to the standard intrinsic viscosity [. eta. ]]₀The form of the relationship of (a) is calculated at each molecular weight M [ eta ]]/[η]₀The average value thereof was taken as the shrinkage factor (g').

The contraction factor (g') is a value averaged when M is 100 to 200 ten thousand.

[ (physical Property 10) Nitrogen content ]

The nitrogen content was measured using a trace total nitrogen analyzer (TN-2100H manufactured by Mitsubishi chemical analysis technology).

[ modified conjugated diene Polymer (sample 1) ]

A tank-type pressure vessel having an internal volume of 10L, an internal height (L) to diameter (D) ratio (L/D) of 4.0, an inlet at the bottom and an outlet at the top was used as a polymerization reactor, and the tank-type pressure vessel was equipped with a stirrer and a jacket for temperature control.

The mixture was mixed under the conditions of 19 g/min of 1, 3-butadiene from which water had been removed in advance, 10.3 g/min of styrene and 143.9 g/min of n-hexane. The mixture contained 10ppm of allenes, 12ppm of acetylenes and 1ppm of amines. The total amount of impurities was 23 ppm.

In a static mixer provided in the middle of a pipe for supplying the mixed solution to the inlet of the reactor, n-butyllithium for inerting the residual impurities was added at 0.08 mmol/min and mixed, and then continuously supplied to the bottom of the reactor. Further, 2-bis (2-tetrahydrofuryl) propane as a polar substance was supplied at a rate of 0.02 g/min and n-butyllithium as a polymerization initiator was supplied at a rate of 0.18 mmol/min to the bottom of the polymerization reactor where vigorous mixing was carried out by a stirrer, and polymerization was continuously carried out. The temperature was controlled in such a manner that the temperature of the polymerization solution at the outlet of the top of the reactor was 75 ℃.

After the polymerization was sufficiently stabilized, a small amount of the polymer solution before the addition of the coupling agent was withdrawn from the outlet at the top of the reactor, and after 0.2g of an antioxidant (BHT) was added per 100g of the polymer, the solvent was removed.

Subsequently, tetraglycidyl-1, 3-bisaminomethylcyclohexane as a modifier was continuously added to the polymer solution flowing out from the outlet of the reactor at a rate of 0.05 mmol/min, and the polymer solution to which the modifier was added was mixed by a static mixer to cause a modification reaction.

To the polymer solution after the modification reaction, an antioxidant (BHT) was continuously added in the form of an n-hexane solution in an amount of 0.2g per 100g of the polymer to terminate the coupling reaction. While the antioxidant was added, oil (Vivatec 500, manufactured by H & R) was continuously added in an amount of 25g relative to 100g of the polymer, and mixing was performed using a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (sample 1). The physical properties of sample 1 are shown in Table 1.

[ modified conjugated diene Polymer (sample 2) ]

A modified conjugated diene polymer (sample 2) was obtained in the same manner as in (sample 1) except that the polymerization initiator was changed to a previously prepared mixed solution of piperidyl lithium (also referred to as "1-lithium piperidine") and n-butyl lithium as aminolithium (the molar ratio of piperidyl lithium to n-butyl lithium was 0.75: 0.25).

The physical properties of sample 2 are shown in Table 1.

[ modified conjugated diene Polymer (sample 3) ]

A modified conjugated diene polymer (sample 3) was obtained in the same manner as in sample 1 except that the modifier was changed to 3-trimethoxysilylpropyl- [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine.

The physical properties of sample 3 are shown in Table 1.

[ modified conjugated diene Polymer (sample 4) ]

A modified conjugated diene polymer (sample 4) was obtained in the same manner as in (sample 3) except that the polymerization initiator was changed to a previously prepared mixed solution of piperidyl lithium (also referred to as "1-lithium piperidine") and n-butyl lithium as aminolithium (the molar ratio of piperidyl lithium to n-butyl lithium was 0.75: 0.25).

The physical properties of sample 4 are shown in Table 1.

[ 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 changed to tris (3-trimethoxysilylpropyl) amine and the amount of the modifier supplied was changed to 0.034 mmol/min.

The physical properties of sample 5 are shown in Table 1.

[ modified conjugated diene Polymer (sample 6) ]

A modified conjugated diene polymer (sample 6) was obtained in the same manner as in sample 5 except that the polymerization initiator was changed to a previously prepared mixed solution of lithium piperidyl (also referred to as "1-lithium piperidine") as lithium amide and n-butyllithium (molar ratio of lithium piperidyl to n-butyllithium was 0.75: 0.25).

The physical properties of sample 6 are shown in Table 1.

[ modified conjugated diene Polymer (sample 7) ]

The procedure of (sample 1) was repeated except that the modifier was changed to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine and the amount of the modifier added was changed to 0.026 mmol/min, to obtain a modified conjugated diene polymer (sample 7).

The physical properties of sample 7 are shown in Table 1.

[ modified conjugated diene Polymer (sample 8) ]

A modified conjugated diene polymer (sample 8) was obtained in the same manner as in sample 7 except that the polymerization initiator was changed to a previously prepared mixed solution of lithium piperidyl (also referred to as "1-lithium piperidine") as lithium amide and n-butyllithium (molar ratio of lithium piperidyl to n-butyllithium was 0.75: 0.25).

The physical properties of sample 8 are shown in Table 1.

[ modified conjugated diene Polymer (sample 9) ]

The mixture was mixed under the conditions of 20.9 g/min of 1, 3-butadiene from which water had been removed in advance, 8.4 g/min of styrene and 143.9 g/min of n-hexane. The mixture contained 10ppm of allenes, 12ppm of acetylenes and 1ppm of amines. The total amount of impurities was 23 ppm.

In a static mixer provided in the middle of a pipe for supplying the mixed solution to the inlet of the reactor, n-butyllithium for inerting the residual impurities was added at 0.08 mmol/min and mixed, and then continuously supplied to the bottom of the reactor. Further, 2-bis (2-tetrahydrofuryl) propane as a polar substance was supplied at a rate of 0.02 g/min and n-butyllithium as a polymerization initiator was supplied at a rate of 0.18 mmol/min to the bottom of the polymerization reactor, which was vigorously mixed by a stirrer, to continuously carry out polymerization. The temperature was controlled in such a manner that the temperature of the polymerization solution at the outlet of the top of the reactor was 75 ℃. After the polymerization was sufficiently stabilized, a small amount of the polymer solution before the addition of the coupling agent was withdrawn from the outlet at the top of the reactor, and after 0.2g of an antioxidant (BHT) was added per 100g of the polymer, the solvent was removed.

Subsequently, 3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine as a modifier was continuously added to the polymer solution flowing out from the outlet of the reactor at a rate of 0.05 mmol/min, and the polymer solution to which the modifier was added was mixed by a static mixer to cause a modification reaction.

To the polymer solution after the modification reaction, an antioxidant (BHT) was continuously added in the form of an n-hexane solution in an amount of 0.2g per 100g of the polymer to terminate the coupling reaction. While the antioxidant was added, 5g of oil (Vivatec 500, manufactured by H & R) was continuously added to 100g of the polymer, and the mixture was mixed by a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene polymer (sample 9). The physical properties of sample 9 are shown in Table 2.

[ modified conjugated diene Polymer (sample 10) ]

A modified conjugated diene polymer (sample 10) was obtained in the same manner as in sample 3 except that the mixing was carried out under the conditions of 21 g/min of 1, 3-butadiene, 8.8 g/min of styrene and 143.9 g/min of n-hexane, and the amount of the polar substance added was changed to 0.015 mmol. The physical properties of sample 10 are shown in Table 2.

[ modified conjugated diene Polymer (sample 11) ]

A modified conjugated diene polymer (sample 11) was obtained in the same manner as in (sample 3) except that the amount of n-butyllithium added as a polymerization initiator was changed to 0.24 mmol/min, the amount of 2, 2-bis (2-tetrahydrofuryl) propane added as a polar substance was changed to 0.01 g/min, and the amount of 3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine added as a modifier was changed to 0.03 mmol/min. The physical properties of sample 11 are shown in Table 2.

[ modified conjugated diene Polymer (sample 12) ]

A modified conjugated diene polymer (sample 12) was obtained in the same manner as in (sample 3) except that the amount of n-butyllithium added as a polymerization initiator was changed to 0.30 mmol/min, the amount of 2, 2-bis (2-tetrahydrofuryl) propane added as a polar substance was changed to 0.03 g/min, and the amount of 3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine added as a modifier was changed to 0.08 mmol/min. The physical properties of sample 12 are shown in Table 2.

[ modified conjugated diene Polymer (sample 13) ]

A modified conjugated diene polymer (sample 13) was obtained in the same manner as in (sample 3) except that the amount of n-butyllithium added as a polymerization initiator was changed to 0.40 mmol/min, the amount of 2, 2-bis (2-tetrahydrofuryl) propane added as a polar substance was changed to 0.04 g/min, and the amount of 3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine added as a modifier was changed to 0.11 mmol/min. The physical properties of sample 13 are shown in Table 2.

[ modified conjugated diene Polymer (sample 14) ]

The mixture of 1, 3-butadiene, styrene and n-hexane contained 15ppm of allenes, 13ppm of acetylenes and 2ppm of amines. The total amount of impurities was 30 ppm. In the same manner as in (sample 3) except for using these, a modified conjugated diene polymer (sample 14) was obtained. The physical properties of sample 14 are shown in Table 2.

[ modified conjugated diene Polymer (sample 15) ]

A modified conjugated diene polymer (sample 15) was obtained in the same manner as in (sample 3) except that the amount of 3-trimethoxysilylpropyl- [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine added as a modifier was changed to 0.01 mmol/min. The physical properties of sample 15 are shown in Table 2.

[ modified conjugated diene Polymer (sample 16) ]

After an autoclave having an internal volume of 10L and equipped with a stirrer and a jacket was purged and dried and purged with nitrogen, 592g of 1, 3-butadiene, 208g of styrene and 5kg of cyclohexane from which impurities such as moisture had been removed in advance were added, 1.47g of 2, 2-bis (2-tetrahydrofuryl) propane was added as a polar substance, and 2.5mmol of a mixed solution of piperidyl lithium and n-butyl lithium (molar ratio of piperidyl lithium to n-butyl lithium was 0.75: 0.25) as lithium amide prepared in advance was added to start polymerization at 52 ℃. The polymerization was carried out as an adiabatic polymerization, the maximum temperature reaching 70 ℃. After polymerization was carried out for 5 minutes from the time when the highest temperature was reached, the obtained reaction solution, that is, a polymer solution containing a conjugated diene polymer composed of a conjugated diene compound and an aromatic vinyl compound was sampled, and the solvent was removed and analyzed.

Then, a cyclohexane solution containing 1.3mmol of 3-trimethoxysilylpropyl- [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine was added to the sampled polymerization solution to react for 15 minutes, and then 2g of antioxidant (BHT) was added to the obtained polymer solution, and the solvent was removed to obtain a modified conjugated diene polymer (sample 16). The physical properties of sample 16 are shown in Table 2.

The meanings of the symbols in tables 1 and 2 are as follows.

12, 2-bis (2-tetrahydrofuryl) propane

2 tetraglycidyl-1, 3-bisaminomethylcyclohexane

33-trimethoxysilylpropyl- [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine

4 tris (3-trimethoxysilylpropyl) amine

5 tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine

6 operating oil (Vivatec 500, H & R Co., Ltd.)

[ modified conjugated diene Polymer compositions (examples 1 to 20, comparative examples 1 to 9) ]

Unvulcanized rubber compositions and vulcanized rubber compositions were produced by kneading the modified conjugated diene polymers (samples 1 to 16), SBR A, SBR B, Natural Rubber (NR) and polybutadiene (BR) shown in tables 1 and 2, as raw material rubbers, by the following methods using the materials shown below.

The respective formulations are listed in tables 3 to 5.

In tables 3 to 5, the numerical values in parentheses represent the amounts of the operating oil contained in the samples.

Modified conjugated diene polymer: samples 1 to 16

SBR A (manufactured by Asahi Kasei corporation, Tufdene4850, glass transition temperature: -12 ℃ C.)

SBR B (manufactured by Asahi Kasei Co., Ltd., Tufdene1834, glass transition temperature: -70 ℃ C.)

NR (Natural rubber, glass transition temperature: -70 ℃ C.)

BR (manufactured by Yu Yongshi Co., Ltd., BR150, glass transition temperature: -105 ℃ C.)

Extender oil (Vivatec 500, manufactured by H & R Co.)

Silica (ULTRASIL 7000GR, nitrogen adsorption specific surface area 175m, manufactured by Evonik Japan K.K.)²/g)

Silane coupling agent (Si 75, Evonik Japan Co., Ltd.)

Carbon Black (SEAST KH (N339) available from Toyobo Co., Ltd.)

Zinc white (Sanjing Metal mining Co., Ltd., Zinc white No. 1)

Stearic acid

Wax: (Sunnoc, a product of Dainixing chemical industries Co., Ltd.)

Anti-aging agent (N-isopropyl-N' -phenyl-p-phenylenediamine)

Sulfur, sulfur

Vulcanization accelerator 1 (N-cyclohexyl-2-benzoceazolylsulphenamide)

Vulcanization accelerator 2 (diphenylguanidine)

(examples 1 to 13, 15 to 20, and comparative examples 1 to 9)

According to the formulations shown in tables 3 to 5, unvulcanized rubber compositions and vulcanized rubber compositions were obtained by kneading in the following manner.

A kneader (internal volume 0.5L) equipped with a temperature control device was used as the first kneading stage, and the raw material rubber, silica, a silane coupling agent, carbon black, zinc white, stearic acid, wax and an antioxidant were used under conditions of a filling rate of 65% and a rotor rotation speed of 50rpm, and kneaded for 4 minutes. At the moment, the discharge temperature is adjusted to 155-160 ℃ through the temperature control of the kneader, and the mixture is obtained.

Subsequently, as a second kneading step, the compound obtained above was cooled to room temperature and then kneaded for 3.5 minutes by the kneader. In this case, the discharge temperature is also adjusted to 155 to 160 ℃ by controlling the temperature of the kneader. The discharge temperature is controlled by measuring the temperature of each compound discharged from the kneader after kneading.

Further, after the compound obtained above was cooled to room temperature, the unvulcanized rubber composition was heated at 70 ℃ for 30 minutes in an oven, and then plasticated as a third kneading stage in a kneader set at 70 ℃ for 30 seconds, then sulfur and a vulcanization accelerator were added, and the mixture was kneaded for 1.5 minutes, and discharged at 105 ℃ to obtain an unvulcanized rubber composition.

The compound mooney viscosity of the obtained unvulcanized rubber composition was evaluated by the following method.

Then, the unvulcanized rubber composition was vulcanized and molded at 160 ℃ for 20 minutes by a press vulcanizer to obtain a vulcanized rubber sheet.

The snow performance, wet road surface performance, abrasion resistance and breaking strength of the vulcanized rubber sheet were evaluated by the following methods.

(example 14)

In the first kneading step, sample 9 as a raw material rubber and silica were kneaded at a rotor speed of 50rpm for 1 minute, and then sample 7 as a raw material rubber, silica, a silane coupling agent, carbon black, zinc white, stearic acid, wax and an antioxidant were kneaded for 4 minutes. At the moment, the discharge temperature is adjusted to 155-160 ℃ through the temperature control of the kneader, and the mixture is obtained.

[ methods of measuring physical Properties ]

(Mooney viscosity of Compound) (physical Property 11)

After the second stage of kneading, the rubber composition was used as a sample, and the Mooney viscosity was measured using a Mooney viscometer (trade name "VR 1132" manufactured by Shanghai Co., Ltd.) according to JIS K6300 using an L-shaped rotor.

The measurement temperature was 100 ℃.

The result of comparative example 1 was indexed to 100 as an index of workability.

A large index indicates good processability.

(viscoelasticity parameters (Properties 12, 13))

For the rubber composition after vulcanization, the viscoelasticity parameter was measured in a torsional mode using a viscoelasticity tester "ARES" manufactured by Rheometric Scientific. The respective measured values were indexed with the result for the rubber composition of comparative example 1 being 100.

Tan δ measured at 0 ℃ at a frequency of 10Hz with a strain of 1% was used as an index of wet road surface performance. The larger the value, the better the wet grip.

Further, the storage modulus (G') measured at-20 ℃ at a frequency of 10Hz and a strain of 1% was used as an index of snow performance. The larger the value, the better the snow performance.

(abrasion resistance (physical Property 14))

The rubber composition after vulcanization was indexed with the result of comparative example 1 being 100 by measuring the abrasion loss at a load of 44.4N and 1000 revolutions in accordance with JIS K6264-2 using an AKRON abrasion tester (manufactured by Antaho Seiko Seisaku-Sho Ltd.). The larger the index is, the better the abrasion resistance is.

(tensile breaking Strength (Property 15))

The rubber composition after vulcanization was indexed with the result of comparative example 1 being 100, by measuring the tensile breaking strength according to the tensile test method of JIS K6251.

(sheet processability (Property 16))

The rubber composition obtained by kneading in the first stage was processed into a sheet-like rubber composition by an open mill set at 70 ℃.

The state of the obtained sheet-shaped rubber composition sheet was visually observed, and 5-stage evaluation was performed according to the following criteria.

High number of points indicates good sheet processability.

5: the consistency during roller operation is good, the sheet surface is smooth, and the sheet edge is not uneven.

4: the consistency during the roll operation was good, but the sheet surface was slightly rough and the sheet edges were also slightly uneven.

3: the consistency during roller operation was slightly poor, the sheet surface was slightly rough, and the sheet edges were also slightly uneven.

2: the continuity during the roller operation was slightly poor, the sheet surface was rough, and the sheet edges were also ragged.

1: the continuity during the roller operation was poor, the sheet surface was rough, and the sheet edges were also ragged.

[ TABLE 3]

[ TABLE 4]

[ TABLE 5]

As shown in tables 6 to 8, it was confirmed that the modified conjugated diene polymer compositions of examples 1 to 20 are excellent in the balance between snow performance and wet road performance and also excellent in wear resistance when produced into a vulcanizate, as compared with the modified conjugated diene polymer compositions of comparative examples 1 to 9.

Industrial applicability

The modified conjugated diene polymer composition of the present invention has industrial applicability in the fields of tire treads, interior/exterior parts of automobiles, vibration-proof rubbers, belts, shoes, foams, various industrial product applications, and the like.

Claims

1. A modified conjugated diene polymer composition comprising:

a rubber component A which is a modified conjugated diene polymer modified with a nitrogen-containing compound and having a glass transition temperature of-35 ℃ or higher;

a filler, a filler and a filler,

the weight average molecular weight of the rubber component A was 20X 10⁴300X 10 above⁴The molecular weight distribution Mw/Mn is 1.6 to 4.0, the modification ratio of the rubber component A is 50 mass% or more,

the rubber component A has a modification ratio of a component having a molecular weight of 1/2 and having a molecular weight of a peak top in a GPC curve as gel permeation chromatography of 1/2 or more relative to the total amount of the conjugated diene polymer, or has a modification ratio of a component having a molecular weight of 1/2 and having a molecular weight of a peak top having the smallest molecular weight when a plurality of the peak tops are present of 1/2 or more relative to the total amount of the conjugated diene polymer.

2. The modified conjugated diene polymer composition according to claim 1, wherein,

the modification ratio of the rubber component A is 75% by mass or more,

the nitrogen content is 25 mass ppm or more.

3. The modified conjugated diene polymer composition according to claim 1, wherein,

the rubber component A has a shrinkage factor g' of 0.70 or less by 3D-GPC.

4. The modified conjugated diene polymer composition according to claim 2, wherein,

the rubber component A has a shrinkage factor g' of 0.70 or less by 3D-GPC.

5. The modified conjugated diene polymer composition according to any one of claims 1 to 4, wherein,

the rubber component B is a modified conjugated diene polymer having a weight average molecular weight of 20X 10⁴300X 10 above⁴Hereinafter, the molecular weight distribution Mw/Mn is 1.6 or more and 4.0 or less, the modification ratio is 50% by mass or more, the modification ratio of the component having a molecular weight of 1/2 of the molecular weight of the peak top in the GPC curve as gel permeation chromatography is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer, or the modification ratio of the component having a molecular weight of 1/2 of the molecular weight of the peak top having the smallest molecular weight in the case where a plurality of the peak tops are present is 1/2 or more of the modification ratio with respect to the total amount of the conjugated diene polymer.

6. A method for producing a modified conjugated diene polymer composition according to any one of claims 1 to 5, the method comprising:

and a step of kneading the kneaded product and the rubber component A.

7. A tire comprising the modified conjugated diene polymer composition according to any one of claims 1 to 5.