KR20150099513A - Method for producing modified conjugated diene rubber - Google Patents

Abstract

(상기 일반식 (Ⅰ) 에 있어서, X 는 상기 중합체의 활성 말단과 반응할 수 있는 원자 혹은 반응기 또는 상기 원자 혹은 상기 반응기 중 어느 하나를 함유하는 탄화수소기이고, R¹ ∼ R⁴ 는 각각 독립적으로 화학적인 단결합 또는 탄소수 1 ∼ 10 의 알킬렌기이고, R⁵ ∼ R¹⁰ 은 각각 독립적으로 탄소수 1 ∼ 10 의 알킬기 또는 탄소수 6 ∼ 12 의 아릴기이고, R⁵ ∼ R¹⁰ 은 R⁵ 와 R⁶ 의 조합, R⁷ 과 R⁸ 의 조합, 또는 R⁹ 와 R¹⁰ 의 조합으로 서로 결합되어, 질소 원자와 함께 고리 구조를 형성하고 있어도 된다.)An alkali metalated aromatic compound having three or more carbon atoms directly bonded to an alkali metal atom and an aromatic ring as a polymerization initiator is used to polymerize a monomer containing at least a conjugated diene compound to obtain a polymer having an active terminal There is provided a process for producing a modified conjugated diene rubber comprising a step of reacting a compound represented by the following general formula (I).

(In the above general formula (I), X is a hydrocarbon group containing an atom capable of reacting with the active terminal of the polymer or a reactive group, the atom or the reactive group, and R ¹ to R ⁴ are each independently is a chemical bond or an alkylene group having 1 to 10 carbon atoms, R ⁵ ~ R ¹⁰ are each independently an aryl group of 1 to 10 carbon atoms in the alkyl group or having 6 to 12 of the group, R ⁵ ~ R ¹⁰ is R ⁵ and R ⁶ , A combination of R ⁷ and R ⁸ , or a combination of R ⁹ and R ¹⁰ to form a cyclic structure together with the nitrogen atom).

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a modified conjugated diene rubber,

The present invention relates to a method for producing a modified conjugated diene rubber, and more particularly, to a method for producing a modified conjugated diene rubber capable of providing a rubber crosslinked product having excellent workability and low heat generation and abrasion resistance ≪ / RTI > The present invention also relates to a modified conjugated diene rubber obtained by this production method, a rubber composition containing the modified conjugated diene rubber, and a rubber crosslinked product thereof.

BACKGROUND ART [0002] In recent years, automobile tires are strongly required to have low heat generation due to environmental problems and resource problems, and excellent wear resistance is demanded from the viewpoint of durability. A tire obtained from a rubber composition containing silica is superior in low heat generation to a tire obtained from a rubber composition blended with a commonly used carbon black. Thus, a tire having a low fuel consumption can be produced by using the tire.

In such a rubber composition, there is known a technique of introducing a functional group having high affinity for silica by reacting a modifying agent to the polymerization active end or the like of the rubber in order to improve affinity between the rubber and silica.

For example, Patent Document 1 discloses a modified conjugated diene-based conjugated diene-based copolymer comprising a conjugated diene-based monomer polymerized with an organolithium-based catalyst prepared by preparing a polyvinyl aromatic compound and lithium at a predetermined molar ratio, And a filler such as silica is added to the rubber. However, although the affinity between rubber and silica is improved in the technique of Patent Document 1, there is a problem that the low heat build-up property is not sufficient and the abrasion resistance is poor. Therefore, there is a problem in that, The characteristics could not necessarily be satisfied.

On the other hand, for example, in Patent Document 2, an alkali metalated aromatic compound having three or more carbon atoms directly bonded to an alkali metal atom and an aromatic ring in one molecule is used as a polymerization initiator, and at least a conjugated diene compound is contained And then polymerizing the monomer mixture obtained by polymerizing the monomer mixture. In this patent document 2, by making the conjugated diene polymer have a radial structure, the affinity with the filler when the filler such as silica is added is improved, so that the low heat build-up property and the wear resistance can be improved .

Japanese Laid-Open Patent Publication No. 2006-306962 International Publication No. 2010/131646

However, according to the rubber composition obtained by adding the filler to the radial conjugated diene polymer obtained by the production method described in Patent Document 2, it is possible to improve low heat build-up and wear resistance, but from the viewpoint of further performance improvement, Further improvement in abrasion resistance is desired. In addition, in Patent Document 2, the active end of the obtained radial conjugated diene polymer is modified by a modifying agent to improve the low heat build-up property and the abrasion resistance. On the other hand, in the technique of Patent Document 2, There has been a problem that a part of the radial conjugated diene polymer is gelated depending on the kind and the denaturing condition, and therefore the processability is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for producing a modified conjugated diene rubber capable of providing a rubber crosslinked product excellent in workability and having low heat generation and abrasion resistance do.

As a result of diligent studies to achieve the above object, the present inventors have found that, by using an alkali metalized aromatic compound having three or more carbon atoms directly bonded to alkali metal atoms and aromatic rings as a polymerization initiator, A modified conjugate capable of providing a rubber crosslinked product having excellent workability and low heat generation and abrasion resistance by polymerizing a monomer containing a compound and reacting the active terminal of the obtained conjugated diene rubber with a predetermined modifier And a diene rubber was obtained, thereby completing the present invention.

That is, according to the present invention, as the polymerization initiator, an alkali metalated aromatic compound having three or more carbon atoms directly bonded to an alkali metal atom and an aromatic ring in one molecule is used to form a monomer containing at least a conjugated diene compound To obtain a conjugated diene rubber having an active terminal; and a second step of reacting the active terminal of the conjugated diene rubber having the active terminal with a compound represented by the following general formula (I) A method for producing a conjugated diene rubber is provided.

[Chemical Formula 1]

(In the above general formula (I), X may react with an active end of the conjugated diene rubber having an active end or an atom or a reactive group capable of reacting with the active end of the conjugated diene rubber having the active end. R ¹ to R ⁴ are each independently a chemical single bond or an alkylene group having 1 to 10 carbon atoms; R ⁵ to R ¹⁰ each independently represents a hydrocarbon group containing 1 to 10 carbon atoms Or an aryl group having 6 to 12 carbon atoms, and R ⁵ to R ¹⁰ are bonded to each other by a combination of R ⁵ and R ⁶ , a combination of R ⁷ and R ⁸ , or a combination of R ⁹ and R ¹⁰ , They may form a ring structure together.)

In the production process of the present invention, in the first step, it is preferable to copolymerize a monomer containing an aromatic vinyl compound in addition to the conjugated diene compound.

In the production method of the present invention, it is preferable that the alkali metalated aromatic compound is obtained by reacting an aromatic compound having three or more carbon atoms directly bonded to the aromatic ring in one molecule with an organic alkali metal compound.

In the production method of the present invention, it is preferable that the aromatic compound having three or more carbon atoms directly bonded to the aromatic ring in one molecule is an aromatic compound represented by the following general formula (II).

(2)

(In the above general formula (II), R ¹¹ to R ¹⁸ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and at least three of R ¹¹ to R ¹⁸ are alkyl groups having 1 to 10 carbon atoms. Is an integer of 0 to 5, and when p is 2 or more, the benzene rings existing in three or more positions may be condensed at arbitrary positions, regardless of the structure represented by the general formula (II).

In the production method of the present invention, it is preferable that X in the compound represented by the general formula (I) is a halogen atom, R ¹ to R ⁴ are a chemical single bond, R ⁵ to R ¹⁰ each independently represent a single bond, Lt; 5 >

In the production method of the present invention, it is preferable that the amount of the compound represented by the general formula (I) in the second step is set so that the amount of the compound represented by the general formula It is preferable that the amount is such that the amount of the atom or the reactive group capable of reacting with the active terminal of the conjugated diene rubber ranges from 0.05 to 5 moles.

Further, according to the present invention, there is provided a modified conjugated diene rubber obtained by any of the above production methods.

According to the present invention, there is also provided a rubber composition comprising 10 to 200 parts by weight of silica relative to 100 parts by weight of a rubber component containing the modified conjugated diene rubber.

It is preferable that the rubber composition of the present invention further comprises a crosslinking agent.

According to the present invention, there is also provided a rubber crosslinked product obtained by crosslinking the rubber composition, and a tire containing the rubber crosslinked product.

According to the present invention, there is provided a modified conjugated diene rubber capable of providing a rubber crosslinked product excellent in workability and having low heat generation and abrasion resistance, a rubber composition containing the modified conjugated diene rubber, Can be obtained by using a composition and can provide a rubber crosslinked product having low pyrogenicity and abrasion resistance.

≪ Process for producing denatured conjugated diene rubber &

The method for producing a modified conjugated diene rubber according to the present invention is characterized in that an alkali metalated aromatic compound having three or more carbon atoms directly bonded to alkali metal atoms and aromatic rings in a molecule is used as the polymerization initiator, (5) is reacted with the active terminal of the conjugated diene rubber having the active terminal to obtain a conjugated diene rubber having an active terminal, and a step of reacting the active terminal of the conjugated diene rubber with a compound represented by the following general formula And a second step.

<First Step>

First, the first step in the production method of the present invention will be described. In the first step in the production method of the present invention, as the polymerization initiator, an alkali metalated aromatic compound having three or more carbon atoms directly bonded to alkali metal atoms and aromatic rings in one molecule is used, and at least a conjugated diene compound Is polymerized to obtain a conjugated diene rubber having an active terminal.

The polymerization initiator used in the first step of the production method of the present invention is an alkali metalated aromatic compound having three or more carbon atoms directly bonded to each of alkali metal atoms and aromatic rings in one molecule. The alkali metal atom contained in the alkali metalated aromatic compound used as the polymerization initiator in the present invention is not particularly limited, but lithium, sodium or potassium is preferable, and lithium is particularly preferable among them. The aromatic ring of the alkali metalated aromatic compound is not particularly limited as long as it is a conjugated ring having aromaticity, and specific examples thereof include electronically neutral aromatic hydrocarbon rings such as benzene ring, naphthalene ring and anthracene ring; An aromatic hydrocarbon ring having negative charges such as cyclopentadienyl anion ring, indenyl anion ring, and fluorenyl anion ring; An aromatic ring containing a hetero atom such as a furan ring, thiophene ring or the like; And the like. Among them, an electrically neutral aromatic hydrocarbon ring is preferable, and a benzene ring is particularly preferable. Alkali metallized aromatic compounds having an electrically neutral aromatic hydrocarbon ring are preferably used in terms of stability and polymerization activity.

In the alkali metalated aromatic compound used in the present invention, the alkali metal atom is usually present in the state of cation in the alkali metalated aromatic compound, and the alkali metal atom is directly present in each of the alkali metal atom and the aromatic ring The bonded carbon atoms are usually in an anionic state in order to bond with such alkali metal atoms in the cationic state. In the alkali metalated aromatic compound used in the present invention, the alkali metal atoms present in the cationic state and the carbon atoms present in the anion state form ionic bonds, .

In the present invention, as the polymerization initiator, by using an alkali metalized aromatic compound having three or more carbon atoms directly bonded to each of alkali metal atoms and aromatic rings in one molecule, 3 The conjugated diene-based polymer chain is allowed to grow with the living polymerizability, with each of the carbon atoms to which at least two or more alkali metal atoms are directly bonded at the polymerization start point. Thus, the resulting conjugated diene rubber may have a radial structure have.

The structure of the alkali metalated aromatic compound to be used as a polymerization initiator in the present invention is not particularly limited as long as it has three or more carbon atoms directly bonded to each of alkali metal atoms and aromatic rings in one molecule, For example, three or more carbon atoms directly bonded to an alkali metal atom may be bonded directly to one aromatic ring, and a ring in which at least one carbon atom directly bonded to the alkali metal atom is directly bonded may be bonded May be combined with three or more.

As the alkali metalated aromatic compound in which three or more carbon atoms directly bonded to an alkali metal atom are directly bonded to one aromatic ring, a compound represented by the following general formula (1) is preferably used.

(3)

In the general formula (1), R ¹⁹ to R ²⁶ are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and an alkali metalated alkyl group having 1 to 10 carbon atoms in which an alkali metal atom is bonded to the? Atom or group, and at least three of R ¹⁹ to R ²⁶ are alkaline metalated alkyl groups having 1 to 10 carbon atoms in which an alkali metal atom is bonded to the? -Position. P is an integer of 0 to 5, and when p is 2 or more, benzene rings existing in three or more positions may be condensed at arbitrary positions, regardless of the structure represented by the general formula (1). For example, when p is 2 or more, there are a plurality of R ¹⁹ and R ²² each, and a plurality of R ¹⁹ or R ^{22 may} also be the same or different.

In the general formula (1), p is 0, and three of R ²⁰ , R ²¹ , R ²³ , R ²⁴ , R ²⁵ , and R ²⁶ are alkaline metals having 1 to 10 carbon atoms , And the rest of R ²⁰ , R ²¹ , R ²³ , R ²⁴ , R ²⁵ , and R ²⁶ is preferably a hydrogen atom.

Alternatively, as the alkali metalized aromatic compound in which three or more aromatic rings directly bonded with at least one carbon atom directly bonded to an alkali metal atom are bonded via a bonding group, a compound represented by the following general formula (2) Is used.

[Chemical Formula 4]

In the general formula (2), R ²⁷ to R ³¹ are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and an alkali metalated alkyl group having 1 to 10 carbon atoms in which an alkali metal atom is bonded to the? Atom or group, and at least one of R ²⁷ to R ³¹ is an alkali metalated alkyl group having 1 to 10 carbon atoms in which an alkali metal atom is bonded to the? -Position. A represents an optional bonding group, and q is an integer of 3 to 100. For example, when q is 2 or more, there are a plurality of R ²⁷ to R ³¹ , and a plurality of R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , or R ³¹ It may be the same or different.

The method of synthesizing an alkali metalated aromatic compound used as a polymerization initiator in the present invention is not particularly limited, but a method in which an organic alkali metal compound is reacted with an aromatic compound having three or more carbon atoms directly bonded to the aromatic ring Is preferably used.

The organic alkali metal compound used for synthesizing the alkali metalated aromatic compound used in the present invention is not particularly limited, but an alkali metal compound having an alkyl group or aryl group is preferably used, and specific examples thereof include methyl lithium N-propyl lithium, isopropyl potassium, n-butyl lithium, s-butyl lithium, t-butyl lithium, n-butyl sodium, n-butyl potassium, n-pentyl lithium, n-amyl lithium, n-octyl lithium, phenyl lithium, naphthyl lithium, phenyl sodium and naphthyl sodium. Among these, an alkali metal compound having an alkyl group is preferable, a lithium compound having an alkyl group is more preferable, and n-butyllithium is particularly preferable.

When alkyl (or aryl) potassium or alkyl (or aryl) sodium is used to synthesize an alkali metalated aromatic compound used in the present invention, a lithium compound having an alkyl group or an aryl group and a potassium compound having an alkoxy group or a sodium compound The desired potassium or sodium compound may be obtained. Examples of the potassium or sodium compound having an alkoxy group used at this time include t-butoxy potassium and t-butoxy sodium. The amount of the potassium or sodium compound having an alkoxy group is not particularly limited, but is usually 0.1 to 5.0 moles, preferably 0.2 to 3.0 moles, and more preferably 0.3 to 2.0 moles, relative to the lithium compound having an alkyl group or an aryl group .

Examples of the aromatic compound having three or more carbon atoms directly bonded to the aromatic ring directly bonded to the aromatic ring which can be used for the synthesis of the alkali metalated aromatic compound include an aromatic compound for obtaining the alkali metalated aromatic compound represented by the above general formula (1) , An aromatic compound represented by the following general formula (3), and an aromatic compound represented by the following general formula (4), which is an aromatic compound for obtaining an alkali metalated aromatic compound represented by the general formula (2).

[Chemical Formula 5]

In the general formula (3), R ¹¹ to R ¹⁸ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and at least three of R ¹¹ to R ¹⁸ are alkyl groups having 1 to 10 carbon atoms. p is an integer of 0 to 5, and when p is 2 or more, benzene rings existing in three or more positions may be condensed at arbitrary positions regardless of the structure represented by the general formula (3). For example, when p is 2 or more, there is a plurality of R ¹¹ and R ¹⁴ each, and a plurality of R ¹¹ or R ^{14 may} be the same or different.

In the general formula (3), p is ^{0, R 12, R 13, R} 15, R 16, R 17, and three of R ¹⁸ is an alkyl group having ^{1 ~ 10, R 12, R} 13, R ¹⁵ , R ¹⁶ , R ¹⁷ , and R ¹⁸ is preferably a hydrogen atom.

[Chemical Formula 6]

In the general formula (4), R ³² to R ³⁶ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and at least one of R ³² to R ³⁶ is an alkyl group having 1 to 10 carbon atoms. A represents an optional bonding group, and q is an integer of 3 to 100. When q is 2 or more, there are a plurality of R ³² to R ³⁶ each, and a plurality of R ³² , R ³³ , R ³⁴ , R ³⁵ , or R ³⁶ having the same It means that it can be done, and it may be different.

Specific examples of the aromatic compound represented by the general formula (3) include 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, hexamethylbenzene, 1,2 , 3-triethylbenzene, 1,2,4-triethylbenzene, 1,3,5-triethylbenzene, 1,2,3-tripropylbenzene, 1,2,4-tripropylbenzene, 1,3 , Benzene having three or more alkyl groups such as 5-tripropylbenzene, 1,3,5-tributylbenzene and 1,3,5-tripentylbenzene; Naphthalenes having three or more alkyl groups such as 2,3,5-trimethylnaphthalene and 1,4,5-trimethylnaphthalene; And the like.

Specific examples of the aromatic compound represented by the general formula (4) include o-methylstyrene oligomer, m-methylstyrene oligomer, p-methylstyrene oligomer, p-ethylstyrene oligomer, Butylstyrene oligomer, p-pentylstyrene oligomer, etc., and polymers of styrene in which at least one hydrogen on the benzene ring is substituted with an alkyl group.

In the present invention, from the viewpoint that the resulting conjugated diene rubber has a radial structure, the alkali metalated aromatic compound used as the polymerization initiator is preferably an aromatic compound having three or more carbon atoms directly bonded to the aromatic ring in one molecule Is preferably obtained by reacting the compound with an organic alkali metal compound. From the viewpoint that the resulting conjugated diene rubber tends to have a more radial structure, an organic alkali metal compound is reacted with an aromatic compound represented by the general formula (3) Is particularly preferable. Therefore, in the present invention, it is preferable to use a polymerization initiator in which at least three carbon atoms directly bonded to an alkali metal atom are directly bonded to one aromatic ring, particularly the compound represented by the above general formula (1) as a polymerization initiator Do. These alkali metalated aromatic compounds may be used singly or in combination of two or more.

A method of reacting an organic alkali metal compound with an aromatic compound having three or more carbon atoms directly bonded to the aromatic ring in one molecule is not particularly limited, but a method of reacting in an inert solvent in an inert atmosphere is preferably used. The inert solvent to be used is not particularly limited as long as it is a solvent capable of dissolving the compound to be reacted, but a hydrocarbon solvent is preferably used. Specifically, aliphatic hydrocarbons such as n-hexane, n-heptane, and n-octane; Alicyclic hydrocarbons such as cyclohexane, cyclopentane and methylcyclohexane; And the like. These solvents may be used singly or in combination of two or more kinds. The amount of the organic alkali metal compound to be used for the aromatic compound having three or more carbon atoms directly bonded to the aromatic ring in the molecule is not particularly limited. However, the amount of the organic alkali metal compound to be used for the aromatic compound , Usually 0.1 to 100 mol, preferably 0.2 to 50 mol, more preferably 0.3 to 10 mol, particularly preferably 0.3 to 1.1 mol. The reaction time and the reaction temperature of the reaction are not particularly limited, but the reaction time is usually from 1 minute to 10 days, preferably from 1 minute to 5 days, and the reaction temperature is usually from -50 ° C to 100 ° C to be.

When an organic alkali metal compound is reacted with an aromatic compound having three or more carbon atoms directly bonded to the aromatic ring in one molecule, a compound having a coordinating ability with an alkali metal atom may be coexisted for the purpose of promoting the reaction . As a compound capable of coordinating to an alkali metal atom, a Lewis base compound containing a hetero atom is preferably used, and a Lewis base compound containing a nitrogen atom or an oxygen atom is particularly preferably used. Specific examples of the Lewis base compound containing a nitrogen atom or an oxygen atom include a chain ether compound such as diethyl ether, anisole, diphenyl ether, dimethoxybenzene, dimethoxyethane, diglyme and ethylene glycol dibutyl ether ; Tertiary amine compounds having one nitrogen atom in the molecule such as trimethylamine and triethylamine; Cyclic ether compounds having one oxygen atom in the molecule such as tetrahydrofuran and tetrahydropyran; Nitrogen-containing heterocyclic compounds such as pyridine, lutidine and 1-methylimidazole; Cyclic ether compounds having two or more oxygen atoms in the molecule such as bis-tetrahydrofuryl propane; N, N ', N', N'-tetramethylethylenediamine, dipiperidinoethane, 1,4-diazabicyclo [2.2.2] octane, Tertiary amine compounds having two or more nitrogen atoms in the molecule such as N '' - pentamethyldiethylenetriamine; A tertiary amide compound having a nitrogen-hetero atom bond in a molecule such as hexamethylphosphoramide; And the like.

The amount of the compound having a coordinating ability to an alkali metal atom is not particularly limited and may be determined depending on the strength of the coordination ability. For example, when a compound having a coordinating ability to an alkali metal atom is a chiral ether compound which is a compound having relatively weak coordination ability or a tertiary amine compound having one nitrogen atom in the molecule, Is generally in the range of 1 to 100 moles, preferably 5 to 50 moles, and more preferably 10 to 25 moles, per 1 mole of alkali metal atoms in the organic alkali metal compound to be reacted with the compound. When a cyclic ether compound or a nitrogen-containing heterocyclic compound having one oxygen atom in the molecule, which is a compound having intermediate coordination ability, is used as a compound having coordination ability to an alkali metal atom, Is generally in the range of 1 to 100 moles, preferably 1 to 20 moles, more preferably 2 to 10 moles, per 1 mole of alkali metal atoms in the organic alkali metal compound to be reacted. As a compound having coordination ability with an alkali metal atom, a cyclic ether compound having two or more oxygen atoms in a molecule, which is a compound having relatively high coordination ability, a tertiary amine compound having two or more nitrogen atoms in the molecule, The amount of the tertiary amide compound having a nitrogen-hetero atom bond in the organic alkali metal compound to be reacted with the aromatic compound is usually 0.01 to 5 mol, preferably 1 to 5 mol, per mol of the alkali metal atom 0.01 to 2 moles, and more preferably 0.01 to 1.5 moles. If the amount of the compound having coordination ability to the alkali metal atom is too large, the reaction may not proceed. These compounds having coordination ability to alkali metal atoms may be used singly or in combination of two or more.

The production efficiency of an alkali metalated aromatic compound having three or more carbon atoms directly bonded to alkali metal atoms and aromatic rings in one molecule is made particularly good and the ratio of the radial polymer in the conjugated diene rubber obtained by polymerization A compound having a coordinating ability with an alkali metal atom, a cyclic ether compound having two or more oxygen atoms in the molecule, a tertiary amine compound having two or more nitrogen atoms in the molecule, and a nitrogen- At least one kind of compound selected from tertiary amide compounds having a hetero atom bond is used and the amount of the compound is in the range of 0.02 to 0.4 moles per mole of alkali metal atoms in the organic alkali metal compound which reacts with the aromatic compound Is particularly preferable.

In the case of reacting an aromatic compound with an organic alkali metal compound, a compound having a coordinating ability to an alkali metal atom is coexisted, and the order of addition is not particularly limited. However, from the viewpoint of making the production efficiency of the alkali metalated aromatic compound particularly good, it is preferable to carry out a process in which an aromatic compound and an organic alkali metal compound are coexisted and then a compound having a coordinating ability to an alkali metal atom is added to the system, And a compound having a coordinating ability with an alkali metal atom are coexisted, and then an organic alkali metal compound is added to the system. By performing the addition in this order, insolubilization due to the formation of a complex of an organic alkali metal compound and a compound having coordination ability with an alkali metal atom is prevented, and the production efficiency of the alkali metalated aromatic compound is particularly good.

In the first step of the production process of the present invention, for example, an alkali metalated aromatic compound having three or more carbon atoms directly bonded to the aromatic ring and the alkali metal atom obtained as described above as a polymerization initiator , A conjugated diene rubber having an active terminal is obtained by polymerizing a monomer containing at least a conjugated diene compound. The conjugated diene compound is not particularly limited and includes, for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-cyclohexadiene and the like. Of these, 1,3-butadiene, isoprene or 1,3-pentadiene is preferable, and 1,3-butadiene and isoprene are particularly preferable. These conjugated diene compounds may be used singly or in combination of two or more.

In the production process of the present invention, it is preferable that the conjugated diene rubber having an active terminal is obtained by copolymerizing a monomer containing an aromatic vinyl compound in addition to the conjugated diene compound. The aromatic vinyl compound is not particularly limited and includes, for example, styrene,? -Methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, Butylstyrene, 5-t-butyl-2-methylstyrene, vinylnaphthalene, dimethylaminomethylstyrene, dimethylaminoethylstyrene, and the like can be used. . Among these, styrene,? -Methylstyrene, or 4-methylstyrene is preferable, and styrene is particularly preferable. These aromatic vinyl compounds may be used singly or in combination of two or more kinds. The conjugated diene rubber having an active terminal used in the present invention preferably contains 50 to 100% by weight of conjugated diene monomer units, particularly preferably 55 to 95% by weight, and the aromatic vinyl monomer unit , More preferably 50 to 0 wt%, and particularly preferably 45 to 5 wt%.

In the production process of the present invention, the conjugated diene rubber having an active terminal may contain, in addition to the conjugated diene compound and the aromatic vinyl compound, other than the conjugated diene compound and the aromatic vinyl compound, Or may be obtained by copolymerizing monomers containing other monomers. Other monomers include, for example,?,? - unsaturated nitriles such as acrylonitrile and methacrylonitrile; Unsaturated carboxylic acids or acid anhydrides such as acrylic acid, methacrylic acid and maleic anhydride; Unsaturated carboxylic acid esters such as methyl methacrylate, ethyl acrylate and butyl acrylate; Nonconjugated dienes such as 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, dicyclopentadiene and 5-ethylidene-2-norbornene; And the like. These monomers are preferably 10% by weight or less, more preferably 5% by weight or less, as monomer units in the conjugated diene rubber having active terminals.

In the production method of the present invention, when the copolymer is obtained by using two or more kinds of monomers, the mode of copolymerization is not particularly limited, and any of random, block, and taper may be used. . By making it a random phase, the resultant rubber cross-linked product is excellent in low heat build-up.

In the production process of the present invention, the polymerization reaction usually proceeds with living properties. Therefore, the ratio of the alkali metal aromatic compound used as the polymerization initiator to the monomer is determined depending on the molecular weight of the target polymer. The amount of the alkali metal in the alkali metalated aromatic compound to one mole is usually selected in the range of 0.000001 to 0.1 mole, preferably 0.00001 to 0.05 mole, particularly preferably 0.0001 to 0.01 mole. If the amount of the alkali metalated aromatic compound used is too small, the molecular weight of the obtained conjugated diene rubber becomes excessively large, which makes handling difficult, or the polymerization reaction may not proceed sufficiently. On the other hand, if the amount of the alkali metalated aromatic compound used is too large, the molecular weight of the resultant conjugated diene rubber may become excessively low, which may result in degradation of the properties as a rubber material.

When the polymerization reaction is carried out, a compound having a coordinating ability to an alkali metal atom as described above may be added to the polymerization reaction system for the purpose of controlling the polymerization rate and the microstructure of the resulting conjugated diene rubber. The amount of the compound having coordination ability to the alkali metal atom is usually 5 mol or less, preferably 4 mol or less, and particularly preferably 1 mol or less, 2 mol or less. If the amount of the compound having coordination ability to the alkali metal atom is too large, there is a fear that the polymerization reaction is inhibited. When a compound having coordinating ability to an alkali metal atom is used in preparing an alkali metal aromatic compound to be used as a polymerization initiator, a solution containing the compound may be used as it is.

Particularly, from the viewpoint of obtaining a rubber crosslinked product to be obtained with excellent low-exothermicity, a cyclic ether compound having two or more oxygen atoms in the molecule, a tertiary amine compound having two or more nitrogen atoms in the molecule, (Wherein the alkali metal compound is not limited to an alkali metalated aromatic compound but may be a compound having at least one kind of group selected from the group consisting of a tertiary amide compound having a nitrogen- Is present in the range of 0.02 to 3.0 moles with respect to 1 mole of alkali metal atoms in the alkali metal compound (which includes all the alkali metal compounds present and acting as the polymerization initiator). By doing so, a conjugated diene rubber having an appropriate vinyl bond content can be obtained, and as a result, the rubber crosslinked product obtained using the conjugated diene rubber can be made excellent in low heat build-up.

The polymerization method of the monomer containing the conjugated diene compound in the production method of the present invention is preferably a solution polymerization method.

The solvent used in the solution polymerization method is not particularly limited as long as it is inert in the polymerization reaction and is a solvent capable of dissolving the monomer or polymerization catalyst. Specific examples of the solvent that can be used include aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene; aliphatic hydrocarbons such as n-hexane, n-heptane, and n-octane; Alicyclic hydrocarbons such as cyclohexane, cyclopentane and methylcyclohexane; Ethers such as tetrahydrofuran, diethyl ether and cyclopentyl methyl ether; And the like. Of these, use of aliphatic hydrocarbons or alicyclic hydrocarbons as a solvent is preferable because the polymerization activity is increased. These solvents may be used singly or in combination of two or more kinds.

The concentration of the monomer in the polymerization solution in the solution polymerization method is not particularly limited, but is usually selected in the range of 1 to 50% by weight, preferably 2 to 45% by weight, and more preferably 5 to 40% by weight. If the concentration of the monomer in the solution is too low, the productivity of the conjugated diene rubber may deteriorate. If the concentration is excessively high, the viscosity of the solution becomes excessively high, and handling thereof may become difficult. The polymerization temperature is not particularly limited, but is usually in the range of -30 캜 to +200 캜, preferably 0 캜 to +180 캜. The polymerization time is not particularly limited, and is usually in the range of 1 minute to 100 hours. As the polymerization mode, any mode such as batch mode or continuous mode can be adopted. When the conjugated diene compound and the aromatic vinyl compound are copolymerized, it is preferable that the randomness of the bond between the conjugated diene monomer unit and the aromatic vinyl monomer unit is easily controlled Lt; / RTI &gt;

In this way, the conjugated diene rubber can be obtained by polymerizing the monomer containing the conjugated diene compound. Further, in the production method of the present invention, since the polymerization reaction usually proceeds with living properties, a polymer having active terminals is present in the polymerization reaction system. Therefore, in the first step, the conjugated diene rubber obtained by the polymerization reaction has an active terminal. On the other hand, in the production method of the present invention, the compound represented by the following general formula (5) is reacted with the active terminal of the conjugated diene rubber obtained by the polymerization reaction in a second step to be described later, Rubber. Particularly, since the conjugated diene rubber having an active terminal obtained in the first step in the production process of the present invention has a radial structure, only a single side of the polymer chain is a conjugated diene rubber The number of active terminals in one molecule is larger than that in the case of the above-mentioned method, so that it can be efficiently denatured, and as a result, the affinity with silica is further improved. In addition, since it has a radial structure due to the polymerization initiator to be used, a multi-branched structure can be obtained without using a coupling agent.

Hereinafter, the second step in the production method of the present invention will be described.

&Lt; Second Step &

The second step in the production method of the present invention is a step of obtaining a modified conjugated diene rubber by reacting a compound represented by the following general formula (5) with the active terminal of the conjugated diene rubber obtained in the above-mentioned first step to be.

(7)

In the general formula (5), X represents an atom or a reactive group capable of reacting with the active terminal of the conjugated diene rubber having the active terminal, or an active terminal of the conjugated diene rubber having the active terminal Wherein R ¹ to R ⁴ are each independently a chemical single bond or an alkylene group having 1 to 10 carbon atoms, and R ⁵ to R ¹⁰ each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms An alkyl group or an aryl group having 6 to 12 carbon atoms, R ⁵ to R ¹⁰ are bonded to each other by a combination of R ⁵ and R ⁶ , a combination of R ⁷ and R ⁸ , or a combination of R ⁹ and R ¹⁰ , Or may form a ring structure.

In the production method of the present invention, the conjugated diene rubber is modified by reacting the active terminal of the conjugated diene rubber with the compound represented by the above general formula (5) to improve the affinity to the filler such as silica , The obtained modified conjugated diene rubber can provide a rubber crosslinked product having excellent processability and low heat resistance and abrasion resistance.

In the general formula (5), the atom or the reactive group capable of reacting with the active terminal of the conjugated diene-based rubber is not particularly limited and may be any one capable of reacting with the active terminal. From the viewpoint of reactivity to the active terminal, A halogen atom, a vinyl group, an alkoxy group, an amino group or an epoxy group is preferable, an epoxy group or a halogen atom is more preferable, a halogen atom is more preferable, and a chlorine atom is particularly preferable.

In the general formula (5), the hydrocarbon group containing either the atom or the above-mentioned group is not particularly limited, but a hydrocarbon group having 1 to 10 carbon atoms is preferable. In addition, the number of carbon atoms does not include the number of carbon atoms constituting the reactor.

In the general formula (5), R ¹ to R ⁴ are each independently a chemical mono-bond or an alkylene group having 1 to 10 carbon atoms, preferably a chemical mono-bond or an alkylene group having 1 to 5 carbon atoms , And chemical bonding is particularly preferable.

In the general formula (5), R ⁵ to R ¹⁰ are each independently an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, More preferably an alkyl group having 1 to 5 carbon atoms, and particularly preferably a methyl group.

Among them, in the production method of the present invention, it is preferable that X in the general formula (5) is a halogen atom, R ¹ to R ⁴ are all chemical single bonds, and R ⁵ To R ¹⁰ are each independently an alkyl group having 1 to 5 carbon atoms, a compound wherein X is a chlorine atom, R ¹ to R ⁴ are all chemical single bonds, and R ⁵ to R ¹⁰ are all methyl groups, desirable.

The amount of the compound represented by the general formula (5) is not particularly limited, but the amount of the atom or the reactive group capable of reacting with the active terminal of the conjugated diene rubber per mole of the alkali metal atom in the alkali metalated aromatic compound used as the polymerization initiator Is preferably in the range of 0.05 to 5 moles, more preferably 0.1 to 3 moles, and particularly preferably 0.5 to 1.5 moles. When the amount of the compound represented by the general formula (5) is set in the above range, the effect of the addition can be made more remarkable. The compounds represented by the above general formula (5) may be used singly or in combination of two or more kinds.

In the second step of the production process of the present invention, the method of reacting the compound represented by the above general formula (5) with the active terminal of the conjugated diene rubber obtained in the above-mentioned first step is not particularly limited, A method of mixing the conjugated diene rubber having an active terminal obtained in the first step and the compound represented by the formula (5) in a solvent capable of dissolving them. As the solvent to be used at this time, those exemplified as solvents to be used in the polymerization of the above-mentioned conjugated diene rubber may be used. At this time, the conjugated diene rubber having the active terminal obtained in the above-mentioned first step is put in a state of being a polymerization solution used for the polymerization, and the compound represented by the above general formula (5) is added thereto The method is preferable because it is simple. The reaction temperature in the second step is not particularly limited, but is usually 0 to 120 占 폚, and the reaction time is not particularly limited, but is usually 1 minute to 1 hour.

When an unreacted active terminal remains after reacting the compound represented by the general formula (5) with a conjugated diene rubber having an active terminal, a polymerization terminator such as alcohol or water such as methanol, ethanol or isopropanol is polymerized To the solution to deactivate the unreacted active terminus.

To the solution of the modified conjugated diene rubber thus obtained, an antioxidant such as a phenolic stabilizer, a phosphorus stabilizer and a sulfur-based stabilizer may be added as desired. The amount of the antioxidant to be added may be appropriately determined depending on the kind thereof. In addition, extruded oil may be blended to form a dielectric rubber, if desired. The extensible flow path includes, for example, paraffinic, aromatic and naphthenic petroleum softeners, vegetable softeners, and fatty acids. When a petroleum softener is used, it is preferable that the content of the polycyclic aromatic group extracted by the method of IP 346 (the inspection method of THE INSTITUTE PETROLEUM in England) is less than 3%. When the extender oil is used, its amount is usually 5 to 100 parts by weight based on 100 parts by weight of the modified conjugated diene rubber. The modified conjugated diene rubber after the denaturation reaction can be obtained by, for example, a method of removing the rubber from the solution such as re-precipitation, removing the solvent under heating, removing the solvent under reduced pressure, removing the solvent by steam (steam stripping) It can be separated and obtained from the reaction mixture by a usual operation.

According to the production process of the present invention, when the polymerization of the conjugated diene compound is carried out in the first step, the alkali metalization having three or more carbon atoms directly bonded to the alkali metal atom and the aromatic ring as the polymerization initiator Since the conjugated diene polymer chain grows with the living polymerizing property by using each of the carbon atoms to which the three or more alkali metal atoms directly bonded in the alkali metalized aromatic compound are directly bonded as polymerization starting points, The resulting conjugated diene rubber may have a radial structure. In the present invention, in the second step, the compound represented by the general formula (5) is reacted with the active terminal of the conjugated diene rubber having such a radial structure to have a radial structure, The modified conjugated diene rubber end-modified with the compound represented by the formula (5) is obtained.

The modified conjugated diene rubber of the present invention thus obtained has a radial structure and thus has improved affinity with a filler and the like. Further, as a modifier for modifying the active terminal thereof, the modified conjugated diene rubber of the general formula (5) (3-dimensional crosslinking) of the conjugated diene rubber at the time of the modification reaction can be effectively prevented, and as a result, the workability can be improved. Further, since the modified conjugated diene rubber of the present invention is modified with the compound represented by the above-mentioned general formula (5) at its active terminal end, the modified conjugated diene rubber can be obtained by modifying the compound represented by the general formula (5) And the filler such as silica is blended to make it possible to further improve the low heat build-up and the abrasion resistance in the case of using a rubber cross-linked product.

The proportion of the radially conjugated diene rubber (that is, the conjugated diene rubber of three or more quarters) in the modified conjugated diene rubber obtained by the production method of the present invention is not particularly limited, but is usually 10 to 100% by weight By weight, preferably 20 to 100% by weight. By incorporating the radial conjugated diene rubber at such a ratio, the processability of the modified conjugated diene rubber can be further improved, and furthermore, the affinity with a filler such as silica and the like can be further improved.

The weight average molecular weight of the modified conjugated diene rubber obtained by the production process of the present invention is not particularly limited, but the value measured by gel permeation chromatography in terms of polystyrene is usually 1,000 to 3,000,000, preferably 10,000 to 2,000,000, And more preferably in the range of 100,000 to 1,500,000. By setting the weight average molecular weight of the modified conjugated diene rubber within the above-mentioned range, the compounding of the silica with the modified conjugated diene rubber becomes easy, and the rubber composition becomes excellent in workability.

The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the modified conjugated diene rubber obtained by the production method of the present invention is not particularly limited, 5.0, and particularly preferably 1.2 to 3.0. By setting the molecular weight distribution of the modified conjugated diene rubber within the above range, the resultant rubber cross-linked product is excellent in low heat build-up.

The Mooney viscosity (ML _{1 + 4} , 100 ° C) of the modified conjugated diene rubber obtained by the production method of the present invention is not particularly limited, but is usually in the range of 20 to 150, preferably 30 to 120. By setting the Mooney viscosity of the modified conjugated diene rubber within the above range, the rubber composition has excellent processability. When the modified conjugated diene rubber is a dielectric rubber, the Mooney viscosity of the dielectric rubber is preferably within the above range.

The vinyl bond content in the conjugated diene unit portion of the modified conjugated diene rubber obtained by the production method of the present invention is usually 1 to 80 mol%, preferably 5 to 75 mol%. By setting the amount of vinyl bond within the above range, the resultant rubber crosslinked product is excellent in low heat build-up.

<Rubber composition>

The rubber composition of the present invention is a composition containing 10 to 200 parts by weight of silica relative to 100 parts by weight of a rubber component containing the modified conjugated diene rubber obtained by the above-mentioned production method of the present invention.

Examples of the silica used in the present invention include dry type white carbon, wet type white carbon, colloidal silica, precipitated silica and the like. Of these, wet-process white carbon containing hydrosilic acid as a main component is preferable. Alternatively, a carbon-silica dual phase filler in which silica is supported on the surface of carbon black may be used. These silicas may be used alone or in combination of two or more. The nitrogen adsorption specific surface area (measured by the BET method according to ASTM D3037-81) of the silica to be used is preferably 50 to 300 m 2 / g, more preferably 80 to 220 m 2 / g, Lt; 2 &gt; / g. The pH of the silica is preferably 5 to 10.

The compounding amount of silica in the rubber composition of the present invention is 10-200 parts by weight, preferably 30-150 parts by weight, more preferably 50-100 parts by weight, relative to 100 parts by weight of the rubber component in the rubber composition . By setting the amount of the silica to be in the above range, the rubber composition has excellent processability, and the obtained rubber cross-linked product is excellent in abrasion resistance and low heat build-up.

A silane coupling agent may be further added to the rubber composition of the present invention from the viewpoint of further improving the low heat build-up property. Examples of the silane coupling agent include vinyltriethoxysilane,? - (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N- (? -Aminoethyl) -? - aminopropyltrimethoxysilane (Triethoxysilyl) propyl) tetrasulfide, [gamma] -trimethoxy silane, bis (3- (triethoxysilyl) propyl) disulfide, Trimethoxysilylpropyldimethylthiocarbamate tetrasulfide, and? -Trimethoxysilylpropylbenzothiazine tetrasulfide, and the like. These silane coupling agents may be used alone or in combination of two or more. The blending amount of the silane coupling agent is preferably 0.1 to 30 parts by weight, more preferably 1 to 15 parts by weight, based on 100 parts by weight of silica.

Further, the rubber composition of the present invention may further contain carbon black such as furnace black, acetylene black, thermal black, channel black, and graphite. Of these, furnace black is preferred. These carbon blacks may be used alone or in combination of two or more. The blending amount of the carbon black is usually 120 parts by weight or less based on 100 parts by weight of the rubber component in the rubber composition.

The method of adding silica to the rubber component containing the modified conjugated diene rubber of the present invention is not particularly limited, and a method of adding and kneading a solid rubber component (dry kneading method) or a modified conjugated diene rubber (Wet-kneading method) or the like can be applied to the solution containing the water-soluble organic solvent.

Further, it is preferable that the rubber composition of the present invention further contains a crosslinking agent. Examples of the crosslinking agent include sulfur compounds such as sulfur and halogenated sulfur, organic peroxides, quinone dioxime, organic polyamine compounds, alkylphenol resins having a methylol group, and the like. Of these, sulfur is preferably used. The blending amount of the crosslinking agent is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, particularly preferably 1 to 4 parts by weight based on 100 parts by weight of the rubber component in the rubber composition.

The rubber composition of the present invention may contain, in addition to the above components, a crosslinking accelerator, a crosslinking activator, an antioxidant, a filler (excluding the above silica and carbon black), an activator, a process oil, a plasticizer, And a tackifier and the like can be compounded in required amounts, respectively.

When a sulfur or a sulfur compound is used as the crosslinking agent, it is preferable to use a crosslinking accelerator and a crosslinking activator in combination. As the crosslinking accelerator, for example, a sulfenamide crosslinking accelerator; A guanidine-based crosslinking accelerator; A thiourea-based crosslinking accelerator; A thiazole-based crosslinking accelerator; A thiuram-based crosslinking accelerator; Dithiocarbamate-based cross-linking accelerators; Xanthan gum based cross-linking accelerator; And the like. Among them, it is preferable to contain a sulfenamide-based crosslinking accelerator. These crosslinking accelerators may be used alone or in combination of two or more. The blending amount of the crosslinking accelerator is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 4 parts by weight, based on 100 parts by weight of the rubber component in the rubber composition.

Examples of the crosslinking activator include higher fatty acids such as stearic acid; Zinc oxide; And the like. These crosslinking activators may be used alone or in combination of two or more. The blending amount of the crosslinking activator is preferably 0.05 to 20 parts by weight, particularly preferably 0.5 to 15 parts by weight, based on 100 parts by weight of the rubber component in the rubber composition.

In the rubber composition of the present invention, other rubber other than the modified conjugated diene rubber obtained by the production method of the present invention described above may be blended. Examples of other rubbers include natural rubber, polyisoprene rubber, emulsion-polymerized styrene-butadiene copolymer rubber, solution-polymerized styrene-butadiene copolymer rubber, polybutadiene rubber (containing a crystal fiber composed of a 1,2-polybutadiene polymer Styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylonitrile-styrene-butadiene copolymer rubber, and the like can be given as examples of the styrene-butadiene copolymer rubber, styrene-isoprene copolymer rubber, butadiene-isoprene copolymer rubber, styrene- . Of these, natural rubber, polyisoprene rubber, polybutadiene rubber, and solution-polymerized styrene-butadiene copolymer rubber are preferable. These rubbers may be used alone or in combination of two or more.

In the rubber composition of the present invention, the modified conjugated diene rubber obtained by the production process of the present invention preferably occupies 10 to 100% by weight, more preferably 40 to 100% by weight, of the rubber component in the rubber composition Do. By containing the modified conjugated diene rubber obtained by the production method of the present invention at such a ratio in the rubber component, it is possible to obtain a rubber crosslinked product excellent in low heat build-up and abrasion resistance.

In order to obtain the rubber composition of the present invention, the respective components may be kneaded according to a conventional method. For example, a component other than a component unstable to heat such as a crosslinking agent or a crosslinking accelerator is kneaded with a modified conjugated diene rubber, An unstable component such as a crosslinking agent or a crosslinking accelerator may be mixed to obtain a desired composition. The kneading temperature of the component other than the component unstable to heat and the modified conjugated diene rubber is preferably 80 to 200 占 폚, more preferably 120 to 180 占 폚, and the kneading time is preferably 30 seconds to 30 minutes. The mixture of the kneaded product and the component unstable to heat is usually carried out after cooling to 100 ° C or lower, preferably 80 ° C or lower.

&Lt; Rubber crosslinked product &gt;

The rubber crosslinked product of the present invention is obtained by crosslinking the rubber composition of the present invention described above.

The rubber cross-linked product of the present invention can be obtained by molding the rubber composition of the present invention using, for example, a molding machine corresponding to a desired shape, for example, an extruder, an injection molding machine, a compressor, , And fixing the shape as a crosslinked product. In this case, it may be crosslinked after molding, or may be crosslinked at the same time as molding. The molding temperature is usually 10 to 200 占 폚, preferably 25 to 120 占 폚. The crosslinking temperature is usually from 100 to 200 ° C, preferably from 130 to 190 ° C, and the crosslinking time is usually from 1 minute to 24 hours, preferably from 2 minutes to 12 hours, particularly preferably from 3 minutes to 6 hours.

Further, depending on the shape and size of the rubber cross-linked product, even if the surface is cross-linked, the cross-linking may not be sufficiently carried out even to the inside, so that secondary cross-linking may be further carried out by heating.

As the heating method, a general method used for crosslinking rubber such as press heating, steam heating, oven heating, hot air heating, and the like may be appropriately selected.

The rubber cross-linked product of the present invention thus obtained is obtained by using the modified conjugated diene rubber obtained by the above-described production method of the present invention, and thus has excellent low heat build-up and abrasion resistance. In particular, since the modified conjugated diene rubber obtained by the production process of the present invention is obtained by using the compound represented by the above general formula (5) as a modifier, occurrence of gelation by the addition of a modifier is effectively inhibited, Therefore, when the silica as the filler is compounded in the modified conjugated diene rubber, the dispersibility of the silica is not lowered due to the influence of the gel component. Therefore, the modified conjugated diene rubber obtained by the production method of the present invention The rubber cross-linked product of the present invention obtained by using the silica as the filler is preferably dispersed in a satisfactory manner, and as a result, the low heat build-up property and the abrasion resistance are particularly excellent.

The rubber bridges of the present invention, taking advantage of such characteristics, for example, can be applied to materials of respective portions of a tire such as a cap tread, a base tread, a carcass, a sidewall, and a bead portion; Hoses, belts, mats, anti-vibration rubber, and various other industrial materials; An impact resistance improving agent for a resin; Resin film buffers; A sole; Rubber shoes; Golf ball; toy ; And the like. In particular, the rubber cross-linked product of the present invention is preferably used as a material for a tire, particularly a material for a low-emission tire, because of its low heat build-up and abrasion resistance.

Example

Hereinafter, the present invention will be described on the basis of further detailed embodiments, but the present invention is not limited to these embodiments. In the following, &quot;% &quot; is by weight unless otherwise specified. The test and evaluation were as follows.

[Molecular weight of rubber]

The molecular weight of the rubber was determined as polystyrene-reduced molecular weight by gel permeation chromatography. Specific measurement conditions were as follows.

Measuring instrument: High-performance liquid chromatograph (trade name: HLC-8220, manufactured by Toso Co., Ltd.)

Column: two GMH-HR-H series products manufactured by Toso Co., Ltd., which were connected in series, were used.

Detector: differential refractometer (trade name: &quot; RI-8220 &quot;

Eluent: tetrahydrofuran

Column temperature: 40 DEG C

[Branch of rubber]

The branching degree of the rubber was measured by a multi-angle light scattering photometer. Specific measurement conditions were as follows.

Pump: manufactured by Waters, trade name &quot; MODEL515 &quot;

Column: Three pieces of "GMH-HR-M", trade name, manufactured by Toso Co., Ltd., connected in series were used.

Detector: Differential refractometer (trade name: RI-2414, manufactured by Waters Corporation)

Detector: Multi-angle light scattering photometer (manufactured by Wyatt Technology, trade name "DAWN EOS")

Eluent: tetrahydrofuran

Column temperature: 23 ° C

[Microstructure of rubber, denaturation of rubber]

^It was measured by ¹ H-NMR.

Measuring instrument: manufactured by JEOL, trade name "JNM-ECA-400WB"

Measurement solvent: Chloroform

[Lithification rate of polymerization initiator]

And measured by GC-MS.

GC: manufactured by Agilent Technologies, trade name "Agilent GC 6890NGC"

MS: manufactured by Agilent Technologies, trade name &quot; Agilent MS 5973 MSD &quot;

Column: manufactured by Agilent Technologies, trade name &quot; DB1701 &quot;

[Gel weight fraction]

A rubber (weight: Wa [g]) was cut into a mesh of # 100 mesh at a size of about 1 mm and immersed in toluene at room temperature (25 ° C) for 24 hours and pulled up. Then, the rubber remaining in the # 100 mesh basket was vacuum dried, and the weight (Wb [g]) after drying was weighed. From these weighing values, the gel weight fraction was obtained from toluene insoluble matter = (Wb / Wa) x 100 (%). Further, the lower the gel weight fraction, the better the processability can be judged.

[Low heat generation]

Using a viscoelasticity measuring apparatus (product name: "ARES", manufactured by Rheometrics Co., Ltd.), a sheet-shaped test piece having a length of 50 mm, a width of 12.7 mm and a thickness of 2 mm was subjected to measurement under the conditions of a dynamic strain of 2.5% Was measured. With respect to this characteristic, the measurement value of Comparative Example 1 was expressed as an index of 100. The smaller this index is, the better the exothermic property is.

[Abrasion resistance]

A disk-shaped test piece having an outer diameter of 50 mm, an inner diameter of 15 mm and a thickness of 10 mm was measured at a load of 1 kgf and a slip ratio of 15% by using an FPS abrasion tester manufactured by Ueshima Corporation. With respect to this characteristic, the measurement value of Comparative Example 1 was expressed as an index of 100. The larger this index is, the better the abrasion resistance is.

[Preparation Example 1: Preparation of polymerization initiator 1 (lithiation of 1,3,5-trimethylbenzene)]

Under a nitrogen atmosphere, 16 parts of cyclohexane, 0.841 parts of 1,3,5-trimethylbenzene and 0.813 parts of tetramethylethylenediamine were added to a glass reaction vessel. Next, while stirring, 1.345 parts of n-butyllithium (0.3 moles of tetramethylethylenediamine per mole of n-butyllithium) was added and reacted with stirring at a reaction temperature of 60 DEG C for 2 days to obtain a solution of the polymerization initiator 1 18.9999 parts of 1,3,5-trimethylbenzene) was obtained. Next, for the purpose of measuring the lithiation rate of the lithiated 1,3,5-trimethylbenzene obtained by the reaction, a few drops of the obtained reaction solution was added to a glass container to which an excess amount of trimethylsilyl chloride was added, and the reaction was carried out for 30 minutes . The catalyst residue was extracted and washed with tap water, and then the solvent was distilled off to obtain a yellow oil-like liquid.

Then, this yellow oil phase liquid was subjected to gas chromatography mass spectrometry (GC-MS). The results were as follows.

Next, ¹ H-NMR measurement was performed on this yellow oil phase liquid. The results were as follows.

Furthermore, each signal in ¹ H-NMR was subjected to ¹ H-detected multi-bond heteronuclear multiple quantum coherence spectrum-NMR (HMBC-NMR) measurement. The results were as follows.

Based on the above attribution by ¹ H-NMR and HMBC-NMR measurement, the molecular ion peak obtained by GC-MS was assigned as follows. (1-trimethylsilylmethyl-3, 5-dimethylbenzene) was obtained in the same manner as EI-MS, m / z = 120 (M + m / z = 336 (M +) is a ternary substituent (1,3,5-tris (trimethylsilylmethyl) (Trimethylsilylmethyl) benzene). From the above, the ratio (molar ratio) of the unsubstituted compound: 1 substituent: 2 substituent: trisubstituted is 3: 3: 24: 70, the methylation rate of the methyl group of 1,3,5-trimethylbenzene is 87% , And the average number of lithium atoms introduced into one molecule of 3,5-trimethylbenzene is 2.49.

[Example 1]

[Preparation of Modified Styrene Butadiene Rubber 1]

800 parts of cyclohexane, 94.8 parts of 1,3-butadiene, 25.2 parts of styrene, and 0.185 parts of tetramethylethylenediamine were added to the autoclave in a nitrogen atmosphere. Then, a solution of the polymerization initiator 1 obtained in Production Example 1 (lithiated 1, (The amount of tetramethylethylenediamine present in the reaction system was 2.0 moles per mole of n-butyllithium used for lithiation of 1,3,5-trimethylbenzene), and the mixture was stirred at 60 占 폚 Polymerization was initiated. Continued for 60 minutes the polymerization reaction, and after confirming that the polymerization conversion of the range of 95% to 100%, in the tris (dimethylamino) chlorosilane (the formula (5) as the modifying agent, X = Cl, R ¹ (R ⁴ = chemical single bond, R ⁵ to R ¹⁰ = CH ₃ ) (amount to be 1.0 mol based on 1 mol of Li contained in Polymerization Initiator 1) was added and the reaction was carried out for 30 minutes. 0.064 part of methanol was added to obtain a solution containing the polymer.

Then, 0.15 part of 2,4-bis [(octylthio) methyl] -o-cresol (trade name: Irganox 1520, manufactured by Ciba Specialty Chemicals Inc.) as an antioxidant was added to 100 parts of the obtained polymer , The solvent was removed by steam stripping and vacuum drying was performed at 60 캜 for 24 hours to obtain a solid modified styrene butadiene rubber 1.

The obtained modified styrene butadiene rubber 1 had an eluted component (peak area ratio 15.2%) having Mn of 164,000, Mw of 207,000 and a molecular weight distribution (Mw / Mn) of 1.27, Mn of 381,000, Mw of 386,000, (Peak area ratio: 70.2%) having an Mn of 741,000, an Mw of 784,000, and a molecular weight distribution (Mw / Mn) of 1.06. The elution component (Mw / Mn) 443,000, Mw of 638,000, and molecular weight distribution (Mw / Mn) of 1.44. It was also confirmed that the degree of branching of the peak on the side of the polymer was high by the measurement of the polygonal light scattering. The modified styrene-butadiene rubber 1 had a styrene unit content of 21.8% and a butadiene unit content of vinyl bond of 60.1 mol%. As a result of ¹ H-NMR measurement of the modified styrene butadiene rubber 1, it was confirmed that a tris (dimethylamino) silyl group was introduced. For this modified styrene butadiene rubber 1, the gel weight fraction was measured according to the above-mentioned method. The results are shown in Table 1.

[Preparation of rubber composition]

Next, 100 parts of the modified styrene butadiene rubber obtained above was subjected to 30 seconds of distillation in a Brabender type mixer having a capacity of 250 ml, and then 50 parts of silica (trade name "Zeosil 1115MP", manufactured by Rhodia) (Trade name: "Aromax T-DAE") and 6.0 parts of a silane coupling agent: bis (3- (triethoxysilyl) propyl) tetrasulfide (trade name "Si69" After kneading at 110 DEG C for 1.5 minutes, 25 parts of silica (trade name "Zeosil 1115MP" manufactured by Rhodia), 3 parts of zinc oxide, 2 parts of stearic acid, and N-phenyl- -Dimethylbutyl) -p-phenylenediene (trade name: NOKRAC 6C, manufactured by Ouchi Shin-Kagaku Kogyo Co., Ltd.) was added and kneaded again for 2.5 minutes to discharge the kneaded product from the mixer. The temperature of the kneaded product at the termination of the kneading was 150 deg. Then, after the kneaded product was cooled to room temperature, the kneaded product was again kneaded in a Brabender type mixer at a starting temperature of 110 DEG C for 3 minutes, and the kneaded product was discharged from the mixer. Next, 1.54 parts of sulfur and 1.5 parts of N-cyclohexyl-2-benzothiazolylsulfenamide (trade name: Knocellar CZ-G, manufactured by Ouchi Shin-Kagaku Kogyo Co., Ltd.) as a crosslinking accelerator , And 1.32 parts of diphenyl guanidine (manufactured by Ouchi Shin-Kagaku Kogyo Co., Ltd., trade name &quot; Knocellar D &quot;) as a crosslinking accelerator were kneaded, and then the rubber composition on the sheet was taken out. Then, the obtained rubber composition was press-crosslinked at 160 占 폚 for 20 minutes to obtain a rubber crosslinked product, and the obtained rubber crosslinked product (test piece) was evaluated for abrasion resistance and low heat releasing property. The results are shown in Table 1. In Table 1, the evaluation results of the abrasion resistance and the low exothermicity are expressed as the ratios in the case where the results of Comparative Example 1 described later are set to 100, respectively.

[Example 2]

[Preparation of Modified Styrene Butadiene Rubber 2]

Except that the blending amount of tris (dimethylamino) chlorosilane as a modifier was changed from 0.157 parts to 0.079 parts (amount to be 0.5 moles relative to 1 mole of Li contained in the polymerization initiator 1) Butadiene rubber 2 was prepared. The obtained modified styrene butadiene rubber 2 had an eluted component (peak area ratio 15.1%) having Mn of 161,000, an Mw of 202,000 and a molecular weight distribution (Mw / Mn) of 1.25, Mn of 373,000, Mw of 378,000, (Peak area ratio: 68.5%) having an Mw of 723,000, an Mw of 763,000 and a molecular weight distribution (Mw / Mn) of 1.06, and an elution component having a molecular weight distribution (Mw / Mn) of 1.01 430,000, an Mw of 615,000, and a molecular weight distribution (Mw / Mn) of 1.43. It was also confirmed that the degree of branching of the peak on the side of the polymer was high by the measurement of the polygonal light scattering. The modified styrene butadiene rubber 2 had a content of styrene units of 21.7% and a content of vinyl bonds of butadiene units of 59.9 mol%. As a result of ¹ H-NMR measurement of the modified styrene butadiene rubber 2, it was confirmed that a tris (dimethylamino) silyl group was introduced. For this modified styrene butadiene rubber 2, the gel weight fraction was measured according to the above-mentioned method. The results are shown in Table 1.

Subsequently, a rubber composition and a rubber cross-linked product were obtained in the same manner as in Example 1 except that the modified styrene butadiene rubber 2 obtained above was used in place of the modified styrene butadiene rubber 1, and evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]

[Production of Modified Styrene Butadiene Rubber 3]

Except that 0.487 parts of tetramethoxysilane (amount equivalent to 4.0 moles of Li contained in the polymerization initiator 1) was used instead of 0.157 part of tris (dimethylamino) chlorosilane as a modifier, Styrene-butadiene rubber 3 was prepared. The obtained modified styrene butadiene rubber 3 had a total of 545,000 Mn, 1,004,000 Mw, and a molecular weight distribution (Mw / Mn) of 1.84 as measured by GPC. The modified styrene-butadiene rubber 3 had a content of styrene units of 21.7% and a content of vinyl bonds of butadiene units of 59.8 mol%. Then, for this modified styrene-butadiene rubber 3, the gel weight fraction was measured according to the above-mentioned method. The results are shown in Table 1.

Subsequently, a rubber composition and a rubber cross-linked product were obtained in the same manner as in Example 1, except that the modified styrene butadiene rubber 3 obtained above was used in place of the modified styrene butadiene rubber 1, and evaluation was carried out in the same manner as in Example 1. [ The results are shown in Table 1.

[Comparative Example 2]

[Preparation of Modified Styrene Butadiene Rubber 4]

Except that 0.187 part of tris (dimethylamino) chlorosilane was used as a modifier, and 0.087 part of trimethylchlorosilane (amount of 1.0 mole relative to 1 mole of Li contained in Polymerization Initiator 1) was used instead of 0.157 part of tris (dimethylamino) Butadiene rubber 4 was prepared. The modified styrene butadiene rubber 4 thus obtained had a Mn of 440,000, a Mw of 629,000 and a molecular weight distribution (Mw / Mn) of 1.43 as a whole in the GPC measurement. The modified styrene butadiene rubber 4 had a styrene unit content of 22.3% and a butadiene unit content of 60.0 mol%. Then, for this modified styrene-butadiene rubber 4, the gel weight fraction was measured according to the above-mentioned method. The results are shown in Table 1.

Subsequently, a rubber composition and a rubber cross-linked product were obtained in the same manner as in Example 1 except that the modified styrene butadiene rubber 4 obtained above was used in place of the modified styrene butadiene rubber 1, and evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3]

[Preparation of Modified Styrene Butadiene Rubber 5]

(Trade name &quot; KF-8012 &quot; manufactured by Shin-Etsu Silicone Co., Ltd.) (1.5 parts relative to 1 mole of Li contained in Polymerization Initiator 1) instead of 0.157 part of tris (dimethylamino) The modified styrene-butadiene rubber 5 was produced in the same manner as in Example 1, The modified styrene butadiene rubber 5 thus obtained had a Mn of 437,000, a Mw of 646,000 and a molecular weight distribution (Mw / Mn) of 1.48 as a whole in the GPC measurement. The modified styrene-butadiene rubber 5 had a styrene unit content of 22.3% and a butadiene unit content of 60.0 mol%. Then, for this modified styrene-butadiene rubber 5, the gel weight fraction was measured according to the above-mentioned method. The results are shown in Table 1.

Subsequently, a rubber composition and a rubber cross-linked product were obtained in the same manner as in Example 1 except that the modified styrene butadiene rubber 5 obtained above was used instead of the modified styrene butadiene rubber 1, and evaluation was carried out in the same manner as in Example 1. [ The results are shown in Table 1.

[Comparative Example 4]

[Production of Modified Styrene Butadiene Rubber 6]

Instead of 0.157 part of tris (dimethylamino) chlorosilane as a modifier, 0.086 part of side chain glycidoxy-modified polyorganosiloxane represented by the following formula (6) (amount to 0.1 mole with respect to 1 mole of Li contained in polymerization initiator 1) Was used in the form of a xylene solution having a concentration of 22%, the modified styrene butadiene rubber 6 was prepared in the same manner as in Example 1. The modified styrene butadiene rubber 6 thus obtained had a total of 438,000 Mn, 626,000 Mn and 1.43 molecular weight distribution (Gw / Mn) in the GPC measurement. The modified styrene-butadiene rubber 6 had a styrene unit content of 21.5% and a butadiene unit content of 59.6 mol%. Then, for this modified styrene-butadiene rubber 6, the gel weight fraction was measured according to the above-mentioned method. The results are shown in Table 1.

[Chemical Formula 8]

Subsequently, a rubber composition and a rubber cross-linked product were obtained in the same manner as in Example 1 except that the modified styrene butadiene rubber 6 obtained above was used in place of the modified styrene butadiene rubber 1, and evaluation was carried out in the same manner as in Example 1. [ The results are shown in Table 1.

[Comparative Example 5]

[Preparation of Modified Styrene Butadiene Rubber 7]

800 parts of cyclohexane, 94.8 parts of 1,3-butadiene, 25.2 parts of styrene, and 0.232 parts of tetramethylethylenediamine were added to the autoclave under nitrogen atmosphere, and then 0.051 part of n-butyllithium was added and polymerization was initiated at 60 캜 . The polymerization reaction was continued for 60 minutes. After confirming that the polymerization conversion rate was in the range of 95% to 100%, 0.157 parts of tris (dimethylamino) chlorosilane as a modifying agent was added and reacted for 30 minutes. Methanol 0.064 Was added to obtain a solution containing the polymer.

Then, 0.15 part of 2,4-bis [(octylthio) methyl] -o-cresol (trade name: Irganox 1520, manufactured by Ciba Specialty Chemicals Inc.) as an antioxidant was added to 100 parts of the obtained polymer The solvent was removed by steam stripping and vacuum drying was carried out at 60 캜 for 24 hours to obtain a solid modified styrene butadiene rubber 7.

The obtained modified styrene butadiene rubber 7 had a Mn of 295,000, an Mw of 312,000, and a molecular weight distribution (Mw / Mn) of 1.06 as measured by GPC. The modified styrene-butadiene rubber 7 had a styrene unit content of 21.1% and a butadiene unit content of 59.8 mol%. The ¹ H-NMR measurement of the modified styrene butadiene rubber 7 confirmed that a tris (dimethylamino) silyl group was introduced. For this modified styrene butadiene rubber 7, the gel weight fraction was measured according to the above-mentioned method. The results are shown in Table 1.

Subsequently, a rubber composition and a rubber cross-linked product were obtained in the same manner as in Example 1 except that the modified styrene butadiene rubber 7 obtained above was used in place of the modified styrene butadiene rubber 1, and evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

From Table 1 it can be seen that an alkali metalated aromatic compound having three or more carbon atoms directly bonded to alkali metal atoms and aromatic rings as a polymerization initiator is used and a compound represented by the above general formula (5) is used as a modifier , The gel component of the modified conjugated diene rubber is substantially not contained, and further, the rubber crosslinked product obtained by using the rubber crosslinked product is excellent in low heat build-up and abrasion resistance (Examples 1 and 2).

On the contrary, when tetramethoxysilane is used as the modifier, the resultant modified conjugated diene rubber contains a large amount of gel component and is inferior in processability. Further, when the crosslinked rubber is used as a rubber cross-linked product, low heat- (Comparative Example 1).

In the case of using trimethylchlorosilane or both terminal amino-modified polyorganosiloxane as the modifier, the resulting modified conjugated diene rubber has a low content of the gel component. However, when the rubber is crosslinked with a rubber, it has low heat generation and wear resistance (Comparative Examples 2 and 3).

When the side chain glycidoxy-modified polyorganosiloxane is used as the modifier, the resulting modified conjugated diene rubber contains a large amount of gel component, and the processability is poor. In the case of using a rubber cross-linked product, Resulting in poor heat generation (Comparative Example 4).

When the n-butyllithium is used as the polymerization initiator, the obtained modified conjugated diene rubber substantially contains no gel component. However, when the crosslinked rubber is used as the rubber crosslinked product, the low-heat-generating property and the abrasion resistance are poor, (Comparative Example 5).

Claims (11)

As the polymerization initiator, an alkali metalated aromatic compound having three or more carbon atoms directly bonded to an alkali metal atom and an aromatic ring in one molecule is used to polymerize a monomer containing at least a conjugated diene compound to obtain a polymer having an active terminal A first step of obtaining a conjugated diene rubber,
And a second step of reacting the active end of the conjugated diene rubber having the active terminal with a compound represented by the following general formula (I).
[Chemical Formula 9]

(In the above general formula (I), X may react with an active end of the conjugated diene rubber having an active end or an atom or a reactive group capable of reacting with the active end of the conjugated diene rubber having the active end. R ¹ to R ⁴ are each independently a chemical single bond or an alkylene group having 1 to 10 carbon atoms; R ⁵ to R ¹⁰ each independently represents a hydrocarbon group containing 1 to 10 carbon atoms Or an aryl group having 6 to 12 carbon atoms, and R ⁵ to R ¹⁰ are bonded to each other by a combination of R ⁵ and R ⁶ , a combination of R ⁷ and R ⁸ , or a combination of R ⁹ and R ¹⁰ , They may form a ring structure together.) The method according to claim 1,
In the first step, a monomer comprising an aromatic vinyl compound is further copolymerized in addition to the conjugated diene compound. 3. The method according to claim 1 or 2,
Wherein the alkali metalated aromatic compound is obtained by reacting an organic alkali metal compound with an aromatic compound having three or more carbon atoms directly bonded to the aromatic ring in one molecule. The method of claim 3,
Wherein the aromatic compound having three or more carbon atoms directly bonded to the aromatic ring in one molecule is an aromatic compound represented by the following general formula (II).
[Chemical formula 10]

(In the above general formula (II), R ¹¹ to R ¹⁸ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and at least three of R ¹¹ to R ¹⁸ are alkyl groups having 1 to 10 carbon atoms. Is an integer of 0 to 5, and when p is 2 or more, the benzene rings existing in three or more positions may be condensed at arbitrary positions, regardless of the structure represented by the general formula (II). 5. The method according to any one of claims 1 to 4,
Wherein X in the compound represented by the general formula (I) is a halogen atom, R ¹ to R ⁴ are each a chemical single bond, and R ⁵ to R ¹⁰ are each independently an alkyl group having 1 to 5 carbon atoms. A method of manufacturing a rubber. 6. The method according to any one of claims 1 to 5,
Wherein the amount of the compound represented by the general formula (I) in the second step is set so that the amount of the compound represented by the general formula (I) and the active terminal of the conjugated diene-based rubber with respect to 1 mol of the alkali metal atom in the alkali metalated aromatic compound used in the first step Wherein the amount of the reactable atom or the reactive group is in the range of 0.05 to 5 moles. A modified conjugated diene rubber obtained by the production method according to any one of claims 1 to 6. A rubber composition comprising 10 to 200 parts by weight of silica relative to 100 parts by weight of a rubber component containing the modified conjugated diene rubber according to claim 7. 9. The method of claim 8,
And a crosslinking agent. A rubber cross-linked product obtained by crosslinking the rubber composition according to claim 9. A tire comprising the rubber cross-linked product according to claim 10.