CN112979876A - Branched conjugated diene polymer, method for producing same, method for producing rubber composition, and method for producing tire - Google Patents

Branched conjugated diene polymer, method for producing same, method for producing rubber composition, and method for producing tire Download PDF

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CN112979876A
CN112979876A CN202011418505.1A CN202011418505A CN112979876A CN 112979876 A CN112979876 A CN 112979876A CN 202011418505 A CN202011418505 A CN 202011418505A CN 112979876 A CN112979876 A CN 112979876A
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conjugated diene
diene polymer
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carbon atoms
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CN112979876B (en
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久村谦太
角谷省吾
关川新一
荒木祥文
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Asahi Kasei Corp
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
    • C08F236/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
    • C08F236/04—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
    • C08F236/10—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated with vinyl-aromatic monomers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/38—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F297/00—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer
    • C08F297/02—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type
    • C08F297/04—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type polymerising vinyl aromatic monomers and conjugated dienes
    • C08F297/044—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type polymerising vinyl aromatic monomers and conjugated dienes using a coupling agent
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F8/00—Chemical modification by after-treatment
    • C08F8/30—Introducing nitrogen atoms or nitrogen-containing groups
    • C08F8/32—Introducing nitrogen atoms or nitrogen-containing groups by reaction with amines
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F8/00—Chemical modification by after-treatment
    • C08F8/42—Introducing metal atoms or metal-containing groups
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L15/00—Compositions of rubber derivatives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
    • C08L9/06—Copolymers with styrene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/014—Additives containing two or more different additives of the same subgroup in C08K
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
    • Y02T10/86—Optimisation of rolling resistance, e.g. weight reduction 

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Abstract

The present invention relates to a branched conjugated diene polymer and a method for producing the same, a method for producing a rubber composition, and a method for producing a tire, and provides a method for producing a branched conjugated diene polymer having excellent fuel economy, wear resistance, wet skid resistance, and breaking strength. A method for producing a branched conjugated diene polymer, comprising the steps of: a polymerization step of polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using an alkali metal compound or an alkaline earth metal compound as a polymerization initiator to obtain a conjugated diene polymer having an active end; and a branching step of reacting a styrene derivative as a branching agent with the active terminal of the conjugated diene polymer to introduce a branched structure.

Description

Branched conjugated diene polymer, method for producing same, method for producing rubber composition, and method for producing tire
Technical Field
The present invention relates to a branched conjugated diene polymer and a method for producing the same, a method for producing a rubber composition, and a method for producing a tire.
Background
In view of environmental load, there has been an increasing demand for reduction in fuel consumption of automobiles. In particular, for automobile tires, improvement in fuel economy is required for materials used for tread portions that are in direct contact with the ground.
In recent years, there has been a demand for development of a material having low rolling resistance, that is, low hysteresis loss.
Meanwhile, since the weight of the tire tends to be reduced, the thickness of the tire tread portion needs to be reduced, and a material having high wear resistance is required for the tire tread portion.
On the other hand, materials used for the tread portion of the tire are required to have excellent wet skid resistance and practically sufficient fracture characteristics from the viewpoint of safety.
Examples of materials that meet these various requirements include rubber materials containing a rubbery polymer and reinforcing fillers such as carbon black and silica.
When a rubber material containing silica is used, the balance between the hysteresis loss factor (an index of fuel economy) and the wet skid resistance can be improved. Further, by introducing a functional group having affinity or reactivity with silica into a terminal part of a molecule of a rubbery polymer having high mobility, dispersibility of silica in a rubber material can be improved, and furthermore, by binding with silica particles, mobility of the terminal part of the molecule of the rubbery polymer can be reduced, and hysteresis loss can be reduced.
On the other hand, as a method for improving the abrasion resistance, there is a method of increasing the molecular weight of the rubbery polymer. However, when the molecular weight is increased, the processability at the time of kneading the rubber-like polymer and the reinforcing filler tends to be deteriorated.
In view of such circumstances, attempts have been made to introduce a branched structure into a rubbery polymer in order to increase the molecular weight without impairing the processability.
For example, a resin composition comprising a modified conjugated diene polymer (obtained by reacting an amino group-containing alkoxysilane with a living terminal of a conjugated diene polymer) and silica has been proposed.
Further, a modified conjugated diene polymer having a branched structure introduced therein, which is obtained by coupling reaction of a polyfunctional silane compound with a polymer active end, has been proposed (see, for example, patent documents 1 and 2).
Documents of the prior art
Patent document
Patent document 1: international publication No. 2007/114203 pamphlet
Patent document 2: international publication No. 2016/133154 pamphlet
Disclosure of Invention
Problems to be solved by the invention
However, in the method of introducing a branched structure into a conjugated diene polymer, such as a method of coupling a polyfunctional silane compound to the active end of a polymer, the degree of branching of the modified conjugated diene polymer obtained by the method greatly depends on the number of groups capable of reacting with the active end of the polymer contained in the polyfunctional silane compound, and does not become more than a reactable group. From the viewpoint of synthesis possibility, there are the following problems: the number of reactive groups that can be imparted to 1 polyfunctional silane is limited, and therefore the degree of branching of the resulting modified conjugated diene polymer is also limited.
Accordingly, an object of the present invention is to provide a method for producing a branched conjugated diene polymer, which can produce a conjugated diene polymer having a high degree of branching by introducing a branch point into a main chain, and which can adjust the lengths of the main chain and side chains and has a high degree of freedom in polymer design, as compared with a case where a branched structure is introduced into a conjugated diene polymer using only a modifier or a coupling agent; thus, a process for producing a branched conjugated diene polymer excellent in fuel economy, abrasion resistance, wet skid resistance and breaking strength can be provided.
Means for solving the problems
The present inventors have intensively studied to solve the above-mentioned problems of the prior art, and as a result, they have found a method for producing a branched conjugated diene polymer, which can introduce a branch point into the main chain by reacting a conjugated diene polymer having an active terminal with a specific styrene derivative as a branching agent, and have completed the present invention.
Namely, the present invention is as follows.
[1]
A method for producing a branched conjugated diene polymer, comprising the steps of:
a polymerization step of polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using an alkali metal compound or an alkaline earth metal compound as a polymerization initiator to obtain a conjugated diene polymer having an active end; and
A branching step of reacting a styrene derivative as a branching agent with the active terminal of the conjugated diene polymer to introduce a branched structure.
[2]
The method for producing a branched conjugated diene polymer according to [1], further comprising a step of adding a conjugated diene compound and/or an aromatic vinyl compound to the reaction system during and/or after the branching step.
[3]
The method for producing a branched conjugated diene polymer according to [1] or [2], further comprising a reaction step of reacting a coupling agent or a polymerization terminator with the active end of the conjugated diene polymer obtained in the branching step.
[4]
The process for producing a branched conjugated diene polymer according to [3], wherein the coupling agent has a group containing a nitrogen atom.
[5]
The process for producing a branched conjugated diene polymer according to [3], wherein the polymerization terminator has a nitrogen atom-containing group.
[6]
The process for producing a branched conjugated diene polymer according to [3] or [5], wherein the polymerization terminator is an alkoxy compound having a nitrogen atom-containing group.
[7]
The process for producing a branched conjugated diene polymer according to [4], wherein the coupling agent is represented by the following formula (a).
[ solution 1]
Figure BDA0002821127030000041
(in the formula (a), R1～R4Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R5～R6Each independently represents an alkylene group having 1 to 20 carbon atoms.
m and n are integers of 1 to 3A plurality of R in the formula (a)1～R6M and n may be the same or different.
In the formula (a), X is represented by any one of the following general formulae (b) to (e). )
[ solution 2]
Figure BDA0002821127030000042
(in the formula (b), R7The hydrocarbon group has 1 to 20 carbon atoms, and may have a partially branched structure or a cyclic structure. R8The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group. )
[ solution 3]
Figure BDA0002821127030000043
(in the formula (c), R9The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group. )
[ solution 4]
Figure BDA0002821127030000044
(in the formula (d), R10The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group. )
[ solution 5]
Figure BDA0002821127030000051
(in the formula (e), R11～R14Each independently represents an alkylene group having 1 to 20 carbon atoms. R15～R18Each independently represents an alkyl group having 1 to 20 carbon atoms or an alkyl group having 6 to 20 carbon atoms Aryl, l and o each independently represent an integer of 1 to 3, and R when a plurality of R's exist15～R18Each independently. )
[8]
The method for producing a branched conjugated diene polymer according to any one of the above [1] to [7], wherein the styrene derivative is a compound represented by the following formula (1) and/or the following formula (2).
[ solution 6]
Figure BDA0002821127030000052
[ solution 7]
Figure BDA0002821127030000053
(in the formulae (1) and (2), R1Represents any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.
X1、X2、X3Is a single bond or an organic group containing any one selected from the group consisting of carbon, hydrogen, nitrogen, sulfur and oxygen.
Y1、Y2、Y3Represents any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom. Y is1、Y2、Y3Independently of each other, and may be the same or different. )
[9]
As described above [8]The process for producing a branched conjugated diene polymer as described in (1), wherein R is represented by the formula1Is a hydrogen atom, Y1Is any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom.
[10]
As described above [8]The process for producing the branched conjugated diene polymer as described in (1), which comprises In the above formula (2), Y2Is any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom.
[11]
As described above [8]The process for producing a branched conjugated diene polymer as described in (1), wherein R is represented by the formula1Is a hydrogen atom, Y1Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom.
[12]
As described above [8]The process for producing a branched conjugated diene polymer as described in (2), wherein Y is2Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom, Y3Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom.
[13]
As described above [8]The process for producing a branched conjugated diene polymer as described in (1), wherein R is represented by the formula1Is a hydrogen atom, Y1Is an alkoxy group having 1 to 20 carbon atoms.
[14]
As described above [8]The process for producing a branched conjugated diene polymer as described in (1), wherein R is represented by the formula1Is a hydrogen atom, X1Is a single bond, Y1Is an alkoxy group having 1 to 20 carbon atoms.
[15]
As described above [8]The process for producing a branched conjugated diene polymer as described in (2), wherein X is2Is a single bond, Y2Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom, X3Is a single bond, Y3Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom.
[16]
A branched conjugated diene polymer which is a reaction product of a conjugated diene polymer having an active end having a branched structure and a compound represented by the following formula (a).
[ solution 8]
Figure BDA0002821127030000071
(in the formula (a), R1～R4Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R5～R6Each independently represents an alkylene group having 1 to 20 carbon atoms.
m and n are integers of 1 to 3, and in the formula (a), a plurality of R1～R6M and n may be the same or different.
In the formula (a), X is represented by any one of the following general formulae (b) to (e). )
[ solution 9]
Figure BDA0002821127030000072
(in the formula (b), R7The hydrocarbon group has 1 to 20 carbon atoms, and may have a partially branched structure or a cyclic structure. R8The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group. )
[ solution 10]
Figure BDA0002821127030000073
(in the formula (c), R9The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group. )
[ solution 11]
Figure BDA0002821127030000074
(in the formula (d), R10The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group. )
[ solution 12]
Figure BDA0002821127030000081
(in the formula (e), R11～R14Each independently represents an alkylene group having 1 to 20 carbon atoms. R15～R18Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, l and o each independently represents an integer of 1 to 3, and R when a plurality of R's are present15～R18Each independently. )
[17]
As described above [16]The branched conjugated diene polymer as described in (1), wherein OR of the compound represented by the formula (a)1and/OR OR3Has a branched structure.
[18]
A rubber composition comprising:
a rubber component containing 10% by mass or more of the branched conjugated diene polymer according to [16] or [17 ]; and
the amount of the filler is 5.0 to 150 parts by mass per 100 parts by mass of the rubber component.
[19]
A method for producing a rubber composition, comprising the steps of:
a step of obtaining a branched conjugated diene polymer by the production method according to any one of the above [1] to [15 ];
a step of obtaining a rubber component containing 10 mass% or more of the branched conjugated diene polymer; and
and a step of obtaining a rubber composition containing 5.0 to 150 parts by mass of a filler per 100 parts by mass of the rubber component.
[20]
A method for manufacturing a tire, comprising the steps of:
a step of obtaining a rubber composition by the method for producing a rubber composition according to [19 ]; and
and a step of molding the rubber composition to obtain a tire.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, there can be provided a method for producing a branched conjugated diene polymer, which can produce a branched conjugated diene polymer having a higher degree of branching than a case of using only a modifier or a coupling agent by introducing a branch point into a main chain, and which can adjust the lengths of the main chain and a side chain and has a high degree of freedom in polymer design; thus, a method for producing a branched conjugated diene polymer having excellent fuel economy, wear resistance, wet skid resistance, and breaking strength can be provided.
Detailed Description
Hereinafter, a specific embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described in detail.
The following embodiments are merely examples for illustrating the present invention, and the present invention is not limited to the following embodiments. The present invention can be suitably modified and implemented within the scope of the gist thereof.
[ Process for producing branched conjugated diene Polymer ]
The method for producing a branched conjugated diene polymer according to the present embodiment includes the steps of:
a polymerization step of polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using an alkali metal compound or an alkaline earth metal compound as a polymerization initiator to obtain a conjugated diene polymer having an active end; and
a branching step of reacting a styrene derivative as a branching agent with the active terminal of the conjugated diene polymer to introduce a branched structure.
The conjugated diene polymer constituting the branched conjugated diene polymer may be a homopolymer of a single conjugated diene compound, a copolymer of different types of conjugated diene compounds, or a copolymer of a conjugated diene compound and an aromatic vinyl compound.
According to the method for producing a branched conjugated diene polymer of the present embodiment, by introducing a branch point into the main chain, a conjugated diene polymer having a high degree of branching can be produced, and the lengths of the main chain and the side chain can be adjusted, as compared with the case where a branched structure is introduced into a conjugated diene polymer using only a coupling agent.
(polymerization Process)
In the polymerization step in the method for producing a branched conjugated diene polymer according to the present embodiment, a conjugated diene polymer having an active end is obtained by polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using an alkali metal compound or an alkaline earth metal compound as a polymerization initiator.
In the polymerization step, the polymerization is preferably carried out by a growth reaction based on a living anion polymerization reaction, whereby a conjugated diene polymer having a living terminal can be obtained.
< polymerization initiator >
As the polymerization initiator, an alkali metal compound or an alkaline earth metal compound is used.
The polymerization initiator preferably uses an organolithium compound, and more preferably an organomonolithium compound.
Examples of the organic monolithium compound include, but are not limited to, low-molecular-weight organic monolithium compounds and soluble oligomer organic monolithium compounds.
In addition, as for the organic monolithium compound, any of a compound having a carbon-lithium bond, a compound having a nitrogen-lithium bond, and a compound having a tin-lithium bond can be used in terms of the bonding form of the organic group and the lithium, for example.
The amount of the polymerization initiator to be used is preferably determined in accordance with the molecular weight of the target conjugated diene polymer.
The amount of the monomer such as the conjugated diene compound used relative to the amount of the polymerization initiator used is related to the degree of polymerization of the target conjugated diene polymer. That is, there is a tendency to be correlated with the number average molecular weight and/or the weight average molecular weight.
Therefore, in order to increase the molecular weight of the conjugated diene polymer, adjustment may be made in such a direction that the amount of the polymerization initiator is decreased, and in order to decrease the molecular weight, adjustment may be made in such a direction that the amount of the polymerization initiator is increased.
Among the organic monolithium compounds, from the viewpoint of being usable in a form in which a nitrogen atom is introduced into the conjugated diene polymer, an alkyllithium compound having a substituted amino group or a lithium dialkylamide is preferable.
In this case, a conjugated diene polymer having a nitrogen atom forming an amino group at the polymerization initiation terminal can be obtained.
The substituted amino group is an amino group having a structure in which active hydrogen is not contained or is protected.
Examples of the alkyllithium compound having an amino group having no active hydrogen include, but are not limited to, 3-dimethylaminopropyllithium, 3-diethylaminopropyllithium, 4- (methylpropylamino) butyllithium, and 4-hexamethyleneiminobutyllithium.
Examples of the alkyllithium compound having an amino group having a structure in which an active hydrogen is protected include, but are not limited to, 3-bistrimethylsilylaminopropyl lithium and 4-trimethylsilylmethylaminobutyl lithium.
Examples of the lithium dialkylamide include, but are not limited to, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium dibutylamide, lithium di-n-hexylamide, lithium diheptylamide, lithium diisopropylamide, lithium dioctylamide, lithium di-2-ethylhexylamide, lithium didecylamide, lithium ethylpropylamide, lithium ethylbutylamide, lithium ethylbenzylamino, lithium methylphenethylamide, lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, lithium morpholinyl, 1-lithium azacyclooctane, 6-lithium-1, 3, 3-trimethyl-6-azabicyclo [3.2.1] octane and 1-lithium-1, 2,3, 6-tetrahydropyridine.
These organic monolithium compounds having a substituted amino group may be used in the form of an organic monolithium compound which is an oligomer soluble in n-hexane or cyclohexane by reacting a polymerizable monomer, for example, a monomer such as 1, 3-butadiene, isoprene or styrene in a small amount.
The organic monolithium compound is preferably an alkyllithium compound in terms of ease of industrial availability and ease of control of the polymerization reaction. In this case, a conjugated diene polymer having an alkyl group at the polymerization initiation end can be obtained.
Examples of the alkyllithium compound include, but are not limited to, n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and lithium stilbene.
The alkyl lithium compound is preferably n-butyl lithium or sec-butyl lithium in view of easiness of industrial availability and easiness of control of polymerization reaction.
These organic monolithium compounds 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 other organometallic compounds 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, alkoxides, sulfonates, carbonates, and amides of alkaline earth metals can be cited.
Examples of the organomagnesium compound include dibutylmagnesium and ethylbutylmagnesium.
Examples of the other organometallic compounds include organoaluminum compounds.
In the polymerization step, examples of the polymerization reaction form include, but are not limited to, batch-type (also referred to as "batch-type") and continuous-type polymerization reaction forms.
In the continuous mode, 1 or 2 or more reactors may be connected. As the continuous reactor, for example, a tank type or tube type reactor with a stirrer is used. In the continuous type, it is preferable that the monomer, the inert solvent and the polymerization initiator are continuously charged into a reactor in which a polymer solution containing the polymer is obtained, and the polymer solution is continuously discharged.
The batch reactor is, for example, a tank reactor with a stirrer. In the batch system, it is preferable to charge the monomer, the inert solvent and the polymerization initiator, add the monomer continuously or intermittently during the polymerization as needed, obtain a polymer solution containing the polymer in the reactor, and discharge the polymer solution after the polymerization is terminated.
In the method for producing a branched conjugated diene polymer according to the present embodiment, in order to obtain a conjugated diene polymer having an active terminal at a high ratio in the polymerization step, a continuous system capable of continuously discharging the polymer and supplying the polymer to a subsequent reaction in a short time is preferable. In the continuous system, the number of reactors is not particularly limited, and 1 or 2 or more reactors connected to each other may be used. The reactor is preferably a tank type or tubular type reactor with a stirrer, which is used to sufficiently contact the monomers and the polymerization initiator in the solution. The number of reactors may be appropriately selected, and is preferably 1 from the viewpoint of saving the space of the production facility, and is preferably 2 or more from the viewpoint of improving the productivity. When 2 or more reactors are used, it is more preferable to add a branching agent described later after the 2 nd reactor.
The polymerization step of the conjugated diene polymer is preferably carried out in an inert solvent.
Examples of the inert solvent include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Examples of the hydrocarbon solvent include, but are not limited to, aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene, and hydrocarbons composed of a mixture of these.
Before the polymerization reaction, it is preferable to treat allenes and acetylenes as impurities with an organometallic compound because a conjugated diene polymer having a high concentration of active terminals and a modified conjugated diene polymer having a high modification ratio tend to be obtained.
In the polymerization step, a polar compound may be added. This enables random copolymerization of the aromatic vinyl compound and the conjugated diene compound. In addition, the polar compound tends to be usable as a vinylating agent for controlling the microstructure of the conjugated diene portion. Further, the effect tends to be exhibited also in acceleration of the polymerization reaction and the like.
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, etc., and is preferably 0.01 mol or more and 100 mol or less based on 1 mol of the polymerization initiator.
Such a polar compound (vinylating agent) can be used in an appropriate amount according to the desired vinyl bond amount as a regulator of the microstructure of the conjugated diene portion of the conjugated diene polymer.
Most of the polar compounds also have an effective randomizing effect in the copolymerization of the conjugated diene compound and the aromatic vinyl compound at the same time, and tend to be useful as a distribution regulator for the aromatic vinyl compound and as a regulator for the styrene block amount.
As a method for randomizing a conjugated diene compound and an aromatic vinyl compound, for example, Japanese patent laid-open publication No. Sho 59-140211 discloses a method in which a copolymerization reaction is initiated with the entire amount of styrene and a part of 1, 3-butadiene, and the remaining 1, 3-butadiene is intermittently added in the middle of the copolymerization reaction.
The polymerization temperature in the polymerization step is preferably a temperature at which living anion polymerization is carried out, and more preferably 0 ℃ to 120 ℃ in view of productivity.
When the polymerization temperature is in such a range, the reaction amount of the branching agent and the coupling agent with respect to the living ends after the termination of the polymerization tends to be sufficiently ensured. The polymerization temperature is more preferably 50 ℃ to 100 ℃.
(branching step)
In the method for producing a branched conjugated diene polymer according to the present embodiment, a branching step of reacting a styrene derivative as a branching agent with the active ends of the conjugated diene polymer obtained in the polymerization step is performed.
The branching structure is formed in the polymer by polymerizing monomers with the branching agent maintaining polymerization activity and reacting the functional groups of the branching agent with the living ends of other polymer chains. The branched conjugated diene polymer having a branched structure introduced thereto may be further polymerized and reacted with a monomer and a branching agent to form a further branched structure, or may be reacted with a modifying agent having a functional group to form a modified conjugated diene polymer, or may be further extended in polymer chain by a coupling reaction. In this manner, the objective branched conjugated diene polymer is obtained by using, as the branching agent, a styrene derivative in which the polymerization reaction is continued as the aromatic vinyl compound and the functional group is reacted with the active terminal of the polymer.
< branching agent >
In the styrene derivative used as the branching agent in the branching step, it is necessary to have a main skeleton having only 1 active end left in a branched portion after the branching reaction, and it is necessary to have a styrene derivative portion formed after the branching reaction sufficiently reactive with other polymerization active ends, from the viewpoints of the continuity of polymerization and the prevention of gelation.
More specifically, the styrene derivative is preferably a compound having a vinyl group and a functional group quantitatively reacting with a polymerization active end of a living anion polymerization on a benzene ring. The functional group of the styrene derivative reacts with the polymerization active terminal one by one, the functional group is detached to form a single bond, and the vinyl group is polymerized with other monomers in the reactor, thereby forming a branched structure in the polymer. The functional group other than the vinyl group of the styrene derivative is a group which is eliminated by a nucleophilic substitution reaction with a polymerization active terminal of the living anion polymerization, and examples thereof include an alkoxy group, a halogen group, an ester group, a formyl group, a ketone group, an amide group, an acid chloride group, an acid anhydride group and an epoxy group.
By having such a structure, the styrene derivative is introduced into the main chain while maintaining the polymerization activity as styrene, and the polymer chain is further extended by further polymerizing other monomers with the end maintaining the activity. In addition, a branched structure can be obtained by reacting the active end of another polymer chain with the functional group of the introduced styrene derivative to form a bond. By repeating this reaction, the branching of the polymer chain increases, the polymer structure becomes more complicated, and the molecular weight further increases.
From the viewpoints of the continuity of polymerization and the controllability of the polymer structure, it is also necessary that the functional group which is released after the styrene derivative moiety reacts with the active end of another polymer chain has little inhibitory effect on polymerization. The phrase "having a small polymerization inhibiting effect" as used herein means that the side reaction of anionic polymerization, such as chain transfer reaction, deactivation during polymerization, or reduction in activity due to an increase in the degree of association of the polymer, is small.
The functional group of the styrene derivative is required to be a functional group that does not excessively increase the polymerization activity, and is further required to be a functional group that does not deactivate the polymerization activity. In the case of polymerizing a polymer by living anionic polymerization, as a functional group which does not deactivate the living terminal, a hard base which does not have a hydrogen atom and is defined based on the Pearson's HASB principle is important, and more specifically, an alkoxy group and a halogen group are exemplified. Among these, the structure of the styrene derivative used as the branching agent in the production method of the present embodiment can be selected from the viewpoints of reactivity with the active terminal and no inhibition of polymerization by the released functional group.
More specifically, from the viewpoint of suppressing chain transfer reaction, suppressing deactivation of active terminals, and preventing gelation, it is preferable to use a branching agent represented by formula (1) below having a styrene skeleton as a main skeleton, or formula (2) having a diphenylethylene skeleton as a main skeleton.
[ solution 13]
Figure BDA0002821127030000141
[ solution 14]
Figure BDA0002821127030000142
(in the formulae (1) and (2), R1Represents any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.
X1、X2、X3Is a single bond or an organic group containing any one selected from the group consisting of carbon, hydrogen, nitrogen, sulfur and oxygen.
Y1、Y2、Y3Represents any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom. Y is1、Y2、Y3Independently of each other, and may be the same or different. )
Regarding the styrene derivative used as the branching agent in the branching step, in the formula (1), R is preferably used from the viewpoint of increasing the branching degree of polymerization1Is a hydrogen atom, Y1Is any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom.
In the present embodiment, the styrene derivative used as the branching agent in the branching step is preferably Y in the formula (2) in order to increase the branching degree2Is any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom.
In addition, in the present embodiment, branching is consideredThe styrene derivative used in the step (A) as a branching agent is more preferably R in the formula (1) from the viewpoints of the persistence of polymerization and the improvement of the branching degree1Is a hydrogen atom, Y1Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom.
In the present embodiment, the styrene derivative used as the branching agent in the branching step is more preferably Y in the formula (2) in view of the continuity of polymerization and the improvement of the branching degree2Is an alkoxy group or a halogen atom, Y3Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom.
In the present embodiment, the styrene derivative used as the branching agent in the branching step is more preferably R in the formula (1) in view of the continuity of polymerization, the improvement of the branching degree and the improvement of the modification ratio1Is a hydrogen atom, Y1Is an alkoxy group having 1 to 20 carbon atoms.
In the present embodiment, the styrene derivative used as the branching agent in the branching step is more preferably R in the formula (1) in view of the continuity of polymerization, the improvement of the branching degree, and the further improvement of the modification ratio1Is a hydrogen atom, X1Is a single bond, Y 1Is an alkoxy group having 1 to 20 carbon atoms.
In the present embodiment, the styrene derivative used as the branching agent in the branching step is more preferably X in the formula (2) in view of the continuity of polymerization, the improvement of the branching degree, and the further improvement of the modification ratio2Is a single bond, Y2Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom, X3Is a single bond, Y3Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom.
Examples of the branching agent represented by the formula (1) include, but are not limited to, trimethoxy (4-vinylphenyl) silane, triethoxy (4-vinylphenyl) silane, tripropoxy (4-vinylphenyl) silane, tributoxy (4-vinylphenyl) silane, triisopropoxy (4-vinylphenyl) silane, trimethoxy (3-vinylphenyl) silane, triethoxy (3-vinylphenyl) silane, tripropoxy (3-vinylphenyl) silane, tributoxy (3-vinylphenyl) silane, triisopropoxy (3-vinylphenyl) silane, trimethoxy (2-vinylphenyl) silane, triethoxy (2-vinylphenyl) silane, tripropoxy (2-vinylphenyl) silane, and the like, Tributoxy (2-vinylphenyl) silane, triisopropoxy (2-vinylphenyl) silane, dimethoxymethyl (4-vinylphenyl) silane, diethoxymethyl (4-vinylphenyl) silane, dipropoxymethyl (4-vinylphenyl) silane, dibutoxymethyl (4-vinylphenyl) silane, diisopropoxymethyl (4-vinylphenyl) silane, dimethoxymethyl (3-vinylphenyl) silane, diethoxymethyl (3-vinylphenyl) silane, dipropoxymethyl (3-vinylphenyl) silane, dibutoxymethyl (3-vinylphenyl) silane, diisopropoxymethyl (3-vinylphenyl) silane, dimethoxymethyl (2-vinylphenyl) silane, di-tert-butyl-ethyl (2-vinylphenyl) silane, di-tert-butyl-ethyl (4-vinylphenyl) silane, di-tert-butyl-ethyl (3-vinylphenyl), Diethoxymethyl (2-vinylphenyl) silane, dipropoxymethyl (2-vinylphenyl) silane, dibutoxymethyl (2-vinylphenyl) silane, diisopropoxymethyl (2-vinylphenyl) silane, dimethylmethoxy (4-vinylphenyl) silane, dimethylethoxy (4-vinylphenyl) silane, dimethylpropoxy (4-vinylphenyl) silane, dimethylbutoxy (4-vinylphenyl) silane, dimethylisopropoxy (4-vinylphenyl) silane, dimethylmethoxy (3-vinylphenyl) silane, dimethylethoxy (3-vinylphenyl) silane, dimethylpropoxy (3-vinylphenyl) silane, dimethylbutoxy (3-vinylphenyl) silane, di-ethoxymethyl (2-vinylphenyl) silane, di-propoxymethyl (2-vinylphenyl) silane, di-propox, Dimethylisopropoxy (3-vinylphenyl) silane, dimethylmethoxy (2-vinylphenyl) silane, dimethylethoxy (2-vinylphenyl) silane, dimethylpropoxy (2-vinylphenyl) silane, dimethylbutoxy (2-vinylphenyl) silane, dimethylisopropoxy (2-vinylphenyl) silane, trimethoxy (4-isopropenylphenyl) silane, triethoxy (4-isopropenylphenyl) silane, tripropoxy (4-isopropenylphenyl) silane, tributoxy (4-isopropenylphenyl) silane, triisopropoxy (4-isopropenylphenyl) silane, trimethoxy (3-isopropenylphenyl) silane, triethoxy (3-isopropenylphenyl) silane, tripropoxy (3-isopropenylphenyl) silane, dimethylethoxy (2-vinylphenyl) silane, dimethylpropoxy (4-isopropenylphenyl) silane, and mixtures thereof, Tributoxy (3-isopropenylphenyl) silane, triisopropoxy (3-isopropenylphenyl) silane, trimethoxy (2-isopropenylphenyl) silane, triethoxy (2-isopropenylphenyl) silane, tripropoxy (2-isopropenylphenyl) silane, tributoxy (2-isopropenylphenyl) silane, triisopropoxy (2-isopropenylphenyl) silane, dimethoxymethyl (4-isopropenylphenyl) silane, diethoxymethyl (4-isopropenylphenyl) silane, dipropoxymethyl (4-isopropenylphenyl) silane, dibutoxymethyl (4-isopropenylphenyl) silane, diisopropoxymethyl (4-isopropenylphenyl) silane, dimethoxymethyl (3-isopropenylphenyl) silane, di (n-propylphenyl) silane, di (n-, Diethoxymethyl (3-isopropenylphenyl) silane, dipropoxymethyl (3-isopropenylphenyl) silane, dibutoxymethyl (3-isopropenylphenyl) silane, diisopropoxymethyl (3-isopropenylphenyl) silane, dimethoxymethyl (2-isopropenylphenyl) silane, diethoxymethyl (2-isopropenylphenyl) silane, dipropoxymethyl (2-isopropenylphenyl) silane, dibutoxymethyl (2-isopropenylphenyl) silane, diisopropoxymethyl (2-isopropenylphenyl) silane, dimethylmethoxy (4-isopropenylphenyl) silane, dimethylethoxy (4-isopropenylphenyl) silane, dimethylpropoxy (4-isopropenylphenyl) silane, dimethylbutoxy (4-isopropenylphenyl) silane, dipropoxyphenyl (4-isopropenylphenyl) silane, dipropoxybutoxy (4-isopropenylphenyl) silane, dipropoxybutyloxy (4-isopropenylphenyl) silane, dipropoxyphenyl (3-isopropenylphenyl, Dimethylisopropoxy (4-isopropenylphenyl) silane, dimethylmethoxy (3-isopropenylphenyl) silane, dimethylethoxy (3-isopropenylphenyl) silane, dimethylpropoxy (3-isopropenylphenyl) silane, dimethylbutoxy (3-isopropenylphenyl) silane, dimethylisopropoxy (3-isopropenylphenyl) silane, dimethylmethoxy (2-isopropenylphenyl) silane, dimethylethoxy (2-isopropenylphenyl) silane, dimethylpropoxy (2-isopropenylphenyl) silane, dimethylbutoxy (2-isopropenylphenyl) silane, dimethylisopropoxy (2-isopropenylphenyl) silane, trichloro (4-vinylphenyl) silane, trichloro (3-vinylphenyl) silane, dimethylisopropoxy (2-isopropenylphenyl) silane, dimethylethoxyphenyl (3-isopropenylphenyl) silane, dimethylethoxyphenyl (2-isopropenylphenyl) silane, dimethyl, Trichloro (2-vinylphenyl) silane, tribromo (4-vinylphenyl) silane, tribromo (3-vinylphenyl) silane, tribromo (2-vinylphenyl) silane, dichloromethyl (4-vinylphenyl) silane, dichloromethyl (3-vinylphenyl) silane, dichloromethyl (2-vinylphenyl) silane, dibromomethyl (4-vinylphenyl) silane, dibromomethyl (3-vinylphenyl) silane, dibromomethyl (2-vinylphenyl) silane, dimethylchloro (4-vinylphenyl) silane, dimethylchloro (3-vinylphenyl) silane, dimethylchloro (2-vinylphenyl) silane, dimethylbromo (4-vinylphenyl) silane, dimethylbromo (3-vinylphenyl) silane, and mixtures thereof, Dimethylbromo (2-vinylphenyl) silane, trimethoxy (4-vinylbenzyl) silane, triethoxy (4-vinylbenzyl) silane, tripropoxy (4-vinylbenzyl) silane.
Among these, preferred are trimethoxy (4-vinylphenyl) silane, triethoxy (4-vinylphenyl) silane, tripropoxy (4-vinylphenyl) silane, tributoxy (4-vinylphenyl) silane triisopropoxy (4-vinylphenyl) silane, trimethoxy (3-vinylphenyl) silane, triethoxy (3-vinylphenyl) silane, tripropoxy (3-vinylphenyl) silane, tributoxy (3-vinylphenyl) silane, triisopropoxy (3-vinylphenyl) silane, and trichloro (4-vinylphenyl) silane, more preferred are trimethoxy (4-vinylphenyl) silane, triethoxy (4-vinylphenyl) silane, tripropoxy (4-vinylphenyl) silane, triethoxy (4-vinylphenyl) silane, and the like, Tributoxy (4-vinylphenyl) silane, triisopropoxy (4-vinylphenyl) silane, trimethoxy (4-vinylbenzyl) silane, triethoxy (4-vinylbenzyl) silane, and further preferred are trimethoxy (4-vinylphenyl) silane and triethoxy (4-vinylphenyl) silane.
Examples of the branching agent represented by the formula (2) include, but are not limited to, 1-bis (4-trimethoxysilylphenyl) ethylene, 1-bis (4-triethoxysilylphenyl) ethylene, 1-bis (4-tripropoxysilylphenyl) ethylene, 1-bis (4-triisopropoxysilylphenyl) ethylene, 1-bis (3-trimethoxysilylphenyl) ethylene, 1-bis (3-triethoxysilylphenyl) ethylene, 1-bis (3-tripropoxysilylphenyl) ethylene, and the like, 1, 1-bis (3-triisopropoxysilphenyl) ethylene, 1-bis (2-trimethoxysilylphenyl) ethylene, 1-bis (2-triethoxysilylphenyl) ethylene, 1-bis (3-tripropoxysilylphenyl) ethylene, 1-bis (2-tripentoxysilylphenyl) ethylene, 1-bis (2-triisopropoxysilphenyl) ethylene, 1-bis (4- (dimethylmethoxysilyl) phenyl) ethylene, 1-bis (4- (diethylmethoxysilyl) phenyl) ethylene, 1-bis (4- (dipropylmethoxysilyl) phenyl) ethylene, 1-bis (4- (dimethylethoxysilyl) phenyl) ethylene, 1, 1-bis (4- (diethylethoxysilyl) phenyl) ethylene, 1-bis (4- (dipropylethoxysilyl) phenyl) ethylene, 1-bis (4-trimethoxysilylbenzyl) ethylene, 1-bis (4-triethoxysilylbenzyl) ethylene, 1-bis (4-tripropoxysilylbenzyl) ethylene, 1-bis (4-tripentoxysilylbenzyl) ethylene.
Among these, 1-bis (4-trimethoxysilylphenyl) ethylene, 1-bis (4-triethoxysilylphenyl) ethylene, 1-bis (4-tripropoxysilylphenyl) ethylene, 1-bis (4-tripentoxysilylphenyl) ethylene, 1-bis (4-triisopropoxysilylphenyl) ethylene and more preferably 1, 1-bis (4-trimethoxysilylphenyl) ethylene are preferred.
By using the branching agents represented by the above formulas (1) and (2), the number of branches is increased, and the effect of improving the wear resistance and the processability is obtained.
The timing of adding the branching agent is not particularly limited and may be selected according to the purpose, and from the viewpoint of increasing the absolute molecular weight of the branched conjugated diene polymer and increasing the coupling ratio, the timing when the conversion of the raw material is 20% or more after the addition of the polymerization initiator is preferable, and the conversion of the raw material is more preferably 40% or more, still more preferably 50% or more, still more preferably 65% or more, and still more preferably 75% or more.
In addition, a monomer as a desired raw material may be further added at the time of the branching step and/or after the branching step, and the polymerization step may be continued after the branching step, or the above-described contents may be repeated.
The post-branching step is defined as a step after adding a branching agent.
The monomer to be added is not particularly limited, but a conjugated diene compound and/or an aromatic vinyl compound is preferable, and particularly when a monomer is added in the branching step, from the viewpoint of improving the modification ratio by reducing the steric hindrance at the branching point of the conjugated diene polymer, the amount of the total amount of the conjugated diene monomer (for example, the total amount of butadiene) used in the polymerization step is preferably 5% or more, more preferably 10% or more, further preferably 15% or more, further more preferably 20% or more, and still further preferably 25% or more. In this case, from the viewpoint of improving the modification ratio, it is particularly preferable to add the monomer in the branching step by a continuous polymerization process in an amount of 5% or more of the total amount of the conjugated diene monomer (for example, the total amount of butadiene) used in the polymerization step.
The length of the main chain or side chain can be adjusted by the timing of adding the branching agent or the amount of the monomer added, and therefore the degree of freedom in polymer design is high.
The branched structure of the branched conjugated diene polymer obtained in the branching step in the method for producing a branched conjugated diene polymer according to the present embodiment is preferably 3 to 24 branches, more preferably 4 to 20 branches, and still more preferably 5 to 18 branches.
When the number of branches is 24 or less, the modified conjugated diene polymer tends to be easily reacted with a modifier having a functional group, and the polymer chain tends to be further extended by a coupling reaction, and when the number of branches is 3 or more, the resulting polymer tends to be excellent in processability and abrasion resistance.
The amount of the branching agent to be added is not particularly limited, and may be selected according to the purpose, and the molar ratio of the branching agent to the amount of the active polymerization initiator is preferably one-half or less percent, more preferably one-third or less fiftieth or more, further preferably one-fourth or less thirty one or more, further preferably one-sixth or less twenty-fifth or more, and further preferably one-eighth or less and one-tenth or more, from the viewpoints of improving the rate of terminal termination reaction of the conjugated diene polymer, improving the coupling rate, and improving the polymerization durability after branching.
Further, as described above, the monomer may be further added at the time of and/or after the branching step, and the polymerization step may be continued after the branching, or the branching agent may be further charged after the addition of the monomer, and the addition of the monomer may be further repeated.
By adding the monomer, the steric hindrance around the branch point can be reduced, whereby the effect of improving the durability of the polymerization and the coupling ratio and the modification ratio can be obtained. This enables formation of a branched structure at a desired position while increasing the molecular weight of the polymer.
The monomer to be added may be an aromatic vinyl compound such as styrene, a conjugated diene compound such as butadiene, or a mixture thereof, and the kind and ratio of the monomer to be polymerized may be the same or different from those of the monomer to be polymerized at first. It is preferable to add an aromatic vinyl compound in order to improve the heat resistance of the polymer.
The mooney viscosity measured at 110 ℃ of the branched conjugated diene polymer obtained in the branching step in the production method of the present embodiment is preferably 10 to 150, more preferably 15 to 140, and even more preferably 20 to 130. More preferably 30 to 100.
When the mooney viscosity is within the above range, the branched conjugated diene polymer obtained by the production method of the present embodiment tends to be excellent in processability and abrasion resistance.
The weight average molecular weight of the branched conjugated diene polymer obtained in the branching step in the production method of the present embodiment is preferably 10000 to 1500000, more preferably 100000 to 1000000, and still more preferably 200000 to 900000.
When the weight average molecular weight is within the above range, the branched conjugated diene polymer obtained by the production method of the present embodiment tends to have excellent processability, abrasion resistance, and a good balance between these properties.
In order to achieve a weight average molecular weight range of 100000 to 1000000, it is necessary to prevent the polymerization initiator from being completely consumed before the coupling step and to make the number of functional groups of the coupling agent 2 or more while forming a branch by controlling the amount of the branching agent to be added to the polymerization initiator to be one-third to one-fifth or more in terms of a molar ratio to the polymerization initiator. In order to achieve a weight average molecular weight range of 200000 to 900000, it is necessary to control the amount of the branching agent to be added to a range of one-third to one-fiftieth in terms of a molar ratio to the polymerization initiator and to control the number of functional groups of the coupling agent to 3 or more.
In the case of producing a modified branched conjugated diene polymer, in order to achieve a weight average molecular weight in the range of 100000 to 1000000, it is necessary to prevent the polymerization initiator from being completely consumed before the coupling step while forming a branch and to make the number of functional groups of the coupling agent 2 or more by controlling the amount of the branching agent to be added to the polymerization initiator in the range of one-third to one-fiftieth or more in terms of a molar ratio; in order to achieve a weight average molecular weight range of 200000 to 900000, it is necessary to control the amount of the branching agent to be added to a range of one-third to one-fiftieth in terms of a molar ratio to the polymerization initiator and to control the number of functional groups of the coupling agent to 3 or more.
The branched conjugated diene polymer obtained by the production method of the present embodiment may be a polymer of a conjugated diene monomer and a branching agent, or may be a copolymer of a conjugated diene monomer, a branching agent, and a monomer other than these.
For example, when a conjugated diene monomer is butadiene or isoprene and is polymerized with a branching agent containing an aromatic vinyl moiety, a polymer having a structure in which the polymer chain is polybutadiene or polyisoprene and the branched moiety contains an aromatic vinyl group is formed. By having such a structure, the linearity of each 1 chain of the polymer chain and the crosslink density after vulcanization can be increased, thereby exhibiting an effect of improving the abrasion resistance of the polymer. Therefore, it is suitable for use in tires, resin-modified products, interior/exterior parts of automobiles, vibration-damping rubbers, shoes, and the like.
When the conjugated diene polymer is used for a tread of a tire, a copolymer of a conjugated diene monomer, an aromatic vinyl monomer and a branching agent is suitable, and the amount of the conjugated diene in the copolymer for use is preferably 40 to 100 mass%, more preferably 55 to 80 mass%.
The amount of the bound aromatic vinyl group in the branched conjugated diene polymer obtained by the production method of the present embodiment is not particularly limited, but is preferably 0 mass% to 60 mass%, more preferably 20 mass% to 45 mass%.
When the amount of the conjugated diene and the amount of the aromatic vinyl bond are within the above ranges, the balance between the hysteresis loss resistance and the wet skid resistance, and the wear resistance and fracture characteristics tend to be more excellent after the vulcanizate is produced.
The amount of the bound aromatic vinyl group can be measured by ultraviolet absorption of a phenyl group, and the amount of the bound conjugated diene can be determined. Specifically, the measurement can be carried out by the method described in the examples below.
In the branched conjugated diene polymer obtained by the production method of the present embodiment, the amount of vinyl groups bonded in the conjugated diene bonding unit is not particularly limited, but is preferably 10 mol% or more and 75 mol% or less, and more preferably 20 mol% or more and 65 mol% or less.
When the vinyl bond content is in the above range, the balance between the hysteresis loss resistance and the wet skid resistance, the wear resistance and the breaking strength after production of the vulcanizate tend to be more excellent.
When the branched conjugated diene polymer is a copolymer of butadiene and styrene, the amount of vinyl bonds (1, 2-bond amount) in the butadiene-bonding unit can be determined by the Hampton method (r.r. Hampton, Analytical Chemistry,21,923 (1949)). Specifically, the measurement can be carried out by the method described in the examples below.
With respect to the microstructure of the branched conjugated diene polymer, when the respective bonding amounts of the branched conjugated diene polymers obtained by the production method of the present embodiment are in the above numerical ranges, and further the glass transition temperature of the branched conjugated diene polymer is in the range of-80 ℃ to-15 ℃, a sulfide having a further excellent balance between low hysteresis loss properties and wet skid resistance tends to be obtained.
With respect to the glass transition temperature, a DSC curve is recorded while raising the temperature in a predetermined temperature range in accordance with ISO 22768:2006, and the peak top (inflection point) of the DSC differential curve is taken as the glass transition temperature.
When the branched conjugated diene polymer obtained by the production method of the present embodiment is a conjugated diene-aromatic vinyl copolymer, the number of blocks in which 30 or more aromatic vinyl units are linked is preferably small or none. More specifically, in the case where the branched conjugated diene polymer obtained by the production method of the present embodiment is a butadiene-styrene copolymer, in a known method of decomposing the polymer by Kolthoff's method (the method described in i.m. Kolthoff, et al, j.polym.sci.1,429 (1946)), and analyzing the amount of polystyrene insoluble in methanol, a block segment in which 30 or more aromatic vinyl units are linked is preferably 5.0 mass% or less, more preferably 3.0 mass% or less, with respect to the total amount of the branched conjugated diene polymer.
When the branched conjugated diene polymer obtained by the production method of the present embodiment is a conjugated diene-aromatic vinyl copolymer, the ratio of the aromatic vinyl units alone is preferably large in order to improve fuel economy.
Specifically, when the branched conjugated diene Polymer obtained by the production method of the present embodiment is a butadiene-styrene copolymer, the branched conjugated diene Polymer is decomposed by a method based on ozonolysis known as a method of Tianzhou et al (Polymer,22,1721(1981)), and the styrene linkage distribution is analyzed by GPC, and in this case, it is preferable that the isolated styrene amount is 40 mass% or more and the linked styrene structure having 8 or more styrene chains is 5.0 mass% or less with respect to the total bound styrene amount.
In this case, the resulting vulcanized rubber tends to have excellent properties with particularly low hysteresis loss.
(reaction procedure)
In the method for producing a branched conjugated diene polymer according to the present embodiment, it is preferable to perform a step of coupling the active end of the conjugated diene polymer obtained through the polymerization step and the branching step with a coupling agent (for example, a reactive compound having 3 or more functions) or a step of reacting the active end of the conjugated diene polymer with a polymerization terminator (for example, a reactive compound having 2 or less functions).
Hereinafter, the step of reacting the coupling agent (coupling step) or the step of reacting the polymerization terminator (polymerization terminating step) will be collectively referred to as a reaction step.
In the reaction step, one end of the active terminal of the conjugated diene polymer is reacted with a coupling agent or a polymerization terminator.
< coupling step >
The method for producing a conjugated diene polymer according to the present embodiment preferably includes a coupling step of coupling the conjugated diene polymer obtained through the polymerization and branching steps with a coupling agent. The molecular chain can be effectively extended by the coupling step, and a branched chain can be introduced into the polymer by using a coupling agent having 3 or more functions. The function of forming a branch is in communication with the step of using a branching agent, but it is preferable from the viewpoint that a known coupling agent can be used to form a branch while introducing a desired element such as nitrogen, sulfur, or silicon by performing the coupling step.
As the coupling step, for example, a coupling step using a reactive compound having 3 or more functions as an active end of the conjugated diene polymer or a coupling step using a coupling agent having a nitrogen atom-containing group (hereinafter sometimes collectively referred to as "coupling agent") is preferable, and a coupling step using a coupling agent represented by the following formula (a) is more preferable.
In the coupling step, for example, a coupling reaction may be carried out with respect to one end of the active end of the conjugated diene polymer using a reactive compound having 3 or more functions, a coupling agent having a nitrogen atom-containing group, or a coupling agent represented by the following formula (a), to obtain a branched conjugated diene polymer.
[ reactive Compound having a functionality of 3 or more ]
In the method for producing a branched conjugated diene polymer according to the present embodiment, the 3 or more functional reactive compound used in the coupling step is preferably a 3 or more functional reactive compound having a silicon atom.
Examples of the reactive compound having 3 or more functional groups and a silicon atom include, but are not limited to, a halogenated silane compound, an epoxidized silane compound, a vinylated silane compound, and an alkoxysilane compound.
Examples of the halosilane compound as the coupling agent include, but are not limited to, methyltrichlorosilane, 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 epoxysilane compound as the coupling agent 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 coupling agent include, but are not limited to, tetramethoxysilane, tetraethoxysilane, triphenoxymethylsilane, 1, 2-bis (triethoxysilyl) ethane, methoxy-substituted polyorganosiloxane, and the like.
[ coupling agent having Nitrogen atom-containing group ]
Examples of the coupling agent having a nitrogen atom-containing group include, but are not limited to, isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, carbonyl compounds having a nitrogen atom-containing group, vinyl compounds having a nitrogen atom-containing group, epoxy compounds having a nitrogen atom-containing group, alkoxysilane compounds having a nitrogen atom-containing group, and protected amine compounds having a nitrogen atom-containing group and capable of forming a primary or secondary amine.
In the coupling agent having a nitrogen atom-containing group, the nitrogen atom-containing functional group is preferably a functional group derived from an amine compound having no active hydrogen, and examples of the amine compound include a tertiary amine compound and a protected amine compound in which the active hydrogen is substituted with a protecting group. Examples of other compounds capable of forming a functional group containing a nitrogen atom include imine compounds represented by the general formula — N ═ C and alkoxysilane compounds bonded to the nitrogen atom-containing group.
Examples of the isocyanate compound which is a coupling agent having a nitrogen atom-containing group 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 which is a coupling agent having a nitrogen atom-containing group 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.
Examples of the carbonyl compound as a coupling agent having a nitrogen atom-containing group include, but are not limited to, 1, 3-dimethyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1-methyl-3- (2-methoxyethyl) -2-imidazolidinone, N-methyl-2-pyrrolidone, N-methyl-2-piperidone, N-methyl-2-quinolone, 4 '-bis (diethylamino) benzophenone, 4' -bis (dimethylamino) benzophenone, methyl-2-pyridinone, methyl-4-pyridinone, propyl-2-pyridinone, bis-4-pyridinone, di-3-ethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, N-methyl-2-piperidone, N-methyl-2-quinolone, N-methyl-2-, 2-benzoylpyridine, N, N, N ', N' -tetramethylurea, N, N-dimethyl-N ', N' -diphenylurea, N, N-diethylamino-formic acid methyl group, N, N-diethylacetamide, N, N-dimethyl-N ', N' -dimethylaminoacetamide, N, N-dimethylpyridine formamide, N, N-dimethylisonicotinamide, etc.
Examples of the vinyl compound as the coupling agent having a nitrogen atom-containing group include, but are not limited to, N-dimethylacrylamide, N-dimethylmethacrylamide, N-methylmaleimide, N-methylphthalimide, N, n-bistrimethylsilylacrylamide, morpholinoacrylamide, 3- (2-dimethylaminoethyl) styrene, (dimethylamino) dimethyl-4-vinylphenylsilane, 4 '-ethenylbis (N, N-dimethylaniline), 4' -ethenylbis (N, N-diethylaniline), 1-bis (4-morpholinophenyl) ethylene, 1-phenyl-1- (4-N, N-dimethylaminophenyl) ethylene and the like.
Examples of the epoxy compound as the coupling agent having a nitrogen atom-containing group include, but are not limited to, epoxy group-containing hydrocarbon compounds bonded to an amino group, and epoxy group-containing hydrocarbon compounds bonded to an ether group.
Examples of such epoxy compounds include, but are not limited to, epoxy compounds represented by the general formula (i).
[ solution 15]
Figure BDA0002821127030000241
In the formula (i), R is a hydrocarbon group having a valence of 2 or more, or an organic group having a valence of 2 or more, which has at least one polar group selected from the group consisting of a polar group having oxygen such as ether, epoxy, ketone, etc., a polar group having sulfur such as thioether, thioketone, etc., a polar group having nitrogen such as tertiary amino, imino, etc.
The hydrocarbon group having a valence of 2 or more is a saturated or unsaturated hydrocarbon group which may be linear, branched or cyclic, and includes an alkylene group, an alkenylene group, a phenylene group and the like. Preferably a hydrocarbon group having 1 to 20 carbon atoms. Examples thereof include methylene, ethylene, butylene, cyclohexylene, 1, 3-bis (methylene) -cyclohexane, 1, 3-bis (ethylene) -cyclohexane, o-phenylene, m-phenylene, p-phenylene, m-xylylene, p-xylylene, and bis (phenylene) -methane.
In the above formula (i), R1、R4Is a hydrocarbon group of 1 to 10 carbon atoms, R1、R4May be the same or different from each other.
In the above formula (i), R2、R5Is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, R2、R5May be the same or different from each other.
In the above formula (i), R3Is a hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (ii).
R1、R2、R3May have a ring structure formed by bonding them to each other.
In addition, R3In the case of a hydrocarbon group, the group may have a cyclic structure in which R and R are bonded to each other. In the case of the above cyclic structure, R is bonded to3The N and R in (A) may be in a direct bond.
In the formula (i), n is an integer of 1 or more, and m is an integer of 0 or 1 or more.
[ solution 16]
Figure BDA0002821127030000251
In the above formula (ii), R1、R2With R of the above formula (i)1、R2Are defined as such, R1、R2May be the same or different from each other.
The epoxy compound which is a coupling agent having a nitrogen atom-containing group preferably has an epoxy group-containing hydrocarbon group, and more preferably has a glycidyl group-containing hydrocarbon group.
The hydrocarbon group containing an epoxy group bonded to an amino group or an ether group is not particularly limited, and examples thereof include a glycidylamino group, a diglycidylamino group, and a glycidyloxy group. Further preferable molecular structures are epoxy group-containing compounds each having a glycidylamino group, a diglycidylamino group and a glycidyloxy group, and examples thereof include compounds represented by the following general formula (iii).
[ solution 17]
Figure BDA0002821127030000252
In the above formula (iii), R is as defined for R in the above formula (i), and R6Is a hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (iv).
R6In the case of a hydrocarbon group, R may be bonded to each other to form a cyclic structure, and in this case, R may be bonded to R6The bound N and R may be in a directly bound form.
In the formula (iii), n is an integer of 1 or more, and m is an integer of 0 or 1 or more.
[ solution 18]
Figure BDA0002821127030000261
The epoxy compound as a coupling agent having a nitrogen atom-containing group is particularly preferably a compound having 1 or more diglycidylamino groups and 1 or more glycidyloxy groups in the molecule.
Examples of the epoxy compound used as the coupling agent having a nitrogen atom-containing group 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' -tetraglycidylmethylenediamine, 4-methylene-bis (N, N-diglycidylaniline), 1, 4-bis (N, N-diglycidylamino) cyclohexane, N, N, N ', N' -tetraglycidylphenyldiamine, 4 '-bis (diglycidylamino) benzophenone, 4- (4-glycidylpiperazinyl) - (N, N-diglycidylamino) aniline, 2- [2- (N, N-diglycidylamino) ethyl ] -1-glycidylpyrrolidine, N, N-diglycidylaniline, 4' -diglycidyldibenzylmethylamine, N, N-diglycidylaniline, N, N-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 alkoxysilane compound which is a coupling agent having a nitrogen atom-containing group 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 Alkane, 3- (3-trimethylsilyl-1-hexahydropyrimidyl) propyltrimethoxysilane, 3-dimethylamino-2- (dimethylaminomethyl) propyltrimethoxysilane, bis (3-dimethoxymethylsilylpropyl) -N-methylamine, bis (3-trimethoxysilylpropyl) -N-methylamine, bis (3-triethoxysilylpropyl) methylamine, tris (trimethoxysilyl) amine, tris (3-trimethoxysilylpropyl) amine, N, N, N ', N' -tetrakis (3-trimethoxysilylpropyl) ethylenediamine, 3-isocyanatopropyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1- Aza-2-silacyclopentane, 2-diethoxy-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-dimethoxy-1- (4-trimethoxysilylbutyl) -1-aza-2-silacyclohexane, 2-dimethoxy-1- (3-dimethoxymethylsilylpropyl) -1-aza-2-silacyclopentane, 2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, 2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2-dimethyl-1-aza-2-silacyclopentane, 2-dimethyl-1-dimethyl-ethyl-1-aza-2-silacyclopentane, 2-dimethyl-1-aza, 2, 2-dimethoxy-1-methyl-1-aza-2-silacyclopentane, 2-dimethoxy-8- (4-methylpiperazinyl) methyl-1, 6-dioxa-2-silacyclooctane, 2-dimethoxy-8- (N, N-diethylamino) methyl-1, 6-dioxa-2-silacyclooctane and the like.
Examples of the protected amine compound which is a coupling agent having a nitrogen atom-containing group and can form a primary or secondary amine include, but are not limited to, 4 '-ethenylbis [ N, N-bis (trimethylsilyl) aniline ], 4' -ethenylbis [ N, N-bis (triethylsilyl) aniline ], 4 '-ethenylbis [ N, N-bis (tert-butyldimethylsilyl) aniline ], 4' -ethenylbis [ N-methyl-N- (trimethylsilyl) aniline ], 4 '-ethenylbis [ N-ethyl-N- (trimethylsilyl) aniline ], 4' -ethenylbis [ N-methyl-N- (triethylsilyl) aniline ], (N-methyl-N- (triethylsilyl) aniline), 4,4 ' -vinylidene bis [ N-ethyl-N- (triethylsilyl) aniline ], 4 ' -vinylidene bis [ N-methyl-N- (t-butyldimethylsilyl) aniline ], 4 ' -vinylidene bis [ N-ethyl-N- (t-butyldimethylsilyl) aniline ], 1- [4-N, N-bis (trimethylsilyl) aminophenyl ] -1- [ 4-N-methyl-N- (trimethylsilyl) aminophenyl ] ethylene, 1- [4-N, N-bis (trimethylsilyl) aminophenyl ] -1- [4-N, N-dimethylaminophenyl ] ethylene, and the like.
As the protected amine compound which is a coupling agent having a nitrogen atom-containing group and can form a primary or secondary amine, examples of the compound having an alkoxysilane and a protected amine in the molecule 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) aminoethylmethyldiethoxysilane, N-bis (trimethylsilyl) alkoxysilane, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, N-bis (trimethylsilyl) alkoxysilane, 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, N- (1, 3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine, N- (1-methylethylidene) -3- (triethoxysilyl) -1-propanamine, N- (1-methylsilylene) -1- (triethoxysilyl) -1-propanamin-e, N-ethylene-3- (triethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -3- (triethoxysilyl) -1-propanamine, N- (4-N, N-dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine, and examples thereof include N- (1-methylpropylidene) -3- (triethoxysilyl) -1-propanamine, N- (1, 3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine, 3- (benzylideneamino) propyltrimethoxysilane, N- (1-methylpropylidene) -3- (triethoxysilyl) -1-propanamine, N- (1, 3-dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -1-propanamine, N- (1,3, 3- (benzylideneamino) propyltriethoxysilane, 3- (benzylideneamino) propyltripropylsilane, and the like.
Particularly preferred examples of the alkoxysilane compound which is a coupling agent having a nitrogen atom-containing group include, but are not limited to, tris (3-trimethoxysilylpropyl) amine, tris (3-triethoxysilylpropyl) amine, tris (3-tripropoxysilylpropyl) amine, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine, tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine, tris (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, tris (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-methyl-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, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tris (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tetrakis (3-trimethoxysilylpropyl) -1, 6-hexanediamine, penta (3-trimethoxysilylpropyl) -diethylenetriamine, tris (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] silane, bis (3-trimethoxysilylpropyl) -bis [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, 3-tris [2- (2, 2-dimethoxy-1-aza-2-silacyclopentane) ethoxy ] silyl-1-trimethoxysilylpropane, 1- [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -3,4, 5-tris (3-trimethoxysilylpropyl) -cyclohexane, 1- [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -3,4, 5-tris (3-trimethoxysilylpropyl) -cyclohexane, 3,4, 5-tris (3-trimethoxysilylpropyl) -cyclohexyl- [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] ether, (3-trimethoxysilylpropyl) phosphate, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] phosphate, bis (3-trimethoxysilylpropyl) phosphate, bis (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] phosphate, and mixtures thereof, 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.
[ coupling agent represented by formula (a) ]
In the method for producing a branched conjugated diene polymer according to the present embodiment, a reaction step of reacting the compound [ a ] represented by the following formula (a) with the active end of the conjugated diene polymer having a branched structure introduced thereto, which is obtained through the polymerization step and the branching step, is preferably performed.
The compound [ A ] is a compound having 2 or more nitrogen atom-containing alkoxysilyl groups in total, and the structure represented by X in the formula (a) is represented by the above-mentioned formulas (b) to (e).
By carrying out the reaction step using the coupling agent represented by the formula (a), a branched conjugated diene polymer having a large number of branches in the polymer chain and modified with a group that interacts with silicon oxide can be obtained.
[ solution 19]
Figure BDA0002821127030000291
In the formula (a), R1～R4Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R5～R6Each independently represents an alkylene group having 1 to 20 carbon atoms.
m and n are integers of 1 to 3, and in the formula (a), a plurality of R1～R6M and n may be the same or different.
In the formula (a), X is represented by any one of the following general formulae (b) to (e).
[ solution 20]
Figure BDA0002821127030000292
In the formula (b), R7The hydrocarbon group has 1 to 20 carbon atoms, and may have a partially branched structure or a cyclic structure. R 8Represents a C1-20 hydrocarbon group or a C6-EThe aryl group of 20 may have a partially branched or cyclic structure in the case of the hydrocarbon group.
[ solution 21]
Figure BDA0002821127030000301
In the formula (c), R9The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group.
[ solution 22]
Figure BDA0002821127030000302
In the formula (d), R10The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group.
[ solution 23]
Figure BDA0002821127030000303
In the formula (e), R11～R14Each independently represents an alkylene group having 1 to 20 carbon atoms.
R15～R18Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, l and o each independently represents an integer of 1 to 3, and R when a plurality of R's are present15～R18Each independently.
Examples of the compound [ A ] used in the modification step, i.e., the reaction step, include, but are not limited to, compounds represented by the following formulae (A-1) to (A-16).
The compound [ a ] may be used alone in 1 kind, or may be used in combination in 2 or more kinds.
< Compound [ A ] used in the modification step: formulae (A-1) to (A-16) >
[ solution 24]
Figure BDA0002821127030000311
[ solution 25]
Figure BDA0002821127030000312
[ solution 26]
Figure BDA0002821127030000321
In the above formulae (A-1) to (A-16), Et is ethyl and Me is methyl.
The reaction of the conjugated diene polymer having an active end obtained in the branching step with the compound [ a ] represented by the above formula (a) may be carried out, for example, as a solution reaction.
The proportion of the compound [ a ] (the total amount thereof in the case of using 2 or more species) is preferably 0.01 mol or more, more preferably 0.05 mol or more based on 1 mol of the metal atom participating in polymerization in the polymerization initiator, from the viewpoint of sufficiently proceeding the coupling reaction. In addition, the upper limit value is preferably less than 2.0 moles, more preferably less than 1.5 moles, based on 1 mole of the metal atom participating in polymerization contained in the polymerization initiator, in order to avoid excessive addition.
The temperature of the coupling reaction using the compound [ A ] represented by the above formula (a) is generally the same as the polymerization reaction, and is preferably-20 to 150 ℃ and more preferably 0 to 120 ℃. If the reaction temperature is low, the viscosity of the polymer after the coupling reaction tends to increase, and if the reaction temperature is high, the polymerization active end is easily inactivated. The reaction time is preferably 1 minute to 5 hours, more preferably 2 minutes to 1 hour.
When the conjugated diene polymer having an active end obtained in the branching step is reacted with the compound [ a ] represented by the formula (a), another modifier or coupling agent may be used together with the compound [ a ].
The other modifier or coupling agent is not particularly limited as long as it is a compound that can react with the active end of the conjugated diene polymer obtained in the polymerization step and the branching step, and a compound known as a modifier or coupling agent for a conjugated diene polymer can be used.
When another modifier or coupling agent is used, the use ratio thereof is preferably 10 mol% or less, more preferably 5 mol% or less.
< branched conjugated diene Polymer obtained by polymerization step, branching step and reaction step >
In the method for producing a branched conjugated diene polymer according to the present embodiment, the branched conjugated diene polymer obtained through the reaction step, particularly the step of reacting with a coupling agent, preferably has a structure derived from a compound having a nitrogen atom-containing group represented by the following general formula (i) or any one of the general formulae (a) to (C).
[ solution 27]
Figure BDA0002821127030000331
In the formula (i), R is a hydrocarbon group having a valence of 2 or more, or an organic group having a valence of 2 or more, which has at least one polar group selected from a polar group having oxygen such as ether, epoxy, ketone, etc., a polar group having sulfur such as thioether, thioketone, etc., a polar group having nitrogen such as tertiary amino, imino, etc.
The hydrocarbon group having a valence of 2 or more is a saturated or unsaturated hydrocarbon group which may be linear, branched or cyclic, and includes an alkylene group, an alkenylene group, a phenylene group and the like. Preferably a hydrocarbon group having 1 to 20 carbon atoms. Examples thereof include methylene, ethylene, butylene, cyclohexylene, 1, 3-bis (methylene) -cyclohexane, 1, 3-bis (ethylene) -cyclohexane, o-phenylene, m-phenylene, p-phenylene, m-xylylene, p-xylylene, and bis (phenylene) -methane.
In the above formula (i), R1、R4Is a hydrocarbon group of 1 to 10 carbon atoms, R1、R4May be the same or different from each other.
In the above formula (i), R2、R5Is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, R2、R5May be the same or different from each other.
In the above formula (i), R3Is a hydrocarbon group having 1 to 10 carbon atoms or a structure represented by the following formula (ii).
R1、R2、R3May have a ring structure formed by bonding them to each other.
In addition, R3In the case of a hydrocarbon group, the group may have a cyclic structure in which R and R are bonded to each other. In the case of the above-mentioned cyclic structure, R is bonded to3The N and R in (A) may be in a direct bond.
In the above formula (i), n is an integer of 1 or more, and m is an integer of 0 or 1 or more.
[ solution 28]
Figure BDA0002821127030000341
In the above formula (ii), R 1、R2With R of the above formula (i)1、R2Are defined as such, R1、R2May be the same or different from each other.
[ solution 29]
Figure BDA0002821127030000342
(in the formula (A), R1～R4Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R5Represents an alkylene group having 1 to 10 carbon atoms, R6Represents an alkylene group having 1 to 20 carbon atoms.
m represents an integer of 1 or 2, n represents an integer of 2 or 3, and (m + n) represents an integer of 4 or more. R when plural number exists1～R4Each independently. )
[ solution 30]
Figure BDA0002821127030000343
(in the formula (B), R1～R6Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R7～R9Each independently represents an alkylene group having 1 to 20 carbon atoms.
m, n and l each independently represent an integer of 1 to 3, and (m + n + l) represents an integer of 4 or more. R when plural number exists1～R6Each independently. )
[ solution 31]
Figure BDA0002821127030000351
(in the formula (C), 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 each case of plural 12～R22M and p are independent of each other and may be the same or different.
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) is an integer of 4 to 10.
A represents a hydrocarbon group having 1 to 20 carbon atoms or an organic group having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom and a phosphorus atom and having no active hydrogen. )
Examples of the coupling agent having a nitrogen atom-containing group represented by the formula (A) include, but are not limited to, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-diethoxy-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-dimethoxy-1- (4-trimethoxysilylbutyl) -1-aza-2-silacyclohexane, 2-dimethoxy-1- (5-trimethoxysilylpentyl) -1-aza-2-silacycloheptane, 2, 2-dimethoxy-1- (3-dimethoxymethylsilylpropyl) -1-aza-2-silacyclopentane, 2-diethoxy-1- (3-diethoxyethylsilylpropyl) -1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-ethoxy-2-ethyl-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1- (3-dimethoxymethylsilylpropyl) -1-aza-2-silacyclopentane -silacyclopentane and 2-ethoxy-2-ethyl-1- (3-diethoxyethylsilylpropyl) -1-aza-2-silacyclopentane.
Among these, m represents 2 and n represents 3 are preferable from the viewpoints of reactivity and interactivity between a functional group of a coupling agent having a nitrogen atom-containing group and an inorganic filler such as silica and processability. Specifically, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane and 2, 2-diethoxy-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane are preferable.
The reaction temperature, reaction time, and the like in the reaction of the coupling agent having a nitrogen atom-containing group represented by the above formula (a) with the polymerization active end are not particularly limited, but the reaction is preferably carried out at 0 ℃ to 120 ℃ for 30 seconds or more.
The total mole number of the alkoxy groups bonded to the silyl group in the compound of the coupling agent having a nitrogen atom-containing group represented by the formula (a) is preferably in a range of 0.6 to 3.0 times, more preferably in a range of 0.8 to 2.5 times, and still more preferably in a range of 0.8 to 2.0 times, the number of moles of the alkali metal compound and/or the alkaline earth metal compound added as the polymerization initiator. The amount of the branched conjugated diene polymer is preferably 0.6 times or more in view of obtaining a sufficient modification ratio, molecular weight and branched structure, and the amount of the branched conjugated diene polymer component is preferably obtained by coupling the polymer terminals to each other in order to improve processability, and is preferably 3.0 times or less in view of the cost of the coupling agent.
The number of moles of the polymerization initiator is preferably 3.0 times by mole or more, more preferably 4.0 times by mole or more, relative to the number of moles of the coupling agent having a nitrogen atom-containing group represented by the formula (a).
Examples of the coupling agent having a nitrogen atom-containing group represented by the formula (B) include, but are not limited to, tris (3-trimethoxysilylpropyl) amine, tris (3-methyldimethoxysilylpropyl) amine, tris (3-triethoxysilylpropyl) amine, tris (3-methyldiethoxysilylpropyl) amine, tris (trimethoxysilylmethyl) amine, tris (2-trimethoxysilylethyl) amine and tris (4-trimethoxysilylbutyl) amine.
Among these, from the viewpoints of reactivity and interactivity between the functional group of the coupling agent and the inorganic filler such as silica and processability, it is preferable that n, m and l in the formula (B) all represent 3. Preferable specific examples thereof include tris (3-trimethoxysilylpropyl) amine and tris (3-triethoxysilylpropyl) amine.
The reaction temperature, reaction time, and the like in the reaction of the coupling agent having a nitrogen atom-containing group represented by the formula (B) with the active end of the conjugated diene polymer obtained in the branching step are not particularly limited, but the reaction is preferably carried out at 0 ℃ to 120 ℃ for 30 seconds or more.
The total mole number of the alkoxy groups bonded to the silyl group in the compound of the coupling agent represented by the formula (B) is preferably in a range of 0.6 to 3.0 times, more preferably in a range of 0.8 to 2.5 times, and still more preferably in a range of 0.8 to 2.0 times, the mole number of lithium constituting the polymerization initiator. The amount of the branched conjugated diene polymer obtained by the production method of the present embodiment is preferably 0.6 times or more in terms of sufficient modification ratio, molecular weight, and branched structure, and the branched conjugated diene polymer component is preferably obtained by coupling the polymer ends to each other in order to improve processability, and is preferably 3.0 times or less in terms of cost of the coupling agent.
The number of moles of the polymerization initiator is preferably 4.0 times by mole or more, more preferably 5.0 times by mole or more, relative to the number of moles of the coupling agent having a nitrogen atom-containing group represented by the formula (B).
In the formula (C), a is preferably represented by any one of the following general formulae (II) to (V).
[ solution 32]
Figure BDA0002821127030000371
(in the formula (II), B1Represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. B1 in the case where a plurality of B1 exist is independent of each other. )
[ solution 33]
Figure BDA0002821127030000372
(in the formula (III), B2A single bond or a C1-20 hydrocarbon group, B3Represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. B in the case where there are plural ones2And B3Each independently. )
[ chemical 34]
Figure BDA0002821127030000373
(in the formula (IV), B4Represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. B in the case of plural4Each independently. )
[ solution 35]
Figure BDA0002821127030000374
(in the formula (V), B5Represents a single bond or a carbon atomA number of 1 to 20 hydrocarbon groups, and a represents an integer of 1 to 10. B in the case of plural5Each independently. )
Examples of the coupling agent having a nitrogen atom-containing group in the case where a in the formula (C) is represented by the formula (II) include, but are not limited to, tris (3-trimethoxysilylpropyl) amine, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) amine, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] amine, tris (3-ethoxysilylpropyl) amine, 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, and mixtures thereof, 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, and mixtures thereof, Tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, tetrakis (3-triethoxysilylpropyl) -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, bis (3-triethoxysilylpropyl) -bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) -1, 3-propanediamine, tetrakis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, bis (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-propanediamine, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] ] -1, 3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tris (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-trimethoxysilylpropyl) -bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-methoxy-1-aza-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-methoxy-2-aza-2-sila-2-azacyclopentane) propyl ester, bis (3-methoxy-1-methoxy-, Tetrakis (3-triethoxysilylpropyl) -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-triethoxysilylpropyl) -bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) -1, 3-propanediamine, tri (3-triethoxysilylpropyl) -1, 3-propanediamine, and mixtures thereof, Tetrakis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, tris (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, tris [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-ethoxysilylpropyl) - [ 1- (2-ethoxy-2-sila-2-azacyclopentane) propyl ] -1, 3-bisaminomethylcyclohexane, bis (3-triethoxy-1-aza-2-sila-2-azacyclopentane) propyl ] -, Tetrakis (3-trimethoxysilylpropyl) -1, 6-hexanediamine and pentakis (3-trimethoxysilylpropyl) -diethylenetriamine.
Examples of the coupling agent having a nitrogen atom-containing group in the case where A in the formula (C) is represented by the formula (III) include, but are not limited to, tris (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine, bis (2-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -methyl-1, 3-propanediamine, bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine, tris (3-triethoxysilylpropyl) -methyl-1, 3-propanediamine, bis (2-triethoxysilylpropyl) - [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] -methyl-1, 3-propanediamine, bis [3- (2, 2-diethoxy-1-aza-2-silacyclopentane) propyl ] - (3-triethoxysilylpropyl) -methyl-1, 3-propanediamine, N1, N1' - (propane-1, 3-diyl) bis (N1-methyl-N3, N3-bis (3- (trimethoxysilyl) propyl) -1, 3-propanediamine) and 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 coupling agent having a nitrogen atom-containing group in the case where A in the formula (C) is represented by the formula (IV) include, but are not limited to, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] silane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) silane, tris [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] silane, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] silane, and the like, 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 (2, 2-methoxy-2-trimethylsilyl-1-aza-2-silacyclopentane) propyl ] silane, bis (2, 2-methoxy-1-aza-2-sila, 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, and bis (3-trimethoxysilylpropyl) -bis [3- (1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane) propyl ] silane -methoxy-2-methyl-1-sila-2-azacyclopentane) propyl ] silane.
Examples of the coupling agent having a group containing a nitrogen atom in the case where a in the formula (C) is represented by the formula (V) include, but are not limited to, 3-tris [2- (2, 2-dimethoxy-1-aza-2-silacyclopentane) ethoxy ] silyl-1- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propane and 3-tris [2- (2, 2-dimethoxy-1-aza-2-silacyclopentane) ethoxy ] silyl-1-trimethoxysilylpropane.
In the formula (C), A is preferably represented by the formula (II) or the formula (III), and k represents 0.
Such a coupling agent having a nitrogen atom-containing group tends to be easily available, and the branched conjugated diene polymer obtained by the production method of the present embodiment tends to be more excellent in the wear resistance and the low hysteresis loss performance after being formed into a vulcanizate. Examples of such a coupling agent having a nitrogen atom-containing group 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- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, bis (3-trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] -1, 3-propanediamine, bis (trimethoxysilylpropyl) - [3- (2, 2-dimethoxy-1-aza-2, Tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisaminomethylcyclohexane, tris (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine, and bis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl ] - (3-trimethoxysilylpropyl) -methyl-1, 3-propanediamine.
In the formula (C), A is more preferably represented by the formula (II) or the formula (III), k is 0, and a is an integer of 2 to 10 in the formula (II) or the formula (III).
This tends to further improve the wear resistance and hysteresis loss performance after vulcanization.
Examples of such a coupling agent having a nitrogen atom-containing group include, but are not limited to, tetrakis [3- (2, 2-dimethoxy-1-aza-2-silacyclopentane) propyl group]-1, 3-propanediamine, tetrakis (3-trimethoxysilylpropyl) -1, 3-bisamineMethylcyclohexane and N1- (3- (bis (3- (trimethoxysilyl) propyl) amino) propyl) -N1-methyl-N3- (3- (methyl (3- (trimethoxysilyl) propyl) amino) propyl) -N3- (3- (trimethoxysilyl) propyl) -1, 3-propanediamine.
The amount of the compound represented by the above formula (C) to be added as the coupling agent having a group containing a nitrogen atom can be adjusted so that the number of moles of the conjugated diene polymer is reacted with the number of moles of the coupling agent in a desired stoichiometric ratio, and thus a desired star-shaped high-branched structure tends to be realized.
The number of moles of the polymerization initiator is preferably 5.0 times by mole or more, more preferably 6.0 times by mole or more, relative to the number of moles of the coupling agent having a nitrogen atom-containing group represented by the formula (C).
In this case, in the formula (C), the number of functional groups of the coupling agent ((m-1). times.i + p.times.j + k) is preferably an integer of 5 to 10, more preferably an integer of 6 to 10.
The branched conjugated diene polymer obtained by the production method of the present embodiment is represented by a modification ratio of the polymer having a nitrogen atom-containing group in the polymer.
The modification ratio is preferably 60% by mass or more, more preferably 65% by mass or more, further preferably 70% by mass or more, further preferably 75% by mass or more, further preferably 80% by mass or more, and particularly preferably 82% by mass or more.
When the modification ratio is 60 mass% or more, the workability in producing a sulfide tends to be excellent, and the wear resistance and the low hysteresis loss performance after producing a sulfide tend to be further excellent.
< branched conjugated diene Polymer obtained by the reaction step when the Compound represented by the formula (a) is used as a coupling agent >
The branched conjugated diene polymer of the present embodiment is preferably a reaction product of a conjugated diene polymer having an active end having a branched structure and a compound represented by the following formula (a).
[ solution 36]
Figure BDA0002821127030000421
In the formula (a), R1～R4Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R5～R6Each independently represents an alkylene group having 1 to 20 carbon atoms.
m and n are integers of 1 to 3, and in the formula (a), a plurality of R1～R6M and n may be the same or different.
In the formula (a), X is represented by any one of the following general formulae (b) to (e).
[ solution 37]
Figure BDA0002821127030000422
In the formula (b), R7The hydrocarbon group has 1 to 20 carbon atoms, and may have a partially branched structure or a cyclic structure. R8The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group.
[ solution 38]
Figure BDA0002821127030000423
In the formula (c), R9The alkyl group may have a partially branched structure or a cyclic structure in the case of the alkyl group.
[ solution 39]
Figure BDA0002821127030000424
In the formula (d), R10Represents a C1-20 hydrocarbon group or a C6-2 hydrocarbon groupThe aryl group of 0 may have a partially branched or cyclic structure in the case of the hydrocarbon group.
[ solution 40]
Figure BDA0002821127030000431
In the formula (e), R11～R14Each independently represents an alkylene group having 1 to 20 carbon atoms.
R15～R18Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, l and o each independently represents an integer of 1 to 3, and R when a plurality of R's are present 15～R18Each independently.
In the modified conjugated diene polymer according to the present embodiment, OR of the compound represented by the formula (a) is preferable1And OR3At least one of them has a branched structure.
In the branched conjugated diene polymer of the present embodiment, a reaction product of the conjugated diene polymer having an active end having a branched structure obtained through the branching step and the compound represented by the formula (a) is a preferable embodiment in terms of a balance between fuel economy performance and processability and abrasion resistance.
In general, a modified conjugated diene polymer having a branched structure has a branch point derived from a coupling agent or a modifier, and as the number of branches increases, reactivity with silica decreases when the rubber composition is formed. In addition, with respect to a polymer having a low branching degree, as the content and molecular weight of the coupling agent and the modifier increase, the viscosity of the compound tends to increase and the processability tends to deteriorate. This makes it difficult to improve the balance between fuel economy performance and workability and wear resistance.
In contrast, in a preferred embodiment of the branched conjugated diene polymer according to the present embodiment, OR of the compound represented by the formula (a) is1And OR3Since a conjugated diene polymer having a branched structure is a preferred embodiment, steric hindrance around the modifier can be reduced and the modified polymer can be made free of steric hindrance The number of branches and the molecular weight are increased in the case of impairing the reactivity of the branched conjugated diene polymer with silica.
Thus, OR of the compound represented by the above formula (a)1And OR3The modified conjugated diene polymer having at least one of the branched structures is preferably an asymmetric structure, that is, a skeleton having a main chain branched structure is preferably formed on one side and a skeleton having no main chain branch introduced thereto is formed on the opposite side, with the coupling agent as the center, and it is more preferable that the branching points of the conjugated diene polymer obtained through the branching step and the branching points of the modified conjugated diene polymer are separated by a molecular chain having a molecular weight of 1 ten thousand or more.
< step of terminating polymerization >
In the method for producing a branched conjugated diene polymer according to the present embodiment, a reaction step of reacting the coupling agent or the polymerization terminator with the active end of the conjugated diene polymer obtained through the polymerization step and the branching step may be performed.
The polymerization termination step is preferably a polymerization termination step performed using a 2-functional reactive compound for the active end of the conjugated diene polymer, or a polymerization termination step performed using a polymerization terminator having a nitrogen atom-containing group (hereinafter sometimes collectively referred to as "polymerization terminator").
In the polymerization termination step, for example, the living end of the polymer obtained in the branching step may be subjected to a polymerization termination reaction using a 2-functional reactive compound or a polymerization terminator having a nitrogen atom-containing group to obtain the desired branched conjugated diene polymer.
[ 2-functional reactive Compound ]
In the method for producing a branched conjugated diene polymer according to the present embodiment, the 2-functional reactive compound used in the polymerization termination step may have any structure, and is preferably a 2-functional reactive compound having a silicon atom.
[ polymerization terminator having Nitrogen atom-containing group ]
In the method for producing a branched conjugated diene polymer according to the present embodiment, the polymerization terminator having a nitrogen atom-containing group used in the polymerization terminating step may have any structure, and preferably has a functional group that reacts with the conjugated diene polymer.
As the polymerization terminator having a nitrogen atom-containing group, an alkoxy compound having a nitrogen atom-containing group is preferable from the viewpoint of improving fuel saving performance.
Examples of the polymerization terminator having a nitrogen atom-containing group include 3- (N, N-dimethylaminopropyl) dimethoxymethylsilane, 3- (N, N-diethylaminopropyl) dimethoxymethylsilane, 3- (N, N-dipropylaminopropyl) dimethoxymethylsilane, 3- (N, N-dimethylaminopropyl) diethoxymethylsilane, 3- (N, N-diethylaminopropyl) diethoxymethylsilane, 3- (N, N-dipropylaminopropyl) diethoxymethylsilane, 3- (N, N-dimethylaminopropyl) dimethoxyethylsilane, 3- (N, N-diethylaminopropyl) dimethoxyethylsilane, 3- (N, N-dipropylaminopropyl) dimethoxyethylsilane, N-dimethylaminopropyl-dimethoxymethylsilane, N-dimethylaminopropyl-dimethoxymethylsilane, N-dimethoxymethyls, 3- (N, N-dimethylaminopropyl) diethoxyethylsilane, 3- (N, N-diethylaminopropyl) diethoxyethylsilane, and 3- (N, N-dipropylaminopropyl) diethoxyethylsilane.
The branched structure of the branched conjugated diene polymer obtained by the above-described polymerization step, branching step, and reaction step in the production method of the present embodiment is more preferably 6 to 36 branches, preferably 8 to 36 branches, more preferably 8 to 24 branches, more preferably 10 to 22 branches, and even more preferably 12 to 20 branches.
The total number of branch points in the branched conjugated diene polymer obtained by the production method of the present embodiment is preferably 2 or more, more preferably 3 or more, still more preferably 4 or more, and yet more preferably 5 or more.
When the total number of the branched structures and the branching points is in the above range, the processability, fuel economy and wear resistance tend to be excellent.
In the case where the branched conjugated diene polymer has a branched structure of 8 to 36 branches and is a modified polymer, the molar ratio of the branching agent used is not less than one-half percent of the polymerization initiator and not less than 3 functional groups of the coupling agent are required in order to construct a structure in which the total number of branching points is not less than 2 to 15. In the case of a polymer not requiring modification, the branching point may be 1 or more.
In order to construct a structure in which the branched structure is not less than 8 branches and not more than 36 branches and the total number of branching points is not less than 3 and not more than 12, it is preferable to use a branching agent having a molar ratio of not more than one third and not more than one fiftieth of the polymerization initiator and a functional group number of the coupling agent of not less than 4 functions.
In order to construct a structure in which the branched structure is 10 to 24 branches and the total number of branching points is 4 to 10 branches, it is preferable to use a structure in which the molar ratio of the branching agent is one sixth to one twentieth to one fiftieth of the polymerization initiator and the number of functional groups of the coupling agent is 5 or more.
In order to construct a structure in which the branched structure is not less than 12 branches and not more than 20 branches and the total number of branching points is not less than 5 and not more than 9, it is preferable to use a branching agent having a molar ratio not more than one eighth and not more than one tenth of the molar ratio of the polymerization initiator and a functional group number of the coupling agent of not less than 6 functions.
(condensation reaction step)
In the method for producing a branched conjugated diene polymer according to the present embodiment, the condensation reaction step may be performed after or before the coupling step, and the condensation reaction may be performed in the presence of a condensation accelerator.
(hydrogenation step)
In the method for producing a branched conjugated diene polymer according to the present embodiment, a hydrogenation step of hydrogenating a conjugated diene portion may be performed.
The method for hydrogenating the conjugated diene portion of the conjugated diene polymer is not particularly limited, and a known method can be used.
A suitable hydrogenation method is a method in which hydrogenation is carried out by blowing gaseous hydrogen into a polymer solution in the presence of a catalyst. The catalyst is not particularly limited, and examples thereof include heterogeneous catalysts such as a catalyst in which a noble metal is supported on a porous inorganic substance; a homogeneous catalyst such as a catalyst obtained by solubilizing a salt of nickel, cobalt or the like and reacting the solubilized salt with an organoaluminum or the like, and a catalyst using a metallocene such as cyclopentadienyl titanium or the like. Among these, a cyclopentadienyl titanium catalyst is preferable in that mild hydrogenation conditions can be selected. In addition, the hydrogenation of the aromatic group can be carried out by using a supported catalyst of a noble metal.
Examples of the hydrogenation catalyst include, but are not limited to: (1) a supported heterogeneous hydrogenation catalyst in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, or diatomaceous earth; (2) so-called ziegler-type hydrogenation catalysts using organic acid salts such as Ni, Co, Fe, and Cr, transition metal salts such as acetylacetone salts, and reducing agents such as organic aluminum; (3) and so-called organometallic complexes such as organometallic compounds of Ti, Ru, Rh, Zr, etc. Further, examples of the hydrogenation catalyst include, but are not limited to, known hydrogenation catalysts described in, for example, Japanese patent publication No. 42-8704, Japanese patent publication No. 43-6636, Japanese patent publication No. 63-4841, Japanese patent publication No. 1-37970, Japanese patent publication No. 1-53851, Japanese patent publication No. 2-9041, and Japanese patent application laid-open No. 8-109219. As a preferred hydrogenation catalyst, a reaction mixture of a cyclopentadienyl titanium compound and a reducing organometallic compound may be mentioned.
(step of adding deactivator and neutralizer)
In the method for producing a branched conjugated diene polymer according to the present embodiment, a deactivator, a neutralizer, or the like may be added to the polymer solution after the above-described coupling step, as necessary.
Examples of the deactivator include, but are not limited to, water; alcohols such as methanol, ethanol, and isopropanol; and so on.
Examples of the neutralizing agent include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and neodecanoic acid (a multi-branched carboxylic acid mixture having 9 to 11 carbon atoms and 10 carbon atoms as the center); aqueous solution of inorganic acid, carbon dioxide.
(Process for adding stabilizer for rubber)
In the method for producing a branched conjugated diene polymer according to the present embodiment, a rubber stabilizer is preferably added from the viewpoint of preventing gel formation after polymerization and improving stability during processing.
As the rubber stabilizer, known rubber stabilizers, for example, antioxidants such as 2, 6-di-t-butyl-4-hydroxytoluene (hereinafter also referred to as "BHT"), n-octadecyl 3- (4 ' -hydroxy-3 ', 5 ' -di-t-butylphenol) propionate, and 2-methyl-4, 6-bis [ (octylthio) methyl ] phenol are preferable, but not limited thereto.
(step of adding softener for rubber)
In the method for producing a branched conjugated diene polymer according to the present embodiment, a softening agent for rubber may be added as needed in order to further improve the productivity of the branched conjugated diene polymer and the processability after a resin composition is prepared by compounding a filler or the like.
The rubber softener is not particularly limited, and examples thereof include extender oil, liquid rubber, and resin.
As a method of adding the softening agent for rubber to the branched conjugated diene polymer, the following methods are preferable, but not limited to: the softening agent for rubber is added to the branched conjugated diene polymer solution, mixed to prepare a polymer solution containing the softening agent for rubber, and then subjected to desolvation.
Preferred extender oils include aromatic oils, naphthenic oils, paraffinic oils, and the like. Among these, in terms of environmental safety and prevention of oil exudation and wet grip properties, it is preferable that the polycyclic aromatic component (PCA) based on the IP346 method is a substitute aromatic oil having a content of 3 mass% or less. As alternative Aromatic oils, there may be mentioned TDAE (Treated distilled Aromatic extract) shown in Kautschuk Gummi Kunststoffe 52(12)799(1999), MES (Mild Extraction Solvate), etc., and RAE (Residual Aromatic extract).
Examples of the preferred liquid rubber include, but are not limited to, liquid polybutadiene, liquid styrene-butadiene rubber, and the like.
The effects when the liquid rubber is added include: the branched conjugated diene polymer and the filler can be blended to improve the processability of the resin composition after the resin composition is produced, and the glass transition temperature of the resin composition can be shifted to a low temperature side, so that the wear resistance, the hysteresis loss property and the low temperature characteristics after the resin composition is produced as a vulcanizate tend to be improved.
Examples of the resin as the softening agent for rubber include, but are not limited to, aromatic petroleum resins, coumarone-indene resins, terpene resins, rosin derivatives (including tung oil resins), tall oil derivatives, rosin ester resins, natural and synthetic terpene resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, mixed aliphatic-aromatic hydrocarbon resins, coumarin-indene resins, phenol resins, p-tert-butylphenol-acetylene resins, phenol-formaldehyde resins, xylene-formaldehyde resins, oligomers of monoolefins, oligomers of diolefins, aromatic hydrocarbon resins, aromatic petroleum resins, hydrogenated aromatic hydrocarbon resins, cyclic aliphatic hydrocarbon resins, hydrogenated hydrocarbon resins, hydrogenated tung oil resins, hydrogenated oil resins, esters of hydrogenated oil resins with monofunctional or polyfunctional alcohols, and the like. One kind of these resins may be used, or two or more kinds may be used in combination. In the case of hydrogenation, the unsaturated group may be completely hydrogenated or a part thereof may remain.
The effects of adding the resin as the softening agent for rubber include: the branched conjugated diene polymer and the filler can be blended to improve the processability after the resin composition is produced, the breaking strength after the resin composition is produced into a vulcanizate tends to be improved, and the wet skid resistance tends to be improved by shifting the glass transition temperature of the resin composition to the high temperature side.
The amount of the extender oil, the liquid rubber, the resin, or the like as the softening agent for rubber is not particularly limited, and is preferably 1 part by mass or more and 60 parts by mass or less, more preferably 5 parts by mass or more and 50 parts by mass or less, and further preferably 10 parts by mass or more and 37.5 parts by mass or less with respect to 100 parts by mass of the branched conjugated diene polymer obtained by the production method of the present embodiment.
When the softening agent for rubber is added in the above range, the branched conjugated diene polymer obtained by the production method of the present embodiment and the filler and the like are blended to obtain a resin composition, which tends to have good processability and good breaking strength and abrasion resistance after being formed into a vulcanizate.
(desolvation step)
In the method for producing a branched conjugated diene polymer according to the present embodiment, a known method can be used as a method for obtaining the obtained branched conjugated diene polymer from the polymer solution. The method is not particularly limited, and examples thereof include: a method in which a polymer is filtered out after separating a solvent by steam stripping or the like, and is further dehydrated and dried to obtain a polymer; a method of concentrating with a flash tank and further devolatilizing with an exhaust extruder or the like; a method of directly performing devolatilization using a rotary dryer or the like.
[ rubber composition and method for producing rubber composition ]
The rubber composition of the present embodiment contains: a rubber component containing 10 mass% or more of the branched conjugated diene polymer produced by the production method of the present embodiment; and a filler in an amount of 5.0 to 150 parts by mass per 100 parts by mass of the rubber component.
The method for producing the rubber composition of the present embodiment includes the steps of: a step of obtaining a branched conjugated diene polymer by the above-mentioned production method; a step of obtaining a rubber component containing 10 mass% or more of the branched conjugated diene polymer; and a step of containing 5.0 to 150 parts by mass of a filler per 100 parts by mass of the rubber component.
In addition, it is preferable to include 10 mass% of the branched conjugated diene polymer obtained by the production method of the present embodiment in the rubber component in order to improve fuel efficiency, processability, and wear resistance.
The filler preferably contains a silica-based inorganic filler.
In the rubber composition, by dispersing the silica-based inorganic filler as a filler, the processability in producing a vulcanizate tends to be more excellent, and the balance between the abrasion resistance, breaking strength, and low hysteresis loss property and wet skid resistance after producing a vulcanizate tends to be more excellent.
The rubber composition preferably contains a silica-based inorganic filler when used for automobile parts such as tires and vibration-damping rubbers, and vulcanized rubber applications such as shoes.
The rubber composition of the present embodiment is obtained by mixing the rubber component containing 10 mass% or more of the branched conjugated diene polymer obtained by the above production method and the above filler.
The rubber component may contain a rubbery polymer other than the branched conjugated diene polymer (hereinafter referred to simply as "rubbery polymer").
Examples of such a rubbery polymer include, but are not limited to, 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 rubbery polymer include, but are not limited to, styrene-based elastomers such as butadiene rubber or a hydrogenated product thereof, isoprene rubber or a hydrogenated product thereof, styrene-butadiene block copolymer or a hydrogenated product thereof, and styrene-isoprene block copolymer or a hydrogenated product thereof, nitrile rubber, and a hydrogenated product thereof.
Examples of the non-diene polymer include, but are not limited to, olefin elastomers such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, and ethylene-octene rubber, butyl rubber, bromobutyl rubber, acrylic rubber, fluorine rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β -unsaturated nitrile-acrylate-conjugated diene copolymer rubber, urethane rubber, and polysulfide rubber.
Examples of the natural rubber include, but are not limited to, RSS 3-5, SMR, and epoxidized natural rubber, which are smoke film adhesives.
The various rubbery polymers mentioned above may be modified rubbers to which a functional group having polarity such as a hydroxyl group or an amino group is added. In the case of use for tire applications, butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber are preferably used.
From the viewpoint of the balance between various properties and processing characteristics of the resin composition, the weight average molecular weight of the rubbery polymer is preferably 2000 to 2000000, more preferably 5000 to 1500000. In addition, a rubber-like polymer having a low molecular weight, so-called liquid rubber, may be used.
These rubbery polymers can be used alone in 1 kind, can also be combined with 2 or more.
When the rubber composition containing the rubber-like polymer is prepared from the rubber composition using the branched conjugated diene polymer obtained by the production method of the present embodiment, the content ratio (mass ratio) of the branched conjugated diene polymer to the rubber-like polymer (branched conjugated diene polymer/rubber-like polymer) is preferably from 10/90 to 100/0, more preferably from 20/80 to 90/10, and still more preferably from 50/50 to 80/20.
Therefore, the branched conjugated diene polymer is contained in the rubber component in an amount of preferably 10 mass% to 100 mass%, more preferably 20 mass% to 90 mass%, and still more preferably 50 mass% to 80 mass%, based on the total amount (100 mass%) of the rubber component.
When the content ratio of the (branched conjugated diene polymer/rubbery polymer) is in the above range, the vulcanizate produced has excellent wear resistance and breaking strength, and the balance between low hysteresis loss resistance and wet skid resistance tends to be good.
Examples of the filler contained in the rubber composition include, but are not limited to, the silica-based inorganic filler, carbon black, metal oxide, and metal hydroxide. Among these, silica-based inorganic fillers are preferred.
The filler can be used alone in 1 kind, also can be combined with more than 2 kinds.
The content of the filler in the rubber composition is 5.0 parts by mass or more and 150 parts by mass or less, preferably 20 parts by mass or more and 100 parts by mass or less, and more preferably 30 parts by mass or more and 90 parts by mass or less, with respect to 100 parts by mass of the rubber component containing the branched conjugated diene polymer.
The content of the filler in the rubber composition is 5.0 parts by mass or more per 100 parts by mass of the rubber component in order to exhibit the effect of adding the filler, and is 150 parts by mass or less per 100 parts by mass of the rubber component in order to sufficiently disperse the filler and practically satisfy the processability and mechanical strength of the rubber composition.
The silica-based inorganic filler is not particularly limited, and a known one 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 fibers 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 silica is preferred because of its excellent balance between the effect of improving the fracture strength and the wet skid resistance.
In the rubber composition, the nitrogen adsorption specific surface area of the silica-based inorganic filler determined by the BET adsorption method is preferably 100m in order to obtain practically excellent wear resistance and breaking strength2300m above g2A ratio of 170m or less2More than 250 m/g2The ratio of the carbon atoms to the carbon atoms is less than g.
In addition, the specific surface area may be relatively small (for example, less than 200 m) as required2The silica-based inorganic filler has a large specific surface area (e.g., 200 m) 2/g or more) of a silica-based inorganic filler.
Particularly when a large specific surface area (e.g., 200 m) is used2A silica-based inorganic filler of/g or more), the rubber composition containing the branched conjugated diene-based polymer has an effect of improving the dispersibility of silica, particularly the abrasion resistance, and tends to have a high balance between good breaking strength and low hysteresis loss.
The content of the silica-based inorganic filler in the rubber composition is preferably 5.0 parts by mass or more and 150 parts by mass or less, and more preferably 20 parts by mass or more and 100 parts by mass or less, with respect to 100 parts by mass of the rubber component including the branched conjugated diene-based polymer obtained by the production method of the present embodiment. The content of the silica-based inorganic filler in the rubber composition is preferably 5.0 parts by mass or more per 100 parts by mass of the rubber component in view of exhibiting the effect of adding the silica-based inorganic filler, and is preferably 150 parts by mass or less per 100 parts by mass of the rubber component in view of sufficiently dispersing the silica-based inorganic filler and practically satisfying the processability and mechanical strength of the rubber composition.
Examples of the carbon black include, but are not limited toFor example, various grades of carbon black such as SRF, FEF, HAF, ISAF, SAF, etc. Of these, the nitrogen adsorption specific surface area is preferably 50m2A carbon black having a dibutyl phthalate (DBP) oil absorption of 80mL/100g or less.
In the rubber composition, the content of the carbon black is preferably 0.5 parts by mass or more and 100 parts by mass or less, more preferably 3.0 parts by mass or more and 100 parts by mass or less, and further preferably 5.0 parts by mass or more and 50 parts by mass or less, with respect to 100 parts by mass of the rubber component including the branched conjugated diene polymer obtained by the production method of the present embodiment. In the rubber composition, the content of carbon black is preferably 0.5 parts by mass or more per 100 parts by mass of the rubber component in terms of the performance required for applications such as tires, including dry grip performance and conductivity, and is preferably 100 parts by mass or less per 100 parts by mass of the rubber component in terms of dispersibility.
The metal oxide is a solid particle having a chemical formula MxOy (M represents a metal atom, and x and y each independently represent an integer of 1 to 6) as a main component of a structural unit.
Examples of the metal oxide include, but are not limited to, aluminum oxide, titanium oxide, magnesium oxide, and zinc oxide.
Examples of the metal hydroxide include, but are not limited to, aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.
The method for producing the rubber composition of the present embodiment may contain a silane coupling agent.
The silane coupling agent has a function of making the interaction between the rubber component and the inorganic filler tight, and has groups having affinity or binding properties with respect to the rubber component and the silica-based inorganic filler, respectively, and is preferably a compound having a sulfur bond moiety and an alkoxysilyl group or silanol group moiety in one molecule. Such a compound is not particularly limited, and examples thereof include bis- [3- (triethoxysilyl) -propyl ] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl ] -disulfide, and bis- [2- (triethoxysilyl) -ethyl ] -tetrasulfide.
The content of the silane coupling agent in the rubber composition is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and still more preferably 1.0 to 15 parts by mass, based on 100 parts by mass of the inorganic filler. When the content of the silane coupling agent is within the above range, the above-mentioned effect of adding the silane coupling agent tends to be more remarkable.
The rubber composition may contain a rubber softener in order to improve the processability thereof.
The amount of the softener for rubber added is represented by the amount of the softener for rubber previously contained in the branched conjugated diene polymer and the other rubbery polymer and the total amount of the softener for rubber added in the preparation of the rubber composition, with respect to 100 parts by mass of the rubber component containing the branched conjugated diene polymer obtained by the production method of the present embodiment.
As the softener for rubber, mineral oil or a liquid or low molecular weight synthetic softener is suitable.
Softening agents for mineral oil-based rubbers, which are called process oils or extender oils, used for softening, extending, and improving the processability of rubbers are mixtures of aromatic rings, naphthenic rings, and paraffinic chains, those having 50% or more of the total carbon atoms in paraffinic chains are called paraffinic chains, those having 30% or more to 45% or less of the total carbon atoms in naphthenic rings are called naphthenic chains, and those having more than 30% of the total carbon atoms in aromatic rings are called aromatic chains. When the conjugated diene polymer of the present embodiment is a copolymer of a conjugated diene compound and a vinyl aromatic compound, the softening agent for rubber used is preferably a softening agent for rubber having an appropriate aromatic content because the softening agent for rubber tends to have good fusibility with the copolymer.
The content of the rubber softener in the rubber composition 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 component. When the content of the rubber softener is 100 parts by mass or less based on 100 parts by mass of the rubber component, bleeding can be suppressed, and stickiness on the surface of the rubber composition can be suppressed.
The method of mixing the branched conjugated diene polymer obtained by the production method of the present embodiment with additives such as other rubbery polymers, silica-based inorganic fillers, carbon black and other fillers, silane coupling agents, and rubber softeners includes, but is not limited to, a melt-kneading method using a general mixer such as an open mill, a banbury mixer, a kneader, a single-screw extruder, a twin-screw extruder, and a multi-screw extruder; a method in which the respective components are dissolved and mixed, and then the solvent is removed by heating.
Among these, a melt kneading method using a roll, a banbury mixer, a kneader, or an extruder is preferable from the viewpoint of productivity and excellent kneading property. Further, any of a method of kneading the rubber component together with other fillers, silane coupling agents and additives at once and a method of mixing the components in several portions can be applied.
The rubber composition may be a vulcanized composition obtained by vulcanizing the rubber composition with a vulcanizing agent. Examples of the vulcanizing agent include, but are not limited to, radical initiators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur-containing compounds. The sulfur-containing compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, polymer polysulfide compounds, and the like.
The content of the vulcanizing agent in the rubber composition is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, per 100 parts by mass of the rubber component. As the vulcanization method, a conventionally known method can be applied, and the vulcanization temperature is preferably 120 ℃ to 200 ℃ and more preferably 140 ℃ to 180 ℃.
In the vulcanization, a vulcanization accelerator may be used as needed. As the vulcanization accelerator, conventionally known materials can be used, and examples thereof include, but are not limited to, sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, thiourea-based, and dithiocarbamate-based vulcanization accelerators. Examples of the vulcanization aid include, but are not limited to, zinc white and stearic acid. The content of the vulcanization accelerator is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, per 100 parts by mass of the rubber component.
In the rubber composition, various additives such as softening agents and fillers other than the above, heat stabilizers, antistatic agents, weather stabilizers, antioxidants, colorants, lubricants and the like may be used within a range not to impair the object of the present embodiment.
As the other softener, a known softener can be used.
Specific examples of the other filler include, but are not limited to, 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 and methods for manufacturing tires ]
The tire of the present embodiment contains the rubber composition of the present embodiment described above.
The method for manufacturing a tire according to the present embodiment includes the steps of: a step of obtaining a branched conjugated diene polymer by the production method of the present embodiment; a step for obtaining a rubber composition containing the branched conjugated diene polymer; and a step of molding the rubber composition.
The rubber composition containing the branched conjugated diene polymer obtained by the production method of the present embodiment is suitably used as a rubber composition for a tire.
The rubber composition for a tire can be used in, but not limited to, various tire parts such as treads, tire carcasses, beads, and bead parts of various tires such as fuel-efficient tires, all season tires, high performance tires, and studless tires. In particular, the rubber composition for a tire is excellent in the balance of abrasion resistance, breaking strength, low hysteresis loss and wet skid resistance after being vulcanized, and therefore is suitable for use as a tread of a fuel-efficient tire or a high-performance tire.
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 and comparative examples.
[ 1 st embodiment ]
The following methods were used to measure various physical properties of the examples and comparative examples [ example 1 ].
Hereinafter, the conjugated diene polymer coupled with the nitrogen atom-containing modifier is described as "coupled conjugated diene polymer".
The unmodified conjugated diene polymer is referred to as "unmodified conjugated diene polymer".
In addition, the conjugated diene polymer having a branched structure is described as a "branched conjugated diene polymer".
(Property 1) Mooney viscosity of Polymer
An unmodified conjugated diene polymer or a conjugated diene polymer coupled with a nitrogen atom-containing modifier (hereinafter also referred to as "coupled conjugated diene polymer") was used as a sample, and the mooney viscosity was measured using a mooney viscometer (trade name "VR 1132" manufactured by shanghai corporation) and an L-shaped rotor according to ISO 289.
The measurement temperature was 110 ℃ in the case of using an unmodified conjugated diene polymer as a sample, and 100 ℃ in the case of using a coupled conjugated diene polymer as a sample.
The sample was first preheated at the test temperature for 1 minute, then the rotor was rotated at 2rpm, and the torque after 4 minutes was measured as the Mooney viscosity (ML)(1+4))。
(Property 2) Mooney stress relaxation Rate
The coupled conjugated diene polymer was used as a sample, and after measuring the mooney viscosity using an L-shaped rotor in accordance with ISO 289 using a mooney viscometer ("VR 1132" manufactured by shanghai corporation), the rotation of the rotor was immediately stopped, the torque at intervals of 0.1 second was recorded in terms of mooney units for a period of 1.6 to 5 seconds after the stop, the slope of the straight line at that time was obtained by plotting the double logarithm of the torque and the time (sec), and the absolute value thereof was used as the mooney stress relaxation rate (MSR).
(Property 3) degree of branching (Bn)
The degree of branching (Bn) of the coupled conjugated diene polymer was measured by GPC-light scattering method with a viscosity detector as follows.
The absolute molecular weight was determined from the results of the light scattering detector and the RI detector based on standard polystyrene and the intrinsic viscosity was determined from the results of the RI detector and the light scattering detector based on standard polystyrene using a Gel Permeation Chromatography (GPC) measuring apparatus (trade name "GPCmax VE-2001" manufactured by Malvern) to which 3 columns using a polystyrene gel as a filler were connected (trade name "GPCmax VE-2001" manufactured by Malvern) and 3 detectors connected in this order of the light scattering detector, the RI detector, and the viscosity detector.
Using linear polymers as the intrinsic viscosity [ eta ]]＝-3.883M0.771The shrinkage factor (g') was calculated as an intrinsic viscosity ratio corresponding to each molecular weight. In the formula, M represents an absolute molecular weight.
Thereafter, using the obtained contraction factor (g '), a branching degree (Bn) defined as g' ═ 6Bn/{ (Bn +1) (Bn +2) } was calculated.
As the eluent, tetrahydrofuran (hereinafter also referred to as "THF") containing 5mmol/L of triethylamine was used.
As the column, those manufactured by Tosoh corporation under the trade names "TSKgel G4000 HXL", "TSKgel G5000 HXL", and "TSKgel G6000 HXL" were used in combination.
20mg of a sample for measurement was dissolved in 10mL of THF to prepare a measurement solution, and 100. mu.L of the measurement solution was injected into a GPC measurement apparatus and measured at an oven temperature of 40 ℃ and a THF flow rate of 1 mL/min.
(Property 4) molecular weight
< measurement conditions 1 >:
an unmodified conjugated diene polymer or a coupled conjugated diene polymer was used as a sample, and a weight average molecular weight (Mw), a number average molecular weight (Mn), and a molecular weight distribution (Mw/Mn) were 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 tokyo corporation) to which 3 columns each having a polystyrene gel as a filler were connected and using an RI detector (trade name "HLC 8020" manufactured by tokyo corporation).
The eluent used was THF (tetrahydrofuran) containing 5mmol/L triethylamine. The column was used by connecting 3 columns with a trade name "TSKgel SuperMultipolypore HZ-H" manufactured by Tosoh corporation, and connecting a trade name "TSK guard column SuperMP (HZ) -H" manufactured by Tosoh corporation as a guard column to the front of the column.
10mg of the sample for measurement was dissolved in 10mL of THF to prepare a measurement solution, and 10. mu.L of the measurement solution was poured into a GPC measurement apparatus and measured under conditions of an oven temperature of 40 ℃ and a THF flow rate of 0.35 mL/min.
Among the various samples measured under the above-mentioned measurement condition 1, those having a molecular weight distribution (Mw/Mn) of less than 1.6 were measured under the following measurement condition 2 again. The measurement value obtained by measurement under the measurement condition 1 was used for a sample having a molecular weight distribution of 1.6 or more measured under the measurement condition 1.
< measurement conditions 2 >:
an unmodified conjugated diene polymer or a coupled conjugated diene polymer was used as a sample, and a chromatogram was measured using a GPC measurement apparatus in which 3 columns each having a polystyrene gel as a filler were connected, and the weight average molecular weight (Mw) and the number average molecular weight (Mn) were obtained based on a calibration curve obtained using standard polystyrene.
The eluent used was THF containing 5mmol/L triethylamine. As for the column, a guard column was used: trade name "TSK guard column SuperH-H" manufactured by Tosoh corporation, column: trade names "TSKgel SuperH 5000", "TSKgel SuperH 6000" and "TSKgel SuperH 7000" manufactured by Tosoh corporation.
An RI detector (trade name "HLC 8020" manufactured by Tosoh corporation) was used under conditions of an oven temperature of 40 ℃ and a THF flow rate of 0.6 mL/min. 10mg of the measurement sample was dissolved in 20mL of THF to prepare a measurement solution, and 20. mu.L of the measurement solution was injected into a GPC measurement apparatus and measured.
The sample having a molecular weight distribution value of less than 1.6, which was measured under the measurement condition 1, was measured under the measurement condition 2.
(Property 5) modification ratio
The modification ratio of the coupled conjugated diene polymer was measured by the column adsorption GPC method as follows.
The measurement was carried out by using, as a sample, a characteristic that the modified basic polymer component was adsorbed on a GPC column using a silica gel as a filler.
The adsorption amount on the silica column was determined from the difference between the chromatogram obtained by measuring a sample solution containing the sample and low-molecular-weight internal standard polystyrene with the polystyrene column and the chromatogram obtained by measuring with the silica column, and the modification ratio was determined.
The details are as follows.
The sample measured under the measurement condition 1 of the above (property 4) and having a molecular weight distribution of 1.6 or more was measured under the measurement condition 3 described below. The sample measured under the above-mentioned measurement condition 1 (property 4) and having a molecular weight distribution value of less than 1.6 was measured under the following measurement condition 4.
< preparation of sample solution >:
a sample solution was prepared by dissolving 10mg of the sample and 5mg of standard polystyrene in 20mL of THF.
< measurement conditions 3 >:
GPC measurement conditions using polystyrene columns:
using a product name "HLC-8320 GPC" manufactured by Tosoh corporation, THF containing 5mmol/L triethylamine was used as an eluent, 10. mu.L of the sample solution was poured into the apparatus, and a chromatogram was obtained using an RI detector under conditions of a column oven temperature of 40 ℃ and a THF flow rate of 0.35 mL/min.
The column was used by connecting 3 units of the trade name "TSKgel SuperMultipolypore HZ-H" manufactured by Tosoh corporation, and connecting the former to a trade name "TSK guard column SuperMP (HZ) -H" manufactured by Tosoh corporation as a guard column.
< measurement conditions 4 >:
mu.L of the sample solution was poured into the apparatus using THF containing 5mmol/L of triethylamine as an eluent and measured.
As for the column, a guard column was used: trade name "TSK guard column SuperH-H" manufactured by Tosoh corporation, column: trade names "TSKgel SuperH 5000", "TSKgel SuperH 6000" and "TSKgel SuperH 7000" manufactured by Tosoh corporation. The measurement was performed using an RI detector (HLC 8020, manufactured by Tosoh corporation) under the conditions of a column oven temperature of 40 ℃ and a THF flow rate of 0.6 mL/min, and a chromatogram was obtained.
GPC measurement conditions using a silica-based column: a sample solution (50. mu.L) was poured into the apparatus using "HLC-8320 GPC" product of Tosoh Corp, using THF as an eluent, and a chromatogram was obtained using an RI detector under conditions of a column oven temperature of 40 ℃ and a THF flow rate of 0.5 ml/min. The column was used under the trade name "Zorbax PSM-1000S", "PSM-300S" or "PSM-60S", and the column was used under the trade name "DIOL 4.6X 12.5mm 5 micron" as a guard column in the preceding stage.
The calculation method of the modification rate comprises the following steps:
the modification ratio (%) was determined by the following formula, with the peak area of the chromatogram using a polystyrene column taken as a whole to be 100, the peak area of the sample taken as P1, the peak area of the standard polystyrene taken as P2, the peak area of the chromatogram using a silica column taken as a whole to be 100, the peak area of the sample taken as P3, and the peak area of the standard polystyrene taken as P4.
Modification rate (%) ([ 1- (P2 × P3)/(P1 × P4) ] × 100
(wherein P1+ P2 is P3+ P4 is 100)
(Property 6) amount of bound styrene
The conjugated diene polymer without the softener for rubber was used as a sample, and 100mg of the sample was dissolved in chloroform to a volume of 100mL to prepare a measurement sample.
The amount (mass%) of bound styrene relative to 100 mass% of the coupled 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) (measuring apparatus: spectrophotometer "UV-2450" manufactured by Shimadzu corporation).
(Property 7) microstructure of butadiene portion (1, 2-vinyl bond amount)
The conjugated diene polymer without the softener for rubber 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 amount (mol%) of 1, 2-vinyl bonds was determined from the absorbance at a predetermined wave number according to the calculation formula of the Hampton method (the method described in R.R. Hampton, Analytical Chemistry 21,923 (1949)) (measuring apparatus: Fourier transform infrared spectrophotometer "FT-IR 230" manufactured by Japan Spectroscopy Co., Ltd.).
(Property 8) molecular weight (absolute molecular weight) measured by GPC-light scattering method
Using a GPC light scattering measurement apparatus in which 3 columns each containing a polystyrene gel as a filler were connected to a sample of a coupled conjugated diene polymer, a chromatogram was measured, and a weight average molecular weight (Mw-i) (also referred to as "absolute 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 in 1L of tetrahydrofuran) was used as an eluent.
With respect to the pillars, the pillars will be protected: trade name "TSK guard column HHR-H" manufactured by Tosoh corporation and column: the trade names "TSKgel G6000 HHR", "TSKgel G5000 HHR" and "TSKgel G4000 HHR" manufactured by Tosoh corporation are used in combination.
A GPC-light scattering measuring apparatus (trade name "Viscotek TDAmax" manufactured by Malvern) was used under conditions of an oven temperature of 40 ℃ and a THF flow rate of 1.0 mL/min.
10mg of a sample for measurement was dissolved in 20mL of THF to prepare a measurement solution, and 200. mu.L of the measurement solution was injected into a GPC measurement apparatus and measured.
[ branched conjugated diene Polymer ]
Example 1-1 coupling of conjugated diene Polymer (sample 1-1)
A polymerization reactor was a tank-type pressure vessel having an internal volume of 10L, a ratio (L/D) of the internal height (L) to the internal diameter (D) of 4.0, an inlet at the bottom, an outlet at the top, a tank-type reactor with a stirrer, and a jacket for temperature control, and 2 units of the pressure vessel were connected.
1, 3-butadiene from which water had been removed in advance was mixed under conditions of 18.6 g/min, 10.0 g/min for styrene and 175.2 g/min for n-hexane. N-butyllithium for inerting, which was a residual impurity, was added to a static mixer provided in the middle of a pipe for supplying the mixed solution to the inlet of the reactor at a rate of 0.103 mmol/min, and the mixture was continuously supplied to the bottom of the reactor. Further, 2-bis (2-tetrahydrofuryl) propane as a polar substance was fed at a rate of 0.081 mmol/min and n-butyllithium as a polymerization initiator was fed at a rate of 0.143 mmol/min to the bottom of the 1 st reactor vigorously mixed by a stirrer, and the reactor internal temperature was maintained at 67 ℃.
The polymer solution was continuously withdrawn from the top of the 1 st stage reactor, continuously fed to the bottom of the 2 nd stage reactor, continuously reacted at 70 ℃ and further fed from the top of the 2 nd stage reactor to a static mixer. When the polymerization was sufficiently stabilized, trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was added from the bottom of the 2 nd reactor at a rate of 0.0190 mmol/min while copolymerizing 1, 3-butadiene and styrene, and polymerization and branching were carried out to obtain a conjugated diene polymer having a main chain branched structure.
Further, at the time when the polymerization reaction and the branching reaction were stable, a conjugated diene polymer solution before the addition of the coupling agent was slightly withdrawn, 0.2g of an antioxidant (BHT) was added per 100g of the polymer, and then the solvent was removed to measure the Mooney viscosity at 110 ℃ and the molecular weights. Physical properties are shown in table 1.
Next, tetraethoxysilane (abbreviated as "a" in the table) as a coupling agent was continuously added at a rate of 0.0480 mmol/min to the polymer solution flowing out from the outlet of the reactor, and mixed by a static mixer to perform a coupling reaction. At this time, the time until the coupling agent was added to the polymer solution flowing out of the outlet of the reactor was 4.8 minutes, the temperature was 68 ℃, and the difference between the temperature in the polymerization step and the temperature before the addition of the coupling agent was 2 ℃. The conjugated diene polymer solution after the coupling reaction was extracted in a small amount, and the amount of bound styrene (property 6) and the microstructure of the butadiene portion (1, 2-vinyl bond amount: property 7) were measured by adding 0.2g of antioxidant (BHT) per 100g of the polymer and then removing the solvent. The measurement results are shown in table 1.
Subsequently, to the polymer solution after the coupling reaction, 0.2g of an antioxidant (BHT) was continuously added at 0.055 g/min (n-hexane solution) per 100g of the polymer to terminate the coupling reaction. SRAE oil (JOMO Process NC140, manufactured by JX riyaite energy corporation) as a softening agent for rubber was continuously added to 100g of the polymer together with an antioxidant in an amount of 25.0g, and mixed by a static mixer. The solvent was removed by steam stripping, whereby a coupled conjugated diene polymer having a 4-branched structure derived from a branching agent (hereinafter also referred to as "branching agent structure (1)") which is a compound represented by the following formula (1) in a part of the main chain and a 3-branched star polymer structure derived from a coupling agent was obtained (sample 1-1).
The physical properties of sample 1-1 are shown in Table 1.
The structure of the coupled conjugated diene polymer was identified by comparing the molecular weight measured by GPC with the branching degree measured by GPC with respect to the polymer before the branching agent was added, the polymer after the branching agent was added, and the polymer in each step after the coupling agent was added. The structure of each sample was identified in the same manner as follows.
[ solution 41]
Figure BDA0002821127030000601
(in the formula (1), R1Represents any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof.
X1Is a single bond or an organic group containing any one selected from the group consisting of carbon, hydrogen, nitrogen, sulfur and oxygen.
Y1Represents any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom. Y is1Independently of each other, and may be the same or different. )
Example 1-2 coupling of conjugated diene Polymer (sample 1-2)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and a 4-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1, except that the amount of the coupling agent was changed from tetraethoxysilane to 1, 2-bis (triethoxysilyl) ethane (abbreviated as "B" in the table) and the amount added was changed to 0.0360 mmol/min (sample 1-2). The physical properties of samples 1 to 2 are shown in Table 1.
Example 1-3 coupling of conjugated diene Polymer (sample 1-3)
A coupled conjugated diene polymer having a 4-branched structure derived from a branching agent structure (1) and a 4-branched star polymer structure derived from a coupling agent in a part of the main chain thereof was obtained in the same manner as in example 1-1 except that the amount of the coupling agent was changed from tetraethoxysilane to 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane (abbreviated as "C" in the table) and the amount thereof added was changed to 0.0360 mmol/min (sample 1-3). The physical properties of samples 1 to 3 are shown in Table 1.
Example 1-4 coupling of conjugated diene Polymer (samples 1-4)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) and a 4-branched star polymer structure derived from the coupling agent in a part of the main chain thereof was obtained in the same manner as in example 1-1 except that the coupling agent was changed from tetraethoxysilane to 2, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane (abbreviated as "D" in the table) and the amount added was changed to 0.0360 mmol/min (sample 1-4). The physical properties of samples 1 to 4 are shown in Table 1.
Example 1-5 coupling of conjugated diene Polymer (samples 1-5)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and a 6-branched star polymer structure derived from the coupling agent (sample 1-5) was obtained in the same manner as in example 1-1, except that the coupling agent was changed from tetraethoxysilane to tris (3-trimethoxysilylpropyl) amine (abbreviated as "E" in the table) and the amount added was changed to 0.0250 mmol/min. The physical properties of samples 1 to 5 are shown in Table 1.
Examples 1 to 6 coupling conjugated diene polymers (samples 1 to 6)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table) and the amount added was changed to 0.0190 mmol/min (sample 1-6). The physical properties of samples 1 to 6 are shown in Table 1.
Examples 1 to 7 coupling conjugated diene polymers (samples 1 to 7)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table) and the amount added was changed to 0.0160 mmol/min (sample 1-7). The physical properties of samples 1 to 7 are shown in Table 1.
Examples 1 to 8 coupling conjugated diene polymers (samples 1 to 8)
The rate of addition of 1, 3-butadiene was changed from 18.6 g/min to 24.3 g/min, the rate of addition of styrene was changed from 10.0 g/min to 4.3 g/min, further, the addition rate of 2, 2-bis (2-tetrahydrofuryl) propane as a polar substance was changed from 0.081 mmol/min to 0.044 mmol/min, the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), the addition amount thereof was changed to 0.0160 mmol/min, otherwise, a coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 (sample 1-8). The physical properties of samples 1 to 8 are shown in Table 1.
Examples 1 to 9 coupling conjugated diene polymers (samples 1 to 9)
The rate of addition of 1, 3-butadiene was changed from 18.6 g/min to 17.1 g/min, the rate of addition of styrene was changed from 10.0 g/min to 11.5 g/min, the rate of addition of 2, 2-bis (2-tetrahydrofuryl) propane as a polar substance was changed from 0.081 mmol/min to 0.089 mmol/min, the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), the amount added was changed to 0.0160 mmol/min, otherwise, a coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 (sample 1-9). The physical properties of samples 1 to 9 are shown in Table 2.
Examples 1 to 10 coupling conjugated diene polymers (samples 1 to 10)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the addition rate of the polar substance 2, 2-bis (2-tetrahydrofuryl) propane was changed from 0.081 mmol/min to 0.200 mmol/min, the addition rate of the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), and the addition amount thereof was changed to 0.0160 mmol/min (sample 1-10). The physical properties of samples 1 to 10 are shown in Table 2.
Examples 1 to 11 coupling conjugated diene polymers (samples 1 to 11)
A coupled conjugated diene polymer having a 2-branched structure derived from the branching agent structure (1) in a part of the main chain and a 4-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to dimethylmethoxy (4-vinylphenyl) silane (abbreviated as "BS-2" in the table), the amount added was changed to 0.0350 mmol/min, the coupling agent was changed from tetraethoxysilane to 1, 2-bis (triethoxysilyl) ethane (abbreviated as "B" in the table), and the amount added was changed to 0.0360 mmol/min (sample 1-11). The physical properties of samples 1 to 11 are shown in Table 2.
Examples 1 to 12 coupling conjugated diene polymers (samples 1 to 12)
A coupled conjugated diene polymer having a 2-branched structure derived from the branching agent structure (1) in a part of the main chain and a 4-branched star polymer structure derived from the coupling agent (sample 1-12) was obtained in the same manner as in example 1-1, except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to dimethylmethoxy (4-vinylphenyl) silane (abbreviated as "BS-2" in the table), the amount added was changed to 0.0350 mmol/min, the coupling agent was changed from tetraethoxy silane to 2, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane (abbreviated as "D" in the table), and the amount added was changed to 0.0360 mmol/min. The physical properties of samples 1 to 12 are shown in Table 2.
Examples 1 to 13 coupling conjugated diene polymers (samples 1 to 13)
A coupled conjugated diene polymer having a 2-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to dimethylmethoxy (4-vinylphenyl) silane (abbreviated as "BS-2" in the table), the amount added was changed to 0.0350 mmol/min, the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), and the amount added was changed to 0.0160 mmol/min (sample 1-13). The physical properties of samples 1 to 13 are shown in Table 2.
Examples 1 to 14 coupling conjugated diene polymers (samples 1 to 14)
A coupled conjugated diene polymer having a 3-branched structure having a branching agent derived from a compound represented by the following formula (2) in a part of the main chain (hereinafter also referred to as "branching agent structure (2)") and a 4-branched star polymer structure derived from the coupling agent (sample 1 to 14) was obtained in the same manner as in example 1 to 1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4- (dimethylmethoxysilyl) phenyl) ethylene (hereinafter simply referred to as "BS-3"), the amount added was changed to 0.0120 mmol/min, the coupling agent was changed from tetraethoxysilane to 1, 2-bis (triethoxysilyl) ethane (hereinafter simply referred to as "B"), and the amount added was changed to 0.0360 mmol/min. The physical properties of samples 1 to 14 are shown in Table 2.
[ solution 42]
Figure BDA0002821127030000631
(in the formula (2), X2、X3Is a single bond or an organic group containing any one selected from the group consisting of carbon, hydrogen, nitrogen, sulfur and oxygen.
Y2、Y3Represents any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom. Y is2、Y3Independently of each other, and may be the same or different. )
Examples 1 to 15 coupling conjugated diene polymers (samples 1 to 15)
The branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4- (dimethylmethoxysilyl) phenyl) ethylene (abbreviated as "BS-3" in the table), the amount added was changed to 0.0120 mmol/min, the coupling agent was changed from tetraethoxysilane to 2, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane (abbreviated as "D" in the table), the amount added was changed to 0.0360 mmol/min, otherwise, a coupled conjugated diene polymer having a 3-branched structure derived from the branching agent structure (2) in a part of the main chain and a 4-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 (sample 1-15). The physical properties of samples 1 to 15 are shown in Table 2.
Examples 1 to 16 coupling conjugated diene polymers (samples 1 to 16)
A coupled conjugated diene polymer having a 3-branched structure derived from the branching agent structure (2) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4- (dimethylmethoxysilyl) phenyl) ethylene (abbreviated as "BS-3" in the table), the amount added was changed to 0.0120 mmol/min, the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), and the amount added was changed to 0.0160 mmol/min (sample 1-16). The physical properties of samples 1 to 16 are shown in Table 2.
Examples 1 to 17 coupling conjugated diene polymers (samples 1 to 17)
A coupled conjugated diene polymer having a 7-branched structure derived from the branching agent structure (2) in a part of the main chain and a 4-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4-trimethoxysilylphenyl) ethylene (abbreviated as "BS-4" in the table), the amount added was changed to 0.0210 mmol/min, the coupling agent was changed from tetraethoxysilane to 1, 2-bis (triethoxysilyl) ethane (abbreviated as "B" in the table), and the amount added was changed to 0.0360 mmol/min (sample 1-17). The physical properties of samples 1 to 17 are shown in Table 3.
Examples 1 to 18 coupling conjugated diene polymers (samples 1 to 18)
A coupled conjugated diene polymer having a 7-branched structure derived from the branching agent structure (2) in a part of the main chain and a 4-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4-trimethoxysilylphenyl) ethylene (abbreviated as "BS-4" in the table), the amount added was changed to 0.0210 mmol/min, the coupling agent was changed from tetraethoxysilane to 2, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane (abbreviated as "D" in the table), and the amount added was changed to 0.0360 mmol/min (sample 1-18). The physical properties of samples 1 to 18 are shown in Table 3.
Examples 1 to 19 coupling conjugated diene polymers (samples 1 to 19)
A coupled conjugated diene polymer having a 7-branched structure derived from the branching agent structure (2) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4-trimethoxysilylphenyl) ethylene (abbreviated as "BS-4" in the table), the amount added was changed to 0.0210 mmol/min, the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), and the amount added was changed to 0.0160 mmol/min (sample 1-19). The physical properties of samples 1 to 19 are shown in Table 3.
Examples 1 to 20 coupling conjugated diene polymers (samples 1 to 20)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to trichloro (4-vinylphenyl) silane (abbreviated as "BS-5" in the table), the amount added was changed to 0.0190 mmol/min, the coupling agent was changed from tetraethoxysilane to 1, 2-bis (triethoxysilyl) ethane (abbreviated as "B" in the table), and the amount added was changed to 0.0360 mmol/min (sample 1-20). The physical properties of samples 1 to 20 are shown in Table 3.
Examples 1 to 21 coupling conjugated diene polymers (samples 1 to 21)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent (samples 1 to 21) was obtained in the same manner as in example 1-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to trichloro (4-vinylphenyl) silane (abbreviated as "BS-5" in the table), the amount added was changed to 0.0190 mmol/min, the coupling agent was changed from tetraethoxy silane to 2, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane (abbreviated as "D" in the table), and the amount added was changed to 0.0360 mmol/min. The physical properties of samples 1 to 21 are shown in Table 3.
Examples 1 to 22 coupling conjugated diene polymers (samples 1 to 22)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent (samples 1 to 22) was obtained in the same manner as in example 1-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to trichloro (4-vinylphenyl) silane (abbreviated as "BS-5" in the table), the amount added was changed to 0.0190 mmol/min, the coupling agent was changed from tetraethoxy silane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), and the amount added was changed to 0.0160 mmol/min. The physical properties of samples 1 to 22 are shown in Table 3.
Examples 1 to 23 coupling conjugated diene polymers (samples 1 to 23)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent (sample 1-23) was obtained in the same manner as in example 1-1 except that the amount of addition of trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was changed from 0.0190 mmol/min to 0.0100 mmol/min, the amount of addition of the coupling agent was changed from tetraethoxy silane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), and the amount of addition thereof was changed to 0.0190 mmol/min. The physical properties of samples 1 to 23 are shown in Table 3.
Examples 1 to 24 coupling conjugated diene polymers (samples 1 to 24)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the amount of addition of trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was changed from 0.0190 mmol/min to 0.0250 mmol/min, the amount of addition of the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), and the amount of addition thereof was changed to 0.0190 mmol/min (sample 1-24). The physical properties of samples 1 to 24 are shown in Table 4.
Examples 1 to 25 coupling conjugated diene polymers (samples 1 to 25)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the amount of addition of trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was changed from 0.0190 mmol/min to 0.0350 mmol/min, the amount of addition of the coupling agent was changed from tetraethoxy silane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), and the amount of addition thereof was changed to 0.0190 mmol/min (sample 1-25). The physical properties of samples 1 to 25 are shown in Table 4.
Examples 1 to 26 coupling conjugated diene polymers (samples 1 to 26)
A coupled conjugated diene polymer having a 4-branched structure derived from a branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from a coupling agent was obtained in the same manner as in example 1-1 except that the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), the amount added was changed to 0.0190 mmol/min, and SRAE oil added as a softening agent for rubber was changed to liquid rubber (liquid polybutadiene LBR-302 manufactured by KURAAY Co., Ltd.). The physical properties of samples 1 to 26 are shown in Table 4.
Examples 1 to 27 coupling conjugated diene polymers (samples 1 to 27)
A coupled conjugated diene polymer having a 4-branched structure derived from a branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from a coupling agent was obtained in the same manner as in example 1-1 except that the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), the amount added was changed to 0.0190 mmol/min, and SRAE oil added as a softening agent for rubber was changed to a Resin (terpene Resin YS Resin PX1250 manufactured by YASUHARA CHEMICAL corporation). The physical properties of samples 1 to 27 are shown in Table 4.
Examples 1 to 28 coupling conjugated diene polymers (samples 1 to 28)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1, except that the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), the amount added was changed to 0.0190 mmol/min, and the SRAE oil added as a softening agent for rubber was changed to a naphthenic oil (Nytex 810 manufactured by Nynas corporation). The physical properties of samples 1 to 28 are shown in Table 4.
Examples 1 to 29 coupling conjugated diene polymers (samples 1 to 29)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), the amount added was changed to 0.0190 mmol/min, and no softener for rubber was added (sample 1-29). The physical properties of samples 1 to 29 are shown in Table 4.
Examples 1 to 30 coupling conjugated diene polymers (samples 1 to 30)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and an 8-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table), the amount of addition thereof was changed to 0.0190 mmol/min, and the amount of addition of SRAE oil added as a softening agent for rubber to 100g of the polymer was changed from 25.0g to 37.5g (sample 1-30). The physical properties of samples 1 to 30 are shown in Table 4.
Examples 1 to 31 conjugated diene polymers (samples 1 to 31)
When the polymerization was sufficiently stabilized, a conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and showing no star-shaped coupling structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was added from the bottom of the 2 nd reactor at a rate of 0.0190 mmol/min and no coupling agent was added (sample 1-31). The physical properties of samples 1 to 31 are shown in Table 5.
Examples 1 to 32 coupling conjugated diene polymers (samples 1 to 32)
A coupled conjugated diene polymer having a partially main chain with a 4-branched structure derived from the branching agent structure (1) and a partially 3-branched star polymer structure derived from the coupling agent (sample 1-32) was obtained in the same manner as in example 1-1 except that trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was added from the bottom of the 2 nd reactor at a rate of 0.0190 mmol/min and the amount of tetraethoxy silane (abbreviated as "A" in the table) as a coupling agent was changed from 0.0480 mmol/min to 0.0120 mmol/min at a time when the polymerization was sufficiently stabilized. The physical properties of samples 1 to 32 are shown in Table 5.
Examples 1 to 33 coupling conjugated diene polymers (samples 1 to 33)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and a partially 8-branched star polymer structure derived from the coupling agent (samples 1 to 33) was obtained in the same manner as in example 1-1 except that trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was added as a coupling agent from the bottom of the 2 nd reactor at a rate of 0.0190 mmol/min, tetraethoxy silane was changed to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table) as a coupling agent, and the amount added was changed to 0.0038 mmol/min at the time when the polymerization was sufficiently stabilized. The physical properties of samples 1 to 33 are shown in Table 5.
Examples 1 to 34 coupling conjugated diene polymers (samples 1 to 34)
A coupled conjugated diene polymer having a partially main chain with a 2-branched structure derived from the branching agent structure (1) and a partially 3-branched star polymer structure derived from the coupling agent (sample 1-34) was obtained in the same manner as in example 1-1 except that dimethylmethoxy (4-vinylphenyl) silane (abbreviated as "BS-2" in the table) as a branching agent was added from the bottom of the 2 nd reactor at a rate of 0.0350 mmol/min and the amount of tetraethoxysilane as a coupling agent was changed from 0.0480 mmol/min to 0.0120 mmol/min at a point when the polymerization was sufficiently stabilized. The physical properties of samples 1 to 34 are shown in Table 5.
Examples 1 to 35 coupling conjugated diene polymers (samples 1 to 35)
When the polymerization was sufficiently stabilized, a coupled conjugated diene polymer having a 3-branched structure derived from the branching agent structure (2) in a part of the main chain and a partially 3-branched star polymer structure derived from the coupling agent was obtained in the same manner as in example 1-1 except that 1, 1-bis (4- (dimethylmethoxysilyl) phenyl) ethylene (abbreviated as "BS-3" in the table) as a branching agent was added from the bottom of the 2 nd reactor at a rate of 0.0120 mmol/min and the amount of tetraethoxysilane as a coupling agent was changed from 0.0480 mmol/min to 0.0120 mmol/min (sample 1-35). The physical properties of samples 1 to 35 are shown in Table 5.
Examples 1 to 36 coupling conjugated diene polymers (samples 1 to 36)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and a star polymer structure derived from 2 branches of the coupling agent (samples 1 to 36) was obtained in the same manner as in example 1-1, except that the coupling agent was changed from tetraethoxysilane to 3- (benzylideneamino) propyltriethoxysilane (abbreviated as "G" in the table) and the amount added was changed to 0.0620 mmol/min. The physical properties of samples 1 to 36 are shown in Table 5.
Examples 1 to 37 coupling conjugated diene polymers (samples 1 to 37)
A coupled conjugated diene polymer having a 4-branched structure derived from the branching agent structure (1) in a part of the main chain and a 4-branched star polymer structure derived from a coupling agent was obtained in the same manner as in example 1-1 except that the 1, 3-butadiene added to the 1 st reactor was changed from 18.6 g/min to 13.95 g/min and 4.65 g/min of 1, 3-butadiene was added from the bottom of the 2 nd reactor together with the branching agent (sample 1-37). The physical properties of samples 1 to 37 are shown in Table 5.
Comparative example 1-1 coupling of conjugated diene Polymer (sample 1-38)
A polymerization reactor was a tank-type pressure vessel having an internal volume of 10L, a ratio (L/D) of the internal height (L) to the internal diameter (D) of 4.0, an inlet at the bottom, an outlet at the top, a tank-type reactor with a stirrer, and a jacket for temperature control, and 2 units of the pressure vessel were connected.
1, 3-butadiene from which water had been removed in advance was mixed under conditions of 18.6 g/min, 10.0 g/min for styrene and 175.2 g/min for n-hexane. N-butyllithium for inerting, which was a residual impurity, was added to a static mixer provided in the middle of a pipe for supplying the mixed solution to the inlet of the reactor at a rate of 0.103 mmol/min, and the mixture was continuously supplied to the bottom of the reactor. Further, 2-bis (2-tetrahydrofuryl) propane as a polar substance was fed at a rate of 0.081 mmol/min and n-butyllithium as a polymerization initiator was fed at a rate of 0.143 mmol/min to the bottom of the 1 st reactor vigorously mixed by a stirrer, and the reactor internal temperature was maintained at 67 ℃.
The polymer solution was continuously withdrawn from the top of the 1 st stage reactor, continuously fed to the bottom of the 2 nd stage reactor, continuously reacted at 70 ℃ and further fed from the top of the 2 nd stage reactor to a static mixer. At the time when the polymerization was sufficiently stabilized, a polymer solution before the addition of the coupling agent was slightly withdrawn, and 0.2g of an antioxidant (BHT) was added per 100g of the polymer, after which the solvent was removed, and the Mooney viscosity at 110 ℃ and various molecular weights were measured. The physical properties are shown in Table 6.
Next, tetraethoxysilane (abbreviated as "a" in the table) as a coupling agent was continuously added at a rate of 0.0480 mmol/min to the polymer solution flowing out from the outlet of the reactor, and mixed by a static mixer to perform a coupling reaction. At this time, the time until the coupling agent was added to the polymer solution flowing out of the outlet of the reactor was 4.8 minutes, the temperature was 68 ℃, and the difference between the temperature in the polymerization step and the temperature before the addition of the coupling agent was 2 ℃. The conjugated diene polymer solution after the coupling reaction was extracted in a small amount, and the amount of bound styrene (property 6) and the microstructure of the butadiene portion (1, 2-vinyl bond amount: property 7) were measured by adding 0.2g of antioxidant (BHT) per 100g of the polymer and then removing the solvent. The measurement results are shown in table 6.
Subsequently, to the polymer solution after the coupling reaction, 0.2g of an antioxidant (BHT) was continuously added at 0.055 g/min (n-hexane solution) per 100g of the polymer to terminate the coupling reaction. SRAE oil (JOMO Process NC140, manufactured by JX riyaite energy corporation) as a softening agent for rubber was continuously added to 100g of the polymer together with an antioxidant in an amount of 25.0g, and mixed by a static mixer. The solvent was removed by steam stripping to obtain a coupled conjugated diene polymer having a 3-branched star polymer structure derived from the coupling agent without a main chain branch derived from the branching agent (samples 1 to 38). The physical properties of samples 1 to 38 are shown in Table 6.
Comparative example 1-2 coupling of conjugated diene Polymer (sample 1-39)
A coupled conjugated diene polymer having a 4-branched star polymer structure derived from a coupling agent without a main chain branch derived from a branching agent was obtained in the same manner as in comparative example 1-1, except that the coupling agent was changed from tetraethoxysilane to 2, 2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane (abbreviated as "D" in the table) and the amount added was changed to 0.0360 mmol/min (sample 1-39). The physical properties of samples 1 to 39 are shown in Table 6.
Comparative examples 1 to 3 coupling conjugated diene polymers (samples 1 to 40)
A coupled conjugated diene polymer having an 8-branched star polymer structure derived from a coupling agent without a main chain branch derived from a branching agent was obtained in the same manner as in comparative example 1-1 except that the coupling agent was changed from tetraethoxysilane to tetrakis (3-trimethoxysilylpropyl) -1, 3-propanediamine (abbreviated as "F" in the table) and the amount added was changed to 0.0190 mmol/min (sample 1-40). The physical properties of samples 1 to 40 are shown in Table 6.
Figure BDA0002821127030000711
Figure BDA0002821127030000721
Figure BDA0002821127030000731
Figure BDA0002821127030000741
Figure BDA0002821127030000751
Figure BDA0002821127030000761
(examples 1-38 to 1-74 and comparative examples 1-4 to 1-6)
Samples 1-1 to 1-40 shown in tables 1 to 6 were used as raw rubbers, and rubber compositions containing the respective raw rubbers were obtained in the following compounding ratios.
(rubber component)
Branched conjugated diene polymer and coupled conjugated diene polymer (samples 1-1 to 1-40): 80 parts by mass (parts by mass excluding rubber softener)
High-cis polybutadiene (trade name "UBEPOL BR 150" manufactured by Utsu Kyoto Co., Ltd.): 20 parts by mass (mixing conditions)
The addition amount of each compounding agent is expressed in parts by mass relative to 100 parts by mass of the rubber component containing no rubber softener.
Silica 1 (trade name "Ultrasil 7000 GR" manufactured by Evonik Degussa corporation) Nitrogen adsorption specific surface area 170m2(iv)/g): 50.0 parts by mass
Silicon oxide 2 (trade name "Zeosil Premium 200 MP" manufactured by Rhodia corporation) having a nitrogen adsorption specific surface area of 220m2(iv)/g): 25.0 parts by mass
Carbon black (trade name "SEAST KH (N339)", manufactured by east China sea carbon corporation): 5.0 parts by mass
Silane coupling agent (trade name "Si 75", bis (triethoxysilylpropyl) disulfide, manufactured by Evonik Degussa corporation): 6.0 parts by mass
SRAE oil (trade name "Process NC 140" manufactured by JX japanese stone energy corporation): 42.0 parts by mass (including an amount added in advance in the form of a softener for rubber contained in samples 1-1 to 1-40)
Zinc white: 2.5 parts by mass
Stearic acid: 1.0 part by mass
Anti-aging agent (N- (1, 3-dimethylbutyl) -N' -phenyl-p-phenylenediamine): 2.0 parts by mass
Sulfur: 2.2 parts by mass
Vulcanization accelerator 1 (N-cyclohexyl-2-benzoceazolylsulfenamide): 1.7 parts by mass
Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass
Aggregate: 239.4 parts by mass
(kneading method)
The above materials were kneaded by the following method to obtain a rubber composition. As the first stage of kneading, a closed kneader (internal volume 0.3L) equipped with a temperature control device was used to knead raw rubber (samples 1-1 to 1-40), a filler (silica 1, silica 2, carbon black), a silane coupling agent, SRAE oil, zinc white, and stearic acid at a filling rate of 65% and a rotor speed of 30 to 50 rpm. At this time, the temperature of the closed mixer was controlled to obtain each rubber composition (compounded material) at a discharge temperature of 155 to 160 ℃.
Subsequently, as a second kneading step, the compound obtained above was cooled to room temperature, and then an antioxidant was added thereto, and kneading was performed again to improve the dispersion of silica. In this case, the discharge temperature of the mixture was also adjusted to 155 to 160 ℃ by controlling the temperature of the mixer.
After cooling, sulfur and vulcanization accelerators 1 and 2 were added to an open mill set at 70 ℃ for kneading in the third stage.
Thereafter, the mixture was molded and vulcanized at 160 ℃ for 20 minutes by a vulcanization press.
The rubber composition before vulcanization and the rubber composition after vulcanization were evaluated. Specifically, the evaluation was performed by the following method. The results are shown in tables 7 to 12.
[ evaluation of characteristics ]
(evaluation 1) Mooney viscosity of Compound
The compound obtained after the second kneading and before the third kneading was used as a sample, and the viscosity was measured after preheating at 130 ℃ for 1 minute in accordance with ISO 289 using a Mooney viscometer and then rotating a rotor at 2 revolutions per minute for 4 minutes. The results of comparative examples 1 to 4 were indexed with 100. The smaller the index, the better the processability.
(evaluation 2) tensile Strength and elongation at Break
Tensile strength and elongation at break were measured in accordance with the tensile test method of JIS K6251, and the results of comparative examples 1 to 4 were indexed with 100. The larger the index is, the better the tensile strength and elongation at break (breaking strength) are.
(evaluation 3) wear resistance
The abrasion loss at a load of 44.4N and 1000 revolutions was measured in accordance with JIS K6264-2 using an AKRON abrasion tester (manufactured by Anthraseiko Seisaku-Sho Ltd.), and the results of comparative examples 1-4 were indexed with 100. The larger the index is, the better the abrasion resistance is.
(evaluation 4) viscoelastic parameters
The viscoelastic parameters were measured in a torsional mode using a viscoelasticity tester "ARES" manufactured by Rheometric Scientific. The results for the rubber compositions of comparative examples 1 to 4 were set to 100, and the respective measured values were indexed.
The tan δ measured at 0 ℃ under the conditions of frequency 10Hz and deformation of 1% was used as an index of wet grip. The larger the index is, the better the wet grip is.
Further, tan δ measured at 50 ℃ under the conditions of a frequency of 10Hz and a strain of 3% was used as an index of fuel economy. The smaller the index, the better the fuel economy.
Further, the elastic modulus (G') measured at 50 ℃ under the conditions of a frequency of 10Hz and a deformation of 3% was used as an index of steering stability. The larger the index, the better the handling stability.
Figure BDA0002821127030000801
Figure BDA0002821127030000811
Figure BDA0002821127030000821
As shown in tables 7 to 12, it was confirmed that examples 1-38 to 1-74 have a lower Mooney viscosity of the compound at the time of producing a vulcanizate, show good processability, and are excellent in wear resistance, handling stability and breaking strength after producing a vulcanizate, and are excellent in the balance between low hysteresis loss property and wet skid resistance, as compared with comparative examples 1-4 to 1-6.
[ example 2 ]
The following methods were used to measure various physical properties of the examples and comparative examples [ example 2 ].
Hereinafter, the conjugated diene polymer coupled with the nitrogen atom-containing modifier composed of the specific compound will be described as "coupled conjugated diene polymer".
The unmodified conjugated diene polymer is referred to as "unmodified conjugated diene polymer".
In addition, the conjugated diene polymer having a branched structure is described as a "branched conjugated diene polymer".
(Property 1) Mooney viscosity of Polymer
An unmodified conjugated diene polymer or a conjugated diene polymer coupled with a nitrogen atom-containing modifier (hereinafter also referred to as "coupled conjugated diene polymer") was used as a sample, and the mooney viscosity was measured using a mooney viscometer (trade name "VR 1132" manufactured by shanghai corporation) and an L-shaped rotor according to ISO 289.
The measurement temperature was 110 ℃ in the case of using an unmodified conjugated diene polymer as a sample, and 100 ℃ in the case of using a coupled conjugated diene polymer as a sample.
The sample was first preheated at the test temperature for 1 minute, then the rotor was rotated at 2rpm, and the torque after 4 minutes was measured as the Mooney viscosity (ML) (1+4))。
(Property 2) Mooney stress relaxation Rate
The coupled conjugated diene polymer was used as a sample, and after measuring the mooney viscosity using an L-shaped rotor in accordance with ISO 289 using a mooney viscometer ("VR 1132" manufactured by shanghai corporation), the rotation of the rotor was immediately stopped, the torque at intervals of 0.1 second was recorded in terms of mooney units for a period of 1.6 to 5 seconds after the stop, the slope of the straight line at that time was obtained by plotting the double logarithm of the torque and the time (sec), and the absolute value thereof was used as the mooney stress relaxation rate (MSR).
(Property 3) degree of branching (Bn)
The degree of branching (Bn) of the coupled conjugated diene polymer was measured by GPC-light scattering method with a viscosity detector as follows.
The absolute molecular weight was determined from the results of the light scattering detector and the RI detector based on standard polystyrene and the intrinsic viscosity was determined from the results of the RI detector and the light scattering detector based on standard polystyrene using a Gel Permeation Chromatography (GPC) measuring apparatus (trade name "GPCmax VE-2001" manufactured by Malvern) to which 3 columns using a polystyrene gel as a filler were connected (trade name "GPCmax VE-2001" manufactured by Malvern) and 3 detectors connected in this order of the light scattering detector, the RI detector, and the viscosity detector.
Using linear polymers as the intrinsic viscosity [ eta ]]＝-3.883M0.771The shrinkage factor (g') was calculated as an intrinsic viscosity ratio corresponding to each molecular weight. In the formula, M represents an absolute molecular weight.
Thereafter, using the obtained contraction factor (g '), a branching degree (Bn) defined as g' ═ 6Bn/{ (Bn +1) (Bn +2) } was calculated.
As the eluent, tetrahydrofuran (hereinafter also referred to as "THF") containing 5mmol/L of triethylamine was used.
As the column, those manufactured by Tosoh corporation under the trade names "TSKgel G4000 HXL", "TSKgel G5000 HXL", and "TSKgel G6000 HXL" were used in combination.
20mg of a sample for measurement was dissolved in 10mL of THF to prepare a measurement solution, and 100. mu.L of the measurement solution was injected into a GPC measurement apparatus and measured at an oven temperature of 40 ℃ and a THF flow rate of 1 mL/min.
(Property 4) molecular weight
< measurement conditions 1 >:
an unmodified conjugated diene polymer or a coupled conjugated diene polymer was used as a sample, and a weight average molecular weight (Mw), a number average molecular weight (Mn), and a molecular weight distribution (Mw/Mn) were 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 tokyo corporation) to which 3 polystyrene gels as fillers were connected (trade name "HLC-8020" manufactured by tokyo corporation) and using an RI detector (trade name "HLC 8020" manufactured by tokyo corporation).
The eluent used was THF (tetrahydrofuran) containing 5mmol/L triethylamine. The column was used by connecting 3 columns with a trade name "TSKgel SuperMultipolypore HZ-H" manufactured by Tosoh corporation, and connecting a trade name "TSK guard column SuperMP (HZ) -H" manufactured by Tosoh corporation as a guard column to the front of the column.
10mg of the sample for measurement was dissolved in 10mL of THF to prepare a measurement solution, and 10. mu.L of the measurement solution was poured into a GPC measurement apparatus and measured under conditions of an oven temperature of 40 ℃ and a THF flow rate of 0.35 mL/min.
Among the various samples measured under the above-mentioned measurement condition 1, those having a molecular weight distribution (Mw/Mn) of less than 1.6 were measured under the following measurement condition 2 again. The sample having a molecular weight distribution value of 1.6 or more, which was measured under the measurement condition 1, was measured under the measurement condition 1.
< measurement conditions 2 >:
an unmodified conjugated diene polymer or a coupled conjugated diene polymer was used as a sample, and a chromatogram was measured using a GPC measurement apparatus in which 3 columns each having a polystyrene gel as a filler were connected, and the weight average molecular weight (Mw) and the number average molecular weight (Mn) were obtained based on a calibration curve obtained using standard polystyrene.
The eluent used was THF containing 5mmol/L triethylamine. As for the column, a guard column was used: trade name "TSK guard column SuperH-H" manufactured by Tosoh corporation, column: trade names "TSKgel SuperH 5000", "TSKgel SuperH 6000" and "TSKgel SuperH 7000" manufactured by Tosoh corporation.
An RI detector (trade name "HLC 8020" manufactured by Tosoh corporation) was used under conditions of an oven temperature of 40 ℃ and a THF flow rate of 0.6 mL/min. 10mg of the measurement sample was dissolved in 20mL of THF to prepare a measurement solution, and 20. mu.L of the measurement solution was injected into a GPC measurement apparatus and measured.
The sample having a molecular weight distribution value of less than 1.6, which was measured under the measurement condition 1, was measured under the measurement condition 2.
(Property 5) modification ratio
The modification ratio of the coupled conjugated diene polymer was measured by the column adsorption GPC method as follows.
The measurement was carried out by using, as a sample, a characteristic that the modified basic polymer component was adsorbed on a GPC column using a silica gel as a filler.
The adsorption amount on the silica column was determined from the difference between the chromatogram obtained by measuring a sample solution containing the sample and low-molecular-weight internal standard polystyrene with the polystyrene column and the chromatogram obtained by measuring with the silica column, and the modification ratio was determined.
The details are as follows.
The sample measured under the measurement condition 1 of the above (property 4) and having a molecular weight distribution of 1.6 or more was measured under the measurement condition 3 described below. The sample measured under the above-mentioned measurement condition 1 (property 4) and having a molecular weight distribution value of less than 1.6 was measured under the following measurement condition 4.
< preparation of sample solution >:
a sample solution was prepared by dissolving 10mg of the sample and 5mg of standard polystyrene in 20mL of THF.
< measurement conditions 3 >:
GPC measurement conditions using polystyrene columns:
using a product name "HLC-8320 GPC" manufactured by Tosoh corporation, THF containing 5mmol/L triethylamine was used as an eluent, 10. mu.L of the sample solution was poured into the apparatus, and a chromatogram was obtained using an RI detector under conditions of a column oven temperature of 40 ℃ and a THF flow rate of 0.35 mL/min.
The column was used by connecting 3 units of the trade name "TSKgel SuperMultipolypore HZ-H" manufactured by Tosoh corporation, and connecting the former to a trade name "TSK guard column SuperMP (HZ) -H" manufactured by Tosoh corporation as a guard column.
< measurement conditions 4 >:
mu.L of the sample solution was poured into the apparatus using THF containing 5mmol/L of triethylamine as an eluent and measured.
As for the column, a guard column was used: trade name "TSK guard column SuperH-H" manufactured by Tosoh corporation, column: trade names "TSKgel SuperH 5000", "TSKgel SuperH 6000" and "TSKgel SuperH 7000" manufactured by Tosoh corporation. The measurement was performed using an RI detector (HLC 8020, manufactured by Tosoh corporation) under the conditions of a column oven temperature of 40 ℃ and a THF flow rate of 0.6 mL/min, and a chromatogram was obtained.
GPC measurement conditions using a silica-based column:
a sample solution (50. mu.L) was poured into the apparatus using "HLC-8320 GPC" product of Tosoh Corp, using THF as an eluent, and a chromatogram was obtained using an RI detector under conditions of a column oven temperature of 40 ℃ and a THF flow rate of 0.5 mL/min. The columns were used in combination with trade names "Zorbax PSA-1000S", "PSA-300S" and "PSA-60S", and in the former stage, a protective column was used in combination with trade name "DIOL 4.6X 12.5mm 5 micron".
The calculation method of the modification rate comprises the following steps:
the modification ratio (%) was determined by the following formula, with the peak area of the chromatogram using a polystyrene column taken as a whole to be 100, the peak area of the sample taken as P1, the peak area of the standard polystyrene taken as P2, the peak area of the chromatogram using a silica column taken as a whole to be 100, the peak area of the sample taken as P3, and the peak area of the standard polystyrene taken as P4.
Modification rate (%) ([ 1- (P2 × P3)/(P1 × P4) ] × 100
(wherein P1+ P2 is P3+ P4 is 100)
(Property 6) amount of bound styrene
The conjugated diene polymer without the softener for rubber was used as a sample, and 100mg of the sample was dissolved in chloroform to a volume of 100mL to prepare a measurement sample.
The amount (mass%) of bound styrene relative to 100 mass% of the coupled 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) (measuring apparatus: spectrophotometer "UV-2450" manufactured by Shimadzu corporation).
(Property 7) microstructure of butadiene portion (1, 2-vinyl bond amount)
The conjugated diene polymer without the softener for rubber 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 amount (mol%) of 1, 2-vinyl bonds was determined from the absorbance at a predetermined wave number according to the calculation formula of the Hampton method (the method described in R.R. Hampton, Analytical Chemistry 21,923 (1949)) (measuring apparatus: Fourier transform infrared spectrophotometer "FT-IR 230" manufactured by Japan Spectroscopy Co., Ltd.).
(Property 8) molecular weight (absolute molecular weight Mw-i) measured by GPC-light scattering method
Using a GPC light scattering measurement apparatus in which 3 columns each containing a polystyrene gel as a filler were connected to a sample of a coupled conjugated diene polymer, a chromatogram was measured, and a weight average molecular weight (Mw-i) (also referred to as "absolute 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 in 1L of tetrahydrofuran) was used as an eluent.
With respect to the pillars, the pillars will be protected: trade name "TSK guard column HHR-H" manufactured by Tosoh corporation and column: the trade names "TSKgel G6000 HHR", "TSKgel G5000 HHR" and "TSKgel G4000 HHR" manufactured by Tosoh corporation are used in combination.
A GPC-light scattering measuring apparatus (trade name "Viscotek TDAmax" manufactured by Malvern) was used under conditions of an oven temperature of 40 ℃ and a THF flow rate of 1.0 mL/min.
10mg of a sample for measurement was dissolved in 20mL of THF to prepare a measurement solution, and 200. mu.L of the measurement solution was injected into a GPC measurement apparatus and measured.
(evaluation 9) Change with time (Mooney viscosity increase after 1 month)
The coupled conjugated diene polymer was stored at normal temperature and normal pressure for 1 month, and the mooney viscosity after storage was measured to calculate the difference from the mooney viscosity measured immediately after polymerization.
The table is expressed as "δ ML mooney viscosity".
The smaller the value, the less the change with time, and the more excellent the quality stability.
[ branched conjugated diene Polymer ]
Example 2-1 branched conjugated diene Polymer (sample 2-1)
A polymerization reactor was a tank-type pressure vessel having an internal volume of 10L, a ratio (L/D) of the internal height (L) to the internal diameter (D) of 4.0, an inlet at the bottom, an outlet at the top, a tank-type reactor with a stirrer, and a jacket for temperature control, and 2 units of the pressure vessel were connected.
1, 3-butadiene from which water had been removed in advance was mixed under conditions of 18.6 g/min, 10.0 g/min for styrene and 175.2 g/min for n-hexane. N-butyllithium for inerting, which was a residual impurity, was added to a static mixer provided in the middle of a pipe for supplying the mixed solution to the inlet of the reactor at a rate of 0.103 mmol/min, and the mixture was continuously supplied to the bottom of the reactor. Further, 2-bis (2-tetrahydrofuryl) propane as a polar substance was fed at a rate of 0.081 mmol/min and n-butyllithium as a polymerization initiator was fed at a rate of 0.143 mmol/min to the bottom of the 1 st reactor vigorously mixed by a stirrer, and the reactor internal temperature was maintained at 67 ℃.
The polymer solution was continuously withdrawn from the top of the 1 st stage reactor, continuously fed to the bottom of the 2 nd stage reactor, continuously reacted at 70 ℃ and further fed from the top of the 2 nd stage reactor to a static mixer. When the polymerization was sufficiently stabilized, trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was added from the bottom of the 2 nd reactor at a rate of 0.0190 mmol/min while copolymerizing 1, 3-butadiene and styrene, and polymerization and branching were carried out to obtain a conjugated diene polymer having a main chain branched structure.
Further, at the time when the polymerization reaction and the branching reaction were stable, the conjugated diene polymer solution before the modifier was added was slightly withdrawn, 0.2g of an antioxidant (BHT) was added per 100g of the polymer, and then the solvent was removed to measure the Mooney viscosity at 110 ℃ and the molecular weights. The physical properties are shown in Table 13.
Then, compound a-1 (the compound represented by (a-1) in compound [ a ] used in the above-mentioned < modification step, abbreviated as "a-1" in the table) as a coupling agent was continuously added at a rate of 0.0360 mmol/min to the polymer solution flowing out from the outlet of the reactor, and mixed by a static mixer to carry out a coupling reaction. At this time, the time until the modifier was added to the polymer solution flowing out of the outlet of the reactor was 4.8 minutes, the temperature was 68 ℃, and the difference between the temperature in the polymerization step and the temperature before the modifier was added was 2 ℃.
The conjugated diene polymer solution after the coupling reaction was extracted in a small amount, and the amount of bound styrene (property 6) and the microstructure of the butadiene portion (1, 2-vinyl bond amount: property 7) were measured by adding 0.2g of antioxidant (BHT) per 100g of the polymer and then removing the solvent. The measurement results are shown in table 13.
Subsequently, to the polymer solution after the coupling reaction, 0.2g of an antioxidant (BHT) was continuously added at 0.055 g/min (n-hexane solution) per 100g of the polymer to terminate the coupling reaction. SRAE oil (JOMO Process NC140, manufactured by JX riyaite energy corporation) as a softening agent for rubber was continuously added to 100g of the polymer together with an antioxidant in an amount of 25.0g, and mixed by a static mixer. The solvent was removed by steam stripping to obtain a branched conjugated diene polymer (sample 2-1).
The physical properties of sample 2-1 are shown in Table 13.
The structure of the branched conjugated diene polymer was determined by comparing the molecular weight measured by GPC with the branching degree measured by GPC with respect to the polymer before the branching agent was added, the polymer after the branching agent was added, and the polymer in each step after the coupling agent was added. The structure of each sample was identified in the same manner as follows.
Example 2-2 branched conjugated diene Polymer (sample 2-2)
A branched conjugated diene polymer (sample 2-2) was obtained in the same manner as in example 2-1 except that the coupling agent was changed from the compound A-1 to the compound A-2 (the compound represented by (A-2) in the compound [ A ] used in the above-mentioned < modification step), "A-2" was used in the following table.
The physical properties of sample 2-2 are shown in Table 13.
Example 2-3 branched conjugated diene Polymer (sample 2-3)
A branched conjugated diene polymer (sample 2-3) was obtained in the same manner as in example 2-1 except that the coupling agent was changed from the compound A-1 to the compound A-4 (the compound represented by (A-4) in the compound [ A ] used in the above-mentioned < modification step), "A-4" in the table, and the amount added was 0.0720 mmol/min.
The physical properties of samples 2 to 3 are shown in Table 13.
Example 2-4 branched conjugated diene Polymer (sample 2-4)
A branched conjugated diene polymer (sample 2-4) was obtained in the same manner as in example 2-1, except that the coupling agent was changed from the compound A-1 to the compound A-6 (the compound represented by (A-6) in the compound [ A ] used in the above-mentioned < modification step ").
The physical properties of samples 2 to 4 are shown in Table 13.
Example 2-5 branched conjugated diene Polymer (sample 2-5)
A branched conjugated diene polymer (sample 2-5) was obtained in the same manner as in example 2-1, except that the coupling agent was changed from the compound A-1 to the compound A-8 (the compound represented by (A-8) in the compound [ A ] used in the above-mentioned < modification step), "A-8" in the table, and the amount added was 0.0720 mmol/min.
The physical properties of samples 2 to 5 are shown in Table 13.
Example 2-6 branched conjugated diene Polymer (sample 2-6)
A branched conjugated diene polymer (sample 2-6) was obtained in the same manner as in example 2-1 except that the coupling agent was changed from the compound A-1 to the compound A-9 (the compound represented by (A-9) in the compound [ A ] used in the above-mentioned < modification step ").
The physical properties of samples 2 to 6 are shown in Table 13.
Example 2-7 branched conjugated diene Polymer (samples 2-7)
A branched conjugated diene polymer (sample 2-7) was obtained in the same manner as in example 2-1, except that the coupling agent was changed from the compound A-1 to the compound A-10 (the compound represented by (A-10) in the compound [ A ] used in the above-mentioned < modification step ").
The physical properties of samples 2 to 7 are shown in Table 13.
Example 2-8 branched conjugated diene Polymer (sample 2-8)
A branched conjugated diene polymer (sample 2-8) was obtained in the same manner as in example 2-1 except that the coupling agent was changed from compound A-1 to compound A-12 (the compound represented by (A-12) in the compound [ A ] used in the above-mentioned < modification step), "A-12" in the table, and the amount added was 0.0720 mmol/min.
The physical properties of samples 2 to 8 are shown in Table 13.
Example 2-9 branched conjugated diene Polymer (samples 2-9)
A branched conjugated diene polymer (sample 2-9) was obtained in the same manner as in example 2-1 except that the coupling agent was changed from compound A-1 to compound A-13 (the compound represented by (A-13) in the compound [ A ] used in the above-mentioned < modification step ], which is abbreviated as "A-13" in the table, and the amount added was changed to 0.0160 mmol/min.
The physical properties of samples 2 to 9 are shown in Table 13.
Examples 2 to 10 branched conjugated diene polymers (samples 2 to 10)
A branched conjugated diene polymer (sample 2-10) was obtained in the same manner as in example 2-1, except that the coupling agent was changed from compound A-1 to compound A-14 (the compound represented by (A-14) in the compound [ A ] used in the above-mentioned < modification step), ("A-14" in the table), and the amount added was changed to 0.0160 mmol/min.
The physical properties of samples 2 to 10 are shown in Table 13.
Example 2-11 branched conjugated diene Polymer (sample 2-11)
A branched conjugated diene polymer (sample 2-11) was obtained in the same manner as in example 2-1, except that the coupling agent was changed from compound a-1 to compound a-15 (the compound represented by (a-15) in compound [ a ] used in the above-mentioned < modification step), "a-15" in the table, and the amount added was 0.0360 mmol/min.
The physical properties of samples 2 to 11 are shown in Table 13.
Examples 2 to 12 branched conjugated diene polymers (samples 2 to 12)
A branched conjugated diene polymer (sample 2-12) was obtained in the same manner as in example 2-1, except that the amount of the branching agent was changed from trimethoxy (4-vinylphenyl) silane to dimethylmethoxy (4-vinylphenyl) silane (abbreviated as "BS-2" in the table) and the amount added was changed to 0.0350 mmol/min.
The physical properties of samples 2 to 12 are shown in Table 14.
Examples 2 to 13 branched conjugated diene polymers (samples 2 to 13)
A branched conjugated diene polymer (sample 2-13) was obtained in the same manner as in example 2-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to dimethylmethoxy (4-vinylphenyl) silane (abbreviated as "BS-2" in the table), the amount added was changed to 0.0350 mmol/min, and the coupling agent was changed from compound A-1 to compound A-2 (the compound represented by (A-2) in the compound [ A ] used in the above-mentioned < modification step ").
The physical properties of samples 2 to 13 are shown in Table 14.
Examples 2 to 14 branched conjugated diene polymers (samples 2 to 14)
A branched conjugated diene polymer (sample 2-14) was obtained in the same manner as in example 2-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to dimethylmethoxy (4-vinylphenyl) silane (abbreviated as "BS-2" in the table), the amount added was changed to 0.0350 mmol/min, the coupling agent was changed from compound A-1 to compound A-14 (the compound represented by (A-14) in the compound [ A ] used in the above-mentioned < modification step), "A-14" in the table), and the amount added was changed to 0.0160 mmol/min.
The physical properties of samples 2 to 14 are shown in Table 14.
Examples 2 to 15 branched conjugated diene polymers (samples 2 to 15)
A branched conjugated diene polymer (sample 2-15) was obtained in the same manner as in example 2-1 except that the amount of the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4- (dimethylmethoxysilyl) phenyl) ethylene (abbreviated as "BS-3" in the table) and the amount thereof added was changed to 0.0120 mmol/min.
The physical properties of samples 2 to 15 are shown in Table 14.
Examples 2 to 16 branched conjugated diene polymers (samples 2 to 16)
A branched conjugated diene polymer (sample 2-16) was obtained in the same manner as in example 2-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4- (dimethylmethoxysilyl) phenyl) ethylene (abbreviated as "BS-3" in the table), the amount added was changed to 0.0120 mmol/min, the coupling agent was changed from compound A-1 (abbreviated as "A-1" in the table) to compound A-2 (the compound represented by (A-2) in the compound [ A ] used in the above-mentioned < modification step), "A-2" in the table, and the amount added was changed to 0.0360 mmol/min.
The physical properties of samples 2 to 16 are shown in Table 14.
Examples 2 to 17 branched conjugated diene polymers (samples 2 to 17)
A branched conjugated diene polymer (sample 2-17) was obtained in the same manner as in example 2-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4- (dimethylmethoxysilyl) phenyl) ethylene (abbreviated as "BS-3" in the table), the amount added was changed to 0.0120 mmol/min, the coupling agent was changed from compound A-1 (abbreviated as "A-1" in the table) to compound A-14 (the compound represented by (A-14) in the compound [ A ] used in the above-mentioned < modification step), "A-14" in the table), and the amount added was changed to 0.0160 mmol/min.
The physical properties of samples 2 to 17 are shown in Table 14.
Examples 2 to 18 branched conjugated diene polymers (samples 2 to 18)
A branched conjugated diene polymer (sample 2-18) was obtained in the same manner as in example 2-1 except that the amount of the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4-trimethoxysilylphenyl) ethylene (abbreviated as "BS-4" in the table) and the amount added was changed to 0.0210 mmol/min.
The physical properties of samples 2 to 18 are shown in Table 14.
Examples 2 to 19 branched conjugated diene polymers (samples 2 to 19)
A branched conjugated diene polymer (sample 2-19) was obtained in the same manner as in example 2-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4-trimethoxysilylphenyl) ethylene (abbreviated as "BS-4" in the table), the amount added was changed to 0.0210 mmol/min, the coupling agent was changed from compound A-1 (abbreviated as "A-1" in the table) to compound A-2 (the compound represented by (A-2) in the compound [ A ] used in the above-mentioned < modification step), "A-2" in the table), and the amount added was changed to 0.0360 mmol/min.
The physical properties of samples 2 to 19 are shown in Table 14.
Examples 2 to 20 branched conjugated diene polymers (samples 2 to 20)
A branched conjugated diene polymer (sample 2-20) was obtained in the same manner as in example 2-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to 1, 1-bis (4-trimethoxysilylphenyl) ethylene (abbreviated as "BS-4" in the table), the coupling agent was changed from compound A-1 (abbreviated as "A-1" in the table) to compound A-14 (the compound represented by (A-14) in the compound [ A ] used in the above-mentioned < modification step >. the compound was abbreviated as "A-14" in the table), and the amount of the branching agent added was changed to 0.0160 mmol/min.
The physical properties of samples 2 to 20 are shown in Table 14.
Examples 2 to 21 branched conjugated diene polymers (samples 2 to 21)
A branched conjugated diene polymer (sample 2-21) was obtained in the same manner as in example 2-1, except that the amount of the branching agent was changed from trimethoxy (4-vinylphenyl) silane to trichloro (4-vinylphenyl) silane (abbreviated as "BS-5" in the table) and the amount added was changed to 0.0190 mmol/min.
The physical properties of samples 2 to 21 are shown in Table 14.
Examples 2 to 22 branched conjugated diene polymers (samples 2 to 22)
A branched conjugated diene polymer (sample 2-22) was obtained in the same manner as in example 2-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to trichloro (4-vinylphenyl) silane (abbreviated as "BS-5" in the table), the amount added was changed to 0.0190 mmol/min, the coupling agent was changed from compound A-1 (abbreviated as "A-1" in the table) to compound A-2 (the compound represented by (A-2) in the compound [ A ] used in the above-mentioned < modification step), "A-2" in the table, and the amount added was changed to 0.0360 mmol/min.
The physical properties of samples 2 to 22 are shown in Table 14.
Examples 2 to 23 branched conjugated diene polymers (samples 2 to 23)
A branched conjugated diene polymer (sample 2-23) was obtained in the same manner as in example 2-1 except that the branching agent was changed from trimethoxy (4-vinylphenyl) silane to trichloro (4-vinylphenyl) silane (abbreviated as "BS-5" in the table), the amount added was changed to 0.0190 mmol/min, the coupling agent was changed from compound A-1 (abbreviated as "A-1" in the table) to compound A-14 (the compound represented by (A-14) in the compound [ A ] used in the above-mentioned < modification step), "A-14" in the table, and the amount added was changed to 0.0160 mmol/min.
The physical properties of samples 2 to 23 are shown in Table 14.
Example A-1 branched conjugated diene Polymer (sample A-1)
A polymerization reactor was a tank-type pressure vessel having an internal volume of 10L, a ratio (L/D) of the internal height (L) to the internal diameter (D) of 4.0, an inlet at the bottom, an outlet at the top, a tank-type reactor with a stirrer, and a jacket for temperature control, and 2 units of the pressure vessel were connected.
1, 3-butadiene from which water had been removed in advance was mixed under the conditions of 14.0 g/min, 10.0 g/min for styrene and 175.2 g/min for n-hexane. N-butyllithium for inerting, which was a residual impurity, was added to a static mixer provided in the middle of a pipe for supplying the mixed solution to the inlet of the reactor at a rate of 0.103 mmol/min, and the mixture was continuously supplied to the bottom of the reactor. Further, 2-bis (2-tetrahydrofuryl) propane as a polar substance was fed at a rate of 0.081 mmol/min and n-butyllithium as a polymerization initiator was fed at a rate of 0.143 mmol/min to the bottom of the 1 st reactor vigorously mixed by a stirrer, and the reactor internal temperature was maintained at 67 ℃.
The polymer solution was continuously withdrawn from the top of the 1 st stage reactor, continuously fed to the bottom of the 2 nd stage reactor, continuously reacted at 70 ℃ and further fed from the top of the 2 nd stage reactor to a static mixer. When the polymerization was sufficiently stabilized, trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was added at a rate of 0.0190 mmol/min from the bottom of the 2 nd reactor while copolymerizing 1, 3-butadiene and styrene, and 1, 3-butadiene was added at 4.6 g/min in parallel to perform polymerization and branching reactions, thereby obtaining a conjugated diene polymer having a main chain branched structure.
Further, at the time when the polymerization reaction and the branching reaction were stable, the conjugated diene polymer solution before the addition of the coupling agent was slightly withdrawn, 0.2g of an antioxidant (BHT) was added per 100g of the polymer, and then the solvent was removed to measure the Mooney viscosity at 110 ℃ and the molecular weights. The physical properties are shown in Table 15.
Next, as a coupling agent, compound a-9 (the compound represented by (a-9) in compound [ a ] used in the above-mentioned < modification step >) was changed from compound a-1, and the compound was added continuously to the polymer solution flowing out from the outlet of the reactor at an amount of 0.0360 mmol/min, and the mixture was mixed by using a static mixer to perform a coupling reaction.
At this time, the time until the coupling agent was added to the polymer solution flowing out of the outlet of the reactor was 4.8 minutes, the temperature was 68 ℃, and the difference between the temperature in the polymerization step and the temperature before the addition of the coupling agent was 2 ℃.
The conjugated diene polymer solution after the coupling reaction was extracted in a small amount, and the amount of bound styrene (property 6) and the microstructure of the butadiene portion (1, 2-vinyl bond amount: property 7) were measured by adding 0.2g of antioxidant (BHT) per 100g of the polymer and then removing the solvent. The measurement results are shown in table 15.
Subsequently, to the polymer solution after the coupling reaction, 0.2g of an antioxidant (BHT) was continuously added at 0.055 g/min (n-hexane solution) per 100g of the polymer to terminate the coupling reaction.
SRAE oil (JOMO Process NC140 manufactured by JX ri te energy corporation) as a softener for rubber was continuously added together with an antioxidant so as to be 25.0g to 100g of the polymer, and mixed by a static mixer.
The solvent was removed by stripping to obtain a branched conjugated diene polymer having a 4-branched structure derived from a branching agent in a part of the main chain and a 4-branched star polymer structure derived from a coupling agent (sample a-1).
The physical properties of sample A-1 are shown in Table 15.
The structure of the polymer was identified by comparing the molecular weight measured by GPC with the branching degree measured by GPC with respect to the polymer before the branching agent was added, the polymer after the branching agent was added, and the polymer in each step after the coupling agent was added.
Example A-2 branched conjugated diene Polymer (sample A-2)
A polymerization reactor was a tank-type pressure vessel having an internal volume of 10L, a ratio (L/D) of the internal height (L) to the internal diameter (D) of 4.0, an inlet at the bottom, an outlet at the top, a tank-type reactor with a stirrer, and a jacket for temperature control, and 2 units of the pressure vessel were connected.
1, 3-butadiene from which water had been removed in advance was mixed under the conditions of 14.0 g/min, 8.0 g/min for styrene and 175.2 g/min for n-hexane. N-butyllithium for inerting, which was a residual impurity, was added to a static mixer provided in the middle of a pipe for supplying the mixed solution to the inlet of the reactor at a rate of 0.103 mmol/min, and the mixture was continuously supplied to the bottom of the reactor. Further, 2-bis (2-tetrahydrofuryl) propane as a polar substance was fed at a rate of 0.081 mmol/min and n-butyllithium as a polymerization initiator was fed at a rate of 0.143 mmol/min to the bottom of the 1 st reactor vigorously mixed by a stirrer, and the reactor internal temperature was maintained at 67 ℃.
The polymer solution was continuously withdrawn from the top of the 1 st stage reactor, continuously fed to the bottom of the 2 nd stage reactor, continuously reacted at 70 ℃ and further fed from the top of the 2 nd stage reactor to a static mixer. When the polymerization was sufficiently stabilized, trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) as a branching agent was added at a rate of 0.0190 mmol/min from the bottom of the 2 nd reactor while copolymerizing 1, 3-butadiene and styrene, and simultaneously 1, 3-butadiene was added at 4.6 g/min and styrene was added at 2.0 g/min, to conduct polymerization and branching, thereby obtaining a conjugated diene polymer having a main chain branched structure.
Further, at the time when the polymerization reaction and the branching reaction were stable, the conjugated diene polymer solution before the addition of the coupling agent was slightly withdrawn, 0.2g of an antioxidant (BHT) was added per 100g of the polymer, and then the solvent was removed to measure the Mooney viscosity at 110 ℃ and the molecular weights. The physical properties are shown in Table 15.
Next, as a coupling agent, compound a-9 (the compound represented by (a-9) in compound [ a ] used in the above-mentioned < modification step >) was changed from compound a-1, and the compound was added continuously to the polymer solution flowing out from the outlet of the reactor at an amount of 0.0360 mmol/min, and the mixture was mixed by using a static mixer to perform a coupling reaction.
At this time, the time until the coupling agent was added to the polymer solution flowing out of the outlet of the reactor was 4.8 minutes, the temperature was 68 ℃, and the difference between the temperature in the polymerization step and the temperature before the addition of the coupling agent was 2 ℃.
The conjugated diene polymer solution after the coupling reaction was extracted in a small amount, and the amount of bound styrene (property 6) and the microstructure of the butadiene portion (1, 2-vinyl bond amount: property 7) were measured by adding 0.2g of antioxidant (BHT) per 100g of the polymer and then removing the solvent. The measurement results are shown in table 15.
Subsequently, to the polymer solution after the coupling reaction, 0.2g of an antioxidant (BHT) was continuously added at 0.055 g/min (n-hexane solution) per 100g of the polymer to terminate the coupling reaction. SRAE oil (JOMO Process NC140 manufactured by JX ri te energy corporation) as a softener for rubber was continuously added together with an antioxidant so as to be 25.0g to 100g of the polymer, and mixed by a static mixer.
The solvent was removed by steam stripping to obtain a branched conjugated diene polymer having a 4-branched structure derived from the branching agent and a 4-branched star polymer structure derived from the coupling agent (sample A-2).
The physical properties of sample A-2 are shown in Table 15.
The structure of the polymer was identified by comparing the molecular weight measured by GPC with the branching degree measured by GPC with respect to the polymer before the branching agent was added, the polymer after the branching agent was added, and the polymer in each step after the coupling agent was added.
Comparative example 2-1 coupling of conjugated diene Polymer (sample 2-24)
A polymerization reactor was a tank-type pressure vessel having an internal volume of 10L, a ratio (L/D) of the internal height (L) to the internal diameter (D) of 4.0, an inlet at the bottom, an outlet at the top, a tank-type reactor with a stirrer, and a jacket for temperature control, and 2 units of the pressure vessel were connected.
1, 3-butadiene from which water had been removed in advance was mixed under conditions of 18.6 g/min, 10.0 g/min for styrene and 175.2 g/min for n-hexane. N-butyllithium for inerting, which was a residual impurity, was added to a static mixer provided in the middle of a pipe for supplying the mixed solution to the inlet of the reactor at a rate of 0.103 mmol/min, and the mixture was continuously supplied to the bottom of the reactor. Further, 2-bis (2-tetrahydrofuryl) propane as a polar substance was fed at a rate of 0.081 mmol/min and n-butyllithium as a polymerization initiator was fed at a rate of 0.143 mmol/min to the bottom of the 1 st reactor vigorously mixed by a stirrer, and the reactor internal temperature was maintained at 67 ℃.
The polymer solution was continuously withdrawn from the top of the 1 st stage reactor, continuously fed to the bottom of the 2 nd stage reactor, continuously reacted at 70 ℃ and further fed from the top of the 2 nd stage reactor to a static mixer. At the time when the polymerization was sufficiently stabilized, a polymer solution before the addition of the modifier was slightly withdrawn, and 0.2g of an antioxidant (BHT) was added per 100g of the polymer, after which the solvent was removed, and the Mooney viscosity at 110 ℃ and various molecular weights were measured. The physical properties are shown in Table 16.
Next, compound a-1 (the compound represented by (a-1) in compound [ a ] used in the above-mentioned < modification step, abbreviated as "a-1" in the table) as a coupling agent was continuously added to the polymer solution flowing out from the outlet of the reactor at a rate of 0.0360 mmol/min, and mixed using a static mixer to carry out a coupling reaction.
At this time, the time until the modifier was added to the polymer solution flowing out of the outlet of the reactor was 4.8 minutes, the temperature was 68 ℃, and the difference between the temperature in the polymerization step and the temperature before the modifier was added was 2 ℃.
The conjugated diene polymer solution after the coupling reaction was extracted in a small amount, and the amount of bound styrene (property 6) and the microstructure of the butadiene portion (1, 2-vinyl bond amount: property 7) were measured by adding 0.2g of antioxidant (BHT) per 100g of the polymer and then removing the solvent. The measurement results are shown in table 16.
Subsequently, to the polymer solution after the coupling reaction, 0.2g of an antioxidant (BHT) was continuously added at 0.055 g/min (n-hexane solution) per 100g of the polymer to terminate the coupling reaction. SRAE oil (JOMO Process NC140 manufactured by JX ri hitachi energy corporation) as a softener for rubber was continuously added together with an antioxidant in an amount of 25.0g per 100g of the polymer, and mixed by a static mixer. The solvent was removed by steam stripping to obtain a coupled conjugated diene polymer (samples 2 to 24). The physical properties of samples 2 to 24 are shown in Table 16.
Comparative example 2-2 coupling of conjugated diene Polymer (sample 2-25)
A coupled conjugated diene polymer (sample 2-25) was obtained in the same manner as in comparative example 1, except that the coupling agent was changed from compound A-1 (abbreviated as "A-1" in the table) to compound A-2 (the compound represented by (A-2) in the compound [ A ] used in the above-mentioned < modification step >, abbreviated as "A-2" in the table).
The physical properties of samples 2 to 25 are shown in Table 16.
Comparative examples 2 to 3 coupling conjugated diene polymers (samples 2 to 26)
A coupled conjugated diene polymer (sample 2-26) was obtained in the same manner as in comparative example 2-1, except that the coupling agent was changed from compound A-1 (abbreviated as "A-1" in the table) to compound A-3 (the compound represented by (A-3) in the compound [ A ] used in the above-mentioned < modification step >, abbreviated as "A-3" in the table), and the amount added was changed to 0.0720 mmol/min.
The physical properties of samples 2 to 26 are shown in Table 16.
Comparative examples 2 to 4 coupling conjugated diene polymers (samples 2 to 27)
A coupled conjugated diene polymer (sample 2-27) was obtained in the same manner as in comparative example 2-1, except that the coupling agent was changed from the compound A-1 to the compound A-6 (the compound represented by (A-6) in the compound [ A ] used in the above-mentioned < modification step, "A-6" in the table).
The physical properties of samples 2 to 27 are shown in Table 16.
Comparative examples 2 to 5 coupling conjugated diene polymers (samples 2 to 28)
A coupled conjugated diene polymer (sample 2-28) was obtained in the same manner as in comparative example 2-1, except that the coupling agent was changed from compound A-1 to compound A-8 (the compound represented by (A-8) in the compound [ A ] used in the above-mentioned < modification step ", which is abbreviated as" A-8 "in the table), and the amount added was 0.0720 mmol/min.
The physical properties of samples 2 to 28 are shown in Table 16.
Comparative examples 2 to 6 coupling conjugated diene polymers (samples 2 to 29)
A coupled conjugated diene polymer (sample 2-29) was obtained in the same manner as in comparative example 2-1, except that the coupling agent was changed from compound A-1 to compound A-9 (the compound represented by (A-9) in compound [ A ] used in the above-mentioned < modification step, "A-9" in the table).
The physical properties of samples 2 to 29 are shown in Table 16.
Comparative examples 2 to 7 coupling conjugated diene polymers (samples 2 to 30)
A coupled conjugated diene polymer (sample 2-30) was obtained in the same manner as in comparative example 2-1, except that the coupling agent was changed from compound A-1 to compound A-10 (the compound represented by (A-10) in the compound [ A ] used in the above-mentioned < modification step >, which is abbreviated as "A-10" in the table).
The physical properties of samples 2 to 30 are shown in Table 16.
Comparative examples 2 to 8 coupling conjugated diene Polymer (samples 2 to 31)
A coupled conjugated diene polymer (sample 2-31) was obtained in the same manner as in comparative example 2-1, except that the coupling agent was changed from compound A-1 to compound A-12 (the compound represented by (A-12) in the compound [ A ] used in the above-mentioned < modification step >, which is abbreviated as "A-12" in the table), and the amount added was 0.0720 mmol/min.
The physical properties of samples 2 to 31 are shown in Table 16.
Comparative examples 2 to 9 coupling conjugated diene polymers (samples 2 to 32)
A coupled conjugated diene polymer (sample 2-32) was obtained in the same manner as in comparative example 2-1, except that the coupling agent was changed from compound A-1 to compound A-13 (the compound represented by (A-13) in the compound [ A ] used in the above-mentioned < modification step ", which is abbreviated as" A-13 "in the table), and the amount added was changed to 0.0160 mmol/min.
The physical properties of samples 2 to 32 are shown in Table 16.
Comparative examples 2 to 10 coupling conjugated diene polymers (samples 2 to 33)
A coupled conjugated diene polymer (sample 2-33) was obtained in the same manner as in comparative example 2-1, except that the coupling agent was changed from compound A-1 to compound A-14 (the compound represented by (A-14) in the compound [ A ] used in the above-mentioned < modification step >, which is abbreviated as "A-14" in the table), and the amount added was changed to 0.0160 mmol/min.
The physical properties of sample 33 are shown in Table 16.
Comparative examples 2 to 11 coupling conjugated diene polymers (samples 2 to 34)
A coupled conjugated diene polymer (sample 2-34) was obtained in the same manner as in comparative example 2-1, except that the coupling agent was changed from compound A-1 to compound A-15 (the compound represented by (A-15) in the compound [ A ] used in the above-mentioned < modification step >, which is abbreviated as "A-15" in the table), and the amount added was 0.0360 mmol/min.
The physical properties of samples 2 to 34 are shown in Table 16.
Comparative example B-1 coupling of conjugated diene Polymer (sample B-1)
A polymerization reactor was a tank-type pressure vessel having an internal volume of 10L, a ratio (L/D) of the internal height (L) to the internal diameter (D) of 4.0, an inlet at the bottom, an outlet at the top, a tank-type reactor with a stirrer, and a jacket for temperature control, and 2 units of the pressure vessel were connected.
1, 3-butadiene from which water had been removed in advance was mixed under conditions of 18.6 g/min, 10.0 g/min for styrene and 175.2 g/min for n-hexane. N-butyllithium for inerting, which was a residual impurity, was added to a static mixer provided in the middle of a pipe for supplying the mixed solution to the inlet of the reactor at a rate of 0.103 mmol/min, and the mixture was continuously supplied to the bottom of the reactor. Further, 2-bis (2-tetrahydrofuryl) propane as a polar substance was fed at a rate of 0.081 mmol/min and n-butyllithium as a polymerization initiator was fed at a rate of 0.143 mmol/min to the bottom of the 1 st reactor vigorously mixed by a stirrer, and the reactor internal temperature was maintained at 67 ℃.
The polymer solution was continuously withdrawn from the top of the 1 st stage reactor, continuously fed to the bottom of the 2 nd stage reactor, continuously reacted at 70 ℃ and further fed from the top of the 2 nd stage reactor to a static mixer.
Further, at the time of stabilization of the polymerization reaction, a conjugated diene polymer solution before the addition of the coupling agent was slightly withdrawn, and 0.2g of an antioxidant (BHT) was added per 100g of the polymer, after which the solvent was removed, and the Mooney viscosity at 110 ℃ and various molecular weights were measured. The physical properties are shown in Table 15.
Subsequently, trimethoxy (4-vinylphenyl) silane (abbreviated as "BS-1" in the table) was added to the polymer solution flowing out of the outlet of the reactor at a rate of 0.0190 mmol/min, and tetraethoxysilane (abbreviated as "A" in the table) was continuously added thereto at a rate of 0.0480 mmol/min, followed by mixing with a static mixer to conduct a coupling reaction.
In Table 15, "BS-1" in comparative example B-1 is described in the column "branching agent", but since "BS-1" and "A" were charged simultaneously, a main chain branched structure could not be formed and the function as a branching agent was not achieved.
At this time, the time until the coupling agent was added to the polymer solution flowing out of the outlet of the reactor was 4.8 minutes, the temperature was 68 ℃, and the difference between the temperature in the polymerization step and the temperature before the addition of the coupling agent was 2 ℃.
The conjugated diene polymer solution after the coupling reaction was extracted in a small amount, and the amount of bound styrene (property 6) and the microstructure of the butadiene portion (1, 2-vinyl bond amount: property 7) were measured by adding 0.2g of antioxidant (BHT) per 100g of the polymer and then removing the solvent. The measurement results are shown in table 15.
Subsequently, to the polymer solution after the coupling reaction, 0.2g of an antioxidant (BHT) was continuously added at 0.055 g/min (n-hexane solution) per 100g of the polymer to terminate the coupling reaction.
SRAE oil (JOMO Process NC140 manufactured by JX ri te energy corporation) as a softener for rubber was continuously added together with an antioxidant so as to be 25.0g to 100g of the polymer, and mixed by a static mixer. The solvent was removed by steam stripping to obtain a coupled conjugated diene polymer (sample B-1).
The physical properties of sample B-1 are shown in Table 15.
The structure of the polymer was identified by comparing the molecular weight measured by GPC with the branching degree measured by GPC with respect to the polymer before the branching agent was added, the polymer after the branching agent was added, and the polymer in each step after the coupling agent was added.
Comparative example B-2 coupling of conjugated diene Polymer (sample B-2)
As the coupling agent, a coupling agent shown in the following (Z-1) (abbreviated as "Z-1" in the table) was used in an amount of 0.0360 mmol/min. A coupled conjugated diene polymer having a 10-branched star polymer structure derived from a coupling agent without a main chain branch derived from a branching agent was obtained in the same manner as in comparative example 2-1 (sample B-2).
The physical properties of sample B-2 are shown in Table 15.
[ solution 43]
Figure BDA0002821127030001001
Figure BDA0002821127030001011
Figure BDA0002821127030001021
Figure BDA0002821127030001031
Figure BDA0002821127030001041
(examples 2-24 to 2-46, examples a-1 to 2, comparative examples 2-12 to 2-22, and comparative examples b-1 to 2)
[ rubber composition ]
The rubber compositions containing the respective raw rubbers were obtained by using the samples 2-1 to 2-34, the samples A-1 to 2, and the samples B-1 to 2 shown in tables 13 to 16 as raw rubbers in the following compounding ratios.
(rubber component)
Branched conjugated diene polymers and coupled conjugated diene polymers (samples 2-1 to 2-34, samples A-1 to 2, and samples B-1 to 2): 80 parts by mass (parts by mass excluding rubber softener)
High-cis polybutadiene (trade name "UBEPOL BR 150" manufactured by Utsu Kyoto Co., Ltd.): 20 parts by mass (mixing conditions)
The addition amount of each compounding agent is expressed in parts by mass relative to 100 parts by mass of the rubber component containing no rubber softener.
Silica 1 (trade name "Ultrasil 7000 GR" manufactured by Evonik Degussa corporation) Nitrogen adsorption specific surface area 170m2(iv)/g): 50.0 parts by mass
Silicon oxide 2 (trade name "Zeosil Premium 200 MP" manufactured by Rhodia corporation) having a nitrogen adsorption specific surface area of 220m2(iv)/g): 25.0 parts by mass
Carbon black (trade name "SEAST KH (N339)", manufactured by east China sea carbon corporation): 5.0 parts by mass
Silane modifier (trade name "Si 75", bis (triethoxysilylpropyl) disulfide, manufactured by Evonik Degussa corporation): 6.0 parts by mass
SRAE oil (trade name "Process NC 140" manufactured by JX japanese stone energy corporation): 42.0 parts by mass (including the amount added in advance in the form of a rubber softener contained in samples 2-1 to 2-34, samples A-1 to 2, and samples B-1 to 2)
Zinc white: 2.5 parts by mass
Stearic acid: 1.0 part by mass
Anti-aging agent (N- (1, 3-dimethylbutyl) -N' -phenyl-p-phenylenediamine): 2.0 parts by mass
Sulfur: 2.2 parts by mass
Vulcanization accelerator 1 (N-cyclohexyl-2-benzoceazolylsulfenamide): 1.7 parts by mass
Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass
Aggregate: 239.4 parts by mass
(kneading method)
The above materials were kneaded by the following method to obtain a rubber composition. As the first stage of kneading, a closed kneader (internal volume 0.3L) equipped with a temperature control device was used to knead raw rubbers (samples 2-1 to 2-34, samples A-1 to 2, and samples B-1 to 2), fillers (silica 1, silica 2, and carbon black), a silane modifier, SRAE oil, zinc white, and stearic acid at a packing ratio of 65% and a rotor speed of 30 to 50 rpm. At this time, the temperature of the closed mixer was controlled to obtain each rubber composition (compounded material) at a discharge temperature of 155 to 160 ℃.
Subsequently, as a second kneading step, the compound obtained above was cooled to room temperature, and then an antioxidant was added thereto, and kneading was performed again to improve the dispersion of silica. In this case, the discharge temperature of the mixture was also adjusted to 155 to 160 ℃ by controlling the temperature of the mixer.
After cooling, sulfur and vulcanization accelerators 1 and 2 were added to an open mill set at 70 ℃ for kneading in the third stage.
Thereafter, the mixture was molded and vulcanized at 160 ℃ for 20 minutes by a vulcanization press.
The rubber composition before vulcanization and the rubber composition after vulcanization were evaluated. Specifically, the evaluation was performed by the following method.
The results are shown in tables 17 to 20.
[ evaluation of characteristics ]
(evaluation 1) Mooney viscosity of Compound
The compound obtained after the second kneading and before the third kneading was used as a sample, and the viscosity was measured after preheating at 130 ℃ for 1 minute in accordance with ISO 289 using a Mooney viscometer and then rotating a rotor at 2 revolutions per minute for 4 minutes. The results of comparative examples 2 to 12 were indexed with 100. The smaller the index, the better the processability.
(evaluation 2) tensile Strength and elongation at Break
Tensile strength and elongation at break were measured in accordance with the tensile test method of JIS K6251, and the results of comparative examples 2 to 12 were indexed with 100. The larger the index is, the better the tensile strength and elongation at break (breaking strength) are.
(evaluation 3) wear resistance
The abrasion loss at a load of 44.4N and 1000 revolutions was measured in accordance with JIS K6264-2 using an AKRON abrasion tester (manufactured by Anthraseiko Seisaku-Sho Ltd.), and the results of comparative examples 2-12 were indexed with 100. The larger the index is, the better the abrasion resistance is.
(evaluation 4) viscoelastic parameters
The viscoelastic parameters were measured in a torsional mode using a viscoelasticity tester "ARES" manufactured by Rheometric Scientific. The results for the rubber compositions of comparative examples 2 to 12 were set to 100, and the respective measured values were indexed.
The tan δ measured at 0 ℃ under the conditions of frequency 10Hz and deformation of 1% was used as an index of wet grip. The larger the index is, the better the wet grip is.
Further, tan δ measured at 50 ℃ under the conditions of a frequency of 10Hz and a strain of 3% was used as an index of fuel economy. The smaller the index, the better the fuel economy.
Further, the elastic modulus (G') measured at 50 ℃ under the conditions of a frequency of 10Hz and a deformation of 3% was used as an index of steering stability. The larger the index, the better the handling stability.
Figure BDA0002821127030001081
Figure BDA0002821127030001091
As shown in tables 17 to 20, it was confirmed that the compounds of examples 2-24 to 2-46 and examples a-1 to 2 had lower Mooney viscosities when producing sulfides, exhibited better processability, and were excellent in abrasion resistance, handling stability and breaking strength after producing sulfides, and were excellent in the balance between low hysteresis loss and wet skid resistance, as compared with comparative examples 2-12 to 2-22 and comparative examples b-1 to 2.
Industrial applicability
The modified conjugated diene polymer obtained by the production method of the present invention has industrial applicability in the fields of tire treads, interior and exterior parts of automobiles, vibration damping rubbers, conveyor belts, footwear, foams, various industrial product applications, and the like.

Claims (20)

1. A method for producing a branched conjugated diene polymer, comprising the steps of:
a polymerization step of polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using an alkali metal compound or an alkaline earth metal compound as a polymerization initiator to obtain a conjugated diene polymer having an active end; and
a branching step of reacting a styrene derivative as a branching agent with the active terminal of the conjugated diene polymer to introduce a branched structure.
2. The method for producing a branched conjugated diene polymer according to claim 1, further comprising a step of adding a conjugated diene compound and/or an aromatic vinyl compound to the reaction system at the time of the branching step and/or after the branching step.
3. The method for producing a branched conjugated diene polymer according to claim 1 or 2, further comprising a reaction step of reacting a coupling agent or a polymerization terminator with the active end of the conjugated diene polymer obtained in the branching step.
4. The method for producing a branched conjugated diene polymer according to claim 3, wherein the coupling agent has a group containing a nitrogen atom.
5. The method for producing a branched conjugated diene polymer according to claim 3, wherein the polymerization terminator has a group containing a nitrogen atom.
6. The method for producing a branched conjugated diene polymer according to claim 3 or 5, wherein the polymerization terminator is an alkoxy compound having a group containing a nitrogen atom.
7. The method for producing a branched conjugated diene polymer according to claim 4, wherein the coupling agent is represented by the following formula (a),
[ solution 1]
Figure FDA0002821127020000011
In the formula (a), R1～R4Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R5～R6Each independently represents an alkylene group having 1 to 20 carbon atoms;
m and n are integers of 1 to 3, and in the formula (a), a plurality of R1～R6M and n are the same or different;
in the formula (a), X is represented by any one of the following general formulas (b) to (e);
[ solution 2]
Figure FDA0002821127020000021
In the formula (b), R7A hydrocarbon group having 1 to 20 carbon atoms, which may have a partially branched structure or a cyclic structure; r8A hydrocarbon group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may have a partially branched structure or a cyclic structure in the case of the hydrocarbon group;
[ solution 3]
Figure FDA0002821127020000022
In the formula (c), R9A hydrocarbon group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may have a partially branched structure or a cyclic structure in the case of the hydrocarbon group;
[ solution 4]
Figure FDA0002821127020000023
In the formula (d), R10A hydrocarbon group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may have a partially branched structure or a cyclic structure in the case of the hydrocarbon group;
[ solution 5]
Figure FDA0002821127020000024
In the formula (e), R11～R14Each independently represents an alkylene group having 1 to 20 carbon atoms; r15～R18Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, l and o each independently represents an integer of 1 to 3, and R when a plurality of R's are present 15～R18Each independently.
8. The method for producing a branched conjugated diene polymer according to any one of claims 1 to 7, wherein the styrene derivative is a compound represented by the following formula (1) and/or the following formula (2),
[ solution 6]
Figure FDA0002821127020000031
[ solution 7]
Figure FDA0002821127020000032
In the formulae (1) and (2), R1Represents any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 20 carbon atoms, and may have a branched structure in a part thereof;
X1、X2、X3a single bond or an organic group containing any one selected from the group consisting of carbon, hydrogen, nitrogen, sulfur and oxygen;
Y1、Y2、Y3represents any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom; the Y is1、Y2、Y3Each independently the same or different.
9. The method for producing a branched conjugated diene polymer according to claim 8, wherein in the formula (1), R is1Is a hydrogen atom, Y1Is any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom.
10. The method for producing a branched conjugated diene polymer according to claim 8, wherein in the formula (2), Y is2Is any one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a halogen atom.
11. The method for producing a branched conjugated diene polymer according to claim 8, wherein in the formula (1), R is1Is a hydrogen atom, Y1Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom.
12. The method for producing a branched conjugated diene polymer according to claim 8, wherein in the formula (2), Y is2Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom, Y3Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom.
13. The method for producing a branched conjugated diene polymer according to claim 8, wherein in the formula (1), R is1Is a hydrogen atom, Y1Is an alkoxy group having 1 to 20 carbon atoms.
14. The method of claim 8The process for producing a branched conjugated diene polymer according to (1), wherein R is represented by the formula1Is a hydrogen atom, X1Is a single bond, Y1Is an alkoxy group having 1 to 20 carbon atoms.
15. The method for producing a branched conjugated diene polymer according to claim 8, wherein in the formula (2), X is2Is a single bond, Y2Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom, X3Is a single bond, Y3Is an alkoxy group having 1 to 20 carbon atoms or a halogen atom.
16. A branched conjugated diene polymer which is a reaction product of a conjugated diene polymer having an active end having a branched structure and a compound represented by the following formula (a),
[ solution 8]
Figure FDA0002821127020000041
In the formula (a), R1～R4Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R5～R6Each independently represents an alkylene group having 1 to 20 carbon atoms;
m and n are integers of 1 to 3, and in the formula (a), a plurality of R1～R6M and n are the same or different;
in the formula (a), X is represented by any one of the following general formulas (b) to (e);
[ solution 9]
Figure FDA0002821127020000042
In the formula (b), R7A hydrocarbon group having 1 to 20 carbon atoms, which may have a partially branched structure or a cyclic structure; r8Represents a C1-20 alkyl group or a C6-20 aryl group, and may have a partially branched structure or a cyclic structure in the case of the alkyl groupStructuring;
[ solution 10]
Figure FDA0002821127020000051
In the formula (c), R9A hydrocarbon group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may have a partially branched structure or a cyclic structure in the case of the hydrocarbon group;
[ solution 11]
Figure FDA0002821127020000052
In the formula (d), R10A hydrocarbon group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may have a partially branched structure or a cyclic structure in the case of the hydrocarbon group;
[ solution 12]
Figure FDA0002821127020000053
In the formula (e), R11～R14Each independently represents an alkylene group having 1 to 20 carbon atoms; r15～R18Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, l and o each independently represents an integer of 1 to 3, and R when a plurality of R's are present 15～R18Each independently.
17. The branched conjugated diene polymer according to claim 16, wherein OR of the compound represented by the formula (a)1and/OR OR3Has a branched structure.
18. A rubber composition comprising:
a rubber component containing 10% by mass or more of the branched conjugated diene polymer according to claim 16 or 17; and
the amount of the filler is 5.0 to 150 parts by mass per 100 parts by mass of the rubber component.
19. A method for producing a rubber composition, comprising the steps of:
a step of obtaining a branched conjugated diene polymer by the production method according to any one of claims 1 to 15;
a step of obtaining a rubber component containing 10 mass% or more of the branched conjugated diene polymer; and
and a step of obtaining a rubber composition containing 5.0 to 150 parts by mass of a filler per 100 parts by mass of the rubber component.
20. A method for manufacturing a tire, comprising the steps of:
a step of obtaining a rubber composition by the method for producing a rubber composition according to claim 19; and
and a step of molding the rubber composition to obtain a tire.
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