Method for producing modified conjugated diene polymer, conjugated diene polymer composition, and tire

Abstract

The invention provides a method for producing a modified conjugated diene-based polymer, a conjugated diene-based polymer composition, and a tire. The preparation method of the modified conjugated diene polymer is characterized by comprising the following steps: S1, adding a non-polar solvent, an aromatic vinyl monomer and a conjugated diene monomer into a polymerization reactor; s2, controlling the internal temperature of the polymerization reactor within a specific temperature range, and adding a polymerization initiator to carry out an impurity removal reaction; s3, adding a polar compound into the polymerization reactor, and initiating a polymerization reaction to obtain a conjugated diene polymer; and S4, reacting the conjugated diene polymer with a modifier to obtain a modified conjugated diene polymer. The method does not need to refine the polymerization solvent in advance, and can stably produce a modified conjugated diene polymer having a highly modified component by simply treating the monomer and the polymerization solvent.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and particularly to a method for manufacturing a modified conjugated diene polymer, a conjugated diene polymer composition, and a tire. Background Art

[0002] In recent years, concerns about environmental issues have been increasing, and thus the demand for low energy consumption of automobiles has been growing day by day. In order to meet such a demand, in terms of tire performance, a reduction in rolling resistance is also being pursued. As a means of reducing the rolling resistance of a tire, optimization of the tire structure has been studied. As a constituent of a tire, the most common means for a rubber composition is to use a rubber composition with lower heat generation. Among them, as the most representative means, a method of modifying the terminal of a conjugated diene polymer is usually adopted. As a means of introducing a functional group to the terminal of a conjugated diene polymer, the following method is usually used: in a hydrocarbon solvent, 1,3-butadiene and styrene are copolymerized using an organolithium catalyst, and then the active terminal, a reactive modifier, and active lithium react to introduce a functional group. These means are used to manufacture various modified conjugated diene polymers suitable for tire tread applications.

[0003] However, in the anionic polymerization process using an organolithium catalyst, there are the following problems: impurities in the raw materials, particularly compounds containing active hydrogen such as hydroxyl, amino, and carboxyl groups, oxygen, alkynes, alkenes, etc., react with the active lithium terminal of the polymer, resulting in the loss of activity of the active terminal. Therefore, when manufacturing a modified conjugated diene polymer, it is impossible to introduce the desired amount of functional groups. Therefore, purification of the monomer and the solvent is important, and dehydration and purification in industrial-scale production usually adopt the distillation method.

[0004] However, the current situation is that these methods are not very effective. On the other hand, in order to obtain sufficient effects, a huge cost is incurred economically.

[0005] To solve this problem, Patent Document 1 proposes the following method: after treating a monomer and a hydrocarbon solvent with an organometallic compound, they are added to a polymerization reactor for anionic polymerization and then modified, thereby manufacturing a modified conjugated diene polymer with a high modification content. In addition, Patent Document 2 proposes a method of reacting an organic alkali metal with a polymerization inhibitor and then performing anionic polymerization. Patent Document 3 proposes a method of purifying a polymerization solvent with an organic alkali metal and then performing anionic polymerization.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-284814

[0009] Patent Document 2: WO2005 / 121189 Gazette

[0010] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2007 - 217557 Summary of the Invention

[0011] Technical Problem to be Solved by the Invention

[0012] In order to solve the above - mentioned technical problems of the prior art, the inventors, through in - depth research, found that after adding a hydrocarbon solvent and all monomers to a polymerization reactor, controlling the internal temperature of the polymerization reactor within a predetermined range, first treating impurities with a specific polymerization initiator, and then adding a polar compound to initiate the polymerization reaction, the above - mentioned technical problems can be solved, and thus the present invention was completed.

[0013] Means for Solving the Technical Problem

[0014] An object of the present invention is to provide a method for producing a modified conjugated diene polymer, which can stably produce a modified conjugated diene polymer having a high modification component by simply treating impurities containing active hydrogen such as water and polymerization inhibitors, monomers containing an oxygen component, and a polymerization solvent.

[0015] That is, the present invention is as follows:

[0016] A first aspect of the present invention relates to a method for producing a modified conjugated diene polymer, which is characterized by including the following steps: S1: adding a non - polar solvent, an aromatic vinyl monomer, and a conjugated diene monomer to a polymerization reactor; S2: controlling the internal temperature of the polymerization reactor within a specific temperature range and adding a polymerization initiator to carry out a de - impurity reaction; S3: adding a polar compound to the polymerization reactor to initiate a polymerization reaction to obtain a conjugated diene polymer; and S4: reacting the conjugated diene polymer with a modifier to obtain a modified conjugated diene polymer.

[0017] In the above - mentioned method for producing a modified conjugated diene polymer, the non - polar solvent is a hydrocarbon solvent, preferably the non - polar solvent is a hydrocarbon having 3 to 8 carbon atoms, and more preferably one or more selected from the group consisting of propane, n - butane, isobutane, n - pentane, isopentane, n - hexane, cyclohexane, propylene, 1 - butene, isobutene, trans - 2 - butene, cis - 2 - butene, 1 - pentene, 2 - pentene, 1 - hexene, 2 - hexene, benzene, toluene, xylene, and ethylbenzene.

[0018] In the above - mentioned method for producing a modified conjugated diene polymer, the specific temperature range is in the range of 20 to 45 °C, preferably in the range of 30 to 40 °C.

[0019] In the method for producing the modified conjugated diene polymer described above, the impurity removal reaction time is 1 to 60 minutes, preferably 3 to 40 minutes, and more preferably 5 to 15 minutes.

[0020] In the method for producing the modified conjugated diene polymer described above, the polymerization initiator is an organolithium compound, preferably an organolithium compound having an alkyl group with 2 to 20 carbon atoms, and more preferably one or more selected from the group consisting of ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, tert-octyllithium, n-decyllithium, phenyllithium, 2-naphthyllithium, 2-butyl-phenyllithium, 4-phenyl-butyllithium, cyclohexyllithium, the reaction product of diisopentylbenzene and butyllithium.

[0021] In the method for producing the modified conjugated diene polymer described above, the polar compound is selected from the group consisting of ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, 2,2-bis(2-oxetanyl)propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinacridone; alkali metal alcohol chloride compounds such as potassium tert-pentoxide, potassium n-butoxide, sodium n-butoxide, sodium tert-pentoxide; phosphine compounds such as triphenylphosphine, and is preferably an ether compound or a tertiary amine compound of the polar compound.

[0022] In the method for producing the modified conjugated diene polymer described above, the amount of the polar compound used is 0.01 to 100 moles relative to 1 mole of lithium in the polymerization initiator.

[0023] In the method for producing the modified conjugated diene polymer described above, the modifier is a polyfunctional compound having two or more epoxy groups in the molecule, and is selected from the group consisting of polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether, glycerol triglycidyl ether; tertiary amines containing epoxy groups such as 4,4'-diglycidyl-diphenylmethylamine, 4,4'-diglycidyl-diphenylmethylamine; diglycidylaniline, diglycidyl phthalate, tetraglycidyl methylxylenediamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, tetraglycidyl-1,3-bis(aminomethyl)cyclohexane and other diglycidylamino compounds, and is preferably one or more selected from the group.

[0024] In the method for producing the modified conjugated diene polymer described above, the modifier is selected from one or more members of the group consisting of N-substituted aminoketones such as 4-dimethylaminobenzophenone, 4-diethylaminobenzophenone, 4-di-tert-butylaminobenzophenone, 4-diphenylaminobenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(di-tert-butylamino)benzophenone, 4,4'-bis(diphenylamino)benzophenone, 4,4'-bis(di vinylamino)benzophenone, 4-dimethylaminoacetophenone, 4-diethylaminoacetophenone, 1,3-bis(diphenylamino)-2-propanone, 1,7-bis-(methylethylamino)-4-heptanone, etc., N-substituted ethylene ureas such as 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-dipropyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1-methyl-3-propyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1-methyl-3-(2-ethoxyethyl)-2-imidazolidinone, 1,3-dimethyl-3,4,5,6-tetrahydropyrimidinone, etc., and their corresponding N-substituted thioethylene ureas.

[0025] In the method for producing the modified conjugated diene polymer described above, the modifier is a polyfunctional compound having two or more epoxy groups in the molecule. For example, it is selected from one or more members of the group consisting of polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether, glycerol triglycidyl ether, etc., tertiary amines containing epoxy groups such as 4,4'-diglycidyl-diphenylmethylamine, 4,4'-diglycidyl-diphenylmethylamine, etc., diglycidylaniline, diglycidyl phthalate, tetraglycidyl methylxylenediamine, tetraglycidyl aminodiphenylmethane, tetraglycidyl p-phenylenediamine, diglycidylaminomethylcyclohexane, tetraglycidyl-1,3-bis(aminomethyl)cyclohexane and other diglycidylamino compounds.

[0026] In the method for producing the modified conjugated diene polymer described above, the modifier is preferably a modifier which is an alkoxysilane compound having at least one nitrogen atom in the molecule.

[0027] In the method for producing the modified conjugated diene polymer described above, in S3, the polymerization end temperature of the conjugated diene polymer is carried out at 120 °C or lower, preferably in the range of 70 to 100 °C, more preferably in the range of 70 to 85 °C.

[0028] The second aspect of the present invention relates to a modified conjugated diene polymer composition, characterized by comprising a modified conjugated diene polymer and a silicon-based inorganic filler, wherein the modified conjugated diene polymer is obtained according to the above manufacturing method, and 60 to 200 parts by mass of the silicon-based inorganic filler is contained per 100 parts by mass of the modified conjugated diene polymer.

[0029] In the above-mentioned modified conjugated diene polymer composition, one or more of carbon black, metal oxide, metal hydroxide, silane coupling agent, vulcanizing agent, vulcanization accelerator, vulcanization aid, and rubber softener are further contained.

[0030] The third aspect of the present invention relates to a tire, characterized by comprising the above-mentioned modified conjugated diene polymer composition.

[0031] Effects of the Invention

[0032] According to the present invention, it is not necessary to refine the anionic polymerization solvent in advance. By simply treating the monomer and the polymerization solvent, a modified conjugated diene polymer having a high modification component can be stably produced. Moreover, a modified conjugated diene polymer composition is provided, which comprises a modified conjugated diene polymer and a silicon-based inorganic filler. When the composition is made into a vulcanizate and applied to a tire tread, excellent effects of achieving a balance between low hysteresis loss and improved anti-slip properties can be realized. Detailed Embodiments

[0033] Hereinafter, the mode for implementing the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The following embodiments are examples for explaining the present invention and are not intended to limit the present invention to the following content. The present invention can be appropriately modified within the scope of its gist.

[0034] <Manufacture of Modified Conjugated Diene Polymer>

[0035] The modified conjugated diene polymer of the present invention is batch-produced by solution polymerization using anionic polymerization. The monomer concentration in the solution is preferably 5% by mass or more, more preferably 10% by mass or more. If the monomer concentration in the solution is 5% by mass or more, the amount of the obtained modified conjugated diene polymer is sufficient, and there is a tendency to reduce costs. In addition, the monomer concentration in the solution is preferably 50% by mass or less, more preferably 30% by mass or less. If the monomer concentration in the solution is 50% by mass or less, the solution viscosity is low, it is easy to stir, and there is a tendency to facilitate polymerization.

[0036] As a specific manufacturing method, it is outlined as follows: After adding all the aromatic vinyl monomers and conjugated diene monomers to a hydrocarbon solvent, a polymerization initiator, i.e., an organolithium compound, is added to the polymerization reactor. By first reacting the impurities in the raw materials with the organolithium compound, the impurities are deactivated. Subsequently, a polar compound is added to initiate the polymerization reaction, and a modifier is added after the polymerization is completed to obtain a modified conjugated diene polymer.

[0037] From the viewpoints of processability and the tensile strength and abrasion resistance of the vulcanizate, the molecular weight distribution (Mw / Mn) of the modified conjugated diene polymer is preferably 1.1 or more, or 1.2 or more. From the viewpoints of the dispersibility of the silica-based inorganic filler and the low hysteresis loss property when forming a vulcanizate, it is preferably 1.5 or less, or 1.4 or less.

[0038] From the viewpoints of the shape stability (especially cold flow resistance) of the rubber component containing the conjugated diene polymer and the tensile strength and abrasion resistance of the vulcanizate of the rubber composition, the weight-average molecular weight of the modified conjugated diene polymer is preferably 200,000 or more and 2,000,000 or less. This weight-average molecular weight is more preferably 300,000 or more, or 400,000 or more, or 500,000 or more; more preferably 1,800,000 or less, or 1,500,000 or less, or 1,000,000 or less.

[0039] The weight-average molecular weight of the modified conjugated diene polymer is a value measured by GPC (gel permeation chromatography). More specifically, it can be measured by the method of the examples described later.

[0040] · Hydrocarbon solvent

[0041] As the hydrocarbon solvent, hydrocarbons having 3 to 8 carbon atoms are preferred. For example, propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propylene, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene, etc. can be cited. They can be used alone or in combination of two or more.

[0042] · Aromatic vinyl monomer

[0043] As the aromatic vinyl monomer, there is no particular limitation. For example, styrene, α-methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, ethyl vinylbenzene, divinylbenzene, 4-cyclohexylstyrene, 2,4,6-trimethylstyrene, etc. can be cited. They can be used alone or in combination of two or more. Among them, from the practical viewpoints such as the ease of purchasing the monomers, styrene is particularly preferred.

[0044] From the viewpoints of improving the dispersibility of the silicon-based inorganic filler in the conjugated diene polymer composition, and improving the mechanical properties and anti-slip properties of the vulcanizate, the content of the aromatic vinyl monomer structural unit in the conjugated diene polymer is preferably 15% by mass or more, or 20% by mass or more. From the viewpoints of avoiding a decrease in the abrasion resistance of the vulcanizate and adjusting the glass transition temperature of the rubber composition, the content of the aromatic vinyl monomer structural unit in the conjugated diene polymer is 45% by mass or less, or 40% by mass or less. The content of the aromatic vinyl monomer structural unit is measured by an ultraviolet spectrophotometer (UV meter), and more specifically, it can be measured by the method described in the examples below.

[0045] · Conjugated diene monomer

[0046] The conjugated diene monomer is not particularly limited, and examples thereof include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, 1,3-hexadiene, etc. They can be used alone or in combination of two or more. Among them, from the practical viewpoints such as the ease of purchasing the monomer, 1,3-butadiene and isoprene are preferred, and 1,3-butadiene is more preferred.

[0047] · Polymerization initiator

[0048] The modified conjugated diene polymer is obtained by anionic polymerization. As the polymerization initiator for anionic polymerization, there is no particular limitation, and an organolithium compound is preferably used. As the organolithium compound, an organolithium compound having an alkyl group with 2 to 20 carbon atoms is preferred, and examples thereof include ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, tert-octyl lithium, n-decyl lithium, phenyl lithium, 2-naphthyl lithium, 2-butyl-phenyl lithium, 4-phenyl-butyl lithium, cyclohexyl lithium, cyclohexyl lithium, the reaction product of diisopentylbenzene and butyl lithium, etc. Among them, from the viewpoints of ease of purchase, safety, etc., n-butyl lithium or sec-butyl lithium is preferred.

[0049] · Deactivation of impurities

[0050] In the present invention, the impurities in the raw materials are first reacted with the organolithium compound in the polymerization reactor to deactivate the impurities. It should be noted that at this time, the polymerization reaction of the aromatic vinyl monomer and the conjugated diene monomer should not be initiated by the organolithium compound. The suitable temperature for deactivating the impurities is in the range of 20 to 45 °C. From the viewpoint of the reactivity between the organolithium compound and the impurities, it is preferably 20 °C or higher; from the viewpoint of suppressing the polymerization reaction of the monomer, it is preferably 45 °C or lower; more preferably, it is in the range of 30 to 40 °C.

[0051] The reaction time of impurities in the raw materials with the organolithium compound ranges from 1 to 60 minutes. From the perspective of the reactivity between the organolithium compound and the impurities, it is preferably 1 minute or more, and from the perspective of suppressing the polymerization reaction of the monomer, it is preferably 60 minutes or less. It is preferably in the range of 3 to 40 minutes, and more preferably in the range of 5 to 15 minutes.

[0052] ·Polar compound

[0053] In a non-polar hydrocarbon solvent, the organolithium compound exists in an associated state and has almost no ability to initiate the polymerization reaction of aromatic vinyl monomers and conjugated diene monomers at a specific temperature. By adding a polar compound to the polymerization system, the association of the organolithium compound can be eliminated, thereby initiating the polymerization reaction.

[0054] Examples of the polar compound include: ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, 2,2-bis(2-oxetanyl)propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinacridine; alkali metal alcohol chloride compounds such as potassium tert-pentoxide, potassium n-butoxide, sodium n-butoxide, sodium tert-pentoxide; phosphine compounds such as triphenylphosphine, etc. These polar compounds can be used alone or in combination of two or more. Ethers or tertiary amine compounds are preferred.

[0055] The polar compound is for the purpose of random copolymerization of aromatic vinyl monomers and conjugated diene monomers. In addition, a small amount of the polar compound can be used as a vinylating agent to control the microstructure of the conjugated diene monomer structural unit.

[0056] The usage amount of the polar compound is selected according to the purpose and the degree of the effect. Usually, relative to 1 mole of lithium in the anionic polymerization initiator, the usage amount of the polar compound is 0.01 to 100 moles.

[0057] Such a polar compound (vinylating agent) can be used in an appropriate amount as a microstructure regulator of the conjugated diene monomer structural unit of the polymer according to the desired vinyl bond amount.

[0058] From the viewpoints of controlling the glass transition temperature of the rubber composition, for example, the balance between low hysteresis loss and anti-slip properties of the vulcanizate for tire treads and the abrasion resistance of the vulcanizate, the vinyl bond amount (1,2-bond amount) in the conjugated diene monomer structural unit is preferably 30 mol% or more, or 35 mol% or more, or 40 mol% or more, or 45 mol% or more; from the viewpoints of the abrasion resistance and breaking strength of the vulcanizate, it is preferably 70 mol% or less, or 65 mol% or less, or 60 mol% or less. Here, when the conjugated diene polymer is a copolymer of butadiene and styrene, the vinyl bond amount in the butadiene monomer structural unit can be determined by the method of Hampton (R.R. Hampton, Analytical Chemistry, 21, 923 (1949)). Specifically, it is measured by the method described in the examples below.

[0059] Most polar compounds have an effective randomizing effect during the copolymerization of conjugated diene monomers and aromatic vinyl monomers, and at the same time, can adjust the distribution of aromatic vinyl monomers and the amount of styrene blocks.

[0060] · Polymerization termination temperature

[0061] The polymerization termination temperature of the conjugated diene polymer may be the temperature at which living anionic polymerization occurs, and is not particularly limited. From the viewpoint of productivity, it is preferably 70 °C or higher, and from the viewpoint of sufficiently ensuring the amount of modification reaction of the living end after polymerization termination, it is preferably carried out at 120 °C or lower. More preferably, it is in the range of 70 to 100 °C, and further preferably in the range of 70 to 85 °C.

[0062] The polymerization termination temperature should take into account that the polymerization is an exothermic reaction, and can be controlled by controlling the monomer concentration and by cooling and heating from the outside of the reactor.

[0063] · Modification reaction

[0064] The modified conjugated diene polymer of the present embodiment modifies the polymerization active end with a modifier. Specifically, using the above-mentioned anionic initiator, i.e., a polymerization initiator, the above-mentioned conjugated diene monomer and aromatic vinyl monomer are copolymerized to prepare a conjugated diene polymer, and then the polymerization active end of the conjugated diene polymer is reacted with a modifier. As the modifier, any modifier that can react with the active end of the polymer can be used, and any modifier can be used. For example, the following substances can be listed.

[0065] (1) A polyfunctional compound having two or more epoxy groups in the molecule. Specifically, examples include polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether and glycerol triglycidyl ether, tertiary amines containing epoxy groups such as 4,4'-diglycidyl-diphenylmethylamine and 4,4'-diglycidyl-diphenylmethylamine, diglycidylaniline, diglycidyl phthalate, tetraglycidyl methylxylenediamine, tetraglycidyl aminodiphenylmethane, tetraglycidyl p-phenylenediamine, diglycidylaminomethylcyclohexane, tetraglycidyl-1,3-bis(aminomethyl)cyclohexane and other diglycidylamino compounds.

[0066] (2) Examples include N-substituted aminoketones such as 4-dimethylaminobenzophenone, 4-diethylaminobenzophenone, 4-di-tert-butylaminobenzophenone, 4-diphenylaminobenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(di-tert-butylamino)benzophenone, 4,4'-bis(diphenylamino)benzophenone, 4,4'-bis(di vinylamino)benzophenone, 4-dimethylaminoacetophenone, 4-diethylaminoacetophenone, 1,3-bis(diphenylamino)-2-acetone, 1,7-bis-(methylethylamino)-4-heptanone, etc., N-substituted ethylene ureas such as 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-dipropyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1-methyl-3-propyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1-methyl-3-(2-ethoxyethyl)-2-imidazolidinone, 1,3-dimethyl-3,4,5,6-tetrahydropyrimidinone, and their corresponding N-substituted thioethyl ureas, etc.

[0067] (3) A compound selected from compounds which are benzophenone compounds or thio-benzophenone compounds having at least one amino group, alkylamino group or dialkylamino group. Specifically, examples include 4,4'-bis(dimethylamino)-benzophenone, 4,4'-bis(diethylamino)-benzophenone, 4,4'-bis(dibutylamino)-benzophenone, 4,4'-diaminobenzophenone, 4-dimethylaminobenzophenone, etc., and thio-benzophenones corresponding thereto. Such benzophenones and thio-benzophenones have at least one amino group, alkylamino group or dialkylamino group on one or both of their benzene rings.

[0068] (4) Alkoxysilane compounds having non-cyclic amino groups and alkoxysilane compounds having cyclic amino groups. Specifically, examples include: alkoxysilane compounds having non-cyclic amino groups such as [3-(dimethylamino)propyl]triethoxysilane, [3-(dimethylamino)propyl]trimethoxysilane, [3-(diethylamino)propyl]triethoxysilane, [3-(diethylamino)propyl]trimethoxysilane, [2-(dimethylamino)ethyl]triethoxysilane, [2-(dimethylamino)ethyl]trimethoxysilane, [3-(dimethylamino)propyl]diethoxymethylsilane, [3-dibutylaminopropyl]triethoxysilane, etc.; alkoxysilane compounds having cyclic amino groups such as 3-hexamethyleneiminopropyltriethoxysilane, 3-hexamethyleneiminopropyltrimethoxysilane, hexamethyleneiminomethyltrimethoxysilane, hexamethyleneiminomethyltriethoxysilane, 2-hexamethyleneiminoethyltriethoxysilane, 2-hexamethyleneiminoethyltrimethoxysilane, 3-pyrrolidinyloxypropyltriethoxysilane, 3-pyrrolidinyloxypropyltrimethoxysilane, 3-heptamethyleneiminopropyltriethoxysilane, 3-dodecamethyleneiminopropyltriethoxysilane, 1-[3-(triethoxysilyl)propyl]-4-methylpiperazine, etc.

[0069] Preferably, it is a modifier for an alkoxysilane compound having at least one nitrogen atom in the molecule. By using this modifier, when a modified conjugated diene polymer composition is prepared, the effect of balancing anti-slip properties and low energy consumption performance is most significant.

[0070] The reaction temperature in the modification reaction step is preferably set to the same temperature as the polymerization end temperature of the conjugated diene polymer, more preferably 70 °C or higher and 120 °C or lower, and further preferably 70 °C or higher and 100 °C or lower.

[0071] The reaction time in the reaction step is preferably 10 seconds or more, more preferably 30 seconds or more. In one embodiment, the reaction time can be 15 minutes or less or 10 minutes or less.

[0072] The modifier can also be diluted with an inert solvent and continuously supplied to the reactor. In the method of adding the modifier to the polymerization reactor, it can also be a method of transferring the polymerization product to another reactor for the reaction step.

[0073] From the viewpoint of obtaining a high modification rate, it is preferable that the time from the polymerization step to the reaction step is shorter, preferably within 10 minutes, more preferably within 5 minutes. It should be noted that the time from the polymerization step to the reaction step refers to the time from after reaching the peak temperature of polymerization to adding the modifier. When the polymerization step is continuous, it refers to the time from when the reaction liquid containing the conjugated diene polymer is discharged from the polymerization reactor to adding the modifier.

[0074] · Reaction termination

[0075] Anionic polymerization can be terminated by adding a reaction terminator commonly used in the art. Such a reaction terminator is not particularly limited, and examples include polar solvents having active protons (e.g., alcohols such as methanol, ethanol, isopropanol, or acetic acid, etc.) and mixtures thereof, or a mixture of one or more of the above polar solvents and non-polar solvents such as hexane and cyclohexane. The addition amount of the reaction terminator is usually about the same molar amount or twice the molar amount relative to the anionic polymerization initiator, which is sufficient.

[0076] At the end of the polymerization process of the modified conjugated diene polymer, if necessary, deactivators, neutralizing agents, etc. can be added. As the deactivator, it is not limited to the following substances. For example, it can be listed: water, alcohols such as methanol, ethanol, isopropanol, etc. Here, the end of the polymerization process means that more than 95 mol% of the added monomers are in a state of being consumed in the polymerization. As the neutralizing agent, it is not limited to the following substances. For example, it can be listed: carboxylic acids such as stearic acid, oleic acid, 2-ethylhexanoic acid (Versatic acid) (a mixture of carboxylic acids having 9 to 11 carbon atoms and having multiple branches centered around 10 carbon atoms), aqueous solutions of inorganic acids, carbon dioxide, etc.

[0077] · Use of rubber stabilizers

[0078] At the end of the polymerization process of the modified conjugated diene polymer, from the viewpoints of preventing gel formation and improving processing stability, it is preferable to add a rubber stabilizer. As the rubber stabilizer, it is not limited to the following substances, and known rubber stabilizers can be used. For example, antioxidants such as 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl 3-(4'-hydroxy-3',5'-di-tert-butylphenyl) propionate, and 2-methyl-4,6-bis[(octylthio)methyl]phenol are preferably used.

[0079] · Use of rubber softeners

[0080] At the end of the polymerization process of the modified conjugated diene polymer, in order to improve the productivity of the polymer and the processability when compounding inorganic fillers, etc. in the manufacture of the conjugated diene polymer composition, if necessary, a rubber softener can be added. As the rubber softener, it is not particularly limited. For example, it can be listed: extender oil, liquid rubber, resin, etc. The liquid rubber can be selected from the above examples. From the viewpoints of processability, productivity, and economy, extender oil is preferred.

[0081] As a method of adding the rubber softener to the conjugated diene polymer, it is not limited to the following substances. A polymer solution containing the rubber softener obtained by adding the rubber softener to the polymer solution and mixing is preferably a method of removing the solvent from the polymer solution.

[0082] As preferred extender oils, for example, aromatic oils, naphthenic oils, paraffin oils, etc. can be cited. Among them, from the viewpoints of environmental safety and anti-seepage oil and wet grip characteristics, an aromatic substitute oil with a polycyclic aromatic (PCA) component of 3% by mass or less based on the IP346 method is preferred. As the aromatic substitute oil, in addition to TDAE (Treated Distillate Aromatic Extracts), MES (Mild Extraction Solvate), etc. described in Kautschuk Gummi Kunststoffe 52(12)799(1999), RAE (Residual Aromatic Extracts) can also be used.

[0083] From the viewpoint of suppressing the aging of the cured product, relative to 100 parts by mass of the conjugated diene polymer, the content of the extender oil is preferably 37.5 parts by mass or less, more preferably 30 parts by mass or less, further preferably 25 parts by mass or less, and most preferably 20 parts by mass or less. In one embodiment, the above content is 5 parts by mass or more, or 10 parts by mass or more, or 15 parts by mass or more.

[0084] · Solvent removal

[0085] As a method for removing the solvent from the polymer solution containing the modified conjugated diene polymer to obtain the modified conjugated diene polymer, a known method can be used. As this method, for example, methods such as steam stripping to separate the solvent, filtering out the polymer, and then dehydrating and drying it to obtain the polymer; concentrating the polymer solution through a rinsing tank and then devolatilizing it through an exhaust extruder, etc.; directly devolatilizing it through a blower, etc. can be cited.

[0086] · Modified conjugated diene polymer composition

[0087] In the conjugated diene polymer composition of the present embodiment, relative to 100 parts by mass of the rubber component containing the modified conjugated diene polymer described above, the silica-based inorganic filler is 60 to 200 parts by mass.

[0088] · Silica-based inorganic filler

[0089] As the silica-based inorganic filler contained in the conjugated diene polymer composition of the present embodiment, solid particles as the main component of the structural unit can use SiO 2 or Si 3 Al.

[0090] For example, inorganic fibrous substances such as silicon, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber can be cited.

[0091] In addition, it is also possible to use silicon-based inorganic fillers that hydrophobize the surface, or a mixture of silicon-based inorganic fillers and inorganic fillers other than silicon-based ones.

[0092] Among them, silicon and glass fiber are preferred, and silicon is more preferred.

[0093] As the silicon, dry silicon, wet silicon, synthetic silicate silicon, etc. can be used. Among them, wet silicon that gives both a remarkable improvement effect on the fracture properties and an anti-slip effect is preferred.

[0094] In the conjugated diene polymer composition of the present embodiment, from the viewpoint of obtaining practically good abrasion resistance and fracture properties, the nitrogen adsorption specific surface area of the silicon-based inorganic filler determined by the BET adsorption method is preferably 170 to 300 m 2 / g, more preferably 200 to 300 m 2 / g.

[0095] As described above, with respect to 100 parts by mass of the rubber component containing the modified conjugated diene polymer, the compounding amount of the silicon-based inorganic filler in the conjugated diene polymer composition is 60 to 200 parts by mass, preferably 70 to 150 parts by mass, and more preferably 80 to 120 parts by mass.

[0096] If the compounding amount of the silicon-based inorganic filler is less than 60 parts by mass, practically good abrasion resistance and fracture properties of the tire tread cannot be exhibited. On the other hand, if it exceeds 200 parts by mass, the dispersibility of the silicon-based inorganic filler deteriorates, the processability of the composition deteriorates, and the mechanical strength decreases, so it is not preferred.

[0097] · Carbon black

[0098] The conjugated diene polymer composition of the present embodiment may further contain carbon black as a reinforcing filler other than the silicon-based inorganic filler.

[0099] Carbon black of various grades such as SRF, FEF, HAF, ISAF, and SAF can be used, and carbon black having a nitrogen adsorption specific surface area of 50 m 2 / g or more and a DBP oil absorption of 80 ml / 100 g is preferred.

[0100] With respect to 100 parts by mass of the rubber component containing 20 parts by mass or more of the modified conjugated diene polymer, the compounding amount of the carbon black is preferably 0.5 to 100 parts by mass, more preferably 3 to 100 parts by mass, and further preferably 5 to 50 parts by mass.

[0101] In order to exhibit the performance of applications such as tires that pursue dry grip performance, conductivity, etc., it is preferred to add 0.5 part by mass or more, and from the viewpoint of dispersibility, it is preferably 100 parts by mass or less.

[0102] · Metal oxides, metal hydroxides

[0103] It should be noted that in the conjugated diene polymer composition of this embodiment, in addition to the silica-based inorganic filler and carbon black, metal oxides and metal hydroxides are also added.

[0104] Metal oxides refer to solid particles with a main component composed of the chemical formula M x O y (where M is a metal atom, and x and y are integers from 1 to 6), for example, alumina, titanium oxide, magnesium oxide, zinc oxide, etc. can be used. In addition, a mixture of a metal oxide and an inorganic filler other than the metal oxide can also be used.

[0105] Metal hydroxides refer to aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, etc.

[0106] · Silane coupling agent

[0107] In addition, in the conjugated diene polymer composition of this embodiment, a silane coupling agent can also be included.

[0108] The silane coupling agent has the function of strengthening the interaction between the rubber component and the silica-based inorganic filler, and has groups with affinity or bonding properties for the rubber component and the silica-based inorganic filler, respectively.

[0109] Examples of the silane coupling agent include: bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide, etc.

[0110] Relative to 100 parts by mass of the above silica-based inorganic filler, the compounding amount of the silane coupling agent is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and further preferably 1 to 15 parts by mass.

[0111] Relative to 100 parts by mass of the silica-based inorganic filler, if the compounding amount of the silane coupling agent is less than 0.1 part by mass, an effective compounding effect cannot be obtained, and an amount exceeding 30 parts by mass is not required.

[0112] · Vulcanizing agent

[0113] The modified conjugated diene copolymer composition of this embodiment can also be made into a vulcanized composition vulcanized with a vulcanizing agent.

[0114] Examples of the vulcanizing agent include free radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfides.

[0115] Sulfides include sulfur monochloride, sulfur dichloride, disulfides, high molecular polysulfide compounds, etc.

[0116] Generally, with respect to 100 parts by mass of the rubber component containing the modified conjugated diene polymer, the amount of the vulcanizing agent used is set to 0.01 to 20 parts by mass, preferably 0.1 to 15 parts by mass.

[0117] As the vulcanization method, existing well-known methods can be applied. The vulcanization temperature can be, for example, 120 to 200 °C, preferably 140 to 180 °C.

[0118] ·Vulcanization accelerators, vulcanization aids

[0119] In addition, during vulcanization, vulcanization accelerators can also be used as needed.

[0120] As the vulcanization accelerators, existing well-known materials can be used. For example, sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, thiourea-based, dithiocarbamate-based vulcanization accelerators, etc. can be listed. In addition, as the vulcanization aids, zinc oxide, stearic acid, etc. can be used.

[0121] Generally, with respect to 100 parts by mass of the rubber component containing the modified conjugated diene polymer, the amount of the vulcanization accelerator used is 0.01 to 20 parts by mass, preferably 0.1 to 15 parts by mass.

[0122] ·Softening agent for rubber

[0123] In order to achieve improved processability, a softening agent for rubber can be incorporated into the conjugated diene polymer composition of the present embodiment. As the softening agent for rubber, mineral oil or liquid or low molecular weight synthetic softening agents are preferably used.

[0124] The mineral oil-based softening agent for rubber, which is called process oil or extender oil and is used to achieve softening, compatibilization, and improvement of processability of rubber, is a mixture of aromatic rings, naphthene rings, and paraffin chains. When the number of carbon atoms of the paraffin chain accounts for more than 50% of the total number of carbon atoms, it is called paraffin-based. When the number of carbon atoms of the naphthene ring is 30 to 45%, it is called naphthene-based. When the number of aromatic carbon atoms exceeds 30%, it is called aromatic-based. As the softening agent for rubber used in the present embodiment, naphthene-based and / or paraffin-based softening agents for rubber are preferably used.

[0125] With respect to 100 parts by mass of the rubber component containing the modified conjugated diene polymer, the compounding amount of the softening agent for rubber is preferably 0 to 100 parts by mass, more preferably 10 to 90 parts by mass, and further preferably 30 to 90 parts by mass. With respect to 100 parts by mass of the rubber component, if the compounding amount of the softening agent for rubber exceeds 100 parts by mass, bleeding is likely to occur, and the surface of the composition may become sticky, so it is not preferred.

[0126] ·Manufacture of modified conjugated diene polymer composition

[0127] The conjugated diene polymer composition of the present embodiment includes a rubber component of a modified conjugated diene polymer and a silica-based inorganic filler, and carbon black, other fillers, a silane coupling agent, a rubber softener, etc. may be incorporated as needed.

[0128] Regarding the method of mixing the constituent materials of the conjugated diene polymer composition, there is no particular limitation. For example, melt-kneading methods using common kneaders such as an open roll, a roll-type mixer, a Banbury mixer, an intermeshing mixer, a single-screw extruder, a twin-screw extruder, and a multi-screw extruder can be cited; and a method of dissolving and mixing each component and then heating to remove the solvent; and so on.

[0129] Among them, a kneading method of a dispersion mixing type using a roll-type mixer or an intermeshing mixer is preferred.

[0130] Examples

[0131] Hereinafter, specific examples and comparative examples will be cited to explain the present embodiment in detail, but the present embodiment is not limited by any of the following examples.

[0132] It should be noted that the analysis of the polymers in the examples and comparative examples was carried out by the following methods.

[0133] ·Molecular weight

[0134] Using a GPC (gel permeation chromatography) measuring device in which three chromatographic columns filled with polystyrene-based gels are connected, a chromatogram was measured, and based on the calibration curve using standard polystyrene, the weight-average molecular weight (Mw) and the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), that is, the molecular weight distribution MD, were determined.

[0135] Specific measurement conditions are as follows. 20 μL of the following measurement solution was injected into the GPC measuring device for measurement.

[0136] ·Measurement conditions

[0137] Device: "HLC-8420GPC" manufactured by Tosoh Corporation

[0138] Mobile phase: Tetrahydrofuran (THF)

[0139] Guard column: "TSKguardcolumn SuperMP" manufactured by Tosoh Corporation

[0140] Separation chromatographic column: Three "TSKgel SuperMultipore HZ-M" manufactured by Tosoh Corporation are connected.

[0141] Column oven temperature: 40 °C

[0142] Flow rate: 0.6 mL / min

[0143] Detector: RI detector (manufactured by Tosoh Corporation, HLC-8420)

[0144] Measurement solution: A measurement solution prepared by dissolving 10 mg of the sample for measurement in 20 mL of THF. Inject 20 μL of this measurement solution into the GPC measurement device.

[0145] · Modification rate

[0146] It is measured by applying the characteristics of the components modified and adsorbed on the GPC chromatographic column filled with silica gel. The modification rate is obtained by measuring the adsorption amount on the silica column from the difference between the chromatogram measured by the polystyrene gel chromatographic column and the chromatogram measured by the silica chromatographic column of the sample solution containing the sample and the low molecular weight internal standard polystyrene.

[0147] (1) Preparation of sample solution

[0148] Dissolve 10 mg of the sample and 5 mg of standard polystyrene in 20 mL of THF to prepare a sample solution.

[0149] (2) GPC measurement conditions using a polystyrene-based chromatographic column

[0150] Use THF as the mobile phase and inject 200 μL of the sample solution into the device for measurement. Use a guard column: "TSKguardcolumn SuperMP" manufactured by Tosoh Corporation, chromatographic column: three "TSKgel SuperMultiporeHZ-M" columns connected in series. Under the conditions of a chromatographic column oven temperature of 40 °C and a THF flow rate of 1.0 mL / min, use an RI detector (manufactured by Tosoh Corporation, "HLC-8420") to measure and obtain a chromatogram.

[0151] (3) GPC measurement conditions using a silica-based chromatographic column

[0152] Use THF as the mobile phase and inject 200 μL of the sample into the device for measurement. Use a guard column: "TSKguardcolumn SuperMP" manufactured by Tosoh Corporation, chromatographic columns: Zorbax PSM―1000S, PSM-300S, PSM-60S. Under the conditions of a chromatographic column oven temperature of 40 °C and a THF flow rate of 0.5 mL / min, use an RI detector (manufactured by Tosoh Corporation, HLC-8420) to measure and obtain a chromatogram.

[0153] (4) Calculation method of modification rate

[0154] The total peak area of the chromatography using a polystyrene-based chromatographic column is set to 100, the peak area of the sample is set to P1, the peak area of the standard polystyrene is set to P2, the total peak area of the chromatography using a silica-based chromatographic column is set to 100, the peak area of the sample is set to P3, the peak area of the standard polystyrene is set to P4, and the modification rate (%) is calculated by the following formula.

[0155] Modification rate (%) = [1 - (P2 × P3) / (P1 × P4)] × 100

[0156] Wherein, P1 + P2 = P3 + P4 = 100

[0157] · Bonded styrene amount

[0158] Using the conjugated diene polymer as a sample, 100 mg of the sample is dissolved in chloroform to a volume of 100 mL to prepare a measurement sample.

[0159] Based on the absorption amount of styrene at the ultraviolet absorption wavelength (near 254 nm) based on phenyl, the amount of bonded styrene (mass %) relative to 100 mass % of the modified conjugated diene polymer as the sample is measured (UV spectrophotometer "Agilent Cary 60" manufactured by Agilent Technologies).

[0160] · Microstructure of the butadiene part: 1,2-vinyl bonding amount

[0161] Using the modified conjugated diene polymer as a sample, 50 mg of the sample is dissolved in 10 mL of carbon disulfide to prepare a measurement sample.

[0162] Using a solution cell, an infrared spectrum in the range of 600 - 1000 cm -1 is measured. Based on the absorbance at a predetermined wave number and according to the calculation formula of Hampton's method (the method described by R.R. Hampton, Analytical Chemistry 21, 923 (1949)), the microstructure of the butadiene part, that is, the 1,2-vinyl bonding amount (mol %), can be obtained (FTIR spectrophotometer "Agilent Cary 630" manufactured by Agilent Technologies).

[0163] Example 1

[0164] A autoclave equipped with a stirrer with an internal volume of 1.5 L and a ratio of internal height (L) to diameter (D) of 2.6 and a hood heater is used as a reactor. 785 g of cyclohexane, 25 g of styrene, and 95 g of 1,3-butadiene are added to the reactor. The inside of the reactor is controlled at 40 °C, and 0.95 mmol of n-butyllithium is added as a polymerization initiator, and impurities are treated for 5 minutes.

[0165] Then, 0.18 mmol of 2,2-bis(2-oxetanyl)propane was added as a polar substance to the reactor, and the polymerization reaction was started. The temperature inside the reactor continuously increased until the peak temperature, which was 79 °C. Immediately afterwards, 0.19 mmol of [3-(dimethylamino)propyl]trimethoxysilane was added as a modifier, and then stirred for 15 minutes.

[0166] 1.0 mmol of ethanol was added as a polymerization terminator to terminate the reaction, and a polymer solution containing a modified conjugated diene polymer was obtained. After adding 0.3 g of 2,6-di-tert-butyl-4-hydroxytoluene as an antioxidant to the obtained polymerization solution, the solvent was removed by steam stripping, and the modified conjugated diene polymer (SBR-1) was obtained by vacuum drying. Table 1 shows the analysis results of SBR-1.

[0167] Example 2

[0168] 785 g of cyclohexane, 31 g of styrene, and 89 g of 1,3-butadiene were added to the same reactor as in Example 1. The temperature inside the reactor was controlled at 40 °C, 0.75 mmol of n-butyllithium was added as a polymerization initiator, and impurities were treated for 10 minutes.

[0169] Then, 0.34 mmol of 2,2-bis(2-oxetanyl)propane was added as a polar substance to the reactor, and the polymerization reaction was started. The temperature inside the reactor continuously increased until the peak temperature, which was 75 °C. Immediately afterwards, 0.13 mmol of [3-(dimethylamino)propyl]trimethoxysilane was added as a modifier, and then stirred for 15 minutes.

[0170] Then, in the same manner as in Example 1, a modified conjugated diene polymer (SBR-2) was obtained. Table 1 shows the analysis results of SBR-2.

[0171] Example 3

[0172] 785 g of cyclohexane, 37 g of styrene, and 83 g of 1,3-butadiene were added to the same reactor as in Example 1. The temperature inside the reactor was controlled at 30 °C, 0.63 mmol of n-butyllithium was added as a polymerization initiator, and impurities were treated for 10 minutes.

[0173] Then, 0.28 mmol of 2,2-bis(2-oxetanyl)propane was added as a polar substance to the reactor, and the polymerization reaction was started. The temperature inside the reactor continuously increased until the peak temperature, which was 70 °C. Immediately afterwards, 0.09 mmol of [3-(dimethylamino)propyl]trimethoxysilane was added as a modifier, and then stirred for 15 minutes.

[0174] Then, by the same method as in Example 1, a modified conjugated diene polymer (SBR-3) was obtained. Table 1 shows the analysis results of SBR-3.

[0175] Example 4

[0176] 785 g of cyclohexane, 31 g of styrene, and 89 g of 1,3-butadiene were added to the same reactor as in Example 1. The inside of the reactor was controlled at 40 °C, and 0.80 mmol of n-butyllithium was added as a polymerization initiator. The impurities were treated for 10 minutes.

[0177] Then, 0.19 mmol of 2,2-bis(2-oxetanyl)propane was added to the reactor as a polar substance, and the polymerization reaction was started. The temperature inside the reactor rose continuously until the peak temperature, which was 76 °C. Immediately afterwards, 0.14 mmol of triethoxy-3-(2-imidazolin-1-yl)propylsilane was added as a modifier, and the mixture was stirred for another 15 minutes.

[0178] Then, by the same method as in Example 1, a modified conjugated diene polymer (SBR-4) was obtained. Table 1 shows the analysis results of SBR-4.

[0179] Example 5

[0180] 785 g of cyclohexane, 43 g of styrene, and 77 g of 1,3-butadiene were added to the same reactor as in Example 1. The inside of the reactor was controlled at 40 °C, and 0.88 mmol of n-butyllithium was added as a polymerization initiator. The impurities were treated for 8 minutes.

[0181] Then, 0.66 mmol of 2,2-bis(2-oxetanyl)propane was added to the reactor as a polar substance, and the polymerization reaction was started. The temperature inside the reactor rose continuously until the peak temperature, which was 78 °C. Immediately afterwards, 0.17 mmol of triethoxy-3-(2-imidazolin-1-yl)propylsilane was added as a modifier, and the mixture was stirred for another 15 minutes.

[0182] Then, by the same method as in Example 1, a modified conjugated diene polymer (SBR-5) was obtained. Table 1 shows the analysis results of SBR-5.

[0183] Comparative Example 1

[0184] 785 g of cyclohexane, 30 g of styrene, and 90 g of 1,3-butadiene were added to the same reactor as in Example 1. The inside of the reactor was controlled at 50 °C, and 0.87 mmol of n-butyllithium was added as a polymerization initiator. The impurities were treated for 10 minutes.

[0185] Then, 0.34 mmol of 2,2-bis(2-oxetanyl)propane was added to the reactor as a polar substance, and the polymerization reaction was started. The temperature inside the reactor continuously rose until the peak temperature, which was 77 °C. Immediately afterwards, 0.16 mmol of [3-(dimethylamino)propyl]trimethoxysilane was added as a modifier, and stirring was continued for 15 minutes.

[0186] Then, a modified conjugated diene polymer (SBR-6) was obtained by the same method as in Example 1. The analysis results of SBR-6 are shown in Table 1.

[0187] Comparative Example 2

[0188] 785 g of cyclohexane, 30 g of styrene, 90 g of 1,3-butadiene were added to the same reaction as in Example 1, and 0.33 mmol of 2,2-bis(2-oxetanyl)propane was added as a polar substance. The temperature inside the reactor was controlled at 40 °C, and 0.81 mmol of n-butyllithium was added as a polymerization initiator to start the polymerization reaction. The temperature inside the reactor continuously rose until the peak temperature, which was 78 °C. Immediately afterwards, 0.14 mmol of [3-(dimethylamino)propyl]trimethoxysilane was added as a modifier, and stirring was continued for 15 minutes.

[0189] Then, a modified conjugated diene polymer (SBR-7) was obtained by the same method as in Example 1. The analysis results of SBR-7 are shown in Table 1.

[0190] [Table 1]

[0191]

[0192] DMS: [3-(dimethylamino)propyl]trimethoxysilane

[0193] IES: triethoxy-3-(2-imidazolin-1-yl)propylsilane

[0194] As can be seen from Table 1, compared with the conjugated diene polymers obtained in Comparative Examples 1 to 2, the modified conjugated diene polymers obtained in Examples 1 to 5 have a high modification rate.

[0195] Application Examples

[0196] Application Examples 1 to 5, Comparative Application Examples 1 to 2

[0197] Using a closed mixer (LaboPlastomill R60) manufactured by Toyo Seiki Seisaku-sho, Ltd. equipped with a temperature control device, raw rubber (from SBR-1 to SBR-7), silicon, silane coupling agent, process oil, zinc oxide, and stearic acid were kneaded according to the compounding conditions in Table 2. At this time, the temperature of the closed mixer was controlled, and the discharge temperature was 155 - 160 °C to obtain each rubber composition (compound).

[0198] The obtained rubber composition was added to a closed mixer set at 55 °C, sulfur, vulcanization accelerator 1, and vulcanization accelerator 2 were added, and kneading was performed at a roll speed of 50 rpm for 10 minutes.

[0199] Then, it was formed into a sheet by an open roll set at 70 °C, and the obtained sheet was vulcanized by vulcanization under pressure at 160 °C for 20 minutes.

[0200] Table 2

[0201]

[0202]

[0203] The rubber composition vulcanized by the following method was evaluated. Table 3 shows the evaluation results.

[0204] · Viscoelastic parameters

[0205] Using a dynamic viscoelasticity measuring device "DMA-50" manufactured by METRAVIB, viscoelastic parameters were measured in shear mode. The respective measured values were indexed with the result of Comparative Example 1 as 100.

[0206] At 50 °C, tanδ measured at a frequency of 10 Hz and a strain of 3% was used as an index for low hysteresis loss property. The smaller the value, the better the low hysteresis loss property.

[0207] In addition, at 0 °C, tanδ measured at a frequency of 10 Hz and a strain of 1% was used as an index for anti-slip property. The larger the value, the better the anti-slip property.

[0208] · Tensile strength and tensile elongation

[0209] According to the tensile test method of JIS K6251, tensile strength and tensile elongation were measured.

[0210] The following substances were used as raw materials.

[0211] · Conjugated diene polymers (from SBR-1 to SBR-6)

[0212] · Silicon (trade name "Ultrasil 7000GR" manufactured by Evonik Degussa GmbH, nitrogen adsorption specific surface area 170 m2 / g)

[0213] · Silane coupling agent (trade name “Si75”, bis(triethoxysilylpropyl) disulfide, manufactured by Evonik Degussa)

[0214] · TDAE oil (trade name “VIVATEC500”, manufactured by H&R)

[0215] · Zinc oxide (trade name “zinc oxide”, manufactured by Sakai Chemical Industry Co., Ltd.)

[0216] · Stearic acid (trade name “Lunac S-90V”, manufactured by Kao Corporation)

[0217] · Antioxidant (trade name “Noclak 6C”, manufactured by Ouchi Shinsei Chemical Co., Ltd.)

[0218] · Sulfur (Sulfax 200S, manufactured by Tsurumi Chemical Industry Co., Ltd.)

[0219] · Vulcanization accelerator 1 (trade name “Nocceler CZ”, N-cyclohexyl-2-benzothiazole sulfenamide, manufactured by Ouchi Shinsei Chemical Co., Ltd.)

[0220] · Vulcanization accelerator 2 (trade name “Nocceler D”, 1,3-diphenylguanidine, manufactured by Ouchi Shinsei Chemical Co., Ltd.)

[0221] [Table 3]

[0222]

[0223] It was confirmed that, compared with the modified conjugated diene polymer compositions obtained in Comparative Application Examples 1 to 2, the modified conjugated diene polymer compositions obtained in Application Examples 1 to 5 were excellent in anti-slip property (loss tangent at 0°C) and grip performance, and had low hysteresis loss (loss tangent at 50°C).

[0224] Obviously, the above embodiments are merely examples for clear illustration and are not intended to limit the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for producing a modified conjugated diene polymer, characterized in that: The following steps are involved: S1: adding a non-polar solvent, an aromatic vinyl monomer and a conjugated diene monomer into a polymerization reactor; S2: controlling the internal temperature of the polymerization reactor within a specific temperature range, and adding a polymerization initiator to carry out an impurity removal reaction; S3: adding a polar compound to the polymerization reactor to initiate a polymerization reaction to obtain a conjugated diene polymer; and S4: reacting the conjugated diene polymer with a modifier to obtain a modified conjugated diene polymer.

2. The method for producing a modified conjugated diene polymer according to claim 1, wherein: The non-polar solvent is a hydrocarbon solvent.

3. The method for producing a modified conjugated diene polymer according to claim 1, characterized in that: The specific temperature range is 20 to 45°C.

4. The method for producing a modified conjugated diene polymer according to claim 1, characterized in that: The impurity removal reaction time is 1 to 60 minutes.

5. The method for producing a modified conjugated diene polymer according to claim 1, wherein: The polymerization initiator is an organic lithium compound.

6. The method for producing a modified conjugated diene polymer according to claim 1, wherein: The polar compound is an ether compound or a tertiary amine compound.

7. The method for producing a modified conjugated diene polymer according to claim 5, characterized in that: The polar compound is used in an amount of 0.01 to 100 mol relative to 1 mol of lithium in the polymerization initiator.

8. The method for producing a modified conjugated diene polymer according to claim 1, characterized in that: The modifier is an alkoxysilane compound modifier having at least one nitrogen atom in the molecule.

9. A modified conjugated diene polymer composition, characterized in that: The modified conjugated diene polymer composition comprises a modified conjugated diene polymer and a silicon inorganic filler, wherein the modified conjugated diene polymer is obtained according to the manufacturing method described in any one of claims 1 to 8, The silicon-based inorganic filler is contained in an amount of 60 to 200 parts by mass per 100 parts by mass of the modified conjugated diene-based polymer.

10. A tire, characterized in that: The invention comprises the modified conjugated diene polymer composition according to claim 9.

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