Diene rubber composition and method for producing same

Abstract

The present invention addresses the problem of providing: a conjugated diene rubber composition which has excellent rebound resilience and wear resistance, while exhibiting good workability during rubber kneading and excellent wet grip performance; and a method for producing this conjugated diene rubber composition.　The present invention provides a diene rubber composition which is obtained by subjecting a mixture of a diene rubber component 1 that is obtained by terminally modifying a conjugated diene polymer 1 with at least one silicon compound that is represented by formula (1) and / or formula (2) and a diene rubber component 2 that is obtained by terminally modifying a conjugated diene polymer 2 with at least one silicon compound that is represented by formula (1) and / or formula (2) to a hydrolysis process, and subsequently drying the resulting product.

Description

Diene-based rubber composition and method for producing the same

[0001] The present invention relates to a diene-based rubber composition, a method for producing the same, and a tire produced using the diene-based rubber composition.

[0002] BACKGROUND ART With regard to diene rubber compositions used in fuel-efficient tires, efforts have been made to improve the rebound resilience, abrasion resistance, processability, wet grip performance, and the like.

[0003] Patent Documents 1 and 2 disclose compositions of high molecular weight conjugated diene rubber and low molecular weight conjugated diene rubber. These rubber compositions are primarily molecularly designed for automobile racing tires.

[0004] Patent Document 3 discloses a rubber composition in which styrene and butadiene are polymerized using alkyllithium as a polymerization initiator, and then a high-molecular-weight component and a low-molecular-weight component are separately produced by reacting them with a silane compound having an R-Si-S-R'- bond, and then the components are mixed together.

[0005] Patent Document 4 discloses a method for producing a composition comprising a high molecular weight component and a low molecular weight component, in which styrene and butadiene are polymerized using an alkyllithium as a polymerization initiator, followed by coupling with a polyfunctional silane compound to produce a high molecular weight component, and the amount of modifier added per remaining unreacted molecule is increased.

[0006] Patent Documents 5 to 7 disclose rubber compositions comprising a high-molecular-weight component having a molecular weight (Mw) of 350,000 g / mol or more and a low-molecular-weight component having a molecular weight (Mw) of less than 10,000, which are prepared by polymerizing styrene and butadiene using alkyllithium as a polymerization initiator, followed by modification with a siloxane compound, as well as silica-blended compositions and silica-carbon black-blended compositions. The techniques described in the above documents satisfy the physical properties tailored to the objectives of each document, but cannot be said to simultaneously satisfy various physical properties such as impact resilience, abrasion resistance, processability during rubber mixing, and wet grip performance.

[0007] Japanese Patent Publication No. 5-74614 Publication Patent No. 3290469 Publication No. 2018-507303 Publication WO2018-56025 Publication Patent No. 6864078 Publication Patent No. 6823708 Publication Patent No. 6799666

[0008] In this situation, the problem that the present invention aims to solve is to provide a conjugated diene-based rubber composition that is excellent in impact resilience and abrasion resistance, has good processability during rubber kneading, and also has excellent wet grip performance, and a method for producing the same.

[0009] In the course of intensive research to solve the above problems, the present inventors have discovered that by combining a diene-based rubber component of a predetermined high molecular weight with a diene-based rubber component of a predetermined low molecular weight, it is possible to provide a diene-based rubber composition that has good processability and is excellent in impact resilience, abrasion resistance, and wet grip performance, and a method for producing the same. As a result of further research, they have completed the present invention.

[0010] That is, the present invention relates to the following: [1] A diene rubber composition obtained by subjecting a diene rubber component 1 obtained by terminally modifying a conjugated diene polymer 1 with at least one silicon compound represented by formula (1) and / or formula (2) and a diene rubber component 2 obtained by terminally modifying a conjugated diene polymer 2 with at least one silicon compound represented by formula (1) and / or formula (2) to a hydrolysis step and then drying, wherein the conjugated diene polymer 1 is obtained by polymerizing a conjugated diene compound and an aromatic vinyl compound and has a peak molecular weight of 400 kJ to 2,000 kg / mol in terms of polystyrene, and the conjugated diene polymer 2 is obtained by polymerizing a conjugated diene compound and an aromatic vinyl compound and has a peak molecular weight of 15 kJ to 60 kg / mol in terms of polystyrene. In the formula, R １ and R ２ are each independently an alkyl group, aromatic group, or aryl group having 1 to 12 carbon atoms, or an alkyl group, aromatic group, or aryl group containing an oxygen atom and / or a nitrogen atom in any of these groups, and X 1 is iodine, bromine, or chlorine, and n and m are each 0, 1, 2, 3, or 4; In the formula, R 3 ~R ８ are each independently an alkyl group, aromatic group, or aryl group having 1 to 12 carbon atoms, or an alkyl group, aromatic group, or aryl group containing an oxygen atom and / or a nitrogen atom in such a group, and R ７ and R ８ and p is a number between 1.5 and 1,000 in increments of 0.5.

[0011] [2] The diene-based rubber composition according to [1] above, wherein the diene moieties in diene-based rubber component 1 have a 1,2-structure or a 3,4-structure of 20 to 70%, the weight ratio of the aromatic vinyl compound component in diene-based rubber component 1 is 10 to 50%, the 1,2-structure or the 3,4-structure of the diene moieties in diene-based rubber component 2 is 40 to 80%, and the weight ratio of the aromatic vinyl compound component in diene-based rubber component 2 is 5 to 35%. [3] The diene-based rubber composition according to [1] or [2] above, wherein the ratio of diene-based rubber component 1 to diene-based rubber component 2 is 10 to 90 phr per 100 phr of diene-based rubber component 1. [4] A rubber compounding composition comprising at least 20 to 150 phr of silica per 100 phr of the total rubber components containing at least 20 phr of the diene-based rubber composition according to [2] or [3] above. [5] A rubber compounding composition containing at least 20 to 150 phr of silica and 5 to 30 phr of carbon black per 100 phr of a total rubber component containing at least 20 phr of the diene rubber composition according to [2] or [3].

[0012] [6] A method for producing a diene rubber composition, comprising: i) initiating polymerization of a conjugated diene compound and an aromatic vinyl compound in a hydrocarbon in the presence of an organolithium compound; ii) terminally modifying the conjugated diene polymer 1 polymerized in i) and having a polystyrene-equivalent peak molecular weight of 400 kJ to 2,000 kg / mol with at least one silicon compound represented by formula (1) and / or formula (2) immediately after polymerization to produce a diene rubber component 1; iii) terminally modifying the conjugated diene polymer 2 polymerized in i) and having a polystyrene-equivalent peak molecular weight of 15 kJ to 60 kg / mol with at least one silicon compound represented by formula (1) and / or formula (2) immediately after polymerization to produce a diene rubber component 2; iv) subjecting the obtained diene rubber component 1 and diene rubber component 2 to a hydrolysis step, preferably steam coagulation, followed by drying; In the formula, R １ and R ２ are each an alkyl group, aromatic group, or aryl group having 1 to 12 carbon atoms, or an alkyl group, aromatic group, or aryl group containing an oxygen atom and / or a nitrogen atom in such a group, and X １ is a halogen atom of iodine, bromine, or chlorine, and n and m are 0, 1, 2, 3, or 4, respectively; In the formula, R 3 ~R ８ are each independently an alkyl group, aromatic group, or aryl group having 1 to 12 carbon atoms, or an alkyl group, aromatic group, or aryl group containing an oxygen atom and / or a nitrogen atom in such a group, and R ７ and R ８ and p is a number between 1.5 and 1,000 in increments of 0.5.

[0013] [7] The method according to [6] above, wherein polymerization of diene rubber component 1 alone, or both diene rubber component 1 and diene rubber component 2, is initiated in the presence of an organolithium compound and a secondary amine compound. [8] The method according to [6] above or [7] above, wherein isoprene is prepolymerized with an organolithium compound during polymerization of diene rubber component 1, and then a conjugated diene compound other than isoprene and an aromatic vinyl compound are polymerized. [9] The method according to any one of [6] to [8] above, wherein, after polymerization of diene rubber component 1, a conjugated diene compound, an aromatic vinyl compound, and optionally a 1,2-structure or 3,4-structure modifier for the diene moiety are subsequently added, and polymerization is resumed in the presence of an organolithium compound.

[0014]

[10] The method according to any one of the above [6] to [9], wherein after the step iii) and before the step iv), a silicon halide compound represented by formula (3) or an alkali metal compound represented by formula (4) is added in an amount that satisfies the condition of formula (5), and then the steam solidification and drying of the step iv) is carried out; In the formula, M 1 is a silicon atom, and R ９ is an alkyl group, an aromatic group, or an aryl group having 1 to 12 carbon atoms; X 2 is a halogen atom of iodine, bromine, or chlorine, and q is 0 or 1; In the formula, M ２ is an alkali metal atom, preferably a lithium atom, a sodium atom, or a potassium atom, and R １０ is an alkyl group, aromatic group, aryl group, or acyl group having 1 to 12 carbon atoms, In the formula, L is the number of moles of the organolithium compound added to initiate polymerization, and M ２ is the number of moles of the alkali metal compound represented by formula (4), and X １ is the number of moles of the silicon compound represented by formula (1), and X ２is the number of moles of the halogenated silicon compound represented by formula (3), n is the same as n in the silicon compound represented by formula (1), and q is the same as q in the halogenated silicon compound represented by formula (3).

[11] The method according to any one of [6] to

[10] above, wherein the ratio of diene rubber component 1 to diene rubber component 2 is 10 to 90 phr per 100 phr of diene rubber component 1.

[0015] The present invention relates to a modified diene rubber composition for silica compounding, which, when used as a tire rubber, has excellent fuel economy and abrasion resistance, good processability during rubber compounding, and good wet grip performance, and to a method for producing the same.

[0016] Examples of conjugated diene compounds used in the present invention include 1,3-butadiene, isoprene, 1,3-pentadiene (piperine), 2,3-dimethyl-1,3-butadiene, and 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferred from the viewpoints of availability and the physical properties of the resulting diene rubber. 1,3-butadiene is particularly preferred. The amount of the conjugated diene compound used in diene rubber component 1, which is the high molecular weight component of the present invention, is 50 to 90% by weight, preferably 60 to 85% by weight. The amount of the conjugated diene compound used in diene rubber component 2, which is the low molecular weight component of the present invention, is 65 to 95% by weight, preferably 70 to 95% by weight.

[0017] Examples of aromatic vinyl compounds used in the present invention include styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, and divinylnaphthalene. Among these, styrene is preferred from the viewpoints of availability and the physical properties of the resulting diene-based rubber. The amount of the aromatic vinyl compound used in diene-based rubber component 1, which is the high-molecular-weight component of the present invention, is 10 to 50% by weight, preferably 15 to 40% by weight. The amount of the aromatic vinyl compound used in diene-based rubber component 2, which is the low-molecular-weight component of the present invention, is 5 to 35% by weight, preferably 5 to 30% by weight.

[0018] The organolithium compound used in the present invention is a lithium compound having 2 to 20 carbon atoms. Examples include ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, tert-octyllithium, n-decyllithium, phenyllithium, 2-naphthyllithium, 2-butyl-phenyllithium, 4-phenyl-butyllithium, cyclohexyllithium, 4-cyclopentyllithium, and 1,4-dilithiobutene-2. In view of industrial availability and stability, n-butyllithium, sec-butyllithium, and tert-butyllithium are preferred, with n-butyllithium and sec-butyllithium being particularly preferred.

[0019] The secondary amine compound used in the present invention is a compound represented by formula (6) or formula (7). In the formula, R １１ , R １２ is an alkyl group, a cycloalkyl group, or an aralkyl group having 1 to 20 carbon atoms, and R １１ and R １２ may be the same or different, and R １３ is a divalent alkylene, bicycloalkane, oxy- or amino-alkylene group having 3 to 12 methylene groups.

[0020] R in formula (6) １１ , R １２ Examples of the amine include methyl, ethyl, butyl, hexyl, octyl, cyclohexyl, 3-phenyl-1-propyl, isobutyl, etc. Specific examples include methylethylamine, diethylamine, dibutylamine, ethylbutylamine, dihexylamine, dioctylamine, butyloctylamine, octylcyclohexylamine, diisobutylamine, butyl(3-phenyl-1-propyl)amine, etc. Dioctylamine and dihexylamine are preferred because of their industrial availability and good solubility in hydrocarbon solvents.

[0021] R in formula (7) １３Examples of the group include trimethylene, tetramethylene, hexamethylene, oxydiethylene, and N-alkylazadiethylene. Specific examples include pyrrolidine, piperidine, hexamethyleneimine, and heptamethyleneimine. Bicyclic rings such as decahydroisoquinoline and perhydroindole are also possible. Pyrrolidine, piperidine, hexamethyleneimine, and heptamethyleneimine are particularly preferred.

[0022] Compounds that are prepolymerized in the presence of an organolithium compound and a secondary amine compound include compounds that have a faster vulcanization rate than butadiene, specifically isoprene, 1,3-pentadiene (piperine), and 2,3-dimethyl-1,3-butadiene. Isoprene is preferred in terms of industrial availability and vulcanization rate.

[0023] Specific examples of the silicon compound represented by formula (1) include the following compounds: tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraphenoxysilane, tetratoluyloxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltrippropoxysilane, methyltributoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrippropoxysilane, ethyltributoxysilane, ethyltriphenoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, ethyltributoxysilane, ethyltriphenoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyltriethoxysilane, methyl ... Vinyldipropoxysilane, Dimethyldibutoxysilane, Dimethyldiphenoxysilane, Diethyldimethoxysilane, Diethyldiethoxysilane, Diethyldipropoxysilane, Diethyldibutoxysilane, Diethyldiphenoxysilane, Vinyltrimethoxysilane, Vinyltriethoxysilane, Vinyltripoxysilane, Vinyltributoxysilane, Vinyltriphenoxysilane, Vinyltri(2-methoxyethoxy)silane, Vinyltri(methylethylketoxime)silane, Methyltri(methylethylketoxime)silane Silane, methyltris(diethylketoxime)silane, ethyltri(methylethylketoxime)silane, ethyltris(dimethylketoxime)silane, allyltriphenoxysilane, octenyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrippropoxysilane, phenyltributoxysilane, phenyltriphenoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, vinyltri(methoxypropoxy)silane, methyltris[2-(dimethyl Examples thereof include methyltris[2-(diethylamino)ethoxy]silane, methyltris[2-(dibutylamino)ethoxy]silane, ethyltris[2-(dimethylamino)ethoxy]silane, ethyltris[2-(diethylamino)ethoxy]silane, ethyltris[2-(dibutylamino)ethoxy]silane, tetrakis[2-(dimethylamino)ethoxy]silane, tetrakis[2-(diethylamino)ethoxy]silane, and tetrakis[2-(dibutylamino)ethoxy]silane.Among these, preferred are ketoximesilanes, trimethoxysilanes, triethoxysilanes, tripropoxysilanes, which are relatively easily hydrolyzed, and aminoethoxysilanes, which are believed to increase the storage stability of diene rubbers while promoting reactivity with silica.

[0024] Specific examples of the aminoalkoxysilane compound represented by formula (1) are shown below: dimethylaminomethyltrimethoxysilane, 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 4-dimethylaminobutyltrimethoxysilane, dimethylaminomethyldimethoxymethylsilane, 2-dimethylaminoethyldimethoxymethylsilane, 3-dimethylaminopropyldimethoxymethylsilane, 4-dimethylaminobutyldimethoxymethylsilane, dimethylaminomethyltriethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, and 3-diethylaminopropyltrimethoxysilane. , 4-dimethylaminobutyltriethoxysilane, dimethylaminomethyldiethoxymethylsilane, 2-dimethylaminoethyldiethoxymethylsilane, 3-dimethylaminopropyldiethoxymethylsilane, 4-dimethylaminobutyldiethoxymethylsilane, N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole, N-allyl-aza-2,2-dimethoxysilacyclopentane, and the like, of which 3-dimethylaminopropyltriethoxysilane, 3-diethylaminopropyltriethoxysilane, and 3-diethylaminopropyltrimethoxysilane are particularly preferred.

[0025] As the silicon halide compound represented by formula (1), specifically, the following compounds can be mentioned.For example, silicon tetrachloride, methyl silicon trichloride, ethyl silicon trichloride, propyl silicon trichloride, butyl silicon trichloride, octyl silicon trichloride, cyclohexyl silicon trichloride, silicon tetrabromide, methyl silicon tribromide, ethyl silicon tribromide, propyl silicon tribromide, butyl silicon tribromide, octyl silicon tribromide, cyclohexyl silicon tribromide, silicon tetraiodide, ethyl silicon triiodide, propyl silicon triiodide, butyl silicon triiodide, octyl silicon triiodide, cyclohexyl silicon triiodide can be mentioned.Among these, preferred are silicon tetrachloride, methyl silicon trichloride, and ethyl silicon trichloride.Particularly preferred are silicon tetrachloride and methyl silicon trichloride.

[0026] A commonly known silicone compound is a compound called silicone oil. The viscosity (mm ２ The ratio ( / s) should be 0.3 to 1000, and more preferably 0.6 to 200. Dimethyl silicone oil and methylphenyl silicone oil belong to this category. Modified silicone oils containing polyether groups, epoxy groups, and dialkylamino groups are also suitable.

[0027] Specific examples of low molecular weight silicon compounds represented by formula (2) include, but are not limited to, the following: 1,1,1,3,3,5,5-heptamethyl-5-methoxytrisiloxane, 1,1,1,3,3,5,5-heptamethyl-5-ethoxytrisiloxane, 1,1,1,3,3,5,5-heptamethyl-5-phenoxytrisiloxane, 1,1,1,3,3,5-hexamethyl-5,5-dimethoxytrisiloxane, 1,1,1,3,3,5-hexamethyl-5,5-diethoxytrisiloxane, 1,1,1,3,3,5-hexamethyl-5,5-diphenoxy Trisiloxane, 1,1,1,3,3-pentamethyl-5,5,5-trimethoxytrisiloxane, 1,1,1,3,3-pentamethyl-5,5,5-triethoxytrisiloxane, 1,1,1,3,3-pentamethyl-5,5,5-triphenoxytrisiloxane, 1,1,3,3-tetramethyl-1,5,5,5-tetramethoxytrisiloxane, 1,1,3,3-tetramethyl-1,5,5,5-tetraethoxytrisiloxane, 1,1,3,3-tetra Methyl-1,5,5,5-tetraphenoxytrisiloxane, 1,3,3-trimethyl-1,1,5,5,5-pentamethoxytrisiloxane, 1,3,3-trimethyl-1,1,5,5,5-pentaethoxytrisiloxane, 1,3,3-trimethyl-1,1,5,5,5-pentaphenoxytrisiloxane, 3,3-dimethyl-1,1,1,5,5,5-hexamethoxytrisiloxane, 3,3-dimethyl-1,1,1,5,5,5-hexaethoxytrisiloxane 1-(3-glycidoxypropyl)-1,1,3,3-tetramethyl-5,5,5-trimethoxytrisiloxane, 1-(3-glycidoxypropyl)-1,1,3,3-tetramethyl-5,5,5-triethoxytrisiloxane, and 1-(3-glycidoxypropyl)-1,1,3,3-tetramethyl-5,5,5-triphenoxytrisiloxane.

[0028] Among the siloxane compounds represented by formula (2), R ７ and R ８Those without " are cyclic siloxane compounds. Specific examples of cyclic siloxane compounds include hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), tetradecamethylcycloheptasiloxane (D7), hexadecamethylcyclooctasiloxane (D8), octadecamethylcyclonanosiloxane (D9), and eicosamethylcyclodecasiloxane (D10). D3, D4, and D5 are preferred. When using a compound of formula (2), it can be used alone, but it is preferred to use a compound of formula (1) in combination, as this produces a branched structure.

[0029] Examples of alkoxysilane compounds having a protecting group that becomes a primary amino group after hydrolysis include N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltripropoxysilane, N,N-bis(trimethylsilyl)-2-aminoethyltrimethoxysilane, N,N-bis(trimethylsilyl)-2-aminoethylmethyldimethoxysilane, N,N-bis(trimethylsilyl)aminoethylmethyldiethoxysilane, 1-trimethylsilyl-2,2-dimethoxy-1-aza-2-silacyclopentane, N,N-diethyl-3-aminopropyltrimethoxysilane, N,N-diethyl-3-aminopropyltriethoxysilane, 2-(triethoxysilylethyl)pyridine, and γ-isocyanatepropyltriethoxysilane. Examples of ketimines include 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 3-trimethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 3-tripropoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, and the like, which are easily hydrolyzed.

[0030] The diene rubber component of the present invention is produced by a solution polymerization reaction, and the conditions for producing the solution-polymerized diene rubber, such as the amounts of raw materials used, reaction temperature, reaction time, etc., are as follows.

[0031] The solution polymerization reaction of diene rubber is carried out using a commonly used method, in which a conjugated diene compound or an aromatic vinyl compound is polymerized in the presence of an organolithium compound and a polar compound such as an ether compound or an amine compound at a temperature of 10 to 120°C for several tens of minutes to several hours. The amount of organolithium compound used is usually in the range of 0.01 to 10 mmol per 100 g of diene rubber. If the amount is less than 0.01 mmol, the molecular weight becomes too high, resulting in an increase in solution viscosity and MV viscosity, which can cause problems in the rubber production process and tire manufacturing process. Furthermore, if the amount exceeds 10 mmol, the molecular weight of the diene rubber becomes too low.

[0032] For the polymerization, as an ether compound for adjusting the microstructure of the diene monomer portion of the diene rubber, particularly the vinyl content (1,2-structure or 3,4-structure of the diene portion), diethyl ether, di-n-butyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, tetrahydrofuran (THF), 2,2-di(2-tetrahydrofuryl)propane (DTHFP), bistetrahydrofurfuryl formal, methyl ether of tetrahydrofurfuryl alcohol, ethyl ether of tetrahydrofuryl alcohol, butyl ether of tetrahydrofurfuryl alcohol, α-methoxytetrahydrofuran, dimethoxybenzene, dimethoxyethane, etc. may be used. Tertiary amine compounds such as triethylamine, pyridine, N,N,N',N'-tetramethylethylenediamine, dipiperidinoethane, N,N-diethylethanolamine methyl ether, N,N-diethylethanolamine ethyl ether, and N,N-diethylethanolamine butyl ether are used as amine compounds. Considering the polymerization rate and modification efficiency, preferred compounds include tetrahydrofuran (THF) and 2,2-di(2-tetrahydrofuryl)propane (DTHFP). The amount of these compounds added, when containing multiple nitrogen atoms or oxygen atoms, is typically 0.01 to 10 moles, preferably 0.2 to 5 moles, per mole of the organolithium compound. Compounds containing one oxygen atom in the molecule, such as tetrahydrofuran, are preferably added in an amount of 0.05 to 10% based on the solvent.

[0033] The polymerization reaction is carried out in a hydrocarbon solvent. Suitable hydrocarbon solvents are selected from aliphatic hydrocarbons, aromatic hydrocarbons, and alicyclic hydrocarbons, particularly those having 3 to 12 carbon atoms, such as propane, n-butane, iso-butane, n-pentane, iso-pentane, cyclopentane, n-hexane, cyclohexane, methylcyclohexane, n-heptane, cycloheptane, propene, 1-butene, iso-butene, trans-2-butene, cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, benzene, toluene, xylene, and ethylbenzene. Preferred are n-pentane, iso-pentane, cyclopentane, n-hexane, cyclohexane, and n-heptane. These solvents can also be used in combination.

[0034] In the present invention, a conjugated diene compound or a conjugated diene compound and an aromatic vinyl compound are primarily anionically polymerized, and the resulting activated diene rubber is then reacted with a silicon compound. These modification reactions are carried out in batch polymerization using an adiabatic method at 0 to 120°C, preferably 20 to 100°C, for a reaction time of 1 to 60 minutes, preferably 5 to 40 minutes. In isothermal polymerization, the reaction time is 30 to 100°C, preferably 50 to 80°C, for a reaction time of 1 to 250 minutes, preferably 30 to 200 minutes. In continuous polymerization, the reaction time is 30 to 100°C, preferably 50 to 80°C.

[0035] The polymerization method used in the present invention can be either batch polymerization or continuous polymerization. For diene rubber, batch polymerization is suitable, particularly for achieving high impact resilience, while continuous polymerization is suitable for diene rubber, particularly for achieving high abrasion resistance and processability. The diene rubber component 1, which is the high molecular weight component of the present invention, can be produced by either batch polymerization or continuous polymerization, but continuous polymerization is preferred. The diene rubber component 2, which is the low molecular weight component of the present invention, can be produced by either batch polymerization or continuous polymerization, but batch polymerization is preferred.

[0036] It is convenient to polymerize the diene rubber component 1 and the diene rubber component 2 of the present invention in separate heavy vessels, but it is also possible to produce both components in one polymerization vessel by adding a predetermined polar compound, conjugated diene compound, aromatic vinyl compound, and initiator after producing the diene rubber component 1.

[0037] In steps ii) and iii), a silicon compound represented by formula (1) is added to produce a diene rubber having a bibranched structure of 40% or less. The amount of silane compound added in steps ii) and iii) is preferably 0.7 to 2 times the number of molecules per molecule of active diene rubber, more preferably 0.9 to 1.5 times. If the amount is less than 0.7, the number of alkoxysilyl groups introduced into the active diene rubber decreases, resulting in reduced reactivity with silica. If the amount is more than 2 times, storage stability deteriorates. When a siloxane compound represented by formula (2) is used in step iii), it is preferably added so that the number of Si-O bonds per molecule of the remaining active diene rubber is at least equal, preferably 1 to 100 times, more preferably 1 to 5 times. In this case, it is also preferable to use a silicon compound having three or more functional groups represented by formula (1) in combination.

[0038] According to the present invention, the branched structure after steam coagulation and drying is the following bibranched structure-A or bibranched structure-A', which is presumed to be stable during rubber storage and highly reactive with silica when compounded with silica. It is presumed that the reaction mechanism is such that bibranched structure-A is produced by condensation of (Rubber)-Si-OH, which is the result of hydrolysis of (Rubber)-Si-OR modified with a silicon compound represented by formula (1). Furthermore, (Rubber)-Si-(O-Si) modified with a silicon compound represented by formula (2) n When -OLi is also neutralized, it becomes (Rubber)-Si-(O-Si) n It is presumed that this will result in -OH. Therefore, it will result in bibranched structure-A', which is similar to bibranched structure-A. Conventional bibranched structure-B has low reactivity with silica. Bibranched structure-A (structure of the present invention): (Rubber)-Si-O-Si-(Rubber) Bibranched structure-A' (structure of the present invention): (Rubber)-Si-O-(Si-O) n -Si-(Rubber) 2-branched structure-B (conventional structure): (Rubber)-Si-(Rubber) The proportions of these branched structures can be determined by GPC during the manufacturing process.

[0039] In the present invention, to further improve the drying process and storage stability, in steps ii) and iii), the reaction between at least one silicon compound represented by formula (1) and / or formula (2) and the activated diene rubber is carried out under conditions that minimize the formation of bi-branched structure-B. Furthermore, prior to the steam coagulation and drying in step v), a silicon halide compound represented by formula (3) or an alkali metal compound represented by formula (4) may be added. This silicon halide compound or alkali metal compound is added under conditions that satisfy formula (5) to neutralize impurities contained in the solvent or monomer, lithium compounds by-produced in the reaction between the activated diene rubber and the silicon compound, unreacted Si-Cl bonds, and by-produced HCl. (Rubber)-Si-OLi is not easily condensed, but neutralization results in (Rubber)-Si-OH. This facilitates the condensation reaction to (Rubber)-Si-O-Si-(Rubber), improving storage stability. The compounds represented by formula (1) and formula (2) may produce acidic or alkaline compounds as by-products depending on the compound used in the modification reaction, and the neutralization method must be changed. In this case, the adjustment is made by adjusting the value of 1.5 ≥ [nX 1 +(4-q)X 2 ] / (L+M 2 ) is preferably in the range of 0.9 or more. If it is 0.9 or less, the alkalinity becomes too high and the condensation reaction becomes difficult. It is preferably 0.95 or more. If it is 1.5 or more, the acidity becomes too high and metal corrosion in the production equipment becomes a problem. It is preferably 1.2 or less.

[0040] The Mooney viscosity (abbreviated as MV, and the measurement conditions are expressed as ML) of the diene rubber obtained in the present invention １＋４／１００℃ ) is preferably in the range of 20 to 150. If it is less than 20, the strength, abrasion resistance and impact resilience will be deteriorated, while if it exceeds 150, the processability etc. will be reduced.

[0041] The content of the 1,2-structure or 3,4-structure in the diene portion of the diene-based rubber in the present invention can generally be varied within a range of 20 to 80%. When emphasis is placed on abrasion resistance, the vinyl content is set to a lower level, while when emphasis is placed on braking performance on wet roads, the vinyl content is set to a higher level. The 1,2-structure or 3,4-structure of the diene portion in the conjugated diene polymer of diene-based rubber component 1, which is the high molecular weight component, is 20 to 70%, preferably 25 to 60%, while the 1,2-structure or 3,4-structure of the diene portion in the conjugated diene polymer of diene-based rubber component 2, which is the low molecular weight component, is 40 to 80%, preferably 45 to 75%. The ratio of diene-based rubber component 1 to diene-based rubber component 2 is 10 to 90 phr, preferably 15 phr to 80 phr, of diene-based rubber component 2 per 100 phr of diene-based rubber component 1. If the content is less than 10 phr, the compounded MV becomes high and processability becomes poor, whereas if the content is more than 90 phr, the rubber composition becomes sticky and difficult to handle.

[0042] An extender oil can also be added to the polymerization reaction solution containing the diene rubber of the present invention. Extender oils commonly used in the rubber industry can be used, including paraffinic extender oils, aromatic extender oils, and naphthenic extender oils. The pour point of the extender oil is preferably -20 to 50°C, more preferably -10 to 30°C. Within this range, a rubber composition can be obtained that is easy to extend and has an excellent balance of tensile properties and low heat buildup. The aromatic carbon content (CA%, Kurtz analysis method) of the extender oil is preferably 20% or more, more preferably 25% or more. The paraffin carbon content (CP%) of the extender oil is preferably 55% or less, more preferably 45%. If the CA% is too low or the CP% is too high, the tensile properties will be insufficient. The content of polycyclic aromatic compounds in the extender oil is preferably less than 3%. This content is measured by IP346 (a testing method of The Institute Petroleum, UK). The content of the extender oil is preferably 0 to 40 parts by weight, more preferably 5 to 30 parts by weight, based on 100 parts by weight of the rubber composition. When the content of the extender oil is within this range, the viscosity of the rubber composition containing silica becomes appropriate, and the balance between tensile properties and low heat buildup is excellent.

[0043] When the diene rubber of the present invention is used as a rubber composition for tires, it can be blended with natural rubber, isoprene rubber, butadiene rubber, emulsion-polymerized styrene-butadiene rubber, etc., within a range that does not essentially impair the effects of the present invention, and kneaded with reinforcing agents such as silica and / or carbon black and various compounding ingredients using a roll mill or Banbury mixer, and then sulfur, vulcanization accelerators, etc. are added to form tire rubber for treads, sidewalls, carcasses, etc. These compositions can also be used for belts, anti-vibration rubber, and other industrial products.

[0044] When the diene rubber of the present invention is used in tires, particularly tire treads, the most suitable reinforcing material to be filled is a filler having hydroxyl groups on its surface, such as silica. Carbon black can also be used in combination. The amount of filler to be filled is preferably 20 to 150 phr, more preferably 30 to 100 phr, per 100 phr of the total rubber components.

[0045] Examples of silica include dry silica, wet silica, colloidal silica, and precipitated silica. Among these, wet silica, which is primarily composed of hydrous silicic acid, is particularly preferred. These silicas can be used alone or in combination of two or more. The particle size of the primary silica particles is not particularly limited, but is preferably 1 to 200 nm, more preferably 3 to 100 nm, and particularly preferably 5 to 60 nm. When the particle size of the primary silica particles is within this range, an excellent balance between tensile properties and low heat buildup is achieved. The particle size of the primary particles can be measured using an electron microscope, specific surface area, or the like.

[0046] For the purpose of further improving the tensile properties and low heat buildup in the rubber composition of the present invention, a silane coupling agent is preferably compounded during rubber compounding. Examples of the silane coupling agent include tetrasulfides such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-tri-iso-propoxysilylpropyl)tetrasulfide, bis(3-tributoxysilylpropyl)tetrasulfide, γ-trimethoxysilylpropyldimethylthiocarbamyl tetrasulfide, and γ-trimethoxysilylpropylbenzothiazyl tetrasulfide; bis(3-triethoxysilylpropyl)disulfide, bis(3-tri-iso-propoxysilylpropyl)disulfide, bis(3-tributoxysilylpropyl)disulfide, γ-trimethoxysilylpropyldimethylthiocarbamyl disulfide, and γ-trimethoxysilylpropylbenzothiazyl disulfide. To avoid scorching during kneading, it is preferable that the silane coupling agent contains four or fewer sulfur atoms per molecule. More preferably, it contains two or fewer sulfur atoms. These silane coupling agents can be used alone or in combination of two or more. The amount of silane coupling agent added is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight, and particularly preferably 2 to 10 parts by weight, per 100 parts by weight of silica.

[0047] Examples of carbon black include grades such as N110, N220, N330, N440, and N550. These carbon blacks can be used alone or in combination of two or more. There are no particular restrictions on the specific surface area of ​​the carbon black, but the nitrogen adsorption specific surface area (N2 SA) is preferably 5 to 200 m 2 / g, more preferably 50 to 150 m 2 / g, particularly preferably 80 to 130 m 2 / g. When the nitrogen adsorption specific surface area is within this range, the tensile properties are more excellent. In addition, the DBP adsorption amount of carbon black is not particularly limited, but is preferably 5 to 300 ml / 100 g, more preferably 50 to 200 ml / 100 g, and particularly preferably 80 to 160 ml / 100 g. When the DBP adsorption amount is within this range, a rubber compounding composition with more excellent tensile properties can be obtained. Furthermore, as carbon black, cetyltrimethylammonium bromide disclosed in JP-A-5-230290 has an adsorption (CTAB) specific surface area of ​​110 to 170 m 2 Abrasion resistance can be improved by using high-structure carbon black having a DBP (24M4DBP) oil absorption of 110 to 130 ml / 100 g after four repeated compressions at a pressure of 24,000 psi. The amount of carbon black added is 1 to 50 parts by weight, preferably 2 to 30 parts by weight, and particularly preferably 3 to 20 parts by weight, per 100 parts by weight of the rubber component.

[0048] The rubber compounding composition of the present invention may contain a vulcanizing agent in an amount of preferably 0.5 to 10 phr, more preferably 1 to 6 phr, per 100 phr of the total rubber components. Typical vulcanizing agents include sulfur, as well as sulfur-containing compounds and peroxides.

[0049] In addition, a sulfenamide-based, guanidine-based, thiuram-based or other vulcanization accelerator may be used in combination with the vulcanizing agent in an amount appropriate for the purpose. Furthermore, zinc oxide, a vulcanization aid, an antioxidant, a processing aid, or the like may be used in an amount appropriate for the purpose.

[0050] Furthermore, the various compounding ingredients in the rubber compounding composition obtained using the diene rubber of the present invention are not particularly limited, and for the purpose of improving processability during kneading or further improving the balance of wet skid characteristics, rebound resilience, and abrasion resistance, in addition to various compounding ingredients such as other extender oils and vulcanizing agents, vulcanization accelerators, zinc oxide, antioxidants, scorch inhibitors, tackifiers, and other fillers that are compounded in ordinary rubber compositions, compatibilizers, for example, organic compounds selected from epoxy group-containing compounds, carboxylic acid compounds, carboxylic acid ester compounds, ketone compounds, ether compounds, aldehyde compounds, hydroxyl group-containing compounds, and amino group-containing compounds, or silicon compounds selected from alkoxysilane compounds, siloxane compounds, and aminosilane compounds, may also be added during kneading.

[0051] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. The physical properties of the polymers were measured according to the following methods.

[0052] The peak molecular weight (Mp) and peak area were calculated as follows. The molecular weight at the highest point of the peak in GPC analysis of conjugated diene polymer 1 immediately after polymerization was taken as the peak molecular weight, and designated as Mp1. After the addition of the silicon compound, peaks corresponding to bi-branched structures, tri-branched structures, tetra-branched structures, etc. appeared. The area of ​​the peak corresponding to Mp1 after modification was designated as C Ｍｐ１ The area of ​​the peak with two or more branches is C Ｍｐ１，２＜ When calculated in the same way from the GPC chart after steam coagulation and drying, rubber molecules with silicon compounds attached to the terminals and rubber molecules with a two-branch structure and silicon compounds attached are condensed, and C Ｍｐ１，Ｄ is C Ｍｐ１ It becomes smaller, C Ｍｐ１，２＜，Ｄ is C Ｍｐ１，２＜ It becomes larger. Ｍｐ１，２＜，Ｄ is C Ｍｐ１，２＜ The larger the Mp1, the greater the storage stability and reactivity with silica. In the present invention, Mp1 is 400 kg / mol or more.

[0053] The molecular weight at the highest point of the peak in GPC analysis of conjugated diene polymer 2 immediately after polymerization is taken as the peak molecular weight, Mp2. After the addition of the silicon compound, peaks corresponding to bi-branched structures, tri-branched structures, tetra-branched structures, etc. appear. The area of ​​the peak corresponding to Mp2 after modification is taken as C. Ｍｐ２ The area of ​​the peak with two or more branches is C Ｍｐ２，２＜ When calculated in the same way from the GPC chart after steam coagulation and drying, rubber molecules with silicon compounds attached to the terminals and rubber molecules with a two-branch structure and silicon compounds attached are condensed, and C Ｍｐ１，Ｄ The area of ​​becomes smaller, and C Ｍｐ２，２＜，Ｄ The area of ​​C becomes larger. Ｍｐ１，２＜，Ｄ is C Ｍｐ１，２＜ The larger the Mp2, the greater the storage stability and reactivity with silica. In the present invention, Mp2 is less than 60 kg / mol.

[0054] The styrene unit content in the polymer is 1 The glass transition temperature (T ｇ ) was measured using a PerkinElmer differential scanning calorimeter (DSC) Model 7 under the condition of cooling to -100°C and then increasing the temperature at a rate of 10°C / min.

[0055] The kneading characteristics and physical properties of the vulcanized rubber were measured by the following methods, and the Mooney viscosity of the rubber compounded composition was measured as follows.

[0056] The kneading of the rubber compounding composition to prepare a vulcanizate was performed in accordance with JIS K 6299:2001 "Rubber - Preparation of test specimens." The kneading conditions for the rubber composition not containing a vulcanizing agent (kneading A) were a Laboplastomill Banbury mixer manufactured by Toyo Seiki Seisaku-sho, Ltd., with a filling rate of approximately 65% ​​(volume ratio), a rotor rotation speed of 50 rpm, and a kneading start temperature of 90°C. The kneading conditions for compounding a vulcanizing agent into the rubber compounding composition after kneading A (kneading B) were an 8-inch roll manufactured by Daihan Co., Ltd., where the vulcanizing agent was compounded at room temperature.

[0057] The temperature dispersion of the viscoelasticity test was measured using a TA INSTRUMENTS RSA3 viscoelasticity measuring device in accordance with JIS K 7244-7:2007 "Plastics - Test methods for dynamic mechanical properties - Part 7: Torsional vibration - Non-resonance method," with a measurement frequency of 10 Hz, a measurement temperature of -50 to 80°C, a dynamic strain of 0.1%, a temperature rise rate of 4°C / min, and a test specimen shape of 5 mm wide x 40 mm long x 1 mm thick. The smaller the tan δ (60°C), the greater the rebound resilience and the lower the heat buildup. The larger the tan δ (0°C), the better the wet grip performance.

[0058] (2) Tensile strength at break (T Ｂ ), modulus, elongation at break, etc. were measured in accordance with JIS K6251:2004.

[0059] Abrasion resistance was measured by the Akron Abrasion Test, Method B, in accordance with JIS K6264-2:2005 "Vulcanized rubber and thermoplastic rubber - Determination of abrasion resistance - Part 2: Test method," and the abrasion resistance of the vulcanized rubber compound composition was expressed as an index, with the abrasion resistance of the control sample set at 100. The higher the index, the better the result.

[0060] The Mooney viscosity is measured at 100°C in accordance with JIS K6300-2001 [ML １＋４／１００℃ ] was measured.

[0061] [Diene Rubber Component 1-1] A 10 L autoclave was thoroughly purged with dry nitrogen, and 5,500 g of cyclohexane was placed in the autoclave. 215 mg (1.17 mmol) of 2,2-di(2-tetrahydrofuryl)propane (DTHFP), 210 g (2.02 mol) of styrene, and 460 g (8.50 mol) of 1,3-butadiene were then placed in the autoclave. The temperature inside the autoclave was adjusted to 25°C, and 74.7 mg (1.17 mmol) of n-butyllithium, effective for polymerization, was added to the autoclave to initiate polymerization. The polymerization was carried out adiabatically, with the maximum temperature reaching 78°C. At this point, 30 g of 1,3-butadiene was added, and polymerization was continued for an additional 5 minutes. 20 mL of the polymerization solution was then extracted from the autoclave and placed in a container thoroughly purged with nitrogen for analysis. The solution was then diluted and subjected to GPC analysis. Subsequently, 0.324 g (1.17 mmol) of 3-diethylaminopropyltriethoxysilane was added to the autoclave and reacted for 15 minutes. This rubber was designated (diene rubber component 1-1). The styrene content in the diene rubber was 30%, and the vinyl content was 44%. Mp by GPC analysis was 560 kg / mol. This solution was later mixed with diene rubber component 2, after which it was desolvated by steam coagulation and dried with a roll at 110°C.

[0062] [Diene Rubber Component 2-1] A 10 L autoclave was thoroughly purged with dry nitrogen, and 5,500 g of cyclohexane was placed in the autoclave. 5.27 g (114 mmol) of 2,2-di(2-tetrahydrofuryl)propane (DTHFP), 200 g (1.92 mol) of styrene, and 770 g (14.24 mol) of 1,3-butadiene were then placed in the autoclave. The temperature inside the autoclave was adjusted to 25°C, and 1.83 g (29 mmol) of n-butyllithium was added to the autoclave to initiate polymerization. The polymerization was carried out adiabatically, with the maximum temperature reaching 88°C. At this point, 30 g of 1,3-butadiene was added, and polymerization was continued for an additional 5 minutes. 20 mL of the polymerization solution was then extracted from the autoclave and placed in a container thoroughly purged with nitrogen for analysis. The solution was then diluted and subjected to GPC analysis. Subsequently, 7.93 g (28.6 mmol) of 3-diethylaminopropyltriethoxysilane was added to the autoclave and reacted for 15 minutes. The remaining solution was desolvated by steam coagulation and dried on a roll at 110°C. This rubber was designated [Diene Rubber Component 2-1]. The styrene content of the diene rubber was 21%, and the vinyl content was 59%. The Mp by GPC analysis was 34 kg / mol.

[0063] [Diene Rubber Component 2-2] [Diene Rubber Component 2-2] was produced in the same manner as [Diene Rubber Component 2-1], except that the amounts of 2,2-di(2-tetrahydrofuryl)propane (DTHFP), n-butyllithium, and 3-diethylaminopropyltriethoxysilane used in [Diene Rubber Component 2-1] were increased to 25.6 g (553 mmol), 8.89 g (141 mmol), and 3-diethylaminopropyltriethoxysilane, respectively, to 38.5 g (139 mmol). The styrene content of the diene rubber was 21%, and the vinyl content was 58%. The Mp by GPC analysis was 7 kg / mol.

[0064] [Diene Rubber Component 2-3] [Diene Rubber Component 2-3] was produced in the same manner as [Diene Rubber Component 2-1], except that the amount of 2,2-di(2-tetrahydrofuryl)propane (DTHFP) used in [Diene Rubber Component 2-1] was increased to 10.5 g (118 mmol). The styrene content in the diene rubber was 20% and the vinyl content was 73%. The Mp by GPC analysis was 38 kg / mol.

[0065] The [Diene Rubber Component 1-1], [Diene Rubber Component 2-1], [Diene Rubber Component 2-2], [Diene Rubber Component 2-3] and emulsion-polymerized ESBR (commercially available JSR #1723 was used as is) prepared in the examples were mixed in the proportions shown in Table 2, coagulated with steam, dried with a heat roll, and then compounded according to the vulcanization physical property compounding recipe in Table 1, and the vulcanization physical properties were evaluated. The evaluation results are also shown in Table 2. Table 2 shows the compounded MV, tensile strength, elongation at break, M ３００ / M １００ The results of the modulus ratio, Acron abrasion resistance, and dynamic viscoelasticity tests are shown. The physical property values, expressed as an index, are set to 100 for Comparative Example 2, with higher values ​​indicating better physical properties. Compared to Comparative Example 2, which is an emulsion-polymerized SBR commonly used in tire applications, Examples 1, 2, and Comparative Example 1 all exhibit superior dynamic viscoelasticity test tan δ (0°C), which corresponds to wet grip performance, and tan δ (60°C), which corresponds to fuel economy. Although the compounded MV is slightly higher, the modulus ratio increases with increasing reinforcing with silica, indicating a high correlation with Acron abrasion resistance. Compared to Comparative Example 1, diene rubber component 2 is good at improving processability when its Mp2 is less than 10 kg / mol, but its effect on improving vulcanized physical properties is small. These property evaluation results indicate that this rubber composition exhibits an excellent balance of fuel economy, abrasion resistance, wet grip performance, and processability, making it a rubber compounded composition.

[0066]

[0067]

[0068] [Diene Rubber Component 1-2] A 5 L autoclave was thoroughly purged with dry nitrogen, and 2890 g of cyclohexane was added. Then, 100 mg (0.544 mmol) of 2,2-di(2-tetrahydrofuryl)propane (DTHFP), 110 g of styrene, and 243 g of 1,3-butadiene were placed in the autoclave. After adjusting the temperature inside the autoclave to 40°C, 87.1 mg (1.36 mmol) of n-butyllithium, effective for polymerization, was added to the autoclave to initiate polymerization. The polymerization temperature increased adiabatically, reaching a maximum temperature of 78°C. At this point, 16 g of 1,3-butadiene was added, and polymerization was continued for an additional 5 minutes. Subsequently, 377 mg (1.36 mmol) of 3-diethylaminopropyltriethoxysilane was added to the autoclave, and the reaction was continued for 15 minutes. This polymerization was repeated six times, and the entire amount was placed in one tank and stirred uniformly. This rubber was designated [Diene Rubber Component 1-2]. The styrene content in the diene rubber was 30% and the vinyl content was 47%. The Mp measured by GPC analysis was 568 kg / mol. This solution was later mixed with diene rubber component 2, desolvated by steam coagulation, and dried with a roll at 110°C.

[0069] [Diene Rubber Component 2-4] A 10 L autoclave was thoroughly purged with dry nitrogen, and 5,500 g of cyclohexane was added. Then, 5.27 g (114 mmol) of 2,2-di(2-tetrahydrofuryl)propane (DTHFP), 200 g (1.92 mol) of styrene, and 770 g (14.24 mol) of 1,3-butadiene were placed in the autoclave. The temperature inside the autoclave was adjusted to 25°C, and 1.83 g (29 mmol) of n-butyllithium was added to the autoclave to initiate polymerization. The polymerization temperature increased adiabatically, reaching a maximum temperature of 83°C. At this point, 30 g of 1,3-butadiene was added, and polymerization was continued for an additional 5 minutes. Subsequently, 7.93 g (28.6 mmol) of 3-diethylaminopropyltriethoxysilane was added to the autoclave, and the reaction was continued for 15 minutes. This solution was stored as is. This rubber was designated as [Diene Rubber Component 2-4]. The styrene content in the diene rubber was 21%. The vinyl content was 69%. The Mp by GPC analysis was 38 kg / mol.

[0070] [Diene Rubber Component 2-5] [Diene Rubber Component 2-5] was produced in the same manner as [Diene Rubber Component 2-4], except that the 3-diethylaminopropyltriethoxysilane used in [Diene Rubber Component 2-4] was replaced with 2.43 g (14.3 mmol) of silicon tetrachloride. The styrene content in the diene rubber was 20%. The vinyl content was 68%. The Mp by GPC analysis was 40.0 kg / mol.

[0071] [Diene Rubber Component 2-6] [Diene Rubber Component 2-6] was produced in the same manner as [Diene Rubber Component 2-4], except that the 3-diethylaminopropyltriethoxysilane used in [Diene Rubber Component 2-4] was replaced with 4.25 g (14.4 mmol) of octamethylcyclotetrasiloxane (D4). The styrene content in the diene rubber was 20%. The vinyl content was 70%. The Mp by GPC analysis was 47 kg / mol.

[0072]

[0049] In Examples 3 to 5, 20 phr of each of diene rubber components 2-4 to 2-6 were mixed with 100 phr of diene rubber component 1-2, and the experimentally prepared [Diene Rubber Component 1-2], [Diene Rubber Component 2-4], [Diene Rubber Component 2-5], and [Diene Rubber Component 2-6], TDAE (aromatic oil), and emulsion-polymerized ESBR (commercially available JSR #1723 was used as is). The mixtures were then desolvated by steam coagulation and dried with a roll at 110°C. In Examples 6 to 8, 40 phr of each of diene rubber components 2-4 to 2-6 were mixed with diene rubber component 1-2, and the mixtures were then desolvated by steam coagulation and dried with a roll at 110°C. The GPC analysis chart was divided into high molecular weight components and low molecular weight components by a simple method of drawing a perpendicular line through the valley of the peak, and the ratio of diene rubber component 1 to diene rubber component 2 was determined from the area, and the results are shown in Table 4.

[0073] The vulcanized materials were compounded according to the vulcanization physical property formulations in Table 3, and the vulcanized physical properties were evaluated. The evaluation results are also shown in Table 4. Table 4 shows the compounded MV, tensile strength, elongation at break, modulus ratio (M300 / M100), Akron abrasion resistance, and dynamic viscoelasticity test results. The physical property values, expressed as indices, are set at 100 for Comparative Example 4, with higher values ​​indicating better physical properties. Compared to Comparative Example 4, which uses emulsion-polymerized SBR commonly used in tire applications, Examples 3 to 8 have higher tensile strength and equal or higher elongation at break. Compared to Comparative Example 4, Examples 3 to 8 have higher modulus ratios, which are said to reflect reactivity with silica, and both Akron abrasion and dynamic viscoelasticity tests are significantly improved. The effect of the type of terminal modifier in diene rubber component 2 is not significantly different between Examples 3 to 5, which use 20 phr of diene rubber component 1, and Examples 6 to 8, which use 40 phr of diene rubber component 1, relative to 100 phr. From the results of these physical property evaluations, it is clear that this rubber composition has an excellent balance of fuel economy, abrasion resistance, wet grip performance, and processability, and is a rubber compounded composition.

[0074]

[0075]

Claims

1. A diene rubber composition obtained by subjecting a diene rubber component 1 obtained by terminally modifying a conjugated diene polymer 1 with at least one silicon compound represented by formula (1) and / or formula (2) and a diene rubber component 2 obtained by terminally modifying a conjugated diene polymer 2 with at least one silicon compound represented by formula (1) and / or formula (2) to a hydrolysis step, followed by drying, The conjugated diene polymer 1 is obtained by polymerizing a conjugated diene compound and an aromatic vinyl compound, and has a peak molecular weight in terms of polystyrene of 400 kJ to 2,000 kg / mol; The conjugated diene polymer 2 is obtained by polymerizing a conjugated diene compound and an aromatic vinyl compound, and has a peak molecular weight in terms of polystyrene of 15 kJ to 60 kg / mol; 【Chemistry 1】 In the formula, R １ and R ２ are each independently an alkyl group, aromatic group, or aryl group having 1 to 12 carbon atoms, or an alkyl group, aromatic group, or aryl group containing an oxygen atom and / or a nitrogen atom in any of these groups, and X 1 is iodine, bromine, or chlorine, and n and m are each 0, 1, 2, 3, or 4; 【Chemistry 2】 In the formula, R 3 ~R ８ are each independently an alkyl group, aromatic group, or aryl group having 1 to 12 carbon atoms, or an alkyl group, aromatic group, or aryl group containing an oxygen atom and / or a nitrogen atom in such a group, and R ７ and R ８ and p is a number between 1.5 and 1,000 in increments of 0.

5. The diene rubber composition.

2. the 1,2-structure or 3,4-structure of the diene part in the diene rubber component 1 is 20 to 70% and the weight ratio of the aromatic vinyl compound component in the diene rubber component 1 is 10 to 50%; The diene rubber composition according to claim 1, wherein the diene moiety in the diene rubber component 2 has a 1,2-structure or a 3,4-structure in an amount of 40 to 80%, and the weight ratio of the aromatic vinyl compound component in the diene rubber component 2 is 5 to 35%.

3. 2. The diene rubber composition according to claim 1, wherein the ratio of diene rubber component 1 to diene rubber component 2 is 10 to 90 phr per 100 phr of diene rubber component 1.

4. A rubber compounding composition comprising at least 20 to 150 phr of silica per 100 phr of a total rubber component containing at least 20 phr of the diene rubber composition according to claim 2 or 3.

5. A rubber compounding composition comprising at least 20 to 150 phr of silica and 5 to 30 phr of carbon black per 100 phr of total rubber components containing at least 20 phr of the diene rubber composition according to claim 2 or 3.

6. 1. A method for producing a diene-based rubber composition, comprising: i) Initiating polymerization of a conjugated diene compound and an aromatic vinyl compound in a hydrocarbon in the presence of an organolithium compound; ii) the conjugated diene polymer 1 polymerized in i) and having a polystyrene-equivalent peak molecular weight of 400 kJ to 2,000 kg / mol is terminal-modified immediately after polymerization with at least one silicon compound represented by formula (1) and / or formula (2) to produce a diene rubber component 1; iii) the conjugated diene polymer 2 polymerized in i) and having a polystyrene-equivalent peak molecular weight of 15 kJ to 60 kg / mol is terminal-modified with at least one silicon compound represented by formula (1) and / or formula (2) immediately after polymerization to produce a diene rubber component 2; iv) subjecting the obtained diene rubber component 1 and diene rubber component 2 to a hydrolysis step, preferably steam coagulation, and then drying; 【Transformation 3】 In the formula, R １ and R ２ are each an alkyl group, aromatic group, or aryl group having 1 to 12 carbon atoms, or an alkyl group, aromatic group, or aryl group containing an oxygen atom and / or a nitrogen atom in such a group, and X １ is a halogen atom of iodine, bromine, or chlorine, and n and m are 0, 1, 2, 3, or 4, respectively; 【Chemistry 4】 In the formula, R 3 ~R ８ are each independently an alkyl group, aromatic group, or aryl group having 1 to 12 carbon atoms, or an alkyl group, aromatic group, or aryl group containing an oxygen atom and / or a nitrogen atom in such a group, and R ７ and R ８ and p is a number between 1.5 and 1,000 in increments of 0.

5. The method.

7. 7. The method according to claim 6, wherein the polymerization of the diene rubber component 1 alone or both the diene rubber component 1 and the diene rubber component 2 is initiated in the coexistence of an organolithium compound and a secondary amine compound.

8. 7. The method according to claim 6, wherein, when polymerizing the diene rubber component 1, isoprene is prepolymerized with an organolithium compound, and then a conjugated diene compound other than isoprene and an aromatic vinyl compound are polymerized.

9. The method according to claim 6, wherein after polymerizing the diene rubber component 1, a conjugated diene compound, an aromatic vinyl compound, and optionally a 1,2-structure or 3,4-structure modifier for the diene moiety are subsequently added, and polymerization is resumed in the coexistence of an organolithium compound.

10. The method according to any one of claims 6 to 9, wherein after step iii) and before step iv), an amount of a silicon halide compound represented by formula (3) or an alkali metal compound represented by formula (4) that satisfies the condition of formula (5) is added, and then steam coagulation and drying in step iv) is carried out, 【Transformation 5】 In the formula, M 1 is a silicon atom, and R ９ is an alkyl group, an aromatic group, or an aryl group having 1 to 12 carbon atoms; X 2 is a halogen atom of iodine, bromine, or chlorine, and q is 0 or 1; 【Transformation 6】 In the formula, M ２ is an alkali metal atom, preferably a lithium atom, a sodium atom, or a potassium atom, and R １０ is an alkyl group, aromatic group, aryl group, or acyl group having 1 to 12 carbon atoms, 【Transformation 7】 In the formula, L is the number of moles of the organolithium compound added to initiate polymerization, and M ２ is the number of moles of the alkali metal compound represented by formula (4), and X １ is the number of moles of the silicon compound represented by formula (1), and X ２ is the number of moles of the halogenated silicon compound represented by formula (3), n is the same as n in the silicon compound represented by formula (1), and q is the same as q in the halogenated silicon compound represented by formula (3); The method.

11. The method according to any one of claims 6 to 9, wherein the ratio of the diene rubber component 1 to the diene rubber component 2 is 10 to 90 phr for 100 phr of the diene rubber component 1.

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