Hydrogenated conjugated diene polymer, polymer composition, crosslinked product and tire

Abstract

Provided is a hydrogenated conjugated diene polymer having a structure formed by bonding a nitrogen-containing compound having two or more alkoxysilyl groups and two or more nitrogen atoms with a plurality of conjugated diene polymer chains. When the composition ratios (molar ratios) of a structural unit represented by formula (1), a structural unit represented by formula (2), a structural unit represented by formula (3), and a structural unit represented by formula (4) in said polymer are respectively signified by p, q, r, and s, a value α expressed by numerical formula (i) is 0.80-0.97. In addition, the equilibrium storage modulus E' of said polymer is 2.4 MPa or more. (i): α = (p + (0.5 × r)) / (p + q + (0.5 × r) + s)

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2019-61722, filed on March 27, 2019, the contents of which are incorporated herein by reference. [Technical field]

[0002] The present disclosure relates to a hydrogenated conjugated diene-based polymer, a polymer composition, a crosslinked product, and a tire. [Background technology]

[0003] Conjugated diene polymers obtained by polymerization using a conjugated diene compound have various excellent properties such as heat resistance, abrasion resistance, mechanical strength, and moldability, and are therefore widely used in various industrial products such as pneumatic tires, anti-vibration rubber, and hoses.

[0004] It is known that rubber compositions used for treads, sidewalls, etc. of pneumatic tires are blended with reinforcing agents such as carbon black and silica together with conjugated diene polymers in order to improve the durability and abrasion resistance of the products. Also, modified conjugated diene polymers obtained by modifying conjugated diene polymers with compounds having silicon or nitrogen have been used in the past in order to increase the affinity between the conjugated diene polymers and the reinforcing agents (see, for example, Patent Documents 1 to 3).

[0005] In recent years, it has been proposed to obtain tire components with high strength and low wear by using a hydrogenated product of a modified conjugated diene polymer having a functional group such as an amino group or an alkoxysilyl group at one or both ends (see Patent Document 4). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2008 / 123164 [Patent Document 2] Japanese Patent Application Publication No. 11-349632 [Patent Document 3] International Publication No. 2017 / 221943 [Patent Document 4] International Publication No. 2014 / 133097 Summary of the Invention [Problem to be solved by the invention]

[0007] Due to recent environmental circumstances and increased awareness of resource and energy conservation, there is a demand for extending the lifespan of rubber products and increasing the number of years of use, as well as reducing the weight and size of products while maintaining performance. Therefore, there is a demand for materials that can produce crosslinked rubber that is stronger than ever before and has excellent abrasion resistance.

[0008] The present disclosure has been made in consideration of the above problems, and an object of the present disclosure is to provide a hydrogenated conjugated diene-based polymer from which a crosslinked rubber having high strength and excellent abrasion resistance can be obtained. [Means for solving the problem]

[0009] The present disclosure provides the following hydrogenated conjugated diene-based polymer, polymer composition, crosslinked body, and tire. [1] A hydrogenated conjugated diene polymer having a structure formed by bonding a nitrogen-containing compound having two or more alkoxysilyl groups and two or more nitrogen atoms to a plurality of conjugated diene polymer chains, wherein when the constituent ratios (molar ratios) of the structural unit represented by the following formula (1), the structural unit represented by the following formula (2), the structural unit represented by the following formula (3), and the structural unit represented by the following formula (4) in the polymer are p, q, r, and s, respectively, the value α represented by the following formula (i) is 0.80 or more and 0.97 or less, and the equilibrium storage modulus E' is 2.4 MPa or more. α=(p+(0.5×r)) / (p+q+(0.5×r)+s) …(i) [ka] [2] A polymer composition comprising the hydrogenated conjugated diene polymer of [1] above and an inorganic filler. [3] A crosslinked body obtained by crosslinking the polymer composition of [2] above. [4] A tire having a tread and / or a sidewall formed using the polymer composition according to [2] above. Effect of the Invention

[0010] According to the hydrogenated conjugated diene-based polymer of the present disclosure, a crosslinked rubber having high strength and excellent abrasion resistance can be obtained. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Matters related to the implementation of the present disclosure will be described in detail below. <Hydrogenated conjugated diene polymer> The hydrogenated conjugated diene polymer of the present disclosure is a polymer terminally modified with a compound having a plurality of silicon atoms and a plurality of nitrogen atoms. Specifically, the hydrogenated conjugated diene polymer is a polymer that satisfies the following (a), (b), and (c): (a) It has a structure formed by bonding a nitrogen-containing compound having two or more alkoxysilyl groups and two or more nitrogen atoms to a plurality of conjugated diene polymer chains. (b) The hydrogenation rate is 80% or more and 97% or less. (c) The equilibrium storage modulus E' is 2.4 MPa or more. The hydrogenated conjugated diene polymer satisfying the above (a) to (c) is produced by a method including the following polymerization step, modification step and hydrogenation step.

[0012] <Polymerization process> This process is a process of polymerizing a monomer containing a conjugated diene compound to obtain a conjugated diene polymer having an active terminal. Examples of the conjugated diene compound used in the polymerization include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 1,3-heptadiene, 2-phenyl-1,3-butadiene, 3-methyl-1,3-pentadiene, and 2-chloro-1,3-butadiene. Among these, at least one selected from the group consisting of 1,3-butadiene, isoprene, and 2,3-dimethyl-1,3-butadiene is preferred, and at least one of 1,3-butadiene and isoprene is more preferred.

[0013] The conjugated diene polymer may be a homopolymer of a conjugated diene compound, but from the viewpoint of increasing the strength of rubber, it is preferable that the conjugated diene compound is a copolymer of an aromatic vinyl compound and a conjugated diene compound. Examples of aromatic vinyl compounds used in polymerization include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, vinylethylbenzene, divinylbenzene, trivinylbenzene, divinylnaphthalene, t-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethylether, N,N-dimethylaminoethylstyrene, N,N-dimethylaminomethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-t-butylstyrene, 3-t-butylstyrene, vinylxylene, vinylnaphthalene, vinylpyridine, diphenylethylene, and tertiary amino group-containing diphenylethylene (e.g., 1-(4-N,N-dimethylaminophenyl)-1-phenylethylene). Of these, styrene and α-methylstyrene are preferred as the aromatic vinyl compound.

[0014] When the conjugated diene polymer is a copolymer of a conjugated diene compound and an aromatic vinyl compound, it is preferably a polymer containing 1,3-butadiene and styrene in the monomer composition, because it has high living properties in anionic polymerization. The copolymer preferably has a random copolymerization portion in which the distribution of the conjugated diene compound and the aromatic vinyl compound is irregular, because it can improve the dispersibility of the filler. When the copolymer is a random copolymer, it may further have a block portion made of a conjugated diene compound or an aromatic vinyl compound together with the random copolymerization portion.

[0015] When the conjugated diene polymer is a copolymer of a conjugated diene compound and an aromatic vinyl compound, the proportion of the aromatic vinyl compound used is preferably 5 to 50 mass%, more preferably 10 to 45 mass%, based on the total amount of the conjugated diene compound and the aromatic vinyl compound used in the polymerization, from the viewpoint of achieving a good balance between the low hysteresis loss property and the wet skid resistance of the resulting crosslinked polymer, and from the viewpoint of obtaining a crosslinked rubber with higher strength. The content of the structural unit derived from the aromatic vinyl compound in the polymer is 1 The values ​​are measured by H-NMR. The conjugated diene compounds and aromatic vinyl compounds may each be used alone or in combination of two or more.

[0016] In the polymerization, a compound other than the conjugated diene compound and the aromatic vinyl compound (hereinafter, also referred to as "other monomer") may be used as a monomer. Examples of the other monomer include acrylonitrile, methyl (meth)acrylate, and ethyl (meth)acrylate. The proportion of the other monomer used is preferably 10% by mass or less, and more preferably 5% by mass or less, based on the total amount of the monomers used in the polymerization.

[0017] The polymerization method used may be any of solution polymerization, gas phase polymerization, and bulk polymerization, but solution polymerization is particularly preferred. The polymerization form may be any of batch and continuous. When using solution polymerization, a specific example of the polymerization method is a method in which a monomer containing a conjugated diene compound is polymerized in an organic solvent in the presence of a polymerization initiator and a randomizer that is used as needed.

[0018] As the polymerization initiator, an alkali metal compound is preferably used.Specific examples of the alkali metal compound include alkyl lithium such as methyl lithium, ethyl lithium, n-propyl lithium, n-butyl lithium, sec-butyl lithium, and t-butyl lithium; 1,4-dilithiobutane, phenyl lithium, stilbene lithium, naphthyl lithium, 1,3-bis(1-lithio-1,3-dimethylpentyl)benzene, 1,3-phenylenebis(3-methyl-1-phenylpentylidene)dilithium, naphthyl sodium, naphthyl potassium, and ethoxy potassium.Among these, the alkali metal compound used as the polymerization initiator is preferably a lithium compound.

[0019] The polymerization reaction may be carried out in the presence of a compound (R) obtained by mixing the above-mentioned alkali metal compound with a compound having a functional group that interacts with silica (hereinafter also referred to as an "initiation modifier"). By carrying out the polymerization in the presence of the compound (R), a functional group that interacts with silica can be introduced into the polymerization initiation terminal of the conjugated diene polymer. In this specification, "interaction" means forming a covalent bond between molecules or forming an intermolecular force weaker than a covalent bond (for example, an electromagnetic force acting between molecules such as an ion-dipole interaction, a dipole-dipole interaction, a hydrogen bond, or a van der Waals force). In addition, the "functional group that interacts with silica" refers to a group having at least one atom that interacts with silica, such as a nitrogen atom, a sulfur atom, a phosphorus atom, or an oxygen atom.

[0020] The compound (R) is preferably a reaction product of a lithium compound such as an alkyl lithium and a compound having a nitrogen atom. The starting modifier to be reacted with the lithium compound is preferably a secondary amine compound, and specific examples thereof include dimethylamine, diethylamine, dipropylamine, dibutylamine, dodecamethyleneimine, N,N'-dimethyl-N'-trimethylsilyl-1,6-diaminohexane, piperidine, pyrrolidine, hexamethyleneimine, heptamethyleneimine, dicyclohexylamine, N-methylbenzylamine, di-(2-ethylhexyl)amine, diallylamine, morpholine, N-(trimethylsilyl)piperazine, N-(tert-butyldimethylsilyl)piperazine, 1,3-ditrimethylsilyl-1,3,5-triazinane, etc.

[0021] When polymerization is performed in the presence of compound (R), an alkali metal compound and an initiating modifier may be mixed in advance to prepare compound (R), and the prepared compound (R) may be added to the polymerization system to perform polymerization. Alternatively, an alkali metal compound and an initiating modifier may be added to the polymerization system, and the two may be mixed in the polymerization system to prepare compound (R), and polymerization may be performed. The amount of polymerization initiator used (the total amount when two or more types are used) is preferably 0.01 to 20 mmol, more preferably 0.05 to 15 mmol, per 100 g of monomer used in the synthesis of the polymer.

[0022] The randomizer can be used for the purpose of adjusting the vinyl bond content, which indicates the content of vinyl bonds in a polymer. Examples of the randomizer include dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-di(tetrahydrofuryl)propane, 2-(2-ethoxyethoxy)-2-methylpropane, triethylamine, pyridine, N-methylmorpholine, and tetramethylethylenediamine. These can be used alone or in combination of two or more.

[0023] The organic solvent used in the polymerization may be any organic solvent inert to the reaction, and may be, for example, an aliphatic hydrocarbon, an alicyclic hydrocarbon, or an aromatic hydrocarbon. Among these, a hydrocarbon having 3 to 8 carbon atoms is preferred, and specific examples thereof include propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-pentyne, 2-pentyne, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene, heptane, cyclopentane, methylcyclopentane, methylcyclohexane, 1-pentene, 2-pentene, and cyclohexene. The organic solvent may be used alone or in combination of two or more.

[0024] In the case of solution polymerization, the monomer concentration in the reaction solvent is preferably 5 to 50% by mass, more preferably 10 to 30% by mass, from the viewpoint of maintaining a balance between productivity and ease of polymerization control. The temperature of the polymerization reaction is preferably -20°C to 150°C, more preferably 0 to 120°C. The polymerization reaction is preferably carried out under a pressure sufficient to keep the monomer substantially in a liquid phase. Such a pressure can be obtained by a method such as pressurizing the inside of a reactor with a gas inert to the polymerization reaction.

[0025] By such a polymerization reaction, a conjugated diene polymer having an active terminal is obtained. The weight average molecular weight (Mw) of the obtained conjugated diene polymer in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 5.0×10 4 ~1.0×10 6 Mw is 5.0×10 4 If it is smaller than 1.0×10, the tensile strength, low heat build-up and abrasion resistance of the resulting crosslinked rubber tend to be easily reduced. 6 If it is larger than 8.0×10, the processability of the rubber composition obtained by using the hydrogenated conjugated diene polymer tends to be deteriorated. 4 ~8.0×10 5and more preferably 1.0×10 5 ~5.0×10 5 It is.

[0026] In the conjugated diene polymer obtained by the above polymerization, the vinyl bond content in the structural units derived from butadiene is preferably 15 to 70% by mass. By making the vinyl bond content 25 mol % or more, the flexibility of the obtained crosslinked rubber is maintained, the processability is good, and the abrasion resistance in the low slip region tends to be excellent. The vinyl bond content is preferably 18% by mass or more, more preferably 20% by mass or more. From the viewpoint of durability, the vinyl bond content of the conjugated diene polymer is preferably 68% by mass or less, more preferably 65% ​​by mass or less. In this specification, the "vinyl bond content" is a value indicating the content ratio of structural units having 1,2-bonds to all structural units derived from butadiene contained in the conjugated diene polymer before hydrogenation, 1 The values ​​were measured by H-NMR.

[0027] <Denaturation process> In this step, the active terminal of the conjugated diene polymer obtained in the polymerization step is reacted with a compound having two or more alkoxysilyl groups and two or more nitrogen atoms (hereinafter also referred to as a "specific compound"). By using the specific compound as a terminal modifying agent, a modified conjugated diene polymer having a branched structure with two or more branches in the polymer chain and modified with a group that interacts with silica can be obtained.

[0028] The specific compound has a plurality of reactive points capable of reacting with the active terminals of the conjugated diene polymer. The number of alkoxysilyl groups in the specific compound (i.e., the number of silicon atoms to which at least one alkoxy group is bonded) is preferably 2 to 6, more preferably 2 to 4, from the viewpoint of achieving both the strength and abrasion resistance of the resulting vulcanized rubber and the processability of the rubber composition. In addition, it is preferable that no active hydrogen is bonded to the nitrogen atom in the specific compound. The number of nitrogen atoms in the specific compound is preferably 2 to 12. In this specification, the term "active hydrogen" refers to a hydrogen atom bonded to an atom other than a carbon atom, and preferably refers to one having a bond energy lower than that of the carbon-hydrogen bond of polymethylene.

[0029] As the specific compound, at least one compound selected from the group consisting of compounds represented by the following formula (5) and compounds represented by the following formula (6) can be preferably used. [ka] (In formula (5), R 1 and R 2 are each independently a hydrocarbyl group having 1 to 20 carbon atoms; R 3 is an alkanediyl group having 1 to 20 carbon atoms, 1 is the group "*-C(R 5 )=N-" or the group "*-N=C(R 5 )-" (However, R 5 is a hydrogen atom or a hydrocarbyl group, and "*" is R 4 It indicates that the bond is bonded to the R. 4 is an m-valent hydrocarbon group having 1 to 20 carbon atoms, or an m-valent group having 1 to 20 carbon atoms which has at least one atom selected from the group consisting of nitrogen atoms, oxygen atoms, and sulfur atoms and has no active hydrogen bonded to said atom. n is an integer of 1 to 3, and m is an integer of 2 to 10. In the formula, multiple R 1 , R 2 , R 3 , A 1 , n is the same or different groups. [ka] (In formula (6), R 6 , R 7 , R 10 and R 11 are each independently a hydrocarbyl group having 1 to 20 carbon atoms; R 8 and R 9 are each independently an alkanediyl group having 1 to 20 carbon atoms; 2 is a group represented by the following formula (7), a group represented by the following formula (8), a group represented by the following formula (9), or a group represented by the following formula (10). w and p each independently represent an integer of 1 to 3. In the formula, multiple R 6 , R 7 , R 10 , R 11 are the same or different groups. [ka] (In formula (7), R 12 , R 13 and R 15 are each independently a hydrocarbyl group having 1 to 20 carbon atoms; R 14 and R 16 are each independently an alkanediyl group having 1 to 20 carbon atoms, q is an integer of 1 to 3, and r is an integer of 0 to 2. 12 ~R 15 and q are the same or different groups. "*" indicates a bond to the nitrogen atom in formula (2). [ka] (In formula (8), R 19 R is an alkanediyl group having 3 to 20 carbon atoms, and forms a ring structure of 5 or more members with the nitrogen atom and silicon atom in the formula. 17 and R 18 are each independently a hydrocarbyl group having 1 to 20 carbon atoms; R 20 is an alkanediyl group having 1 to 20 carbon atoms, and s is 1 or 2. 17 , R 18are the same or different groups. "*" indicates a bond to the nitrogen atom in formula (6). [ka] (In formula (9), R 23 R is an alkanediyl group having 1 to 20 carbon atoms. 21 is a hydrocarbylidene group having 1 to 20 carbon atoms, R 22 is an alkanediyl group or alkenediyl group having 1 to 20 carbon atoms, and forms a ring structure of 5 or more members together with the two adjacent nitrogen atoms. "*" indicates a bond to the nitrogen atom in formula (6). [ka] (In formula (10), R 26 is a hydrocarbylene group having 1 to 20 carbon atoms, R 24 and R 25 are each independently a hydrocarbyl group having 1 to 20 carbon atoms, or R 24 and R 25 are combined together and R 24 and R 25 represents a ring structure having 4 to 20 carbon atoms formed together with the nitrogen atom to which R is bonded, or 24 and R 25 are combined together and R 24 and R 25 The nitrogen atom to which R is bonded 24 and R 25 represents a ring structure of 5 or more members formed together with a nitrogen atom or oxygen atom different from the nitrogen atom to which it is bonded. "*" indicates a bond to the nitrogen atom in formula (6).

[0030] (Compound represented by the above formula (5)) In the above formula (5), R 1 , R 2 Examples of the hydrocarbyl group include an alkyl group having 1 to 20 carbon atoms, an allyl group, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms. 3 The alkanediyl group of R preferably has 1 to 10 carbon atoms, and more preferably has 2 to 10 carbon atoms.3 is preferably linear. A 1 R has 5 For the hydrocarbyl group, R 1 and R 2 In terms of a high effect of improving the silica dispersibility, n is preferably 2 or 3, and more preferably 3.

[0031] R 4 Examples of the m-valent hydrocarbon group include groups in which m hydrogen atoms have been removed from a chain hydrocarbon having 1 to 20 carbon atoms, an alicyclic hydrocarbon having 3 to 20 carbon atoms, or an aromatic hydrocarbon having 6 to 20 carbon atoms. Specific examples of aromatic hydrocarbons include a ring structure represented by the following formula (11) and a polycyclic structure formed by linking two or more such ring structures (such as a biphenyl group). [ka] (In formula (11), r1 is an integer of 0 to 5.)

[0032] R 4 When m is an m-valent group having 1 to 20 carbon atoms, which has at least one atom selected from the group consisting of nitrogen atoms, oxygen atoms, and sulfur atoms and has no active hydrogen bonded to the atom, preferred specific examples include m-valent heterocyclic groups and m-valent groups having a tertiary amine structure. The heterocyclic group is preferably a conjugated system, and examples thereof include groups in which m hydrogen atoms have been removed from a single ring or condensed ring such as pyridine, pyrimidine, pyrazine, quinoline, naphthalidine, furan, or thiophene, or a ring portion of a structure in which a plurality of such single rings or condensed rings are linked together. m is an integer of 2 to 10. m is preferably 2 to 6 from the viewpoint of processability of the rubber composition.

[0033] Specific examples of the compound represented by the above formula (5) include compounds represented by the following formulas (M-1) to (M-4). 25 represents a hydrogen atom or an alkyl group, and n1 represents an integer of 1 to 8. [ka]

[0034] (Compound represented by the above formula (6)) In the above formulas (6) to (10), R 6 , R 7 , R 10 , R 11 , R 12 , R 13 , R 15 , R 17 , R 18 , R 24 and R 25 Examples of the hydrocarbyl group having 1 to 20 carbon atoms include an alkyl group having 1 to 20 carbon atoms, an allyl group, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms. 8 , R 9 , R 14 , R 16 , R 20 , R 21 , R 22 , R 23 and R 24 The alkanediyl group, alkenediyl group, and hydrocarbylidene group having 1 to 20 carbon atoms preferably have 1 to 10 carbon atoms, and more preferably have 2 to 10 carbon atoms. 19 Preferably, it has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. In the above formula (8), R 19 The ring structure formed by the nitrogen atom and the silicon atom is preferably a 5- to 7-membered ring, more preferably a 5- or 6-membered ring. 21 , R 22 The ring structure formed by two adjacent nitrogen atoms is preferably a 5- to 12-membered ring, more preferably a 5- to 7-membered ring. In the above formula (10), R 24 and R 25 But R 24 and R 25 are combined together and R 24 and R 25 When R represents a ring structure having 4 to 20 carbon atoms formed together with the nitrogen atom to which it is bonded, the ring structure preferably has 4 to 9 carbon atoms, and more preferably has 4 to 6 carbon atoms.24 and R 25 But R 24 and R 25 are combined together and R 24 and R 25 The nitrogen atom to which R is bonded 24 and R 25 represents a 5- or greater ring structure formed together with a nitrogen atom or an oxygen atom different from the nitrogen atom to which it is bonded, the ring structure is preferably a 5- to 10-membered ring, more preferably a 5- to 7-membered ring. Specific examples of the 5- or greater ring structure include a piperazine ring structure and a morpholine ring structure. In terms of the high effect of improving silica dispersibility, w, p, and q are preferably 2 or 3, and more preferably 3. For the same reason, s is preferably 2.

[0035] Specific examples of the compound represented by the above formula (6) include A 2 is a group represented by the above formula (7), for example, N,N,N',N'-tetra(3-trimethoxysilylpropyl)ethylenediamine, N,N,N',N'-tetra(3-triethoxysilylpropyl)ethylenediamine, N,N,N'-tris(3-trimethoxysilylpropyl)-N'-methyl-ethylenediamine, N,N,N',N'-tetra(3-trimethoxysilylpropyl)-1,3-propanediamine, N,N,N',N'-tetra(3-trimethoxysilylpropyl)-1,4-butanediamine, bis(3-trimethoxysilylpropyl)-[2-(dimethylamino)ethyl]amine, etc.; A in the above formula (6) 2is a group represented by the above formula (8), for example, bis(3-trimethoxysilylpropyl)-[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethyl]amine, bis(3-triethoxysilylpropyl)-[2-(2,2-diethoxy-1-aza-2-silacyclopentane)ethyl]amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, bis(3-trimethoxysilylpropyl)-[2-(2,2-dimethoxy-1-aza-2-silacyclohexane)ethyl]amine, bis(3-trimethoxysilylpropyl)-[2-(2,2-dimethoxy-1-aza-2-silacyclooctane)ethyl]amine, etc.; A in the above formula (6) 2 Examples of the compound in which is a group represented by the above formula (9) include N,N-bis(3-trimethoxysilylpropyl)-3-imidazolylpropylamine; A in the above formula (6) 2 is a group represented by the above formula (10), for example, bis(3-trimethoxysilylpropyl)-(3-dimethylaminopropyl)amine, etc. can be mentioned.

[0036] The reaction between the conjugated diene polymer having an active end and the specific compound is preferably carried out as a solution reaction. The use ratio of the specific compound (the total amount when two or more types are used) is preferably 0.01 mol or more, more preferably 0.05 mol or more, per mol of the metal atom involved in the polymerization of the polymerization initiator, from the viewpoint of sufficiently proceeding the modification reaction and obtaining a crosslinked rubber having high strength and high improvement effect in abrasion resistance and fuel economy. In addition, the use ratio of the specific compound is preferably less than 2.0 mol, more preferably less than 1.5 mol, per mol of the metal atom involved in the polymerization of the polymerization initiator, in order to avoid deterioration of processability and excessive addition. Note that, as the specific compound, one type may be used alone, or two or more types may be used in combination.

[0037] The temperature of the modification reaction is usually the same as that of the polymerization reaction, and is preferably -20°C to 150°C, and more preferably 0 to 120°C. If the reaction temperature is low, the viscosity of the polymer after modification tends to increase, and if the reaction temperature is high, the polymerization active terminals are easily deactivated. The reaction time is preferably 1 minute to 5 hours, and more preferably 2 minutes to 1 hour.

[0038] In the reaction of the conjugated diene polymer having an active terminal with the specific compound, a compound different from the specific compound (hereinafter referred to as "other modifier or coupling agent") may be used together with the specific compound. The other modifier or coupling agent is not particularly limited as long as it is a compound capable of reacting with the active terminal of the conjugated diene polymer obtained by the above polymerization, and a compound known as a modifier or coupling agent for a conjugated diene polymer (for example, a nitrogen-containing alkoxysilane compound other than the specific compound, a glycidyl group-containing polysiloxane, etc.) can be used. When the other modifier or coupling agent is used, the proportion of the other modifier or coupling agent is preferably 10 mol% or less, more preferably 5 mol% or less.

[0039] The modified conjugated diene polymer contained in the reaction solution can be isolated by a known solvent removal method such as steam stripping and a drying procedure such as heat treatment.

[0040] <Hydrogenation reaction> In this step, the modified conjugated diene polymer obtained by the above modification step is hydrogenated. Any method and conditions for the hydrogenation reaction can be used as long as a modified conjugated diene polymer with a desired hydrogenation rate can be obtained. Examples of such hydrogenation methods include a method using a catalyst mainly composed of an organometallic compound of titanium as a hydrogenation catalyst, a method using a catalyst composed of an organic compound of iron, nickel, or cobalt and an organometallic compound such as alkylaluminum, a method using an organic complex of an organometallic compound such as ruthenium or rhodium, and a method using a catalyst in which a metal such as palladium, platinum, ruthenium, cobalt, or nickel is supported on a carrier such as carbon, silica, or alumina. Among various methods, a method in which hydrogenation is carried out under mild conditions of low pressure and low temperature using a homogeneous catalyst composed of an organometallic compound of titanium alone or an organometallic compound of titanium and an organometallic compound of lithium, magnesium or aluminum (JP Patent Publication No. 63-4841 and JP Patent Publication No. 1-37970) is industrially preferred, and also has high hydrogenation selectivity to the double bonds of butadiene, making it suitable for the purpose of the present disclosure.

[0041] The hydrogenation of the modified conjugated diene polymer obtained by the above modification step is preferably carried out using a solvent which is inactive to the catalyst and which the conjugated diene polymer is soluble in. Preferred solvents are aliphatic hydrocarbons such as n-pentane, n-hexane, and n-octane, alicyclic hydrocarbons such as cyclohexane and cycloheptane, aromatic hydrocarbons such as benzene and toluene, and ethers such as diethyl ether and tetrahydrofuran, either alone or as a mixture mainly composed of these.

[0042] The hydrogenation reaction is generally carried out by maintaining the conjugated diene polymer at a predetermined temperature under hydrogen or an inert atmosphere, adding a hydrogenation catalyst with or without stirring, and then introducing hydrogen gas to pressurize to a predetermined pressure. The inert atmosphere means an atmosphere that does not react with the participants in the hydrogenation reaction, and examples of such an atmosphere include helium, neon, and argon. Air and oxygen are not preferred because they oxidize the catalyst and cause the catalyst to be deactivated. Nitrogen is also not preferred because it acts as a catalyst poison during the hydrogenation reaction and reduces the hydrogenation activity. In particular, it is most suitable that the hydrogenation reactor has an atmosphere of hydrogen gas alone.

[0043] The hydrogenation reaction process for obtaining the hydrogenated conjugated diene polymer may be a batch process, a continuous process, or a combination thereof. When a titanocene diaryl compound is used as the hydrogenation catalyst, it may be added to the reaction solution as it is, or may be added as a solution in an inert organic solvent. When the catalyst is used as a solution, the inert organic solvent used may be any of various solvents that do not react with the participants in the hydrogenation reaction. The inert organic solvent used is preferably the same solvent as that used in the hydrogenation reaction. The preferred amount of the catalyst added is 0.02 to 20 mmol per 100 g of the conjugated diene polymer before hydrogenation.

[0044] In the hydrogenated conjugated diene-based polymer of the present disclosure, when the constituent ratios (molar ratios) in the polymer of a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and a structural unit represented by the following formula (4) are p, q, r, and s, respectively, the value α represented by the following formula (i) is 0.80 or more and 0.97 or less. α=(p+(0.5×r)) / (p+q+(0.5×r)+s)…(i) [ka]

[0045] The hydrogenated conjugated diene polymer obtained by terminal modification with a specific compound has an α of 0.80 or more and 0.97 or less, so that a crosslinked rubber having high strength and excellent abrasion resistance can be obtained. In order to obtain a crosslinked rubber having excellent abrasion resistance (particularly, abrasion resistance at a low slip ratio), α is more preferably 0.84 or more, even more preferably 0.86 or more, and particularly preferably 0.88 or more. In addition, α in the above formula (i) corresponds to the hydrogenation rate of the hydrogenated conjugated diene polymer. For example, when α is 0.80, the hydrogenation rate of the hydrogenated conjugated diene polymer is 80%. In addition, in order to obtain a crosslinked rubber having better fuel economy performance, α is more preferably 0.96 or less, and even more preferably 0.95 or less. In addition, the hydrogenation rate of the polymer can be adjusted by the hydrogenation reaction time, etc. In this specification, the hydrogenation rate is 1 The values ​​were measured by H-NMR.

[0046] A preferred method for obtaining a hydrogenated conjugated diene polymer modified with a specific compound is to solution polymerize a monomer containing butadiene in the presence of an alkali metal compound, modify the polymer with a specific compound using the resulting polymer solution as is, and then subject the polymer to a hydrogenation step, which is industrially useful. In this case, the hydrogenated conjugated diene polymer is obtained by removing the solvent from the solution obtained above and isolating the polymer. The polymer can be isolated by a known solvent removal method such as steam stripping and a drying operation such as heat treatment.

[0047] The weight average molecular weight (Mw) of the obtained hydrogenated conjugated diene polymer in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 1.5×10 to obtain a crosslinked rubber having high strength, low heat buildup and excellent abrasion resistance. 5 ~2.0×10 6 The Mw of the hydrogenated conjugated diene polymer is more preferably 1.8×10 5 More preferably, it is 2.0×10 5 More preferably, Mw is 1.6×10 6Less than 1.4×10, more preferably 6 The weight average molecular weight of the hydrogenated conjugated diene polymer is a value determined from the maximum peak molecular weight of a GPC curve measured by GPC after hydrogenating a reaction product of a conjugated diene polymer having an active terminal and a specific compound.

[0048] In addition, the molecular weight distribution of the total amount of the polymer (i.e., an aggregate of different molecular weights) of the hydrogenated conjugated diene polymer obtained by the above production method, as measured by GPC, is preferably 1.1 or more and 2.0 or less. A molecular weight distribution of 1.1 or more is preferable in terms of excellent processability, and a molecular weight distribution of 2.0 or less is preferable because the fuel economy of the obtained vulcanized rubber can be sufficiently increased. The molecular weight distribution of the hydrogenated conjugated diene polymer obtained by the above reaction is more preferably 1.20 or more, and even more preferably 1.23 or more. In addition, the molecular weight distribution is more preferably 1.7 or less, and even more preferably 1.5 or less.

[0049] The peak top molecular weight of the smallest peak of the obtained hydrogenated conjugated diene polymer measured by GPC is preferably 1.0×10 5 ~2.0×10 6 The peak top molecular weight of the smallest peak is in the range of 1.0×10 5 When the molecular weight is 1.1×10 or more, the strength and abrasion resistance of the resulting vulcanized rubber can be sufficiently improved, and the cold flow property can be further improved. 5 More preferably, it is 1.2×10 5 In order to improve processability and viscoelastic properties, the peak top molecular weight of the peak with the smallest molecular weight is preferably 1.8×10 6 More preferably, it is 1.2×10 6 The following is the result.

[0050] According to the above-mentioned production method, a hydrogenated conjugated diene polymer having a storage modulus (equilibrium storage modulus E') of 2.4 MPa or more measured by a dynamic viscoelasticity test (measurement mode: tension, measurement temperature: -80°C to 150°C, heating rate: 5°C / min, tensile strain: 0.1%, frequency: 1 Hz) can be obtained. When the equilibrium storage modulus E' of the hydrogenated conjugated diene polymer modified with a specific compound is 2.4 MPa or more, it is preferable in that a vulcanized rubber having high strength and greatly improved abrasion resistance (particularly, abrasion resistance at a low slip rate) can be obtained. From this viewpoint, the equilibrium storage modulus E' is preferably 2.6 or more, more preferably 2.8 or more. In addition, from the viewpoint of sufficiently ensuring the processability of the obtained polymer composition, the equilibrium storage modulus E' of the hydrogenated conjugated diene polymer is preferably 5.0 or less, more preferably 4.5 or less, and even more preferably 4.2 or less. The equilibrium storage modulus E' can be adjusted, for example, by the hydrogenation rate of the polymer. In this case, when the hydrogenation rate is increased, the equilibrium storage modulus E' tends to increase.

[0051] According to the above-mentioned production method, it is possible to obtain a hydrogenated conjugated diene polymer having a branched structure in which two or more conjugated diene polymer chains are bonded to the reaction points (alkoxysilyl groups, etc.) of the specific compound, and a hydrogenation rate of 80 to 97%. In addition, a polymer having a high equilibrium storage modulus E' of 2.4 or more can be obtained by reacting a modifier (specific compound) having multiple nitrogen atoms and multiple alkoxysilyl groups with a conjugated diene polymer having an active terminal to form a highly branched structure and a high hydrogenation rate of 80 to 97%. By using such a polymer, it is possible to sufficiently suppress cold flow and improve the shape stability (storage stability) of the vulcanized rubber, and it is also possible to obtain a vulcanized rubber having high strength and excellent abrasion resistance.

[0052] <Polymer Composition> The polymer composition of the present disclosure contains the hydrogenated conjugated diene polymer and an inorganic filler. The content of the hydrogenated conjugated diene polymer in the polymer composition is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more, based on the total amount of the polymer composition. The content of the hydrogenated conjugated diene polymer is preferably 50% by mass or less, more preferably 40% by mass or less, based on the total amount of the polymer composition.

[0053] As the inorganic filler, one or both of silica and carbon black can be preferably used. Examples of silica include wet silica (hydrated silicic acid), dry silica (anhydrous silicic acid), colloidal silica, precipitated silica, calcium silicate, and aluminum silicate. Among these, wet silica is particularly preferred from the viewpoint of improving the fracture properties and achieving both wet grip properties and low rolling resistance. In addition, the use of highly dispersible silica is also preferred from the viewpoint of improving the dispersibility in the polymer composition and improving the physical properties and processability. The silica can be used alone or in combination of two or more types.

[0054] Examples of carbon black include, but are not limited to, GPF, FEF, HAF, ISAF, SAF, etc. A good reinforcing effect can be obtained by using carbon black as an inorganic filler. In addition to silica and carbon black, various reinforcing fillers such as clay and calcium carbonate may be blended into the polymer composition as an inorganic filler. Silica alone or a combination of carbon black and silica is preferably used. The total amount of silica and carbon black in the polymer composition is preferably 20 to 130 parts by mass, more preferably 25 to 110 parts by mass, based on 100 parts by mass of the total amount of the polymer components contained in the polymer composition.

[0055] The polymer composition of the present disclosure may contain a crosslinking agent. Examples of the crosslinking agent include sulfur, sulfur halides, organic peroxides, quinone dioximes, organic polyamine compounds, and alkylphenol resins having a methylol group, and sulfur is usually used. The amount of sulfur is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the total amount of the polymer components contained in the polymer composition.

[0056] The polymer composition of the present disclosure may contain other rubber components in addition to the hydrogenated conjugated diene polymer obtained above. The type of such rubber components is not particularly limited, but includes butadiene rubber (BR, for example, high cis BR with 90% or more cis-1,4 bonds, BR containing syndiotactic-1,2-polybutadiene (SPB), etc.), styrene butadiene rubber (SBR), natural rubber (NR), isoprene rubber (IR), styrene isoprene copolymer rubber, butadiene isoprene copolymer rubber, etc., and more preferably BR and SBR. The content ratio of the other rubber components in the polymer composition is preferably 80% by mass or less, more preferably 60% by mass or less, based on the total amount of the hydrogenated conjugated diene polymer and the other rubber components.

[0057] The polymer composition may contain a process oil commonly used for extending elastomers as an oil for oil extension. The process oil is compounded into the rubber composition by, for example, directly adding the oil during rubber compounding. Preferred process oils include various oils known in the art, such as aromatic oils, paraffinic oils, naphthenic oils, vegetable oils, and oils with low polycyclic aromatic compound content (low PCA oils), such as mild extraction solvate (MES), treated distillate aromatic extract (TDAE), special residual aromatic extract (SRAE), and heavy naphthenic oil. Examples of commercially available MES, TDAE, and SRAE include Catenex SNR (heavy paraffin obtained by dewaxing distillate oil with a solvent) manufactured by Shell as MES, Vivatec 500 manufactured by H&R Wasag AG as TDAE, and NC140 manufactured by Japan Energy Corp. as SRAE. The amount of the process oil to be blended is preferably 10 to 100 parts by mass based on 100 parts by mass of the total amount of the polymer components contained in the polymer composition.

[0058] In addition to the above-mentioned components, the polymer composition may contain various additives that are generally used in rubber compositions for tires, such as antioxidants, zinc oxide, stearic acid, softeners, sulfur, vulcanization accelerators, silane coupling agents, compatibilizers, vulcanization aids, processing aids, scorch inhibitors, etc. The blending ratios of these additives may be appropriately selected depending on the various components within a range that does not impair the effects of the present disclosure.

[0059] The polymer composition of the present disclosure can be applied to various rubber products as a crosslinked body by kneading the polymer component, inorganic filler, and other components blended as necessary using a kneader such as an open kneader (e.g., roll) or an internal kneader (e.g., Banbury mixer), molding, and then crosslinking (vulcanization). Specifically, the crosslinked body can be applied to tire applications such as tire treads, undertreads, carcasses, sidewalls, and bead parts; sealing materials such as packings, gaskets, weather strips, and O-rings; interior and exterior skin materials for various vehicles such as automobiles, ships, aircraft, and railways; building materials; anti-vibration rubbers for industrial machinery and equipment; various hoses and hose covers such as diaphragms, rolls, radiator hoses, and air hoses; belts such as power transmission belts; linings; dust boots; medical equipment materials; fenders; insulating materials for electric wires; and other industrial products.

[0060] According to the hydrogenated conjugated diene-based polymer of the present disclosure, it is possible to obtain a crosslinked product having excellent physical properties required for tire applications, such as strength, abrasion resistance, and fuel efficiency. Therefore, the polymer composition containing the hydrogenated conjugated diene-based polymer of the present disclosure can be suitably used particularly as a material for tire treads, sidewalls, or both.

[0061] Tires can be manufactured by a conventional method. For example, the polymer composition is mixed in a kneader, formed into a sheet, and then arranged in a predetermined position (for example, in the case of a sidewall, on the outside of the carcass) and vulcanized in a conventional manner to form a tread rubber or a sidewall rubber, thereby obtaining a pneumatic tire. EXAMPLES

[0062] Hereinafter, the present disclosure will be described in detail based on examples, but the present disclosure is not limited to these examples. In the examples and comparative examples, "parts" and "%" are based on mass unless otherwise specified. The measurement methods for various physical properties of the polymer are shown below.

[0063] [Evaluation of polymer properties] Vinyl bond content (%): For the polymer before hydrogenation, 1 H-NMR was used to measure. Bound styrene content (%): For the polymer before hydrogenation, 400MHz 1 H-NMR was used to measure. 1st peak weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn): For the polymer before hydrogenation, a chart based on the molecular weight converted to polystyrene was obtained by gel permeation chromatography (GPC), and the values ​​were determined based on the chart. The specific measurement conditions for GPC are as follows: (GPC measurement conditions) Measuring instrument: HLC-8020 (Tosoh Corporation) Column: Two GMH-HR-H columns (manufactured by Tosoh Corporation) were connected in series. Detector: Differential refractometer RI-8020 (Tosoh Corporation) Eluent: Tetrahydrofuran Column temperature: 40℃ Flow rate: 1.0ml / min Sample concentration: 10mg / 20ml Hydrogenation rate (%) and α: 400MHz 1 The carbon black was determined by H-NMR. Cold flow (C / F): Cold flow was measured by extruding the polymer through a 1 / 4 inch orifice at a pressure of 3.5 pounds per square inch and a temperature of 70°C. To reach a steady state, the polymer was left to stand for 10 minutes, after which the extrusion rate was measured and expressed in grams per minute (mg / min). The smaller the cold flow value, the better the shape stability (storage stability). A cold flow value of less than 1.0 was judged as "good (A)", between 1.0 and 2.0 as "fair (B)", and 2.0 or more as "poor (C)". Equilibrium storage modulus E' (MPa): Using a dynamic viscoelasticity measuring device (manufactured by TA Instruments), the equilibrium storage modulus E' was measured in tension mode under the following conditions: measurement temperature -80°C to 150°C, heating rate 5°C / min, tensile strain 0.1%, and frequency 1Hz.

[0064] <Synthesis of hydrogenated conjugated diene polymer> [Example 1: Synthesis of hydrogenated conjugated diene polymer A and its physical properties] In a nitrogen-purged 50-liter autoclave reactor, 25,600 g of cyclohexane, 66 g of tetrahydrofuran, 960 g of styrene, and 2,176 g of 1,3-butadiene were charged. After adjusting the temperature of the contents of the reactor to 40°C, 33 mmol of n-butyllithium was added as a polymerization initiator to start polymerization. The polymerization was carried out under adiabatic conditions, and the maximum temperature reached 85°C. When the polymerization conversion reached 99% (20 minutes after the start of polymerization), 64 g of 1,3-butadiene was added over 2 minutes, and then 13 mmol of a compound represented by the following formula (N-1) was added as a terminal reactant and the reaction was carried out for 15 minutes. Next, the reaction solution was heated to 80°C or higher and hydrogen was introduced into the system. Next, 2.2 g of [bis(η5-cyclopentadienyl)titanium(furfuryloxy)chloride] as a hydrogenation catalyst, 3.6 g of diethylaluminum chloride, and 0.9 g of n-butyllithium were added, and the reaction was carried out while maintaining the hydrogen pressure at 0.7 MPa or higher. After reaching a predetermined cumulative hydrogen flow rate, the reaction solution was returned to room temperature and pressure and withdrawn from the reaction vessel to obtain a polymer solution. Next, 14 g of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, and the polymer solution was added to a desolvation tank containing water (a ratio of 200 parts by mass of water to 100 parts by mass of polymer solution), and the solvent was removed by steam stripping (steam temperature: 190°C) for 1 hour at a liquid phase temperature of 95°C in the desolvation tank, and the mixture was dried using a heated roll adjusted to 110°C to obtain a hydrogenated conjugated diene polymer A. The polymerization recipe for hydrogenated conjugated diene polymer A is shown in Table 1 below, and various physical property values ​​of the obtained hydrogenated conjugated diene polymer A are shown in Table 2 below. [ka]

[0065] [Examples 2 to 6: Synthesis of hydrogenated conjugated diene polymers B to F and their properties] Hydrogenated conjugated diene polymers B to F were obtained in the same manner as in Example 1, except that the polymerization recipe was changed as shown in Table 1 below, and the hydrogenation rate was changed as shown in Table 2 below. In Example 5, 26 mmol of piperidine was charged into the autoclave reactor together with cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene. In Example 6, 33 mmol of a compound represented by the following formula (K-2) was charged into the autoclave reactor together with cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene. Various physical property values ​​of the obtained hydrogenated conjugated diene polymers B to F are shown in Table 2 below. [Comparative Example 1: Synthesis of Unhydrogenated Conjugated Diene Polymer P and Its Properties] Except for changing the polymerization recipe as shown in Table 1 below and not carrying out the hydrogenation treatment, the same method as in Example 1 was used to obtain a non-hydrogenated modified conjugated diene polymer P. The various physical properties of the obtained conjugated diene polymer P are shown in Table 2 below. [Comparative Examples 2 to 6: Synthesis of Hydrogenated Conjugated Diene Polymers Q to U and Their Properties] Hydrogenated conjugated diene polymers Q to U were obtained in the same manner as in Example 1, except that the polymerization recipe was changed as shown in Table 1 below, and the hydrogenation rate was changed as shown in Table 2 below. Various physical property values ​​of the obtained hydrogenated conjugated diene polymers Q to U are shown in Table 2 below.

[0066] [Table 1]

[0067] In Table 1, "-" means that the compound in the corresponding column was not used. The abbreviations for the polymerization initiators and terminal reactants are as follows (the same applies to Table 2 below). K-1: Piperidine K-2: a compound represented by the following formula (K-2): N-1: a compound represented by the above formula (N-1) N-2: A compound represented by the following formula (N-2): N-3: A compound represented by the following formula (N-3): N-4: A compound represented by the following formula (N-4): N-5: Silicon tetrachloride [ka]

[0068] [Table 2]

[0069] <Production of Rubber Composition and Crosslinked Polymer> Using the (hydrogenated) conjugated diene polymers A to F and P to U produced above, each component was blended according to the blending recipe shown in Table 3 below, and the blended components were kneaded to produce rubber compositions. The kneading was performed in the following manner. Using a plastomill (capacity: 250 ml) equipped with a temperature control device, the hydrogenated or non-hydrogenated modified conjugated diene polymers (A to F, P to U), silica, a silane coupling agent, an extender oil, stearic acid, zinc oxide, and an antioxidant were blended and kneaded under the conditions of a filling rate of 72% and a rotation speed of 60 rpm in the first stage of kneading. Next, in the second stage of kneading, the blend obtained above was cooled to room temperature, and then a vulcanization accelerator and sulfur were blended and kneaded. The obtained rubber composition was molded and vulcanized in a vulcanizing press at 160°C for a predetermined time to obtain a crosslinked rubber (vulcanized rubber). In addition, the breaking strength, wear resistance at a low slip ratio, and rolling resistance (fuel economy characteristics) were evaluated as follows. The results are shown in Table 4 below. (1) Breaking strength: The crosslinked polymer was used as a measurement sample, and the tensile strength at break (TB) was measured according to JIS K6251: 2010. The larger the value, the higher and more favorable the breaking strength is. (2) Abrasion resistance: The crosslinked polymer was used as a measurement sample, and the abrasion amount was measured at a temperature of 50°C and a slip ratio of 15% using a Lambourn abrasion tester (manufactured by Shimada Giken Co., Ltd.) in accordance with JIS K6264-2:2005. The measurement results are expressed as an index with the reciprocal of the abrasion amount of Comparative Example 1 set to 100, and the larger the value, the better the abrasion resistance. (3) Rolling resistance (50°C tan δ): Crosslinked rubber was used as a measurement sample, and ARES-RDA (manufactured by TA Instruments) was used to measure under conditions of shear strain of 0.7%, angular velocity of 100 radians per second, and 50°C. The measurement results are expressed as an index with Comparative Example 1 set at 100, and the larger the value, the smaller the energy loss and the better the rolling resistance (fuel economy).

[0070] [Table 3]

[0071] [Table 4]

[0072] As can be seen from the results of Table 4 above, by producing vulcanized rubber using the rubber compositions of Examples 1 to 6, the breaking strength and abrasion resistance were greatly improved compared to the rubber compositions of Comparative Example 1 and Comparative Example 2 using (hydrogenated) conjugated diene polymers with hydrogenation rates of 0% and 70%. In addition, the rubber compositions of Examples 1 to 6 significantly improved fuel economy properties while maintaining excellent breaking strength and abrasion resistance compared to the rubber composition of Comparative Example 3 using a hydrogenated conjugated diene polymer with a hydrogenation rate of 98%. In addition, compared to the rubber compositions of Comparative Example 4 using compound (N-3) as a terminal reactant, Comparative Example 5 using compound (N-4), and Comparative Example 6 using silicon tetrachloride, the breaking strength and fuel economy properties of the vulcanized rubber were greatly improved by using the rubber compositions of Examples 1 to 6. From these results, it was confirmed that the hydrogenated conjugated diene polymers A to F could provide vulcanized rubber with high strength and excellent abrasion resistance. In addition, the vulcanized rubber obtained using the hydrogenated conjugated diene polymers A to F also had excellent rolling resistance (fuel economy performance).

Claims

1. A hydrogenated conjugated diene polymer, The nitrogen-containing compound has two or more alkoxysilyl groups and two or more nitrogen atoms, and has a structure formed by bonding the nitrogen-containing compound to a plurality of conjugated diene polymer chains. When the constituent ratios (molar ratios) of the structural unit represented by the following formula (1), the structural unit represented by the following formula (2), the structural unit represented by the following formula (3), and the structural unit represented by the following formula (4) in the polymer are p, q, r, and s, respectively, the value α represented by the following mathematical formula (i) is 0.80 or more and 0.97 or less, The molecular weight distribution as measured by gel permeation chromatography (GPC) is 1.1 or more and 2.0 or less, and A hydrogenated conjugated diene polymer having an equilibrium storage modulus E' of 2.4 MPa or more. α=(p+(0.5×r)) / (p+q+(0.5×r)+s)…(i) 【Chemistry 1】

2. The hydrogenated conjugated diene polymer according to claim 1 , wherein the conjugated diene polymer chain has a structural unit derived from an aromatic vinyl compound.

3. 3. The hydrogenated conjugated diene polymer according to claim 1, wherein the conjugated diene polymer chain is a random copolymer chain of a conjugated diene compound and an aromatic vinyl compound.

4. The hydrogenated conjugated diene polymer according to any one of claims 1 to 3, wherein the nitrogen-containing compound is at least one selected from the group consisting of a compound represented by the following formula (5) and a compound represented by the following formula (6): 【Chemistry 2】 (In formula (5), R １ and R ２ are each independently a hydrocarbyl group having 1 to 20 carbon atoms; R ３ is an alkanediyl group having 1 to 20 carbon atoms; A １ is the group "*-C(R ５ )=N-" or the group "*-N=C(R ５ ) -" (However, R ５ is a hydrogen atom or a hydrocarbyl group, and "*" is R ４ It indicates that the bond is bonded to the ４ is an m-valent hydrocarbon group having 1 to 20 carbon atoms, or an m-valent group having 1 to 20 carbon atoms which has at least one atom selected from the group consisting of nitrogen atoms, oxygen atoms, and sulfur atoms and to which no active hydrogen is bonded. n is an integer of 1 to 3, and m is an integer of 2 to 10. In the formula, multiple R １ , R ２ , R ３ , A １ , n are the same or different groups. 【Chemistry 3】 (In formula (6), R ６ , R ７ , R １０ and R １１ are each independently a hydrocarbyl group having 1 to 20 carbon atoms; R ８ and R ９ are each independently an alkanediyl group having 1 to 20 carbon atoms; A ２ is a group represented by the following formula (7), a group represented by the following formula (8), a group represented by the following formula (9), or a group represented by the following formula (10). w and p each independently represent an integer of 1 to 3. ６ , R ７ , R １０ , R １１ are the same or different groups.) 【Chemistry 4】 (In formula (7), R １２ , R １３ and R １５ are each independently a hydrocarbyl group having 1 to 20 carbon atoms; R １４ and R １６ are each independently an alkanediyl group having 1 to 20 carbon atoms, q is an integer of 1 to 3, and r is an integer of 0 to 2. １２ ~R １５ , q are the same or different groups. "*" indicates a bond to the nitrogen atom in formula (6). 【Chemistry 5】 (In formula (8), R １９ is an alkanediyl group having 3 to 20 carbon atoms, and forms a ring structure of 5 or more members with the nitrogen atom and the silicon atom in the formula. １７ and R １８ are each independently a hydrocarbyl group having 1 to 20 carbon atoms; R ２０ is an alkanediyl group having 1 to 20 carbon atoms, and s is 1 or 2. １７ , R １８ are the same or different groups. "*" indicates a bond to the nitrogen atom in formula (6). 【Chemistry 6】 (In formula (9), R ２３ is an alkanediyl group having 1 to 20 carbon atoms. ２１ is a hydrocarbylidene group having 1 to 20 carbon atoms, R ２２ is an alkanediyl group or alkenediyl group having 1 to 20 carbon atoms, and forms a ring structure of 5 or more members together with the two adjacent nitrogen atoms. "*" indicates a bond to the nitrogen atom in formula (6). 【Chemistry 7】 (In formula (10), R ２６ is a hydrocarbylene group having 1 to 20 carbon atoms, R ２４ and R ２５ are each independently a hydrocarbyl group having 1 to 20 carbon atoms, or R ２４ and R ２５ are combined together and R ２４ and R ２５ represents a ring structure having 4 to 20 carbon atoms formed together with the nitrogen atom to which R is bonded, or ２４ and R ２５ are combined together and R ２４ and R ２５ and a nitrogen atom to which R is bonded. ２４ and R ２５ represents a ring structure having 5 or more members formed together with a nitrogen atom or oxygen atom different from the nitrogen atom to which it is bonded. "*" indicates a bond to the nitrogen atom in formula (6).

5. The peak top molecular weight of the polymer having the smallest molecular weight is 1.0 x 10 ５ ~2.0 x 10 ６ The hydrogenated conjugated diene polymer according to any one of claims 1 to 4, wherein the molecular weight of the polymer is in the range of

6. The hydrogenated conjugated diene polymer according to any one of claims 1 to 5, wherein the α is 0.88 or more and 0.97 or less.

7. A polymer composition comprising the hydrogenated conjugated diene-based polymer according to any one of claims 1 to 6 and an inorganic filler.

8. A crosslinked body obtained by crosslinking the polymer composition according to claim 7.

9. A tire having a tread and / or a sidewall formed using the polymer composition according to claim 7.

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