TW202337933A - Polymer composition and method for producing same, crosslinked product, and tire - Google Patents

Abstract

Provided is a polymer composition containing: (A) a conjugated diene polymer that has a random copolymer part of a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, and that does not have a block comprising a structural unit derived from an aromatic vinyl compound, the value α of the conjugated dinen polymer, as represented by mathematical expression (i), is 0.60-0.98 where the composition ratios (molar ratios) in the polymer of the structural units represented by formulas (1), (2), (3) and (4) are p, q, r, s respectively; and (B) a hindered phenol compound having a molecular weight of 250-2000. [alpha] = (p + (0.5 * r)) / (p + q + (0.5 * r) + s) ... (i).

Description

Polymer composition and manufacturing method thereof, cross-linked product and tire

The present disclosure relates to a polymer composition, a manufacturing method thereof, a cross-linked product and a tire.

Conjugated diene-based polymers obtained by polymerization of conjugated diene compounds are widely used in pneumatic tires (pneumatic tires) because they have excellent various properties such as heat resistance, wear resistance, mechanical strength, and molding processability. tire) or anti-vibration rubber, hoses and other industrial products.

As a polymer composition used for manufacturing treads, sidewalls, etc. of pneumatic tires, it is known that a conjugated diene-based polymer is blended in order to improve the durability or wear resistance of the product. At the same time, inorganic fillers such as carbon black or silica are formulated as reinforcing agents. In addition, conventionally, in order to improve the affinity between conjugated diene polymers and reinforcing agents, conjugated diene polymers modified with compounds containing silicon or nitrogen have been used (for example, see Patent Documents 1 to 3 ).

In addition, in recent years, it has been proposed to use hydrogenated conjugated diene polymers, which are hydrides of conjugated diene polymers having functional groups such as amino groups or alkoxysilyl groups at one or both ends, to obtain high A tire member excellent in strength and wear resistance (see Patent Document 4). [Prior art documents] [Patent Document]

[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

[Problem to be solved by the invention]

We studied thermoplastic materials that exhibit rubber elasticity by introducing styrene blocks into hydrogenated conjugated diene polymers to create spatial constraints. However, the hydrogenated conjugated diene-based polymer having a styrene block may have insufficient properties (for example, strength or viscoelastic properties) as a cross-linked product due to relaxation due to the glass transition temperature of the styrene block. Therefore, as a hydrogenated conjugated diene-based polymer for obtaining a cross-linked product, research has mainly focused on hydrogenating and using a random copolymer of 1,3-butadiene and styrene.

However, since the copolymer obtained by hydrogenating a random copolymer of 1,3-butadiene and styrene does not have a block that functions as a limiting phase, it has high fluidity. Therefore, when making the conjugated diene system In the step of drying the polymer, the conjugated diene polymer is likely to adhere to equipment (for example, to a drying furnace). In addition, when polymers are likely to adhere to equipment, there is a possibility that equipment contamination may occur due to volatile components derived from polymers that adhere to and remain in the equipment, or thermal accumulation combustion of polymers remaining in the equipment may occur. Therefore, it is necessary to periodically purge the equipment, etc., which may increase the step load during manufacturing and reduce productivity.

When the solvent is removed from the polymer solution containing the conjugated diene polymer and the conjugated diene polymer is recovered, a solvent removal operation such as steam stripping is usually performed. In the desolvation operation, it is difficult to strictly manage the time for desolvation in industrial production steps. On the other hand, the Munich viscosity of the conjugated diene polymer may change due to variations in the time for desolvation, and the quality of the polymer may become unstable. In this case, since the quality of the polymer is unstable, the performance of the cross-linked product may be reduced.

The present disclosure has been made in view of the above-mentioned problems, and one of its purposes is to provide a polymer composition that can reduce the step load and stabilize the quality in the production process of the conjugated diene-based polymer, and at the same time obtain performance. Reduce inhibited cross-links. [Means to solve the problem]

Through this disclosure, the following polymer compositions and their manufacturing methods, cross-linked products and tires are provided.

[1] A polymer composition containing: (A) a conjugated diene polymer, when a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), and the following When the structural units represented by the formula (3) and the structural units represented by the following formula (4) in the polymer are represented by p, q, r, and s in the polymer, the following mathematical formula ( i) represents a value α of 0.60 to 0.98, has a random copolymerized portion of a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, and does not contain a random copolymer of a structural unit derived from an aromatic vinyl compound. a block of structural units of a base compound; and (B) a hindered phenol compound with a molecular weight of 250 to 2,000. α=(p+(0.5×r))/(p+q+(0.5×r)+s) …(i) [Chemistry 1]

[2] A cross-linked product formed by cross-linking the polymer composition of [1]. [3] A tire having a tread, a sidewall, or both formed using the polymer composition of [1]. [4] A method for producing a polymer composition, which is a method for producing the polymer composition of [1], including: adding a conjugated diene compound and an aromatic vinyl compound in the presence of an alkali metal or an alkaline earth metal. The step of polymerizing the monomer of the base compound and performing hydrogenation to obtain a polymer solution containing the component (A); mixing the polymer solution and the component (B) to obtain a polymer solution containing the component (A). The steps of making a mixed solution of component A) and component (B); and the step of desolventizing and drying the mixed solution. [Effects of the invention]

By this disclosure, it is possible to reduce the step load and stabilize the quality in the production process of the conjugated diene-based polymer. In addition, by stabilizing the quality in the polymer production process, it is possible to obtain a cross-linked product in which performance degradation is suppressed.

Hereinafter, matters related to implementation of this disclosure will be described in detail. In addition, in this specification, the numerical range described using "～" means the range including the numerical value written before and after "～" as a lower limit value and an upper limit value.

"Polymer Composition" The polymer composition of the present disclosure (hereinafter also referred to as "this composition") contains (A) a conjugated diene-based polymer, and (B) a hindered phenol compound with a molecular weight of 250 to 2,000. Hereinafter, the components contained in this composition and optionally blended components will be described in detail.

<(A) component: conjugated diene polymer> The conjugated diene polymer as component (A) (hereinafter also referred to as "(A) conjugated diene polymer") is the following highly saturated polymer, that is, when 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 following formula (4 ) represented by the structural units in the polymer are respectively p, q, r, s, the value α represented by the following mathematical formula (i) is a highly saturated polymer of 0.60 to 0.98 polymer. α=(p+(0.5×r))/(p+q+(0.5×r)+s) …(i) [Chemistry 2]

In addition, (A) the conjugated diene-based polymer is a random copolymerized portion in which structural units derived from a conjugated diene compound and structural units derived from an aromatic vinyl compound are randomly arranged, and does not include a structural unit derived from a conjugated diene compound. Random copolymer of blocks of structural units of aromatic vinyl compounds.

(A) The conjugated diene-based polymer has no particular molecular structure as long as it is a copolymer having a random copolymerized portion of a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound. limited. (A) The conjugated diene polymer may be a linear polymer (hereinafter also referred to as "linear polymer") or a polymer having a multi-branched structure (hereinafter also referred to as "branched polymer"). ”), or a mixture of these. Thus, the conjugated diene polymer can be obtained due to the difference in the treatment time (hereinafter also referred to as "desolvation time") when removing the solvent from the polymer solution containing (A) the conjugated diene polymer. From the viewpoint of a cross-linked product in which the change in Munich viscosity is small and the decrease in physical properties (for example, decrease in strength or viscoelastic properties) is suppressed, the (A) conjugated diene-based polymer preferably contains four or more branches. Branched polymers.

In addition, when used as a tire, in terms of obtaining a cross-linked product excellent in low fuel consumption performance (rolling resistance performance), (A) the conjugated diene-based polymer preferably contains a functional group (hereinafter Polymers (also referred to as "specific functional groups") (hereinafter also referred to as "polymers containing functional groups"), the functional groups include a group selected from the group consisting of nitrogen, oxygen, sulfur, phosphorus, tin and silicon at least one element in .

The position of the specific functional group in the functional group-containing polymer is not particularly limited. Examples of polymers containing functional groups include polymers having specific functional groups in the molecular chain (that is, between the terminals of the molecular chain), at the terminals of the molecular chain, or both. In the case where the functional group-containing polymer has a specific functional group at the end of the molecular chain, the functional group-containing polymer may have a specific functional group at the polymerization starting end, or may have a specific functional group at the polymerization ending end, or it may Both of the polymerization start terminal and the polymerization terminal terminal have specific functional groups. In addition, the functional group-containing polymer may have a specific functional group in a part of the terminals in one polymer molecule, or may have a specific functional group in all the terminals in one polymer molecule. In order to improve the fuel efficiency improvement effect of the cross-linked product, it is preferable that the functional group-containing polymer has specific functional groups at two or more terminals.

Here, the "functional group" in this specification is a group having a specific structure within the molecule of an organic compound, and refers to an atomic group or a bonding system that provides characteristics to the compound. Examples of specific functional groups possessed by the functional group-containing polymer include: primary amine group, secondary amine group, tertiary amine group, nitrogen-containing group in which two hydrogen atoms of the primary amine group are protected, A nitrogen-containing group formed by protecting one hydrogen atom of the secondary amine group, a phosphorus-containing group formed by protecting two hydrogen atoms of the primary phosphine group, a tertiary amine group, an imine group, a pyridyl group, and a secondary amine group. A phosphorus-containing group formed by protecting one hydrogen atom of the phosphine group, a tertiary phosphine group, an epoxy group, a thioepoxy group, a hydroxyl group, an oxygen-containing group formed by protecting a hydrogen atom of the hydroxyl group, and a thiol group , a sulfur-containing group in which the hydrogen atom of the thiol group is protected, a nitrogen-containing heterocyclic group (for example, a group with a heterocyclic ring such as a pyridine ring or an imine ring), a hydrocarbyloxysilyl group, or a hydrocarbyloxycarbonyl group , ether bond, thioether bond, the following bonding patterns, etc. [Chemical 3]

(A) The functional group-containing polymer contained in the conjugated diene polymer is preferably a conjugated diene polymer having an active terminal, and a conjugated diene polymer having an active terminal similar to that of the conjugated diene polymer. reaction points and reaction products of compounds with specific functional groups (hereinafter also referred to as "modified polymers"). In a compound (hereinafter also referred to as a "modifier") having a reaction site with an active terminal and a specific functional group possessed by a conjugated diene-based polymer, the number of reaction sites with the active terminal may be one, or Can be more than two. Specific examples of the specific functional group that the modifier has include the same groups and bonds as specific examples of the specific functional group that the functional group-containing polymer has. Such a modified polymer can be obtained by using a coupling agent or a terminal modifier described below as a modifier when producing the modified polymer.

Furthermore, when (A) the conjugated diene-based polymer contains a branched polymer and a functional group-containing polymer (preferably a modified polymer), the branched polymer and the functional group-containing polymer may be They are separate polymers with different molecular structures or physical properties. In addition, by allowing the branched polymer that is the (A) conjugated diene-based polymer to have a specific functional group, the (A) conjugated diene-based polymer can include a branched polymer and a functional group-containing polymer. From the viewpoint of further reducing the change in Munich viscosity with respect to desolvation time and stabilizing the quality, (A) the conjugated diene polymer is preferably a branched polymer containing a specific functional group, From the viewpoint of stabilizing quality and improving formulation properties such as tensile strength, it is more preferable to include a branched polymer having specific functional groups at two or more terminals, and further more preferably to include a branched polymer having specific functional groups at four or more terminals. Branched polymers with functional groups.

(A) The conjugated diene polymer is an aggregate of polymers having a structural unit derived from a conjugated diene compound. Specific forms of the (A) conjugated diene polymer include the following forms [a1] to [a5]. [a1] A polymer containing one or more polymers selected from the group consisting of a branched polymer with four or more branches (hereinafter also referred to as the "first polymer") and a linear polymer and a branched polymer with three or less branches. (hereinafter also referred to as the "second polymer"), and the first polymer and the second polymer are in the form of functional group-containing polymers. [a2] contains a first polymer and a second polymer, and the first polymer among the first polymer and the second polymer is in the form of a functional group-containing polymer. [a3] contains a first polymer and a second polymer, and the second polymer among the first polymer and the second polymer is in the form of a functional group-containing polymer. [a4] contains the second polymer but does not contain the first polymer, and the second polymer is in the form of a functional group-containing polymer. [a5] Contains a first polymer and a second polymer, and neither the first polymer nor the second polymer has a specific functional group. Among these, it is preferable to contain a first polymer and a second polymer in terms of improving the improvement effect of reducing the load in the manufacturing step and improving the physical properties of the formulation. The first polymer and the second polymer are preferably The morphology of the polymer with functional groups.

(A) The conjugated diene polymer can be produced by a method including the following polymerization step and hydrogenation step. In addition, (A) the conjugated diene polymer can also be produced by a method that includes at least one of the following reaction steps and modification steps in addition to the polymerization step and the hydrogenation step. method. Hereinafter, a method for producing the (A) conjugated diene polymer will be described, together with a description of the molecular structure, etc. of the (A) conjugated diene polymer.

＜Polymerization step＞ The polymerization step is a step of polymerizing a monomer containing a conjugated diene compound and an aromatic vinyl compound to obtain a conjugated diene polymer having an active terminal.

Examples of the conjugated diene compound used in polymerization include: 1,3-butadiene, isoprene (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, 2-chloro -1,3-butadiene, etc. 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 more preferred is One or both of 1,3-butadiene and isoprene. The conjugated diene compound may be a single type or two or more types.

Examples of the aromatic vinyl compound used in polymerization include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4- Dimethylstyrene, 2,4-diisopropylstyrene, 4-tert-butylstyrene, 5-tert-butyl-2-methylstyrene, vinylethylbenzene, divinylbenzene , trivinylbenzene, divinylnaphthalene, tert-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, N,N-bis Methylaminoethylstyrene, N,N-dimethylaminomethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-tert-butyl Styrene, 3-tert-butylstyrene, vinylxylene, vinylnaphthalene, vinylpyridine, diphenylethylene, diphenylethylene containing tertiary amine groups (such as 1-(4-N,N -Dimethylaminophenyl)-1-phenylethene) etc. As the aromatic vinyl compound, among these, one or both of styrene and α-methylstyrene is preferred. The aromatic vinyl compound may be one type alone or two or more types.

Among them, the conjugated diene polymer (A) is preferably a copolymer containing 1,3-butadiene and styrene in its monomer composition in terms of high activity in anionic polymerization. (A) The conjugated diene-based polymer is formulated in this composition by having a random copolymerized portion with irregular distribution of structural units derived from the conjugated diene compound and structural units derived from the aromatic vinyl compound. In the case of an inorganic filler, the dispersibility of the inorganic filler can be improved.

The ratio of the structural units derived from the aromatic vinyl compound in the (A) conjugated diene polymer is preferably more than 0 mass % and It is 45 mass % or less. By setting it within the above range, a cross-linked product with high strength and excellent wear resistance can be obtained while maintaining the processability of the polymer composition. The proportion of the structural units derived from the aromatic vinyl compound is more preferably 2 mass % or more, further preferably 5 mass % or more, relative to all the structural units constituting the conjugated diene polymer (A). In addition, the ratio of the structural units derived from the aromatic vinyl compound relative to all the structural units constituting the conjugated diene polymer (A) is more preferably 40 mass % or less, more preferably 38 mass % or less, and still more preferably Preferably, it is 35 mass % or less. The content ratio of ^the structural unit derived from the aromatic vinyl compound in the polymer is a value measured by ¹ H-nuclear magnetic resonance ( ¹ H-NMR).

Furthermore, (A) the conjugated diene-based polymer may have a random copolymerization part, and may be formed by adding a conjugated diene compound after random copolymerization of a conjugated diene compound and an aromatic vinyl compound. A chain portion derived from a structural unit of a conjugated diene compound. Among them, (A) the conjugated diene-based polymer does not have a block containing a structural unit derived from an aromatic vinyl compound.

Here, in this specification, (A) the conjugated diene-based polymer "does not have a block containing a structural unit derived from an aromatic vinyl compound" does not exclude (A) as long as the effect of the present disclosure is not impaired. ) The conjugated diene-based polymer has a chain portion derived from a structural unit derived from an aromatic vinyl compound, which is formed by adding an aromatic vinyl compound or the like into the reactor. Specifically, it is preferable that at least 99 mass % of the structural units derived from the aromatic vinyl compound in the conjugated diene-based polymer (A) constitute a random copolymerized part. In addition, it is preferable that 90 mass % or more of the total amount of structural units derived from the conjugated diene compound in the conjugated diene-based polymer (A) constitute a random copolymerized part, and more preferably 92 mass % or more Form a random copolymer.

The monomer used in the polymerization reaction to obtain (A) the conjugated diene-based polymer may include compounds other than the conjugated diene compound and the aromatic vinyl compound (hereinafter also referred to as "other monomers"). Examples of other monomers include acrylonitrile, methyl (meth)acrylate, ethyl (meth)acrylate, and the like. The usage ratio of other monomers is preferably 10 mass% or less, more preferably 5 mass% or less relative to the total amount of monomers used in polymerization.

As the polymerization method used, any of a solution polymerization method, a gas phase polymerization method, and a bulk polymerization method can be used. Particularly preferred among these is the solution polymerization method. In addition, as the polymerization method, either a batch type or a continuous type can be used. When a solution polymerization method is used, an example of a specific polymerization method includes a polymerization initiator and a vinyl content adjuster (hereinafter also referred to as a randomizer (hereinafter also referred to as a randomizer)) in an organic solvent. A method of polymerizing monomers containing conjugated diene compounds and aromatic vinyl compounds in the presence of a randomizer).

As a polymerization initiator, a metal compound having an alkali metal or an alkaline earth metal can be used. Among these, compounds containing alkali metals are preferred. Specific examples of alkali metal compounds include alkyl lithiums such as methyllithium, ethyllithium, n-propyllithium, n-butyllithium, 2nd-butyllithium, and 3rd-butyllithium; 1,4-butylene Dilithium (1,4-dilithiobutane), phenyllithium, stilbenelithium, naphthyllithium, 1,3-bis(1-lithio-1,3-dimethylpentyl)benzene, 1,3 -Phenylenebis(3-methyl-1-phenylpentylene)dilithium, sodium naphthyl, potassium naphthyl, potassium ethoxide, etc. Among these, lithium compounds are preferred.

In addition, the metal compound used as a polymerization initiator may be a metal amide compound containing an alkali metal or an alkaline earth metal. By performing the polymerization for obtaining (A) the conjugated diene-based polymer in the presence of a metal amide compound, it is possible to start the polymerization at the polymerization starting end of the conjugated diene-based polymer (in the case of a branched polymer). free terminal part) to introduce an amine group (preferably a secondary amine group or a tertiary amine group). The (A) conjugated diene-based polymer obtained by polymerizing a monomer in the presence of a metal amide compound can further improve the strength of the cross-linked product, and when used for tires, the cross-linked polymer can further improve the cross-linked product. It is better in terms of improving the low fuel consumption performance of the combined object.

As the metal amide compound, a compound obtained by mixing a lithium compound (eg, alkyl lithium, etc.) and a compound having a nitrogen atom (hereinafter also referred to as "starting and terminal modifier") is preferred. The starting and terminal modifier is preferably a secondary amine compound. Specific examples thereof include: dimethylamine, diethylamine, dipropylamine, dibutylamine, dodecylmethyleneimine, N,N'-dimethyl-N'-trimethyl Silyl-1,6-diaminohexane, piperidine, pyrrolidine, hexamethyleneimine, heptamethyleneimine, dicyclohexylamine, N-methylbenzylamine, di-( 2-ethylhexyl)amine, diallylamine, morpholine, N-(trimethylsilyl)piperazine, N-(tert-butyldimethylsilyl)-4-piperazine, 1, 3-Di-trimethylsilyl-1,3,5-triazacyclohexane, etc.

Furthermore, when polymerization is performed in the presence of a metal amide compound, the metal amide compound can be prepared by mixing a lithium compound and an initial terminal modifier in advance, and the prepared metal amide compound can be added to the polymerization agent. polymerization in the system. Alternatively, a lithium compound and an initial and terminal modifier may be added to the polymerization system, and the two may be mixed in the polymerization system to prepare a metal amide compound for polymerization. During polymerization, the usage amount of the polymerization initiator is preferably 0.01 mmol to 20 mmol, more preferably 0.05 mmol to 15 mmol, based on 100 g of the monomer used in the synthesis of the polymer.

The randomizing agent can be used to adjust the vinyl bond content, which indicates the vinyl bond content in the polymer, and the like. Examples of the randomizing agent include: dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-bis(tetrahydrofuranyl) )Propane, 2-(2-ethoxyethoxy)-2-methylpropane, triethylamine, pyridine, N-methylmorpholine, tetramethylethylenediamine, dodecylbenzenesulfonic acid Potassium etc. A randomizing agent can be used individually by 1 type or in combination of 2 or more types.

As the organic solvent used in the polymerization, an organic solvent that is inert in the polymerization reaction can be preferably used. Specific examples of the organic solvent used for polymerization include chain or cyclic aliphatic hydrocarbons, aromatic hydrocarbons, and the like. Among these, hydrocarbons having 3 to 8 carbon atoms are preferred. Specific examples thereof include propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, and propylene. , 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene, heptane, cyclopentene alkane, methylcyclopentane, methylcyclohexane, 1-pentene, 2-pentene, cyclohexene, etc. In addition, as the organic solvent, one type may be used alone or two or more types may be used in combination.

In the case of solution polymerization, from the viewpoint of maintaining a balance between productivity and ease of polymerization control, the monomer concentration in the reaction medium is preferably 5% by mass to 50% by mass, and more preferably 10% by mass. ~30% by mass. The temperature of the polymerization reaction is preferably -20°C to 150°C, more preferably 0°C to 120°C. In addition, the polymerization reaction is preferably performed under a pressure sufficient to substantially maintain the monomer in a liquid phase. Such pressure can be obtained by pressurizing the inside of the reactor with a gas that is inert in the polymerization reaction. By this polymerization reaction, a conjugated diene polymer having an active terminal can be obtained.

In the conjugated diene-based polymer obtained by the polymerization, the vinyl bond content in the structural unit derived from 1,3-butadiene is preferably 15 mol% to 85 mol%. By setting the vinyl bond content to 15 mol% or more, the flexibility of the obtained cross-linked product is maintained and the processability becomes good. In addition, the wear resistance in the low sliding region tends to be excellent. The vinyl bond content is preferably 20 mol% or more, more preferably 25 mol% or more. In addition, from the viewpoint of durability, the vinyl bond content of the conjugated diene polymer is preferably 75 mol% or less, more preferably 65 mol% or less. In addition, in this specification, "vinyl bond content" means having 1 with respect to all the structural units derived from 1,3-butadiene that the conjugated diene polymer before hydrogenation has. , the value of the content ratio of the 2-bond structural unit. The vinyl bond content is measured using a ¹ H-NMR device.

＜Reaction steps＞ In the reaction step, the conjugated diene polymer obtained in the polymerization step and a compound having four or more functional groups capable of reacting with the active terminals of the conjugated diene polymer (hereinafter also referred to as " Coupling agent") reaction steps. Through the reaction between a conjugated diene polymer having an active terminal and a coupling agent, four or more molecular chains of the conjugated diene polymer are bonded to one molecule of the coupling agent, thereby obtaining a polymer containing four or more branches. The branched polymer is a conjugated diene polymer (A).

As the coupling agent, a compound having at least one element selected from the group consisting of nitrogen, oxygen, sulfur, phosphorus, tin and silicon (hereinafter also referred to as "specific element") can be preferably used. When a compound containing a specific element is used as a coupling agent, it is preferable in that the strength of the obtained cross-linked product can be further improved. Furthermore, by using a compound having a specific element as a coupling agent, a modified polymer as (A) the conjugated diene-based polymer can be obtained.

Specific examples of such a coupling agent include tetrachlorosilane, bis(trichlorosilyl)ethane, and the like. In addition, as the coupling agent, as the functional group having a specific element, a functional group having the following functional groups, that is, a nitrogen-containing group in which two hydrogen atoms of the primary amine group are protected, or one hydrogen atoms of the secondary amine group can also be used. Atom-protected nitrogen-containing groups, tertiary amine groups, imine groups, nitrogen-containing heterocyclic groups (such as groups with heterocyclic groups such as pyridine rings and imine rings), hydroxyl groups, and hydrogen atoms of hydroxyl groups are A compound in which the hydrogen atom of a protected oxygen-containing group or a thiol group is protected, such as a sulfur-containing group or a hydrocarbyloxysilyl group (hereinafter also referred to as "functional group F1").

Specific examples of the coupling agent having the functional group F1 include: N,N,N',N'-tetrakis(3-trimethoxysilylpropyl)ethylenediamine, N,N,N',N' -Tetrakis(3-triethoxysilylpropyl)ethylenediamine, N,N,N'-Tris(3-trimethoxysilylpropyl)-N'-methyl-ethylenediamine, N, N,N',N'-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, N,N,N',N'-tetrakis(3-trimethoxysilylpropyl) )-1,4-butanediamine, bis(3-trimethoxysilylpropyl)-[2-(dimethylamino)ethyl]amine, bis(3-trimethoxysilylpropyl) -[2-(2,2-Dimethoxy-1-aza-2-silylcyclopentane)ethyl]amine, bis(3-triethoxysilylpropyl)-[2-( 2,2-diethoxy-1-aza-2-silylcyclopentane)ethyl]amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethyl Oxy-1-aza-2-silyl)propyl]amine, bis(3-trimethoxysilylpropyl)-[2-(2,2-dimethoxy-1-nitrogen) Hetero-2-silylcyclohexane)ethyl]amine, bis(3-trimethoxysilylpropyl)-[2-(2,2-dimethoxy-1-aza-2-silyl) Cycloctane)ethyl]amine, N,N-bis(3-trimethoxysilylpropyl)-3-imidazolylpropylamine, bis(3-trimethoxysilylpropyl)-(3- Dimethylaminopropyl)amine, compounds represented by each of the following formulas (M-1) to (M-4), etc. [Chemical 4] (In formula (M-1), R ²⁰ represents a hydrogen atom or an alkyl group; n1 represents an integer from 1 to 8)

When a conjugated diene-based polymer having an active end is reacted with a coupling agent, it is preferable to use a polymer obtained by using a starting end modifier as the conjugated diene-based polymer having an active end, thereby obtaining A branched polymer with a nitrogen-containing functional group at the end and a branch number of four or more. (A) The conjugated diene-based polymer can be obtained by preparing a polymer composition including a branched polymer having a nitrogen-containing functional group at its terminal and having a branch number of four or more. The cross-linked material has better strength and viscoelastic properties.

The reaction between the conjugated diene polymer having an active terminal and the coupling agent is preferably carried out in the form of a solution reaction. The amount of the coupling agent used (the total amount when two or more types are used) can be appropriately set so that (A) the content ratio of the four or more branched polymers in the conjugated diene-based polymer falls within the desired range. . (A) In the manufacturing step (especially the drying process) of the conjugated diene-based polymer, the adhesion of the polymer to the equipment is suppressed, equipment contamination caused by the retention of the polymer and heat storage combustion of the retained polymer are suppressed, and the From the viewpoint of stabilizing quality due to changes in Munich viscosity caused by differences in desolvation time, and from the viewpoint of obtaining high-strength cross-linked products by stabilizing polymer quality, compared to polymerization initiators (i.e. The amount of the coupling agent used is preferably 0.01 mol or more, more preferably 0.02 mol or more per 1 mol of metal atoms participating in the polymerization contained in the metal compound). In addition, from the viewpoint of adjusting the coupling ratio to a desired value, obtaining a polymer composition showing good processability, and obtaining a cross-linked product with excellent viscoelastic properties, the participation of the polymerization initiator is The usage amount of the coupling agent is preferably 0.2 mol or less per 1 mol of polymerized metal atoms, more preferably 0.1 mol or less. In addition, as a coupling agent, one type may be used alone, or two or more types may be used in combination.

In the coupling reaction, the reaction temperature is usually within the same range as the polymerization reaction. Specifically, it is preferably -20°C to 150°C, more preferably 0°C to 120°C. If the reaction temperature is low, the viscosity of the polymer after the reaction tends to increase. If the reaction temperature is high, the polymerization active terminals are likely to be deactivated. The reaction time is preferably 1 minute to 5 hours, more preferably 2 minutes to 1 hour.

By the coupling reaction, a pre-hydrogenated (A) conjugated diene-based polymer including a branched polymer having four or more branches can be obtained. The conjugated diene polymer after the coupling reaction may include a linear polymer. The linear polymer contained in the polymer solution after the coupling reaction is an unreacted polymer that has not reacted with the coupling agent among the linear polymers contained in the conjugated diene polymer having an active terminal.

＜Modification steps＞ The conjugated diene polymer obtained through the polymerization step or the reaction step can also be directly used in the subsequent hydrogenation step. In addition, the conjugated diene-based polymer obtained by the polymerization step or the reaction step may be treated as follows before the hydrogenation step: the active terminals of the conjugated diene-based polymer have specific functional groups and can be combined with The conjugated diene polymer has an active terminal reaction compound (excluding the coupling agent, also referred to as "terminal modifier" below) that reacts. By performing such treatment, when the conjugated diene polymer obtained by the polymerization step or the reaction step contains a polymer having an active terminal, (A) the conjugated diene polymer can be made to contain A polymer in which the molecular chain of a linear conjugated diene polymer is bonded to a terminal modifier (that is, it has a specific functional group). In addition, the terminal modifier is a compound different from the coupling agent in that the conjugated diene polymer has one to three active terminal reaction sites.

Preferable specific examples of the terminal modifier include 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 5] (In formula (5), A ¹¹ has at least one element selected from the group consisting of nitrogen, phosphorus, oxygen, sulfur and silicon, does not have active hydrogen, and is composed of nitrogen, ^phosphorus , oxygen, Monovalent functional groups bonded to carbon atoms contained in sulfur, silicon, or carbonyl groups, or (thio)epoxy groups; R ³³ and R ³⁴ are each independently a hydrocarbon group; R ³⁵ is a hydrocarbon group; t is 0~ An integer of 2; where, when t is 2, multiple R ³³ in the formula are the same or different from each other; when t is 0 or 1, multiple R ³⁴ in the formula are the same or different from each other) [ 6] (In formula (6), A ¹² has at least one element selected from the group consisting of nitrogen, phosphorus, oxygen, sulfur, and silicon, does not have active hydrogen, and is composed of nitrogen, phosphorus, and oxygen relative to R ³⁹ , sulfur, or silicon-bonded monovalent functional group, or a hydrocarbon group with 1 to 20 carbon atoms; R ³⁶ and R ³⁷ are each independently a hydrocarbon group; R ³⁸ is a hydrocarbon group; R ³⁹ is a single bond or a hydrocarbon group; u is 0 or 1; where, when u is 0, multiple R ³⁷ in the formula are the same or different from each other)

In the formulas (5) and (6), when R ³³ , R ³⁴ , R ³⁶ , R ³⁷ and A ¹² are hydrocarbon groups, the hydrocarbon group is preferably linear or branched with 1 to 20 carbon atoms. an alkyl group, a cycloalkyl group with 3 to 20 carbon atoms, or an aryl group with 6 to 20 carbon atoms. The hydrocarbylene group represented by R ³⁸ and R ³⁹ is preferably a linear or branched alkylene group having 1 to 20 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. . The hydrocarbyl group represented by R ³⁸ is preferably a linear or branched alkanediyl group having 1 to 20 carbon atoms. t is preferably 0 or 1.

When A ¹¹ is the monovalent functional group, A ¹¹ has at least one element selected from the group consisting of nitrogen, phosphorus, oxygen, sulfur, and silicon, and when A ¹² is the monovalent functional group, In the case of a functional group, at least one element selected from the group consisting of nitrogen, phosphorus, oxygen, sulfur, and silicon contained in A ¹² may be protected by, for example, a trisubstituted hydrocarbylsilyl group. In addition, in this specification, active hydrogen refers to a hydrogen atom bonded to an atom other than a carbon atom, and preferably refers to a hydrogen atom having a lower bonding energy than the carbon-hydrogen bond of polymethylene. (Thio)epoxy group means including an epoxy group and a thioepoxy group.

A ¹¹ may be a group that can become an onium ion by an onium salt generating agent. When the terminal modifier has such a group (A ¹¹ ), excellent shape retention properties can be imparted to the polymer. Specific examples of A ¹¹ include a nitrogen-containing group in which two hydrogen atoms of a primary amine group are protected, a nitrogen-containing group in which one hydrogen atom of a secondary amine group is protected, and a tertiary amine group. , imine group, pyridyl group, phosphorus-containing group formed by protecting two hydrogen atoms of the primary phosphine group, phosphorus-containing group formed by protecting one hydrogen atom of the secondary phosphine group, tertiary phosphine group, ring Oxygen group, thioepoxy group, oxygen-containing group formed by protecting the hydrogen atom of hydroxyl group, sulfur-containing group formed by protecting the hydrogen atom of thiol group, hydrocarbyloxycarbonyl group, etc. Among these, in terms of good affinity with silica, a group having a nitrogen atom is preferred, and a tertiary amine group or a primary amine group having two hydrogen atoms protected is more preferred. Nitrogen base. In addition, the protected group refers to a group in which A ¹¹ and A ¹² are converted into an inert functional group with respect to the polymerization active terminal. The onium salt generator is Bronsted acid or a compound that generates Bronsted acid upon contact with water.

Specific examples of the terminal modifier include compounds represented by formula (5), such as N,N-bis(trimethylsilyl)aminopropyltrimethoxysilane and N,N-dimethyl Aminopropyltriethoxysilane､N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane､N,N',N'-tris(trimethylsilyl) )-N-(2-Aminoethyl)-3-aminopropyltriethoxysilane､3-(4-trimethylsilyl-1-piperazinyl)propylmethyldimethoxy Silane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, etc.

Specific examples of the compound represented by formula (6) include: 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1,2-azasicyclopentane; 2,2-diethoxy-1-(3-trimethoxysilylpropyl)-1,2-azasicyclopentane､2,2-dimethoxy-1-phenyl-1, 2-Azasilylcyclopentane, 1-trimethylsilyl-2,2-dimethoxy-1-aza-2-silylcyclopentane､2-(2,2-dimethoxy -1,2-azasicyclopentan-1-yl)-N,N-diethylethan-1-amine､2-(2,2-dimethoxy-1,2-azasisil Cyclopentan-1-yl)-N,N-dimethylethane-1-amine､3-(2,2-dimethoxy-1,2-azasilylcyclopentan-1-yl) -N,N-diethylpropane-1-amine, etc. As the terminal modifier, one type may be used alone, or two or more types may be used in combination.

The reaction between the conjugated diene polymer having an active terminal and the terminal modifier can be carried out in the form of a solution reaction, for example. The solution reaction can be performed using either a batch method or a continuous method. At this time, the method of adding the terminal modifier is not particularly limited, and examples include a method of adding it all at once, a method of adding it in batches, a method of adding it continuously, and the like.

The amount of the terminal modifier used can be appropriately set according to the type of compound used in the reaction. The amount of the terminal modifier is preferably 0.05 mol or more, more preferably 0.1 mol or more per 1 mol of metal atoms participating in the polymerization reaction contained in the polymerization initiator. By setting the usage amount of the terminal modifier to 0.1 molar equivalent or more, the modification reaction can fully proceed, and the effect of improving the dispersion of the inorganic filler can be enhanced. In addition, the amount of the terminal modifier is preferably 1.0 mol or less, more preferably 0.8 mol or less per 1 mol of metal atoms participating in the polymerization reaction contained in the polymerization initiator.

In the modification reaction using a terminal modifier, the reaction temperature is usually the same as the polymerization reaction temperature, and is preferably -20°C to 150°C, more preferably 0°C to 120°C, and even more preferably 20°C to 100°C. If the temperature of the modification reaction is low, the viscosity of the polymer solution tends to increase. In addition, if the temperature of the modification reaction is high, the polymerization active terminals are likely to be deactivated. The reaction time during terminal modification is preferably 1 minute to 5 hours, more preferably 2 minutes to 1 hour.

(A) The coupling rate of the conjugated diene-based polymer can be determined based on the ratio of branched polymers present in the (A) conjugated diene-based polymer or the molecular weight of the conjugated diene-based polymer having an active terminal. The number of functional groups of the coupling agent used is set. From the viewpoint of suppressing the change in Munich viscosity caused by the difference in desolubilization time of (A) the conjugated diene-based polymer and stabilizing the quality, the coupling rate of the (A) conjugated diene-based polymer is relatively low. Preferably it is 10% or more, more preferably 15% or more, and still more preferably 20% or more. In addition, from the viewpoint of obtaining a polymer composition with good processability or a cross-linked product with excellent viscoelastic properties, the coupling rate of (A) the conjugated diene polymer is preferably 70% or less, More preferably, it is 60% or less, and still more preferably, it is 50% or less.

Here, in this specification, the "coupling rate" refers to the amount of linear conjugated diene polymer having an active terminal used in the reaction between the linear conjugated diene polymer having an active terminal and the modifier. The proportion (mass %) of the linear conjugated diene polymer consumed in the reaction among the chain conjugated diene polymers. Specifically, it represents the amount of the polymer used in the reaction with the coupling agent or the terminal modifier (more specifically, an aggregate of linear polymers having an active terminal) relative to the total amount of the polymer via the coupling agent. The proportion (mass %) of a polymer in which two or more linear conjugated diene polymer molecular chains are bonded by a mixture or a terminal modifier. The coupling rate can be determined from a GPC curve obtained using a gel permeation chromatograph (GPC). It is a molecule formed by bonding two or more linear conjugated diene polymer molecular chains. The components of the waveform are separated and calculated from their peak area ratios.

Furthermore, for the conjugated diene polymer having an active terminal obtained by the polymerization step, without performing both the reaction step and the modification step, the conjugated diene polymer having the active terminal can be After the polymer reacts with a polymerization terminator such as alcohol, the subsequent hydrogenation step is performed. In this case, it is preferable to obtain a conjugated diene-based polymer having a specific functional group by using an initial terminal modifier in the polymerization step.

＜Hydrogenation step＞ In the hydrogenation step, the conjugated diene polymer obtained by the polymerization step, reaction step or modification step is hydrogenated (hereinafter also referred to as "hydrogenation"). As for the method and conditions of the hydrogenation reaction, any method and conditions can be used as long as a conjugated diene polymer with a desired hydrogenation rate can be obtained. Examples of these hydrogenation methods include: a method using a catalyst containing an organic metal compound of titanium as the hydrogenation catalyst as a main component; a method using an organic metal compound containing iron, nickel, cobalt, and an organic metal compound such as alkyl aluminum Methods using compound catalysts; methods using organic complexes of organic metal compounds such as ruthenium and rhodium; methods using palladium, platinum, ruthenium, cobalt, nickel and other metals supported on carbon, silica, alumina and other carriers Catalyst methods, etc. In various methods, an organometallic compound of titanium is used alone, or a homogeneous catalyst containing an organometallic compound of titanium and an organometallic compound of lithium, magnesium, or aluminum is used (for example, Japanese Patent Publication No. Sho 63-4841, Japanese Patent Publication No. 63-4841, The catalyst described in Japanese Patent Publication No. 1-37970), the method of hydrogenating under mild conditions of low pressure and low temperature is industrially preferable. In addition, the hydrogenation selectivity for the double bond of butadiene is also appropriately high. .

The hydrogenation of the conjugated diene polymer is preferably carried out using a solvent that is inert to the catalyst and in which the conjugated diene polymer is soluble. Preferred solvents include: n-pentane, n-hexane, n-octane and other chain aliphatic hydrocarbons; cyclohexane, cycloheptane and other cyclic aliphatic hydrocarbons; benzene, toluene and other aromatic hydrocarbons; diethyl ether , tetrahydrofuran and other ethers. The solvent used for hydrogenation may be one of the above-mentioned compounds, or a mixture containing these compounds as the main component.

The hydrogenation reaction is generally carried out by maintaining the conjugated diene polymer at a predetermined temperature in hydrogen or an inert environment, adding a hydrogenation catalyst with or without stirring, and then introducing hydrogen gas and adding the hydrogenation reaction. Press to the specified pressure. The so-called inert environment refers to an environment that does not react with substances participating in the hydrogenation reaction, and examples thereof include helium, neon, argon, and the like. Air or oxygen is undesirable because it oxidizes the catalyst and deactivates the catalyst. In addition, nitrogen is undesirable because it acts as a catalyst poison during the hydrogenation reaction and reduces the hydrogenation activity. In particular, it is optimal to provide a hydrogen-only environment in the hydrogenation reactor.

The hydrogenation reaction process may use any of a batch process, a continuous process, and a combination thereof. In addition, when a titanocene diaryl compound is used as a hydrogenation catalyst, it can be added directly to the reaction solution alone or in the form of a solution in an inert organic solvent. When the catalyst is used in the form of a solution, various solvents that do not react with substances involved in the hydrogenation reaction can be used as the inert organic solvent. The same solvent as the solvent used in the hydrogenation reaction is preferred. In addition, the preferred addition amount of the catalyst is 0.02 mmol to 20 mmol per 100 g of the conjugated diene polymer before hydrogenation.

(A) In the conjugated diene polymer, when the structural unit represented by the formula (1), the structural unit represented by the formula (2), the structural unit represented by the formula (3), and the structural unit represented by the formula ( 4) When the constituent ratios (molar ratios) of the represented structural units in the polymer are respectively p, q, r, and s, the value α represented by the mathematical formula (i) is 0.60 or more and 0.98 or less. α=(p+(0.5×r))/(p+q+(0.5×r)+s) …(i)

If the value α of the (A) conjugated diene-based polymer is less than 0.60, the (A) conjugated diene-based polymer has a large amount of unsaturated bonds, so the change in the Munich viscosity caused by the difference in desolvation time becomes If it is large, the quality of the (A) conjugated diene polymer becomes unstable, or the heat storage combustibility of the (A) conjugated diene polymer attached to the equipment tends to increase. In addition, due to the instability of the quality of the conjugated diene polymer (A), the strength or viscoelastic properties of the cross-linked product may be reduced. When the value α of the conjugated diene polymer (A) exceeds 0.98, crosslinking cannot be sufficiently performed, and there is a tendency that the strength of the crosslinked product or the viscoelastic properties of the crosslinked product may be reduced. From this point of view, the value α of the conjugated diene polymer (A) is more preferably 0.65 or more, more preferably 0.70 or more, and still more preferably 0.75 or more. In addition, the value α of the conjugated diene polymer (A) is more preferably 0.97 or less, still more preferably 0.95 or less, still more preferably 0.92 or less.

In addition, the value α represented by the mathematical formula (i) corresponds to the hydrogenation rate of the conjugated diene polymer. For example, when α is 0.60, the hydrogenation rate of the conjugated diene polymer is 60%. The hydrogenation rate and value α of the conjugated diene polymer can be adjusted by adjusting the time of the hydrogenation reaction or controlling the cumulative supply amount of hydrogen. In this specification, the hydrogenation rate is a value measured using a ¹ H-NMR device. Regarding p, q, r, and s in the formula (i), for example, when the constituent ratio of each structural unit of the formulas (1) to (4) in the polymer is expressed in mol%, p, q, r, and s can each take values from 0% to 100% (where the total value of p, q, r, and s is less than 100%).

A preferred method for obtaining (A) a conjugated diene-based polymer is the following method: in the presence of a polymerization initiator (preferably a metal amide compound), a polymer containing 1,3-butadiene and benzene is Ethylene monomer is solution polymerized, and a coupling agent is added to the obtained polymer solution to perform a coupling reaction. After that, a terminal modifier is added if necessary, and then the polymer solution is subjected to a hydrogenation step. This method is superior in that it can obtain a cross-linked product excellent in various physical properties (strength, viscoelastic properties, etc.) and is effectively used industrially.

(A) The conjugated diene-based polymer has a polystyrene-equivalent weight average measured using a gel permeation chromatography (GPC) from the viewpoint of obtaining a cross-linked product with high strength and excellent abrasion resistance. The molecular weight (Mw) is preferably 1.5×10 ⁵ to 2.0×10 ⁶ . The Mw of the conjugated diene polymer is more preferably 1.8×10 ⁵ or more, further preferably 2.0×10 ⁵ or more. In addition, Mw is more preferably 1.6×10 ⁶ or less, and further preferably 1.4×10 ⁶ or less. In addition, the weight average molecular weight of the conjugated diene-based polymer described here is a value calculated from the total peak value of the GPC curve measured by GPC before hydrogenation. Hereinafter, it is also called "total average molecular weight".

In addition, for (A) the conjugated diene-based polymer, the molecular weight distribution (weight average molecular weight (Mw) versus number average molecular weight (Mn) of the total amount of the polymer (that is, an aggregate of different molecular weights) measured by GPC ) (weight average molecular weight/number average molecular weight)) is preferably 1.1 or more and 4.0 or less. When the molecular weight distribution is 1.1 or more, it is preferable because the processability is excellent. When it is 4.0 or less, it is preferable because the low hysteresis loss of the obtained cross-linked product can be sufficiently improved. (A) The molecular weight distribution of the conjugated diene-based polymer is more preferably 1.2 or more. In addition, the molecular weight distribution of (A) the conjugated diene-based polymer is more preferably 3.5 or less, further preferably 3.0 or less.

(A) The conjugated diene-based polymer preferably has a peak top molecular weight of a peak with the smallest molecular weight measured by GPC (hereinafter also referred to as "1st peak molecular weight") in the range of 0.8×10 ⁵ to 1.0×10 ⁶ . When the 1st peak molecular weight is 0.8×10 ⁵ or more, the strength of the obtained cross-linked product can be fully improved, and the viscoelastic properties and processability can be improved at the same time. The 1st peak molecular weight is more preferably 0.9×10 ⁵ or more, further preferably 1.0×10 ⁵ or more. In addition, from the viewpoint of making the viscoelastic properties and workability more excellent, the 1st peak molecular weight is more preferably 8.0×10 ⁵ or less, and further preferably 5.0×10 ⁵ or less. In addition, the 1st peak molecular weight is a value calculated from the GPC curve measured by GPC before hydrogenation.

(A) The conjugated diene polymer preferably includes a branched polymer with four or more branches, and one or more polymers selected from the group consisting of a linear polymer and a branched polymer with three or less branches ( second polymer). More specifically, the second polymer is a hydrogenated product of the conjugated diene-based polymer obtained by the polymerization step or a conjugated diene-based polymer obtained by the reaction step and is not related to The hydride of the polymer reacted with the coupling agent. From the viewpoint of improving the strength of the cross-linked product, the second polymer preferably has a specific functional group in part or all of the terminal portions, and more preferably has a specific functional group in all of the terminal portions. For example, a linear polymer in which both ends are modified can be obtained by using a metal amide compound as a polymerization initiator in the polymerization step while performing the modification step.

The ratio of the four or more branched polymers in the (A) conjugated diene polymer is preferably 10 mass % or more relative to the total amount (100 mass %) of the (A) conjugated diene polymer. By setting the ratio of the four or more branched polymers in the (A) conjugated diene-based polymer to the above range, it is possible to suppress problems caused by differences in the desolvation time of the (A) conjugated diene-based polymer. Munich viscosity changes, thereby achieving quality stabilization, which is better in this regard. (A) The proportion of the branched polymer having four or more branches in the conjugated diene-based polymer is more preferably 15% by mass or more, and further preferably 20% by mass or more. In addition, from the viewpoint of improving the processability of the polymer composition and the viscoelastic properties of the cross-linked product, the proportion of the branched polymer having four or more branches in the (A) conjugated diene-based polymer is preferably 70 The content is % by mass or less, more preferably 60 % by mass or less, and still more preferably 50 % by mass or less. (A) The proportion (mass %) of a branched polymer with four or more branches in the conjugated diene-based polymer can be calculated as follows: based on the GPC curve obtained using GPC, dividing four or more linear The components of the coupled polymer are separated by the waveform of the molecules to which the conjugated diene polymer is bonded.

The proportion of the modified polymer in the (A) conjugated diene polymer is preferably 60 mass % or more relative to the total amount of the (A) conjugated diene polymer. By setting the proportion of the modified polymer in the (A) conjugated diene polymer to the above range, the obtained cross-linked product can have good strength and viscoelastic properties. (A) The proportion of the modified polymer in the conjugated diene-based polymer is more preferably 70 mass% or more, further preferably 80 mass% or more. Furthermore, the proportion (mass %) of the modified polymer in (A) the conjugated diene-based polymer is determined by comparing the proportion of the linear polymer having a partial structure derived from the terminal modifier with the coupling rate. The value calculated by adding. The reaction rate of the terminal modifier in the reaction between the conjugated diene polymer having an active terminal and the terminal modifier can be calculated as follows: a polymer solution modified by the terminal modifier Gas chromatography was performed to quantify the unreacted terminal modification dose.

<(B) Component: Hindered phenol compound> This composition contains a hindered phenol compound (hereinafter also referred to as "(B) compound") with a molecular weight of 250 to 2,000. Here, the "hindered phenol compound" in this specification refers to carbons that have carbon atoms adjacent to both sides of the carbon to which the hydroxyl group is bonded among the carbons constituting the aromatic ring (preferably a benzene ring) to which the hydroxyl group is bonded. A compound in which a partial structure (hereinafter also referred to as a "hindered phenol structure") of a group having 1 or more carbon atoms is bonded (that is, at two ortho positions with respect to the hydroxyl group).

In the hindered phenol structure, a group with a carbon number of 1 or more bonded to adjacent carbons on both sides of the carbon to which the hydroxyl group is bonded (hereinafter also referred to as "specific group It suffices that it is within the above range and is not particularly limited. Examples of the specific group Xb include a saturated or unsaturated chain hydrocarbon group having 1 to 40 carbon atoms, a saturated or unsaturated alicyclic hydrocarbon group having 3 to 40 carbon atoms, and an aromatic hydrocarbon group having 6 to 40 carbon atoms. And groups in which one or more of the methylene groups and hydrogen atoms in these hydrocarbon groups are substituted with functional groups (such as hydroxyl, (meth)acrylyl, -O-, -S-, etc.). This suppresses the heat storage combustion of the polymer that adheres to the equipment and remains in the step of producing (A) the conjugated diene polymer (especially the drying process of the polymer), and suppresses the burning caused by the deviation in the desolvation time. From the viewpoint of stabilizing the quality by changing the viscosity and obtaining a cross-linked product showing good characteristics, at least one of the two specific groups Xb in the hindered phenol structure preferably has a carbon number of 2 or more, more preferably 4. above.

(B) At least one of the two specific groups Xb in the hindered phenol structure of the compound is preferably a tertiary carbon bonded to a carbon constituting an aromatic ring. That is, the compound (B) preferably has a carbon bonded to at least one of the carbons adjacent to both sides of the carbon in the aromatic ring to which the hydroxyl group is bonded, and the carbon is a quaternary carbon.

Examples of such hindered phenol compounds include: N-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate, tetrakis- 3-(3',5'-Di-tert-butyl-4-hydroxyphenyl)propionate}methane, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butyl phenyl)butane, distearyl(4-hydroxy-3-methyl-5-tert-butylbenzyl)malonate, triethylene glycol-bis{3-(3-tert-butyl) methyl-5-methyl-4-hydroxyphenyl)propionate}, 1,6-hexanediol-bis{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate Ester}, 2,4-bis-(N-octylthio)-6-(4-hydroxyphenyl)3,5-di-tert-butyl-aniline-1,3,5-triazine, 2 , 2-thiodiethylene bis{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate}, 2,2-thiodiethylenebis(4-methyl-6-th Tributylphenol), 2,2'-methylenebis-(4-ethyl-6-tert-butylphenol), N,N'-hexamethylenebis[3-(3,5-di -tert-butyl-4-hydroxyphenyl)propionamide], 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, 1,3,5-trimethyl- 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl ester)benzene, bis(3,5-di-tert-butyl-4-hydroxybenzyl ester) sulfide, tris(3,5-di-tert-butyl-4-hydroxybenzyl ester) (3,5-Di-tert-butyl-4-hydroxybenzyl)-isocyanurate, 2,4-bis{(octylthio)methyl}-O-cresol, isooctyl- 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N'-bis{3-(3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionyl hydrazine, (meth)acrylate compounds with hindered phenol structure, etc.

Examples of the (meth)acrylate compound having a hindered phenol structure include compounds represented by the following formula (7). [Chemical 7] (In formula (7), R ¹ to R ⁵ are independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; R ⁶ is a hydrogen atom or a methyl group)

In the formula (7), examples of the alkyl group having 1 to 10 carbon atoms represented by R ¹ to R ⁵ include: methyl, ethyl, n-propyl, isopropyl, n-butyl, second butyl, Isobutyl, tert-butyl, 1,1-dimethylpropyl, etc. Among these, ^R1 and ^R2 are preferably isopropyl, 2nd butyl, 3rd butyl, or 1,1-dimethyl in terms of high stabilization effect and ease of production. Propyl and other sterically hindered bulky alkyl groups. From the viewpoint of suppressing the formation reaction of a quinoid structure accompanied by hydrogen abstraction, R ³ and R ⁴ are preferably a tert-butyl group and a 1,1-dimethylpropyl group. R ⁵ is preferably methyl, ethyl, n-propyl and n-butyl.

As the compound (B), the effect of suppressing equipment contamination caused by volatile components or exudates during the drying process of the polymer can be improved, and the effect of reducing the step load in the step of producing the (A) conjugated diene-based polymer can be improved. In addition, it can stabilize the quality by suppressing changes in Munich viscosity caused by deviations in desolvation time, improve the strength and viscoelastic properties of cross-linked materials, or improve fuel consumption when used in tires. Among them, hindered phenol compounds having an unsaturated group are preferably used in terms of improving effects on various characteristics. When the compound (B) has an unsaturated group, examples of the unsaturated group include vinyl, (meth)acrylyl, vinylphenyl, and the like. Among these, the hindered phenol compound having an unsaturated group as the component (B) preferably has a (meth)acryl group, and is more preferably a compound represented by formula (7). Among them, preferred is a compound in which R ¹ and R ² are tert-butyl groups, R ³ and R ⁴ are methyl groups, and R ⁵ and R ⁶ are hydrogen atoms in formula (7), or R ¹ to R ⁴ are the third butyl group. A compound in which tripentyl, R ⁵ is a methyl group, and R ⁶ is a hydrogen atom.

(B) The molecular weight of the compound is 250 to 2,000. When the molecular weight of the hindered phenol compound prepared in the present composition is less than 250, the hindered phenol compound is easily phase-transferred to the mixed solvent during the desolvation step, so the residual amount in the polymer tends to decrease, and the polymerization may not be sufficiently suppressed. Thermal combustion of polymer components attached to the equipment or the volatilization of components during the drying process of objects. Therefore, the process of removing components adhering to the equipment needs to be performed frequently, and the step load increases. In addition, when the molecular weight of the hindered phenol compound exceeds 2,000, the compatibility with (A) the conjugated diene-based polymer decreases, which may lead to a decrease in performance. From this point of view, the molecular weight of the compound (B) is preferably 300 or more, more preferably 350 or more. In addition, the molecular weight of the compound (B) is preferably 1,800 or less, more preferably 1,500 or less, further preferably 1,200 or less.

The compounding amount of the (B) compound (the total amount when two or more types are used) is preferably 0.1 parts by mass or more and 2.2 parts by mass or less relative to 100 parts by mass of the (A) conjugated diene-based polymer. By setting the compounding amount of the (B) compound to 0.1 parts by mass or more, the change in the Munich viscosity with respect to the desolvation time can be further reduced, and in the drying process of the (A) conjugated diene-based polymer When used, it can reduce the heat storage combustibility of (A) the conjugated diene polymer, and at the same time, it can improve various properties such as the strength or viscoelastic properties of the cross-linked product, or the low fuel consumption performance when used in tires. From this point of view, the compounding amount of the (B) compound is more preferably 0.2 parts by mass or more, more preferably 0.4 parts by mass or more, based on 100 parts by mass of the (A) conjugated diene polymer. In addition, by setting the compounding amount of the (B) compound to 2.2 parts by mass or less, the effect of suppressing equipment contamination caused by volatile components or exudates during the drying process of the polymer tends to be improved, and the use of the compound tends to be suppressed. The strength of the cross-linked product obtained from the composition is reduced, or the fuel consumption performance when used in tires is reduced. The compounding amount of the (B) compound is more preferably 1.8 parts by mass or less, more preferably 1.4 parts by mass or less, and still more preferably 1.0 parts by mass or less relative to 100 parts by mass of the (A) conjugated diene polymer. In addition, as the (B) compound, one type may be used alone, or two or more types may be used in combination.

＜Other ingredients＞ In addition to containing (A) the conjugated diene polymer and (B) the compound, this composition may further contain the following components.

･(C) Ingredient: Specific stabilizer The present composition may further contain, as component (C), at least one compound selected from the group consisting of phosphorus-based stabilizers and organic sulfur-based stabilizers and having a molecular weight of 250 to 2,000 (hereinafter also referred to as "( C) Specific stabilizer"). By containing the compound (B) and the specific stabilizer (C), this composition can achieve the effect of further reducing the change in Munich viscosity with respect to desolvation time and achieving quality stability using a smaller amount of additives, or The effect of suppressing regenerative combustion or component volatilization caused by adhesion of the (A) conjugated diene polymer to equipment during the drying process of the (A) conjugated diene polymer. This can improve the performance of equipment contamination or cross-linked products in a well-balanced manner.

As (C) the specific stabilizer, a compound having a molecular weight in the range of 250 to 2,000 that is known as a phosphorus-based antioxidant or an organic sulfur-based antioxidant can be used. Specific examples of these include tris(2,4-di-tert-butylphenyl)phosphite, tetrakis(2,4-di-tert-butylphenyl)phosphite, and phosphorus-based stabilizers with a molecular weight of 250 to 2,000. Tributylphenyl)-4,4'-biphenyl phosphite, tris(nonylphenyl)phosphite, distearyl pentaerythritol diphosphite, bis(2,4,di-th Tributylphenyl)pentaerythritol phosphite, bis(2,6,di-tert-butyl-4-methylphenyl)pentaerythritol phosphite, 2,2-methylenebis(4,6-di -Tertiary butylphenyl)octyl phosphite, tetrakis(2,4-di-tertiary butylphenyl)4,4'-biphenyl-di-phosphite, etc. As the phosphorus-based stabilizer, one type may be used alone or two or more types may be used in combination.

Specific examples of organic sulfur-based stabilizers with a molecular weight of 250 to 2,000 include disodecyl thiodipropionate, distetradecyl thiodipropionate, and disoctadecyl thiodipropionate. , bis[3-(dodecylthio)propionic acid]2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanedi esters, pentaerythritol tetrakis (3-dodecylthiopropionate), thiobis (N-phenyl-β-naphthylamine) and other organic thioacid compounds. As the organic sulfur-based stabilizer, one type may be used alone or two or more types may be used in combination.

The compounding amount of (C) the specific stabilizer (the total amount when two or more types are used) is preferably 0.01 parts by mass or more and 2.0 parts by mass or less based on 100 parts by mass of the conjugated diene polymer (A). The compounding amount of (C) the specific stabilizer is more preferably 0.02 parts by mass or more, further preferably 0.05 parts by mass or more, based on 100 parts by mass of the (A) conjugated diene polymer. In addition, the compounding amount of (C) the specific stabilizer is more preferably 1.5 parts by mass or less, and still more preferably 1.2 parts by mass or less based on 100 parts by mass of the (A) conjugated diene-based polymer. By adjusting the compounding amount of the specific stabilizer (C) to the above range, it is possible to further reduce the additive amount of the compound (B) and at the same time, obtain the effect of further reducing the change in the Munich viscosity with respect to the deviation in the desolvation time. , or the effect of suppressing regenerative combustion or component volatilization caused by (A) conjugated diene polymer adhering to equipment during drying processing. Furthermore, as (C) the specific stabilizer, only a phosphorus-based stabilizer may be used, only an organic sulfur-based stabilizer may be used, or a phosphorus-based stabilizer and an organic sulfur-based stabilizer may be used in combination.

･(D) Ingredient: Inorganic filler This composition may contain inorganic fillers. Examples of the inorganic filler include silica and carbon black, and fillers other than silica and carbon black (hereinafter also referred to as "other fillers"). The inorganic filler prepared in this composition preferably contains one or both of silica and carbon black.

･(D-1) Ingredients: Silicon dioxide This composition may contain silicon dioxide. The blending amount of silica is preferably in the range of 20 to 120 parts by mass, more preferably 30 to 100 parts by mass relative to 100 parts by mass of the rubber component containing the (A) conjugated diene polymer. Scope. When the compounding amount of silica is 20 parts by mass or more relative to 100 parts by mass of the rubber component, the low hysteresis loss, damage characteristics, and abrasion resistance of the polymer composition can be sufficiently improved, and when it is 120 parts by mass or less , which can fully improve the processability of the polymer composition.

In this specification, the "rubber component" contained in the polymer composition refers to a polymer that can be thermally cured to obtain a cured product exhibiting rubber elasticity. This hardened product exhibits the following properties: It undergoes large deformation with a small force at room temperature (for example, deformation that elongates to more than 2 times when stretched at room temperature), and quickly returns to approximately its original shape when the force is removed. shape.

The silica is not particularly limited, and examples thereof include wet silica (water-containing silicic acid), dry silica (anhydrous silicic acid), calcium silicate, aluminum silicate, and the like. Among these, wet silica is preferred. As silica, one type may be used alone, or two or more types may be used in combination. In addition, the Brunauer-Emmett-Teller (BET) specific surface area of silica (a value measured in accordance with International Organization for Standardization (ISO) 5794/1) is preferably 40 m ² / g to 350 m ² /g, more preferably 80 m ² /g to 350 m ² /g, particularly preferably 120 m ² /g to 350 m ² /g. Silica having a BET specific surface area within this range has the advantage of achieving both rubber reinforcing properties and dispersibility in (A) the modified diene polymer. As such silica, "Nipsil AQ" (BET specific surface area = 205 m ² /g) and "Nipsil KQ" manufactured by Tosoh Silica Co., Ltd. can be used. ", commercially available products such as "Ultrasil VN3" (BET specific surface area = 175 m ² /g) manufactured by Degussa.

The silicon dioxide prepared in this composition may use two or more types with different specific surface areas in combination. Specifically, CTAB (cetyltrimethylammonium bromide) with a specific surface area of 180 m ² /g or more, BET with a specific surface area of 185 m ² /g or more, and an aggregate size of 45 nm can also be used together. The above first silica and the second silica have a CTAB specific surface area of 95 m ² /g or less and a BET specific surface area of 100 m ² /g or less. Furthermore, the CTAB specific surface area of silica is measured according to American Society for Testing Materials (ASTM) D3765-92.

This composition may contain first silica with a CTAB specific surface area of 180 m ² /g or more, a BET specific surface area of 185 m ² /g or more, an aggregate size of 45 nm or more, and a CTAB specific surface area of 95 m ² /g or less. , the second silica with a BET specific surface area of less than 100 m ² /g. By using such first silica and second silica in combination, the first silica having a small average primary particle size but a relatively large aggregate size can be dispersed well in the rubber component. In this way, the dispersion of silica is improved, and excellent fracture strength, wear resistance, low fuel consumption and processability can be obtained.

The CTAB specific surface area of the first silica is preferably 190 m ² /g or more, more preferably 195 m ² /g or more, and further preferably 197 m ² /g or more. When the CTAB specific surface area is less than 180 m ² /g, it will tend to be difficult to obtain sufficient improvement in fracture strength and wear resistance. The CTAB specific surface area of the first silica is preferably 350 m ² /g or less, more preferably 300 m ² /g or less, further preferably 250 m ² /g or less. When the CTAB specific surface area exceeds 350 m ² /g, the dispersibility is poor and it is easy to aggregate, so the physical properties tend to decrease.

The BET specific surface area of the first silica is preferably 190 m ² /g or more, more preferably 195 m ² /g or more, and further preferably 210 m ² /g or more. If the BET specific surface area is less than 185 m ² /g, it will tend to be difficult to obtain sufficient improvement in fracture strength and wear resistance. The BET specific surface area is preferably 350 m ² /g or less, more preferably 300 m ² /g or less, further preferably 260 m ² /g or less. When the BET specific surface area exceeds 350 m ² /g, the dispersibility is poor and aggregation is easy, so the physical properties tend to decrease. In addition, the BET specific surface area of silica was measured according to ASTM D3037-81.

The aggregate size of the first silicon dioxide is 45 nm or more, preferably 50 nm or more, more preferably 55 nm or more, and further preferably 60 nm or more. In addition, the aggregate size is preferably 100 nm or less, more preferably 80 nm or less, further preferably 70 nm or less, and particularly preferably 67 nm or less. By having such aggregation size, it can provide excellent low fuel consumption and wear resistance while having good dispersibility (processability). In addition, the aggregate size of silica can be measured by the method described in Japanese Patent Application Laid-Open No. 2011-140613.

The average primary particle diameter of the first silica is preferably 25 nm or less, more preferably 22 nm or less, further preferably 17 nm or less, particularly preferably 14 nm or less. The lower limit of the average primary particle size is not particularly limited, but it is preferably 3 nm or more, more preferably 5 nm or more, and still more preferably 7 nm or more. Although it has such a small average primary particle diameter, the dispersibility (processability) of silica can be further improved by having a carbon black-like structure having such aggregation size, thereby further improving fuel consumption and wear resistance. Consumability. Furthermore, the average primary particle size of silica can be measured by observing silica using a transmission or scanning electron microscope, and measuring the particle size of more than 400 primary particles of silica observed within the field of view. Find it by averaging it.

The CTAB specific surface area of the second silica is preferably 10 m ² /g or more, more preferably 20 m ² /g or more, and further preferably 30 m ² /g or more. When the CTAB specific surface area is less than 10 m ² /g, the reinforcing property is reduced, and it may become difficult to fully ensure the mechanical strength or wear resistance required for the polymer composition for tire manufacturing. The CTAB specific surface area is preferably 80 m ² /g or less, more preferably 60 m ² /g or less, further preferably 50 m ² /g or less. When the CTAB specific surface area exceeds 95 m ² /g, the dispersibility of silica becomes poor, and it may become difficult to improve the fracture strength and abrasion resistance.

The BET specific surface area of the second silica is preferably 10 m ² /g or more, more preferably 20 m ² /g or more, and further preferably 30 m ² /g or more. When the BET specific surface area is less than 10 m ² /g, the reinforcing property decreases, making it sometimes difficult to ensure the mechanical strength or wear resistance required for the polymer composition for tire manufacturing. The BET specific surface area is preferably 85 m ² /g or less, more preferably 60 m ² /g or less, further preferably 50 m ² /g or less. When the BET specific surface area exceeds 100 m ² /g, the dispersibility of silica becomes poor, and it may become difficult to improve the fracture strength and abrasion resistance.

The average primary particle diameter of the second silica is preferably 20 nm or more, more preferably 25 nm or more, further preferably 30 nm or more, particularly preferably 35 nm or more, and most preferably 55 nm or more. In addition, the upper limit of the average primary particle size is not particularly limited, but is preferably 500 nm or less, more preferably 200 nm or less, further preferably 100 nm or less, and particularly preferably 70 nm or less. By having such an average primary particle diameter, the breaking strength and abrasion resistance can be fully ensured.

･(D-2) Component: Carbon black From the viewpoint of the destruction characteristics and abrasion resistance of the polymer composition, the present composition preferably contains carbon black. The carbon black is not particularly limited. Examples include: general purpose furnace black (GPF), fast extruding furnace black (FEF), high abrasion furnace black (HAF) ), intermediate super abrasion furnace black (ISAF), super abrasion furnace black (SAF) grade carbon black. The nitrogen adsorption specific surface area (N2SA) of carbon black is not particularly limited, but is preferably 50 m ² /g to 200 m ² /g, and more preferably 70 m ² /g to 150 m ² /g. Nitrogen adsorption specific surface area (N2SA) is measured on the surface of carbon black in accordance with Japanese Industrial Standards (JIS) K6217-2:2001 "Part 2: Method for Determining Specific Surface Area - Nitrogen Adsorption Method - Single Point Method" The value of nitrogen adsorption amount. One type of carbon black may be used alone, or two or more types may be used in combination. The blending amount of the carbon black in the present composition is preferably in the range of 1 to 150 parts by mass, more preferably 5 to 120 parts by mass relative to 100 parts by mass of the conjugated diene polymer (A). Scope.

･(D-3) Component: Other fillers In addition to silica and carbon black, this composition may also contain other fillers as inorganic fillers. Examples of other fillers include alumina (Al ₂ O ₃ ) such as γ-alumina and α-alumina, and alumina monohydrate such as boehmite and diaspore. (Al ₂ O ₃ ·H ₂ O), gibbsite, bayerite and other aluminum hydroxides [Al(OH) ₃ ], aluminum carbonate [Al ₂ (CO ₃ ) ₃ ], Magnesium hydroxide [Mg(OH) ₂ ], magnesium oxide (MgO), magnesium carbonate (MgCO ₃ ), talc (3MgO·4SiO ₂ ·H ₂ O), attapulgite (5MgO·8SiO ₂ ·9H ₂ O), titanium white (TiO ₂ ), titanium black (TiO _2n-1 ), calcium oxide (CaO), calcium hydroxide [Ca(OH) ₂ ], aluminum magnesium oxide (MgO·Al ₂ O ₃ ), clay ( Al ₂ O ₃ ·2SiO ₂ ), kaolin (Al ₂ O ₃ ·2SiO ₂ ·2H ₂ O), pyrophyllite (Al ₂ O ₃ ·4SiO ₂ ·H ₂ O), bentonite (Al ₂ O ₃ ·4SiO ₂ ·2H ₂ O), aluminum silicate (Al ₂ SiO ₅ ·Al ₄ ·3SiO ₄ ·5H ₂ O, etc.), magnesium silicate (Mg ₂ SiO ₄ , MgSiO ₃ , etc.), calcium silicate (Ca ₂ SiO ₄ , etc. ), calcium aluminum silicate (Al ₂ O ₃ ·CaO · 2SiO _2, etc.), calcium magnesium silicate (CaMgSiO ₄ ), calcium carbonate (CaCO ₃ ), zirconium oxide (ZrO ₂ ), zirconium hydroxide [ZrO(OH) ₂ ·nH ₂ O], zirconium carbonate [Zr(CO ₃ ) ₂ ], various zeolites, crystalline aluminosilicates containing charge-correcting hydrogen, alkali metals or alkaline earth metals, etc.

In this composition, the blending amount of the inorganic filler containing silica and carbon black is preferably 30 parts by mass or more, more preferably 100 parts by mass of the rubber component containing the conjugated diene polymer (A) More than 40 parts by mass. In addition, the compounding amount of the inorganic filler is preferably 150 parts by mass or less, more preferably 130 parts by mass or less based on 100 parts by mass of the rubber component containing the (A) conjugated diene polymer. If the compounding amount of the inorganic filler in the present composition is within the above range, when the present composition is applied to the tread of a tire, it is possible to improve the tire's low rolling resistance, braking performance on wet road surfaces, and dryness. The road handling performance and abrasion resistance are more highly balanced.

･(E) Component: Other rubber components The present composition may contain only (A) conjugated diene polymer as a rubber component. In addition to (A) conjugated diene polymer, it may also contain (A) conjugated diene polymer within a range that does not impair the effect of the present disclosure. A) Rubber components different from conjugated diene polymers (hereinafter also referred to as "other rubber components"). As other rubber components, for example, natural rubber, isoprene rubber, butadiene rubber, emulsion polymerized styrene-butadiene rubber or solution polymerized styrene-butadiene rubber, butyl rubber, halogenated butadiene rubber can be used. At least one diene-based rubber selected from base rubber and ethylene-propylene rubber. Among these, the other rubber components are preferably natural rubber, butadiene rubber, or styrene-butadiene rubber. The manner in which other rubber components are mixed with (A) the conjugated diene polymer is not particularly limited. For example, other rubber components may be mixed with (A) the conjugated diene-based polymer during usual kneading using a banbury mixer or rollers, or may be added to the polymerized The polymer solution containing (A) the conjugated diene polymer is mixed with other rubber components, and then the solvent removal and drying steps are performed.

The compounding amount of other rubber components is preferably 80 mass % or less, more preferably 60 mass %, relative to the total amount of the rubber component ((A) conjugated diene polymer and other components) contained in the polymer composition. %the following.

In this composition, from the viewpoint of further improving dry grip performance, wet grip performance and burst resistance, liquid rubber may be used as part or all of other rubber components.

Examples of liquid rubber include liquid polyisoprene (liquid IR), liquid polybutadiene (liquid BR), liquid styrene-butadiene copolymer (liquid SBR), and liquid rubber. Ethylene-propylene copolymer (liquid EP), etc. For example, liquid SBR having a weight average molecular weight of 1,000 to 100,000, preferably 2,000 to 80,000 can be used. In addition, the weight average molecular weight in this specification means the weight average molecular weight in polystyrene conversion analyzed by gel permeation chromatography (GPC). In addition, the liquid rubber used in this composition refers to the rubber which has fluidity at 23 degreeC.

･(F) Component: Thermoplastic/Thermosetting resin This composition may contain a thermoplastic/thermosetting resin (hereinafter, also referred to as "(F) resin"). As (F) resin, from the viewpoint of obtaining a cross-linked product with better various characteristics such as strength, abrasion resistance, and crack growth resistance, it is preferably selected from the group consisting of styrene-based resins, polyethylene, and C5-based resins. , at least one of the group consisting of C9-based resin, C5/C9-based resin, dicyclopentadiene-based resin, alkylphenol-based resin, and terpene-based resin. As the (F) resin, one type may be used alone, or two or more types may be used in combination.

Here, the styrene-based resin is a polymer obtained using a styrenic-based monomer, and it is preferred that the styrenic-based resin has 20 mass % or more of polyethylene based on the total amount of monomer units contained in the styrenic-based resin. A polymer composed of styrenic monomer structural units. Examples of styrenic monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, and p-tertiary styrene. Butylstyrene, p-phenylstyrene, phosphorus chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc. The styrenic monomer is preferably at least one of styrene and α-methylstyrene among these.

The styrenic resin may be a homopolymer obtained by polymerizing one styrenic monomer, or may be a copolymer obtained by copolymerizing two or more styrenic monomers. In addition, the styrene-based resin may be a copolymer obtained by using a styrene-based monomer and other monomers copolymerizable with the styrene-based monomer. Examples of other monomers include: acrylonitriles such as acrylonitrile and methacrylonitrile; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate; Dienes such as chloroprene, butadiene and isoprene; olefins such as 1-butene and 1-pentene; α,β-unsaturated carboxylic acids such as maleic anhydride or their anhydrides, etc.

The softening point of the styrenic resin is preferably 30°C or higher, more preferably 60°C or higher, further preferably 80°C or higher. When the softening point is 30° C. or higher, the cross-linked product tends to have an improvement effect on crack growth resistance. In addition, the softening point of the styrene-based resin is preferably 160°C or lower, more preferably 130°C or lower, and even more preferably 100°C or lower. When the softening point is 160° C. or lower, the dispersibility of the resin becomes good, and crack growth resistance, abrasion resistance, and breaking strength tend to be easily improved. In addition, in this disclosure, the softening point of styrenic resin is a value measured using a ball-and-ball softening point measuring device according to the method specified in JIS K6220-1:2015. The temperature of the ball on the sample when it falls to the floor.

As the styrene-based resin, a block polymer (thermoplastic elastomer) having a conjugated diene-based polymer block as a soft segment and a polystyrene-based block as a hard segment can also be used. It is preferable to use such a block polymer because the effect of improving the crack growth resistance can be further enhanced. Furthermore, in the conjugated diene-based polymer block of the block polymer, part of the carbon-carbon double bonds in the structural units derived from the conjugated diene compound can be hydrogenated.

Examples of the conjugated diene compound constituting the conjugated diene polymer block include 1,3-butadiene, isoprene, and 2,3-dimethyl-1,3-butadiene. Diene, 1,3-pentadiene, 1,3-hexadiene, etc. As this conjugated diene compound, one type may be used alone, or two or more types may be used in combination. Among these, the conjugated diene compound is preferably at least one of 1,3-butadiene and isoprene. The content ratio of the conjugated diene unit in the block polymer is preferably 20 mass% or more, more preferably 30 mass% or more. In addition, the content ratio of the conjugated diene unit is preferably 80 mass% or less, more preferably 70 mass% or less.

In order to further improve the breaking strength, the content ratio of the polystyrene-based block in the block polymer is preferably 20 mass % or more. In addition, the content ratio of the polystyrene-based block is preferably 80 mass% or less, more preferably 70 mass% or less. Furthermore, the content ratios of the polystyrene-based block, the conjugated diene-based polymer block, and the conjugated diene unit in the block polymer can be calculated from the integral ratio of ^{the 1} H-NMR spectrum.

Specific examples of the block polymer include styrene-butadiene block copolymers, styrene-isoprene block copolymers, and epoxy styrene-butadiene block copolymers. compounds, block copolymers obtained by hydrogenating part of the conjugated diene polymer blocks of styrene-butadiene block copolymers or styrene-isoprene block copolymers, etc. . More specifically, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene- Butylene-styrene block copolymer (SBBS), epoxides of styrene-butadiene-styrene block copolymer, and hydrogenated products of these copolymers, etc. As the block polymer, in terms of easy cross-linking, among these, SBS or SIS having a soft segment unhydrogenated conjugated diene polymer block, or benzene can be preferably used. Epoxide of ethylene-butadiene-styrene block copolymer.

Examples of polyethylene include low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), and the like. C5 series resin is a solid polymer (C5 series synthetic petroleum resin) obtained by polymerizing the C5 fraction using a Friedel-Crafts type catalyst (AlCl ₃ or BF _3, etc.). Specific examples of C5-based resins include: copolymers containing isoprene, cyclopentadiene, 1,3-pentadiene, 1-pentene, etc. as main components; 2-pentene and dicyclopentene Copolymers of dienes; polymers with 1,3-pentadiene as the main component, etc.

C9 series resin is a solid polymer (C9 series synthetic petroleum resin) obtained by polymerizing the C9 fraction using a Friedel-Quaft type catalyst (AlCl ₃ or BF _3, etc.). Specific examples of C9-based resins include copolymers containing indene, methylindene, vinyltoluene, etc. as main components. C5/C9 series resin is a solid polymer (C5/C9 series synthetic petroleum resin) obtained by polymerizing the C5 to C9 fraction using a Friedel-Quaft type catalyst (AlCl ₃ or BF ₃ , etc.). Specific examples of C5/C9-based resins include copolymers containing vinyltoluene, indene, etc. as main components. Among C5/C9-based resins, from the viewpoint of compatibility with rubber components, resins containing less C9 or higher components are preferred. Specifically, in the C5/C9-based resin, the content of C9 or higher components in the total amount of the resin is preferably less than 50% by mass, and more preferably less than 40% by mass.

Dicyclopentadiene-based resin refers to a petroleum resin using dicyclopentadiene in the C5 fraction as a main raw material. Specific examples of dicyclopentadiene-based resins include: Maruzen Petrochemical Co., Ltd.'s trade name "Marukarez M" series (M-890A, M-845A, M-990A, etc.) . Examples of the alkylphenol-based resin include alkylphenol-acetylene resins such as p-tert-butylphenol-acetylene resin, alkylphenol-formaldehyde resins with a low degree of polymerization, and the like.

Terpene-based resin is turpentine obtained when rosin is obtained from trees of the genus Pinus, or is a solid resin obtained by blending a polymer component separated therefrom and polymerizing it using a Friedel-Quaft type catalyst. Examples thereof include β-pinene resin, α-pinene resin, and the like. As this terpene-based resin, commercially available products can be used. For example, "YS resin" series (trade name: PX-1250, TR-105, etc.) manufactured by Yasuhara Chemical Co., Ltd., Hercules (HERCULES) company's trade name "PICCOLYTE" series (A115, S115, etc.), etc.

Typical examples of terpene-aromatic compound resins include terpene-phenol resins. The terpene-phenol resin can be obtained by reacting terpenes and various phenols using a Friedel-Quaft type catalyst, or by further condensing the terpenes with formalin. The terpenes used as raw materials are not particularly limited, but monoterpene hydrocarbons such as α-pinene or limonene are preferred, and α-pinene is more preferred, and α-pinene is particularly preferred. In addition, as the terpene-phenol resin, a terpene-phenol resin with a small phenol component ratio is preferred. Here, "the ratio of the phenol component is small" means that the phenol component in the total amount of the resin is less than 50% by mass, and preferably 40% by mass or less. Furthermore, if a terpene-aromatic compound resin, particularly a terpene-phenol resin, is used as the (F) resin, the processing performance can be further improved. As the terpene-aromatic compound resin, commercially available products can be used. Examples of commercially available products include the trade names "Tamanol 803L", "Tamanol 901" (manufactured by Arakawa Chemical Industry Co., Ltd.), the trade names "YS Perista" (Polystar) (registered trademark)" series (manufactured by Yasuhara Chemical Co., Ltd.), etc.

The compounding ratio of the resin (F) is preferably 1 part by mass or more relative to 100 parts by mass of the rubber component contained in the composition. By blending 1 part by mass or more of (F) resin, the wear resistance, breaking strength and crack growth resistance of the cross-linked product obtained by using the present composition can be fully improved by adding (F) resin. It is better to improve the effect. (F) The compounding ratio of the resin is more preferably 3 parts by mass or more, and more preferably 7 parts by mass or more based on 100 parts by mass of the rubber component. In addition, from the viewpoint of maintaining various properties of the present composition well, the proportion of the resin (F) is preferably 50 parts by mass or less per 100 parts by mass of the rubber component contained in the composition, and more preferably 30 parts by mass or less, more preferably 25 parts by mass or less. In addition, as the (F) resin, one type may be used alone, or two or more types may be used in combination.

･(G) Ingredients: Silane coupling agent In this composition, a silane coupling agent can be blended to further improve the dispersion of silica. The silane coupling agent used is not particularly limited. The silane coupling agent is preferably a sulfur-containing silane coupling agent, and examples thereof include bis(3-triethoxysilylpropyl)tetrasulfide and bis(3-triethoxysilylpropyl)disulfide. substance, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, γ-mercaptopropyltriethoxysilane, 3-octylthiopropyltriethoxysilane, etc.

The compounding amount of the silane coupling agent is preferably 1 to 20 parts by mass relative to 100 parts by mass of silica contained in the composition. When the blending amount of the silane coupling agent is less than 1 part by mass, the blending amount is small, and the effect of improving the dispersion of silica may be reduced. On the other hand, when the compounding amount of the silane coupling agent exceeds 20 parts by mass, the processability of the polymer composition and the elongation at break of the cross-linked product may decrease. The compounding amount of the silane coupling agent is preferably 5 to 15 parts by mass relative to 100 parts by mass of silica contained in the composition.

･(H) Ingredients: Cross-linking agent This composition may contain a cross-linking agent. By containing a cross-linking agent in this composition, a cross-linked product with improved strength and wear resistance can be obtained. Examples of the crosslinking agent include sulfur, sulfur halide, organic peroxides, quinodioximes, organic polyamine compounds, alkylphenol resins having a hydroxymethyl group, and the like, and sulfur is usually used. The compounding amount of the cross-linking agent is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass relative to 100 parts by mass of the total amount of rubber components contained in the composition.

･(I) Ingredient: Filler oil In this composition, as the oil used for oil filling (filler oil), a process oil generally used for oil filling elastomers can be prepared. The method of adding process oil is not particularly limited. For example, the process oil can be developed and then desolvated to prepare an oil-extended rubber into the polymerized conjugated diene polymer solution, or it can be prepared by adding the process oil to the solution used to obtain the rubber mixture (formulated rubber). The process oil is added directly during mixing to prepare the process oil into the polymer composition. Preferred process oils include various oils known in the art, such as aromatic oils, paraffin oils, naphthenic oils, vegetable oils, and oils with low polycyclic aromatic compound content (low polycyclic aromatic compound content). Polycyclic aromatics (PCA) oil), such as mild extraction solvate (MES: mild extraction solvate), oil obtained by treating aromatic extracts from distilled oil (TDAE: treated distillate aromatic extract), Special residual aromatic extract (SRAE: special residual aromatic extract) from residual oil and heavy naphthenic oil, etc. Examples of commercially available MES, TDAE, and SRAE include Catenex SNR (heavy paraffin obtained by dewaxing distilled oil with a solvent) manufactured by Shell as MES, TDAE as Vivatec 500 manufactured by H&R Wasag AG and NC140 manufactured by Japan Energy Corp. as SRAE, etc. The blending amount of the process oil is preferably 10 to 100 parts by mass relative to 100 parts by mass of the total amount of polymer components contained in the polymer composition.

In this composition, in addition to the above-mentioned ingredients, zinc oxide, stearic acid, softeners, vulcanization accelerators, compatibilizers, vulcanization aids, processing aids, anti-scorch agents, etc. can also be prepared to obtain vulcanized rubber. Various additives commonly used in polymer compositions. The mixing ratio of these components can be appropriately selected based on the various components within a range that does not impair the effects of the present disclosure.

"Method for Manufacturing Polymer Composition" This composition can be obtained by mixing (A) a conjugated diene polymer and (B) a compound. The form of the present composition obtained by mixing the (A) conjugated diene polymer and the (B) compound is not particularly limited. In terms of improvement: the effect of suppressing changes in the Munich viscosity of the (A) conjugated diene-based polymer obtained by desolvation with respect to the difference in desolvation time of the (A) conjugated diene-based polymer, From the viewpoint of the effect of suppressing regenerative combustion or component volatilization caused by equipment contamination during the drying process, the present composition is preferably obtained by polymerizing (A) a conjugated diene-based polymer after polymerization. The (B) compound is added to the polymer solution of the product to mix the (A) conjugated diene polymer and the (B) compound, and then the solvent is removed and dried.

Specifically, the present composition is preferably produced by a method including the following steps A, B and C. Step A: In the presence of an alkali metal or an alkaline earth metal, a monomer containing a conjugated diene compound and an aromatic vinyl compound is polymerized and hydrogenated to obtain a conjugated diene-based polymer containing (A) polymer solution. Step B: a step of mixing the polymer solution obtained in step A and the compound (B) to obtain a mixed liquid containing the conjugated diene polymer (A) and the compound (B). Step C: A step of desolvating and drying the mixed solution obtained in step B.

Step A includes the polymerization step and the hydrogenation step, and is a step that optionally includes one or both of the reaction step and the modification step. The details of each step apply as described.

In step B, from the viewpoint of simplification of the production step, it is preferable to directly use the polymer solution containing (A) the conjugated diene-based polymer obtained in step A, and combine the polymer solution with (B) Compound mixing. The compounding amount of (B) compound is as mentioned above. When the (C) specific stabilizer is blended in the present composition, the (A) conjugation can be mixed by blending the (C) specific stabilizer during kneading to obtain the blended composition (so-called blended rubber). Diene polymer and (C) specific stabilizer. In addition, in step B, the (C) specific stabilizer may be added to the polymer solution to mix the (A) conjugated diene polymer and the (C) specific stabilizer. The latter (the form in which (C) the specific stabilizer is added to the polymer solution in step B) is preferred in terms of fully enhancing the effect of the preparation of the (C) specific stabilizer. In the case where (C) the specific stabilizer is added to the polymer solution in step B, the (C) specific stabilizer may be added to the polymer solution simultaneously with the (B) compound, or may be added to the (B) compound at the same time. (C) Specific stabilizer is added to the polymer solution before or after addition. The compounding amount of (C) compound is as mentioned above.

In step C, the method of removing the solvent from the mixed liquid containing (A) the conjugated diene polymer and (B) the compound and drying the mixture is not particularly limited. In order to remove the solvent from the mixed liquid and dry it, for example, a known solvent removal operation such as steam stripping and a drying operation such as heat treatment can be performed.

According to steps A to C, a solid polymer composition (hereinafter also referred to as "polymer composition P") from which the solvent is removed can be obtained as one form of the present composition. The polymer composition P may be solid particles (crumbs) or a rubber bale obtained by compression-molding crumbs into a desired shape (for example, a rectangular parallelepiped shape). In the polymer composition P, the total content of the (A) conjugated diene polymer, (B) compound, and optionally blended (I) extender oil is preferably 95 mass % or more relative to the entire composition, More preferably, it is 97 mass % or more.

By blending the various components (component (D) to component (I), etc.) as necessary in the obtained polymer composition P, a blended composition (hereinafter also referred to as "Polymer composition Q"). The compounded composition can be obtained by mixing various additives (component (D) to component (I), etc.) arbitrarily used in the polymer composition for obtaining vulcanized rubber into the polymer composition P. It is preferred to use: Mixing is performed using mixers such as open mixers (e.g. rollers), closed mixers (e.g. Banbury mixers). The compounded rubber thus obtained is cross-linked (vulcanized) after molding processing to obtain a cross-linked product (i.e., vulcanized rubber).

The cross-linked product obtained using the polymer composition of the present disclosure including (A) a conjugated diene polymer and (B) a compound can be applied to various rubber products. Specifically, the cross-linked product obtained by using the present composition can be applied to tires such as tire tread, under tread, carcass, sidewall, and bead part. Usage: gaskets, gaskets, weather strips, O-rings and other sealing materials; internal and external packaging materials for automobiles, ships, aircraft, railways and other vehicles; building materials; industrial machinery or equipment Anti-vibration rubbers; diaphragms, rollers, radiator hoses, air hoses and other hoses and hose covers; power transmission belts, etc. Category; lining; dust boot; medical machine materials; fender; insulation materials for wires; other industrial products, etc.

By the polymer composition of the present disclosure containing (A) a conjugated diene-based polymer and (B) a compound, it is possible to suppress equipment adhesion of the (A) conjugated diene-based polymer during drying and at the same time suppress Regenerative combustion or volatilization of components caused by the polymer attached to the equipment alleviates the step load in the manufacturing process, and at the same time, a cross-linked product with good physical properties required for tire applications such as tensile strength and viscoelastic properties can be obtained. Therefore, the polymer composition containing (A) the conjugated diene-based polymer and (B) the compound can be particularly preferably used as a material for the tread, sidewall, or both of the tire.

The manufacture of tires can be carried out according to conventional methods. For example, the polymer composition is mixed using a kneading machine, and the sheet-shaped ones are arranged at a predetermined position (for example, the outside of the frame in the case of a sidewall) according to a conventional method and vulcanized to form a tread or sidewall to obtain a pneumatic tire.

Through the disclosure described above, the following methods are provided. [Mode 1] A polymer composition containing: (A) a conjugated diene polymer, when the structural unit represented by the formula (1), the structural unit represented by the formula (2), and the When the structural unit represented by the above formula (3) and the structural unit represented by the above formula (4) in the polymer (molar ratio) are respectively set to p, q, r, s, the above mathematical formula (i) The value α represented by is 0.60 to 0.98, and has a random copolymerized portion of a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, and does not contain a structural unit derived from an aromatic vinyl compound. A block of structural units of a vinyl compound; and (B) a hindered phenol compound with a molecular weight of 250 to 2,000. [Aspect 2] The polymer composition according to [Aspect 1], wherein the content of the component (B) is 0.1 to 2.2 parts by mass relative to 100 parts by mass of the component (A). [Aspect 3] The polymer composition according to [Aspect 1] or [Aspect 2], wherein the component (A) contains a polymer having a functional group selected from the group consisting of nitrogen, oxygen, At least one element from the group consisting of sulfur, phosphorus, tin and silicon. [Mode 4] The polymer composition according to [Mode 3], wherein the component (A) contains a modified polymer, and the modified polymer is a conjugated diene polymer having an active terminal. Generated by reaction with a compound having a functional group containing at least one element selected from the group consisting of nitrogen, oxygen, sulfur, phosphorus, tin and silicon and having a reaction site with the active terminal material, the proportion of the modified polymer is 80 mass % or more relative to the total amount of the component (A). [Aspect 5] The polymer composition according to any one of [Aspect 1] to [Aspect 4], wherein the component (A) contains a branched polymer with a branch number of 4 or more. [Aspect 6] The polymer composition according to [Aspect 5] or [Aspect 6], wherein the proportion of branched polymers with a branch number of 4 or more is 15% by mass relative to the total amount of component (A). above. [Aspect 7] The polymer composition according to [Aspect 5] or [Aspect 6], wherein the branched polymer having a branch number of 4 or more has a nitrogen-containing functional group at the terminal. [Aspect 8] The polymer composition according to any one of [Aspect 1] to [Aspect 7], wherein the molecular weight of component (B) is 350 to 1,200. [Aspect 9] The polymer composition according to any one of [Aspect 1] to [Aspect 8], wherein the (B) component contains a compound having a carbon-carbon unsaturated bond. [Aspect 10] The polymer composition according to any one of [Aspect 1] to [Aspect 9], further containing at least one selected from the group consisting of a phosphorus-based stabilizer and an organic sulfur-based stabilizer. And it has a molecular weight of 250 to 2,000. [Aspect 11] The polymer composition according to any one of [Aspect 1] to [Aspect 10], wherein the value α is 0.75 to 0.92. [Mode 12] The polymer composition according to any one of [Mode 1] to [Mode 11], wherein the total of the component (A), the component (B), and optionally blended extending oil The content is 95% by mass or more relative to the entire composition. [Aspect 13] The polymer composition according to any one of [Aspect 1] to [Aspect 11], further containing an inorganic filler. [Mode 14] A cross-linked product cross-linked with the polymer composition described in any one of [Mode 1] to [Mode 11] and [Mode 13]. [Aspect 15] A tire having a tread, a sidewall, or both formed using the polymer composition according to any one of [Aspect 1] to [Aspect 11] and [Aspect 13]. [Mode 16] A method for producing a polymer composition according to any one of [Mode 1] to [Mode 13], including: in the presence of an alkali metal or an alkaline earth metal , the step of polymerizing a monomer containing a conjugated diene compound and an aromatic vinyl compound and hydrogenating it to obtain a polymer solution containing the component (A); combining the polymer solution with the The steps of mixing the component (B) to obtain a mixed solution containing the component (A) and the component (B); and desolvating and drying the mixed solution. [Example]

Hereinafter, specific description will be given based on Examples, but the present disclosure is not limited to these Examples. In addition, "parts" and "%" in Examples and Comparative Examples are based on mass unless otherwise specified. Methods for measuring various physical property values of polymers are shown below.

[Evaluation of polymer characteristics] ･Vinyl bond content (mol%): Measured with a 400 MHz ¹ H-NMR device for the polymer before hydrogenation. ･Bonded styrene content (%): Measured with a 400 MHz ¹ H-NMR device for the polymer before hydrogenation. ･1st peak molecular weight: For the polymer before hydrogenation, a graph of polystyrene-converted molecular weight was obtained using gel permeation chromatography (GPC, product name: HLC-8020, manufactured by Tosoh Corporation). Calculate the retention time of the peak with the longest retention time in the GPC curve obtained above. Specific measurement conditions are as follows. (Measurement conditions) Column: Two GMH-HR-H (manufactured by Tosoh Corporation) were connected in series. Detector: Differential refractometer RI-8020 (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran Column temperature: 40°C Flow rate: 1.0 mL/min Sample concentration: 10 mg/20 mL ･Total average molecular weight: before hydrogenation The polymer was determined by converting the total peak value of the GPC curve obtained using GPC (product name: HLC-8020, manufactured by Tosoh Corporation) into polystyrene. The assay conditions were the same as described. ･Coupling rate (mass %): Based on the GPC curve obtained using GPC (product name: HLC-8020, manufactured by Tosoh Corporation) for the polymer before hydrogenation, two or more linear conjugated The waveform components of molecules in which the molecular chains of the diene polymer are bonded are separated and calculated based on their peak area ratios. ･Hydrogenation rate (%) and α: Calculated from the ¹ H-NMR spectrum measured with a 100 MHz device using tetrachlorethylene as the solvent. ･Content of polymer with four or more branches (mass %): For the polymer before hydrogenation, the GPC curve obtained by using GPC (product name: HLC-8020, manufactured by Tosoh Corporation) was divided into four or more branches. The waveform components of molecules in which the molecular chains of the linear conjugated diene polymer are bonded are separated and calculated based on their peak area ratio. ･Modified polymer content (mass %): Calculated by adding the coupling rate (C/E) to the proportion of linear polymer modified with a terminal modifier (W1) (modified Polymer content = W1+C/E). The ratio W1 is the molar number of the polymerization initiator (M1) used in polymer production, the molar number of the coupling agent (M2), and the molar amount of the terminal modifier consumed when modifying with the terminal modifier. The number (M3) and the coupling rate (C/E) are calculated using the following equations. W1[%]=(100-C/E)×M3/(M1-4×M2) Furthermore, the mole number of the terminal modifier (M3) consumed when the terminal modifier is used for modification is calculated by It is calculated by measuring the unreacted terminal modifier in the polymer solution after the modification reaction using gas chromatography.

<Production of hydrogenated conjugated diene polymer> [Production Example 1: Preparation and physical properties of hydrogenated conjugated diene polymer A-1] Into an autoclave reactor with an internal volume of 50 liters that has been replaced with nitrogen, 25900 g of cyclohexane, 65 g of tetrahydrofuran, 0.6 g of potassium dodecylbenzenesulfonate, 740 g of styrene, 1,3 -Butadiene 2849 g, piperidine 30 mmol. After adjusting the temperature of the contents of the reactor to 42°C, a cyclohexane solution containing n-butyllithium (39 mmol) was added to start polymerization. The polymerization is carried out under adiabatic conditions. After the polymerization conversion rate reached 99%, 111 g of 1,3-butadiene (additional butadiene) was added, and polymerization was performed for another 3 minutes to obtain a reaction liquid containing a polymer. Add 2.0 mmol of tetrachlorosilane to the obtained reaction solution and let it react for 5 minutes. Then add 28 mmol of N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane and let it react. React for 15 minutes. Next, the temperature of the reaction liquid was set to 80° C. or higher, hydrogen was introduced into the system, and the reaction was carried out for 1 hour. A small amount of the polymer solution is extracted from the reaction vessel and used for analysis to obtain a conjugated diene polymer before hydrogenation. Then, 1.64 g of diethyl aluminum chloride, 3.67 g of bis(eta5-cyclopentadienyl)titanium (furfuryloxy) chloride, and 1.67 g of n-butyllithium were added while maintaining the hydrogen pressure at 1.0 MPa. hydrogenation reaction. After the reaction, hydrogen is supplied to maintain the hydrogen pressure above 0.7 MPa to allow the reaction to reach a prescribed hydrogen accumulation value. Then, the reaction liquid is returned to normal temperature and pressure, and is extracted from the reaction vessel to obtain a hydrogenated conjugated diene system. Polymer solution of polymer A-1. A small amount of the obtained polymer solution was extracted, desolvated by steam stripping, and dried using a hot roller adjusted to 130° C. to obtain hydrogenated conjugated diene polymer A-1. The polymerization formula of the hydrogenated conjugated diene polymer A-1 is shown in Table 1, and the various physical property values of the hydrogenated conjugated diene polymer A-1 are shown in Table 3.

[Manufacturing Examples 2 to 14, Comparative Manufacturing Examples 2 to 4: Production of hydrogenated conjugated diene polymer and its physical properties] Except that the polymerization formula was changed as described in Table 1 and Table 2, and the hydrogenation rate was changed as described in Table 3 and Table 4, a hydrogenated conjugated diene system was obtained by the same method as Production Example 1. Polymer A-2 ~ Hydrogenated conjugated diene polymer A-12, Hydrogenated conjugated diene polymer A-14 ~ Hydrogenated conjugated diene polymer A-16, Hydrogenated conjugated diene polymer A-19. A polymer solution of hydrogenated conjugated diene polymer A-20. Furthermore, in Production Examples 2 to 14, hydrogenated conjugated diene polymers A-2 to hydrogenated conjugated diene polymers A-12, hydrogenated conjugated diene polymers A-19, and Hydrogenated conjugated diene polymer A-20 and hydrogenated conjugated diene polymer A-14 to hydrogenated conjugated diene polymer A-16 were produced in Comparative Production Examples 2 to 4, respectively. Hydrogenated conjugated diene polymer A-2 to hydrogenated conjugated diene polymer A-12, hydrogenated conjugated diene polymer A-14 to hydrogenated conjugated diene polymer A-16, hydrogenated Tables 3 and 4 show various physical property values of conjugated diene polymer A-19 and hydrogenated conjugated diene polymer A-20.

[Comparative Production Example 11: Production and physical properties of hydrogenated conjugated diene polymer A-13] Into a nitrogen-substituted autoclave reactor with an internal volume of 50 liters, 25,900 g of cyclohexane, 65 g of tetrahydrofuran, and 600 g of styrene were added. After adjusting the temperature of the contents of the reactor to 42°C, a cyclohexane solution containing n-butyllithium (39 mmol) was added to start polymerization. The polymerization is carried out under adiabatic conditions. After the polymerization conversion rate reaches 99%, the reaction solution is cooled to 30°C, 700 g of styrene and 2289 g of 1,3-butadiene are added, and further temperature-raising polymerization is performed. After the polymerization conversion rate reached 99%, 28 mmol of N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane was added and allowed to react for 5 minutes. Next, the temperature of the reaction solution was set to 80°C or higher, hydrogen was introduced into the system and the reaction was carried out for 1 hour, and then a small amount of the polymer solution was extracted from the reaction vessel for analysis purposes to obtain the conjugated diene polymer before hydrogenation. Then, 1.64 g of diethyl aluminum chloride, 3.67 g of bis(eta5-cyclopentadienyl)titanium (furfuryloxy) chloride, and 1.67 g of n-butyllithium were added while maintaining the hydrogen pressure at 1.0 MPa. hydrogenation reaction. After the reaction, hydrogen is supplied to keep the hydrogen pressure above 0.7 MPa to allow the reaction to reach a prescribed hydrogen accumulation value. Then, the reaction liquid is returned to normal temperature and pressure, and is extracted from the reaction vessel to obtain a polymer solution. The obtained polymer solution was desolvated by steam stripping and dried using a hot roller adjusted to 130° C., thereby obtaining hydrogenated conjugated diene polymer A-13. The polymerization recipe of the hydrogenated conjugated diene polymer A-13 is shown in Table 2, and the various physical property values of the obtained hydrogenated conjugated diene polymer A-13 are shown in Table 4.

[Comparative Production Example 5, Comparative Production Example 6: Production and physical properties of hydrogenated conjugated diene polymer A-17 and hydrogenated conjugated diene polymer A-18] Polymer A-17 containing hydrogenated conjugated diene was obtained by the same method as Comparative Production Example 1 except that the polymerization recipe was changed as described in Table 2 and the hydrogenation rate was changed as described in Table 4. , a polymer solution of hydrogenated conjugated diene polymer A-18. Table 4 shows various physical property values of hydrogenated conjugated diene polymer A-17 and hydrogenated conjugated diene polymer A-18.

[Table 1] Manufacturing example 1 Manufacturing example 2 Manufacturing example 3 Manufacturing example 4 Manufacturing example 5 Manufacturing example 6 Manufacturing example 7 Manufacturing example 8 Manufacturing example 9 Manufacturing example 10 Polymer name A-1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10 Polymerization recipe solvent : Cyclohexane (g) 25900 25900 25900 25900 25900 25900 25900 25900 25900 25900 Vinyl content adjuster :Tetrahydrofuran (g) 65 80 180 70 65 65 65 65 65 65 :V-1 (g) 0.6 - 0.6 - 0.6 0.6 0.6 0.6 0.6 0.6 polymerized monomer : Styrene (block) (g) - - - - - - - - - - : Styrene (g) 740 370 1280 940 740 740 740 740 740 740 : Butadiene (g) 2849 3219 2309 2649 2849 2849 2849 2849 2849 2849 : Added butadiene (g) 111 111 111 111 111 111 111 111 111 111 polymerization initiator : n-butyllithium (mmol) 39 39 39 39 39 39 39 39 39 39 : Compound INI-1 (mmol) 30 30 30 30 - 30 30 30 30 - terminal modifier : Compound Md-1 (mmol) 28 20 28 28 28 28 28 34 28 - Coupling agent : Compound Cp-1 (mmol) 2.0 3.0 2.0 2.0 2.0 2.0 2.0 - 2.0 2.0

[Table 2] Manufacturing example 11 Manufacturing example 12 Comparative manufacturing example 1 Comparative manufacturing example 2 Comparative manufacturing example 3 Comparative Manufacturing Example 4 Comparative manufacturing example 5 Comparative Manufacturing Example 6 Manufacturing example 13 Manufacturing example 14 Polymer name A-11 A-12 A-13 A-14 A-15 A-16 A-17 A-18 A-19 A-20 Polymerization recipe solvent : Cyclohexane (g) 25900 25900 25900 25900 25900 25900 25900 25900 25900 25900 Vinyl content adjuster :Tetrahydrofuran (g) 65 65 65 65 65 65 65 65 65 65 :V-1 (g) 0.6 0.6 - 0.6 0.6 0.6 - - 0.6 0.6 polymerized monomer : Styrene (block) (g) - - 600 - - - 600 600 - - : Styrene (g) 740 740 700 740 740 740 700 700 740 740 : Butadiene (g) 2849 2849 2289 2849 2849 2849 2289 2289 2849 2849 : Added butadiene (g) 111 111 111 111 111 111 111 111 111 111 polymerization initiator : n-butyllithium (mmol) 39 39 39 39 39 39 39 39 39 39 : Compound INI-1 (mmol) 30 30 - 30 30 30 30 - 30 30 terminal modifier : Compound Md-1 (mmol) 28 28 28 28 28 28 28 28 28 28 Coupling agent : Compound Cp-1 (mmol) 2.0 2.0 - 2.0 2.0 2.0 2.0 2.0 2.0 2.0

In Table 1 and Table 2, "-" means the compound in the corresponding column is not used. The abbreviations of the vinyl content adjuster, initial terminal modifier, terminal modifier and coupling agent are as follows. V-1: Potassium dodecylbenzene sulfonate INI-1: piperidine Md-1: N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane Cp-1: Tetrachlorosilane

[table 3] Manufacturing example 1 Manufacturing example 2 Manufacturing example 3 Manufacturing example 4 Manufacturing example 5 Manufacturing example 6 Manufacturing example 7 Manufacturing example 8 Manufacturing example 9 Manufacturing example 10 Polymer name A-1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10 Bonded styrene content (wt%) 20 10 35 25 19 19 twenty one twenty one 20 20 Vinyl bond content (mol%) 33 35 48 36 33 35 36 35 35 35 1st peak molecular weight (×10 ⁴ ) twenty one 20 19 20 19 19 19 20 19 19 Total average molecular weight (×10 ⁴ ) 30 36 28 30 28 28 28 20 28 28 Coupling rate (%) twenty three 32 twenty one 20 twenty one twenty one twenty one 0 twenty one twenty one Hydrogenation rate (%) 82 89 79 76 82 62 97 87 84 85 α 0.82 0.89 0.79 0.76 0.82 0.62 0.97 0.87 0.84 0.85 Reaction rate of terminal modifier (%) 99 99 99 99 99 99 99 99 99 - Content of modified polymer (wt%) 92 82 92 92 92 92 92 87 92 twenty one Content of branched polymers with more than four branches (wt%) twenty two 31 20 20 20 20 20 0 20 20

[Table 4] Manufacturing example 11 Manufacturing example 12 Comparative manufacturing example 1 Comparative manufacturing example 2 Comparative manufacturing example 3 Comparative Manufacturing Example 4 Comparative manufacturing example 5 Comparative Manufacturing Example 6 Manufacturing example 13 Manufacturing example 14 Polymer name A-11 A-12 A-13 A-14 A-15 A-16 A-17 A-18 A-19 A-20 Bonded styrene content (wt%) 20 20 35 20 20 20 35 35 20 20 Vinyl bond content (mol%) 35 35 36 36 35 35 35 35 35 34 1st peak molecular weight (×10 ⁴ ) 19 19 19 19 19 19 19 19 19 19 Total average molecular weight (×10 ⁴ ) 28 28 19 28 28 28 28 27 28 28 Coupling rate (%) twenty one twenty one 0 twenty one twenty one twenty one twenty one 20 twenty one twenty one Hydrogenation rate (%) 85 85 85 93 72 5 46 99 85 85 α 0.85 0.85 0.85 0.93 0.72 0.05 0.46 0.99 0.85 0.85 Reaction rate of terminal modifier (%) 99 99 99 99 99 99 99 99 99 99 Content of modified polymer (wt%) 92 92 72 92 92 92 92 92 92 92 Content of branched polymers with more than four branches (wt%) 20 20 0 20 20 20 20 19 20 20

＜Manufacturing of polymer compositions and cross-linked products＞ [Example 1] ･Production of polymer composition P In the polymer solution containing the hydrogenated conjugated diene polymer A-1 obtained in Production Example 1, 0.2 parts by mass of the hydrogenated conjugated diene polymer A-1 was mixed with The hindered phenol compound B-1 of the component (B), the hindered phenol compound B-2 of 0.3 parts by mass, and the phosphate ester compound C-1 of the component (C) are 0.3 parts by mass. The obtained mixed liquid was desolvated by steam stripping for 2 hours and dried with a hot roller adjusted to 130°C, thereby obtaining a hydrogenated conjugated diene polymer A-1 and a hindered phenol compound B. -1. Polymer composition P-1 of hindered phenol compound B-2 and phosphate compound C-1. Table 5 shows the formulation formula of polymer composition P-1.

･Production of polymer composition Q and cross-linked products Using the polymer composition P-1 produced as described above, each component was prepared according to the preparation recipe shown in Table 7 and kneaded to produce the polymer composition Q-1. Mixing is performed as follows. Using a plastomill with a temperature control device (internal volume: 250 mL), first as the first stage of kneading, the polymer composition P- is prepared at a filling rate of 72% and a rotation speed of 60 rpm. 1. Mix silicon dioxide, carbon black, silane coupling agent, filler oil, stearic acid, zinc oxide and anti-aging agent. Next, as the second stage of kneading, the obtained preparation is cooled to room temperature, a vulcanization accelerator and sulfur are prepared, and kneaded. The kneaded polymer composition Q-1 is molded and vulcanized under pressure at 160° C. for a predetermined time to obtain a cross-linked product (vulcanized rubber). In addition, as the evaluation of the production process, the MV change rate, regenerative combustion inhibitory property and volatility due to the extension of the desolvation time were evaluated as follows, and as the preparation physical property evaluation, the tensile strength, and rolling resistance were evaluated. The results are shown in Table 8.

(1) MV change rate caused by prolonged desolvation time Polymer composition P' was obtained in the same manner except that the steam stripping time in the production of polymer composition P was changed from 2 hours to 8 hours. The Munich viscosity (MV) was measured for the polymer composition P and the polymer composition P', respectively, and the MV measurement values (MV-P, MV-P') were obtained respectively. Munich viscosity is measured in accordance with JIS K6300-1, using an L spindle, under the conditions of 1 minute preheating, 4 minutes of rotor operating time, and a temperature of 100°C. Using the MV measured values (MV-P, MV-P'), the MV change rate is calculated by the following equation. MV change rate=MV-P'/MV-P It is considered that the smaller the value of the MV change rate obtained is, and the closer it is to 1.0, the better the quality stability in the desolvation step, and the load on step management can be reduced and the more effective the use can be. Based on the following judgment criteria, AA~ C makes a decision. AA: 0.8 or more and less than 1.2 A: 1.2 or more and less than 1.5 B: 1.5 or more and less than 2.0 C: 2.0 or more or less than 0.8

(2) Regenerative combustion inhibition 350 g of polymer composition P was cut into 0.5 cm squares to obtain angular crumbs. Angular crumbs were put into a SUS metal mesh with a diameter of 10 cm, and a thermocouple for temperature measurement was placed in the gear oven so that the angular crumbs were in contact with each other. Set the gearbox to 170°C to operate, and measure the maximum temperature reached by the thermocouple during ventilation and heating for 8 hours. The lower the maximum reaching temperature, the greater the regenerative combustion suppression effect. The risk of regenerative ignition of polymer composition particles attached or retained inside and outside the drying furnace or extruder during the manufacturing process is small, and the frequency of equipment cleaning can be reduced, which can reduce the risk of ignition. Step load can be judged as effective use. Based on the maximum reached temperature, the regenerative combustion inhibitory properties are judged using A to C according to the following judgment criteria. A: The maximum reached temperature is less than 180℃ B: The maximum reaching temperature is above 180℃ and less than 210℃, the allowable range C: The maximum reached temperature is above 210℃, which is not allowed

(3) Volatility Using 10 mg of polymer composition P, determine the 0.5 wt% thermogravimetric reduction temperature (Td0.5) from 40°C at a temperature rise rate of 5°C/minute using a thermogravimetric measuring device under an atmospheric flow of 200 mL/minute. Here, the measurement temperature when the weight of the polymer composition P decreases to 0.5% by weight is defined as the 0.5% mass thermogravimetric reduction temperature (Td0.5). The higher the temperature of Td0.5, the more volatile components can be suppressed around the drying furnace or extruder during the manufacturing step, and the more it can suppress the degradation of the working environment at the manufacturing site or reduce the frequency of equipment cleaning, etc., and reduce the step load, it can be judged to be effective. use. From Td0.5, the volatility is determined using A to C based on the following criteria. A: Above 280℃ B: Above 170℃ and below 280℃, allowable range C: Below 170℃, not allowed

(4) Tensile strength The cross-linked product was used as a measurement sample, and a tensile test was performed in accordance with JISK6251:2010. Here, a dumbbell-shaped No. 3 shape was used as a test sample, and the stress at break (TB) and the elongation at break (EB) were measured at room temperature. It shows that the larger the numerical values of TB and EB are, the greater the breaking strength is, the higher the mechanical strength of the material is, and the better it is. The evaluation was performed based on the value of TB and was evaluated by an index based on Comparative Example 1. It can be said that the larger the numerical value, the greater the tensile strength and the better the strength. Based on the obtained tensile strength value, the tensile strength was determined using AA to C according to the following judgment criteria. AA: 110 or above A: More than 100 and less than 110 B: More than 80 and less than 100, acceptable range C: less than 80

(5) Rolling resistance The cross-linked product was used as a measurement sample, and measured using a dynamic spectrometer (manufactured by Rheometrics, USA) under the conditions of tensile dynamic strain of 0.7%, angular velocity of 100 radians per second, and 70°C. It is represented by the index based on Comparative Example 1, and the rolling resistance is evaluated by the index. The larger the value, the smaller and better the rolling resistance. Based on the obtained index, the rolling resistance is judged using AA to C according to the following judgment criteria. AA: 125 and above A: 115 or more and less than 125 B: More than 105 and less than 115, acceptable range C: less than 105

[Example 2 to Example 14, Comparative Example 1 to Comparative Example 6] Each polymer solution containing hydrogenated conjugated diene polymer A-2 to hydrogenated conjugated diene polymer A-20 was used instead of the polymer solution containing hydrogenated conjugated diene polymer A-1. The types and amounts are as shown in Table 5 and Table 6, except that the same procedure as in Example 1 was performed to prepare polymer compositions P-2 to P-20 as polymer composition P, respectively. In addition, when producing the polymer composition P, in Examples 2 to 14, hydrogenated conjugated diene polymer A-2 to hydrogenated conjugated diene polymer A-12, hydrogenated copolymer were used. Polymer solutions containing hydrogenated conjugated diene polymer A-19 and hydrogenated conjugated diene polymer A-20 were used in Comparative Examples 1 to 6, respectively. A polymer solution of hydrogenated conjugated diene polymer A-18. In addition, each component was prepared and kneaded according to the preparation recipe shown in Table 7 in the same manner as in Example 1, except that polymer composition P-2 to polymer composition P-20 were used instead of polymer composition P-1. , thereby producing polymer compositions Q-2 to Q-20 respectively. In addition, cross-linked products were produced using each of the produced polymer compositions Q-2 to Q-20, and various evaluations were performed in the same manner as in Example 1. The results are shown in Table 8 and Table 9.

[table 5] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Hydrogenated conjugated diene polymer Kind A-1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10 Blended quantity (parts by mass) 100 100 100 100 100 100 100 100 100 100 Hindered phenol compounds (250≦Mw≦2,000) B-1 0.2 0 0.2 0 0.5 0.2 0.1 0.2 0.2 0 B-2 0.3 0.4 0.6 0 0 0 0.5 0 0 0.5 B-3 0 0.5 0 1 0 0.3 0 0.3 0.3 0.3 B-1~B-3 total 0.5 0.9 0.8 1.0 0.5 0.5 0.6 0.5 0.5 0.8 Phosphorus stabilizer C-1 0.3 0.3 0.3 0.3 0.6 0.2 0.2 0.3 0 0.3 Organic sulfur stabilizer C-2 0 0 0 0.3 0 0 0 0 0 0 Hindered phenol compounds (Mw＜250) H-1 0 0 0 0 0 0 0 0 0 0 Polymer composition P name P-1 P-2 P-3 P-4 P-5 P-6 P-7 P-8 P-9 P-10 Polymer composition Q name Q-1 Q-2 Q-3 Q-4 Q-5 Q-6 Q-7 Q-8 Q-9 Q-10

[Table 6] Example 11 Example 12 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Example 13 Example 14 Hydrogenated conjugated diene polymer Kind A-11 A-12 A-13 A-14 A-15 A-16 A-17 A-18 A-19 A-20 Blended quantity (parts by mass) 100 100 100 100 100 100 100 100 100 100 Hindered phenol compounds (250≦Mw≦2,000) B-1 0 0.5 0 0 0 0 0.5 0 0 0.7 B-2 0 0.5 0 0 0 0 0 0 0 0.7 B-3 0.3 0.5 0.3 0 0 0.5 0 0.3 0.1 0.7 B-1~B-3 total 0.3 1.5 0.3 0.0 0.0 0.5 0.5 0.3 0.1 2.1 Phosphorus stabilizer C-1 0.2 0.5 0 0 0 0 0.4 0 0.2 0.5 Organic sulfur stabilizer C-2 0 0 0 0 0 0 0 0 0 0 Hindered phenol compounds (Mw＜250) H-1 0 0 0 0.2 2.0 0 0 0 0 0 Polymer composition P name P-11 P-12 P-13 P-14 P-15 P-16 P-17 P-18 P-19 P-20

In Table 5 and Table 6, "-" means that the compound in the corresponding column is not used. The abbreviations of additives are as follows. B-1: n-octadecyl-3-(4-hydroxy-3,5-di-tert-butylphenyl)-propionate B-2: 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl=acrylate B-3: Pentaerythritol = Tetrakis [3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate] C-1: Tris(2,4-di-tert-butylphenyl)phosphite C-2: 2,2-bis({[3-(dodecylthio)propyl]oxy}methyl)-1,3-propanediyl=bis[3-(dodecyl thio)propionate] H-1: 2,6-di-tert-butyl-4-methylphenyl

[Table 7] Preparation formula (polymer composition Q) (phr) Polymer composition P 100 Silicon dioxide*1) 38 Carbon black*2) 37 Silane coupling agent*3) 3.2 Filling oil*4) 34 stearic acid 2.0 zinc oxide 3.0 Anti-aging agent*5) 1.0 Vulcanization accelerator CZ *6) 1.8 Vulcanization accelerator D *7) 1.5 sulfur 1.5 *1) ZEOSIL 1165MP manufactured by Rhodia *2) Seast 3 manufactured by Tokai Carbon *3) Si75 *4 manufactured by Evonik ) Process oil T-DAE manufactured by ENEOS Co., Ltd. *5) Ozonone 6C manufactured by Seiko Chemical Co., Ltd. *6) Nocceler CZ manufactured by Ouchi Shinko Chemical Industry Co., Ltd. *7) Large Nocceler D manufactured by Naishin Shin Chemical Industries Co., Ltd.

[Table 8] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Hydrogenated conjugated diene polymer in polymer composition Q A-1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10 Manufacturing step evaluation MV change rate caused by prolonged desolvation time AA AA AA A A B AA B A AA Regenerative combustion inhibition A A A A A B A A B A Volatility A A A A A A A A A A Blending physical properties tensile strength AA AA A A B B B AA A B rolling resistance AA A AA AA A AA B A A B

[Table 9] Example 11 Example 12 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Example 13 Example 14 Hydrogenated conjugated diene polymer in polymer composition Q A-11 A-12 A-13 A-14 A-15 A-16 A-17 A-18 A-19 A-20 Manufacturing step evaluation MV change rate caused by prolonged desolvation time B AA A C C C B A B AA Regenerative combustion inhibition B A A C B C C A B A Volatility A B A B C A A A A B Blending physical properties tensile strength A B B B B C C C B B rolling resistance B B C C C B C C B B

As shown in Table 8 and Table 9, the polymer compositions of Examples 1 to 14 were evaluated as "AA" and "A" in terms of MV change rate, regenerative combustion inhibitory property, and volatility due to prolonged desolvation time. Or "B". Based on these results, it can be said that the polymer compositions of Examples 1 to 14 can reduce the load in the production process and have good quality stability. In addition, the cross-linked products obtained from the polymer compositions of Examples 1 to 14 have high tensile strength and good rolling resistance, showing excellent compounding characteristics.

On the other hand, the rolling resistance evaluation of the polymer composition of Comparative Example 1 in which a hydrogenated conjugated diene-based polymer having a styrene block was blended was “C”. In addition, the polymer compositions of Comparative Example 2 and Comparative Example 3, which do not contain a hindered phenol compound with a molecular weight of 250 or more, and the polymer of Comparative Example 4, which contains a hydrogenated conjugated diene-based polymer with a hydrogenation rate of 5%. The evaluation of the MV change rate of the composition due to the prolongation of the desolvation time was "C". Compared with the polymer compositions of Examples 1 to 14, it can be said that the quality stability in the desolvation step is poor and the step management is poor. The load is also large. The polymer composition of Comparative Example 3 was evaluated as "C" in terms of volatility and rolling resistance, and the polymer composition of Comparative Example 4 was evaluated as "C" in terms of regenerative combustion inhibitory properties and tensile strength. The polymer composition of Comparative Example 5, in which a hydrogenated conjugated diene-based polymer having a styrene block and a hydrogenation rate of 46% was blended, was evaluated as "C" in terms of regenerative combustion inhibitory properties, tensile strength, and rolling resistance. , the polymer composition of Comparative Example 6, which was formulated with a hydrogenated conjugated diene polymer having a styrene block and a hydrogenation rate of 99%, had improved regenerative combustion inhibition properties, but the evaluation of tensile strength and rolling resistance is "C".

From the above results, it is clear that a polymer composition containing a structural unit derived from a conjugated diene compound has an α value represented by the formula (1) of 0.6 or more and 0.98 or less. A conjugated diene-based polymer with a random copolymerization part with a structural unit derived from an aromatic vinyl compound and having no block containing a structural unit derived from an aromatic vinyl compound, and a molecular weight of 250 to 2,000 The polymer composition of the hindered phenol compound can reduce the step load and stabilize the quality in the production process of the conjugated diene polymer, and can also obtain a cross-linked product in which performance degradation is suppressed.

without

without

Claims (16)

A polymer composition containing: (A) a conjugated diene polymer, when the structural unit represented by the following formula (1), the structural unit represented by the following formula (2), and the following formula (3) ) and the structural units represented by the following formula (4) in the polymer are represented by p, q, r, and s, respectively, the following formula (i) The expressed value α is 0.60 to 0.98, and has a random copolymerized portion of a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, and does not include a structural unit derived from an aromatic vinyl compound. Blocks of structural units; and (B) hindered phenol compounds with a molecular weight of 250 to 2,000, α=(p+(0.5×r))/(p+q+(0.5×r)+s)…(i) . The polymer composition according to claim 1, wherein the content of the component (B) is 0.1 to 2.2 parts by mass relative to 100 parts by mass of the component (A). The polymer composition according to claim 1, wherein the (A) component includes a polymer having a functional group, and the functional group includes a polymer selected from the group consisting of nitrogen, oxygen, sulfur, phosphorus, tin and silicon. At least one element in the group. The polymer composition according to claim 3, wherein the (A) component includes a modified polymer, and the modified polymer is a conjugated diene polymer having an active terminal and the following compound: That is, a reaction product of a compound having a functional group containing at least one element selected from the group consisting of nitrogen, oxygen, sulfur, phosphorus, tin and silicon and having a reaction point with the active terminal, The proportion of the modified polymer is 80% by mass or more relative to the total amount of component (A). The polymer composition according to claim 1, wherein the component (A) contains a branched polymer with a branch number of 4 or more. The polymer composition according to claim 5, wherein the proportion of branched polymers with a branch number of 4 or more is 15 mass % or more relative to the total amount of component (A). The polymer composition according to claim 5, wherein the branched polymer with a branch number of 4 or more has a nitrogen-containing functional group at the end. The polymer composition according to claim 1, wherein the molecular weight of component (B) is 350 to 1,200. The polymer composition according to claim 1, wherein the (B) component contains a compound having a carbon-carbon unsaturated bond. The polymer composition according to claim 1 further contains at least one component selected from the group consisting of a phosphorus-based stabilizer and an organic sulfur-based stabilizer and having a molecular weight of 250 to 2,000. The polymer composition according to claim 1, wherein the value α is 0.75 to 0.92. The polymer composition according to claim 1, wherein the total content of the component (A), the component (B), and optionally blended filler oil is 95 mass % or more relative to the entire composition. The polymer composition as claimed in claim 1 further contains an inorganic filler. A cross-linked product formed by cross-linking the polymer composition described in any one of claims 1 to 11 and 13. A tire formed with a tread, a sidewall, or both using the polymer composition according to any one of claims 1 to 11 and 13. A method for manufacturing a polymer composition, which is a method for manufacturing the polymer composition as described in any one of claims 1 to 13, including: The step of polymerizing a monomer containing a conjugated diene compound and an aromatic vinyl compound in the presence of an alkali metal or an alkaline earth metal, and hydrogenating it to obtain a polymer solution containing the component (A) ; The step of mixing the polymer solution and the component (B) to obtain a mixed solution containing the component (A) and the component (B); and The mixture is desolvated and dried.