Conjugated diene polymer composition and tire

Abstract

To provide a conjugated diene polymer composition excellent in rolling resistance, grip performance on a wet road surface, and in wear resistance when formed into a tire.SOLUTION: The conjugated diene polymer contains 10 to 90 pts.mass of a conjugated diene polymer (A) having a glass transition temperature of -20°C or higher and 10 to 90 pts.mass of conjugated diene polymer (B) having a glass transition temperature of - 25°C or lower, in which the conjugated diene polymer (A) has an absolute molecular weight due to a GPC-light scattering measurement method with a viscosity detector is 40×104 or larger and 5000×104 or smaller and the degree of branching (Bn) due to the GPC-light scattering measurement method with a viscosity detector is 8 or larger.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a conjugated diene-based polymer composition and a tire. [Background technology]

[0002] 2. Description of the Related Art There has been an increasing demand for improved fuel economy in automobiles, and this has led to a demand for improvements in the materials used in automobile tires, particularly in the tire treads that come into contact with the ground. In recent years, there has been a demand for the development of materials having low rolling resistance, i.e., low hysteresis loss. In addition, to reduce the weight of tires, it is necessary to reduce the thickness of the tread, and materials with high abrasion resistance are also required. On the other hand, from the viewpoint of safety, materials used for tire treads are required to have excellent wet skid resistance and sufficient fracture properties for practical use.

[0003] As a rubber material that meets the above-mentioned requirements, for example, there is a rubber composition containing a rubber-like polymer and a reinforcing filler such as carbon black or silica. It is already known that the use of silica as a reinforcing filler improves the balance between low hysteresis loss and wet skid resistance in a rubber composition.

[0004] Also, attempts have been made to improve the dispersibility of silica in a rubber composition by introducing a functional group having affinity or reactivity with silica to the molecular end of a rubber-like polymer with high mobility, and further to reduce the mobility of the molecular end of the rubber-like polymer by bonding with silica particles, thereby reducing hysteresis loss and improving wear resistance and fracture strength. For example, a composition of silica and a modified conjugated diene polymer obtained by reacting an alkoxysilane containing an amino group with the active end of a conjugated diene polymer has been proposed (see, for example, Patent Documents 1 to 3).

[0005] On the other hand, it is known that if an attempt is made to reduce the hysteresis loss in the tread portion in order to further reduce the rolling resistance of the tire, the grip performance on wet road surfaces will decrease. In view of this, it has been proposed that a modified conjugated rubber composition containing a specific modified conjugated diene polymer, a silica-based inorganic filler, and a tackifier, i.e., a thermoplastic resin, has excellent low rolling properties and grip performance on wet road surfaces (see, for example, Patent Document 4). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2005-290355 A [Patent Document 2] Japanese Patent Application Publication No. 11-189616 [Patent Document 3] JP 2003-171418 A [Patent Document 4] JP 2018-28018 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, since thermoplastic resins have low affinity with silica-based inorganic fillers, in the modified conjugated rubber composition containing the thermoplastic resin described in Patent Document 4, the dispersibility of the silica-based inorganic filler is deteriorated, and the hysteresis loss is increased. From this viewpoint, this leads to a deterioration in the rolling resistance of the tire, and further, the interface reinforcing effect of the silica-based inorganic filler is reduced, resulting in a problem of a deterioration in abrasion resistance.

[0008] Therefore, an object of the present invention is to provide a conjugated diene polymer composition which can provide a tire having excellent rolling resistance, grip performance on wet road surfaces, and abrasion resistance. [Means for solving the problem]

[0009] Means for Solving the Problems of the Prior Art As a result of intensive research and investigation, the present inventors have found that a conjugated diene-based polymer composition containing two types of conjugated diene-based polymers (A) and (B) having different glass transition temperatures, wherein the conjugated diene-based polymer (A) has an absolute molecular weight within a predetermined range and a degree of branching (Bn) within a predetermined range, when made into a tire, has excellent rolling resistance, grip performance on wet road surfaces and abrasion resistance, and have completed the present invention. That is, the present invention is as follows.

[0010] [1] 10 to 90 parts by mass of a conjugated diene polymer (A) having a glass transition temperature of -20°C or higher; 10 to 90 parts by mass of a conjugated diene polymer (B) having a glass transition temperature of −25° C. or lower; Contains The conjugated diene polymer (A) has an absolute molecular weight of 40×10 as measured by a GPC-light scattering method with a viscosity detector. 4 Over 5000 x 10 4 and the branching degree (Bn) measured by the viscosity detector-equipped GPC-light scattering method is 8 or more. the law of nature, the conjugated diene polymer (A) is a conjugated diene polymer having a star-shaped polymer structure with three or more branches, at least one branched chain of the star-shaped structure has a moiety derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group, and the polymer chain is branched at the moiety derived from the vinyl-based monomer containing an alkoxysilyl group or a halosilyl group; Conjugated diene polymer composition. [2] The conjugated diene polymer composition according to [1] above, wherein the conjugated diene polymer (B) has a glass transition temperature of −55° C. or lower. [3] The conjugated diene polymer composition according to [1] or [2] above, containing 0.5 parts by mass or more and 30 parts by mass or less of a thermoplastic resin relative to 100 parts by mass of the total amount of the conjugated diene polymers (A) and (B). [4] The conjugated diene polymer composition according to any one of [1] to [3] above, wherein the conjugated diene polymer (A) and / or the conjugated diene polymer (B) are modified. [5] The conjugated diene polymer composition according to [4] above, wherein the conjugated diene polymer (A) has a modification rate of 60 mass % or more. [6] The conjugated diene polymer composition according to any one of [3] to [5], wherein the content of the thermoplastic resin is 0.5 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the total amount of the conjugated diene polymers (A) and (B). 〔7〕 the portion of the conjugated diene polymer (A) derived from the vinyl monomer containing an alkoxysilyl group or a halosilyl group is a monomer unit based on a compound represented by the following formula (1) or (2), the polymer chain has a branching point due to the monomer unit based on the compound represented by the following formula (1) or (2), and at least one end of the conjugated diene polymer (A) is coupled with a coupling agent; Any one of [1] to [6] The conjugated diene polymer composition according to claim 1.

[0011] [ka]

[0012] [ka]

[0013] (In formula (1), R 1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. R 2 ~R 3 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. R when multiple exist 1 ~R 3 are each independent. X 1 represents an independent halogen atom. m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.) (In formula (2), R 2 ~R 5 Each of R independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may partially have a branched structure. 2 ~R 5 are each independent. X 2 ~X 3 represents an independent halogen atom. m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3. a represents an integer of 0 to 2, b represents an integer of 0 to 3, and c represents an integer of 0 to 3. (m+n+l) represents 3.)

[0014] 〔8〕 In the formula (1), R 1 is a hydrogen atom, and m=0. 〔7〕 The conjugated diene polymer composition according to claim 1. 〔9〕 The present invention relates to a conjugated diene polymer (A) having a monomer unit based on a compound represented by the formula (2), wherein m=0 and b=0 in the formula (2). 〔7〕 The conjugated diene polymer composition according to claim 1. 〔10〕 In the formula (1), R 1 is a hydrogen atom, m=0, and l=0. [7] or [8] The conjugated diene polymer composition according to claim 1. 〔11〕 The above-mentioned conjugated diene polymer (A) has a monomer unit based on a compound represented by the above-mentioned formula (2), in which m=0, l=0, a=0, and b=0. [7] or [9]The conjugated diene polymer composition according to claim 1. 〔12〕 In the formula (1), R 1 is a hydrogen atom, l=0, and n=3, [7], [8], and

[10] 2. The conjugated diene polymer composition according to claim 1 . 〔13〕 The above [1] to 〔12〕 A tire comprising the conjugated diene polymer composition according to any one of claims 1 to 5. Effect of the Invention

[0015] According to the present invention, it is possible to provide a conjugated diene polymer composition which, when made into a tire, is excellent in rolling resistance, grip performance on wet road surfaces, and abrasion resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described in detail. It should be noted that the following embodiment is merely an example for explaining the present invention, and the present invention is not limited to the following embodiment. The present invention can be practiced with appropriate modifications within the scope of the gist of the present invention.

[0017] [Conjugated diene polymer composition] The conjugated diene polymer composition of the present embodiment is 10 to 90 parts by mass of a conjugated diene polymer (A) having a glass transition temperature of -20°C or higher; 10 to 90 parts by mass of a conjugated diene polymer (B) having a glass transition temperature of −25° C. or lower; Contains: The conjugated diene polymer (A) has an absolute molecular weight of 40×10 as measured by a GPC-light scattering method with a viscosity detector. 4 Over 5000 x 10 4or less, and the branching degree (Bn) measured by the above-mentioned GPC-light scattering method with a viscosity detector is 8 or more. According to the conjugated diene polymer composition of the present embodiment, a rubber composition having excellent rolling resistance, grip performance on wet road surfaces, and abrasion resistance can be obtained.

[0018] (Conjugated diene polymer (A)) The conjugated diene polymer (A) contained in the conjugated diene polymer composition of the present embodiment has a glass transition temperature of −20° C. or higher and an absolute molecular weight of 40×10 as measured by a GPC-light scattering method with a viscosity detector. 4 Over 5000 x 10 4 and the branching degree (Bn) measured by a GPC-light scattering method with a viscosity detector is 8 or more. The conjugated diene polymer (A) contains a conjugated diene compound as a monomer unit, and may contain an aromatic vinyl compound, and may further contain other monomer units. However, it is preferable that the aromatic vinyl compound and the conjugated diene compound are the main components, and the ratio of these is 90 mass% or more, and more preferably 95 mass% or more. The rubber component for a tire tread generally does not contain any components other than an aromatic vinyl compound and a conjugated diene compound. In addition, from the viewpoint of improving grip performance on wet road surfaces, the conjugated diene polymer composition of the present embodiment contains 10 to 90 parts by mass of the conjugated diene polymer (A) based on the total mass of the conjugated diene polymer composition (100 parts by mass). From the viewpoint of improving abrasion resistance, the amount of the conjugated diene polymer (A) is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and from the viewpoint of reducing rolling resistance, it is preferably 80 parts by mass or less, more preferably 70 parts by mass or less.

[0019] <Glass Transition Temperature of Conjugated Diene Polymer (A)> The conjugated diene polymer (A) contained in the conjugated diene polymer composition of the present embodiment has a glass transition temperature of -20°C or higher. The glass transition temperature can be controlled within the above-mentioned range by adjusting the microstructure of the conjugated diene polymer (A), i.e., by adjusting the amount of the aromatic vinyl compound in the conjugated diene polymer (A) or the amount of vinyl bonds in the conjugated diene compound. Specifically, when the conjugated diene polymer (A) is a copolymer of an aromatic vinyl compound and a conjugated diene compound, the glass transition temperature can be improved by increasing the amount of the aromatic vinyl compound or increasing the amount of vinyl bonds in the conjugated diene compound. The method for making the glass transition temperature of the conjugated diene polymer (A) -20 ° C or higher is not particularly limited, but for example, the glass transition temperature can be set in the above range by making the amount of aromatic vinyl compound 30 to 45 mass % and the amount of vinyl bond in the conjugated diene compound 10 to 70 mass %. When the glass transition temperature is in the above range, the grip performance tends to be further improved. The glass transition temperature is measured by recording a DSC curve while increasing the temperature within a predetermined temperature range in accordance with ISO22768:2006, and the peak top (inflection point) of the DSC differential curve is determined as the glass transition temperature. Specifically, the glass transition temperature can be measured by the method described in the examples below. The upper limit of the glass transition temperature of the conjugated diene polymer (A) is not particularly limited, but it is preferably not more than 0° C. When it is within this range, the rolling resistance tends to be further improved.

[0020] <Absolute molecular weight of conjugated diene polymer (A)> From the viewpoint of the wear resistance and fracture properties of the conjugated diene polymer composition of the present embodiment, the conjugated diene polymer (A) has an absolute molecular weight of 40×10 or less as determined by GPC-light scattering method measurement with a viscosity detector. 4 Over 5000 x 10 4 The following is the result. Generally, polymers with branched structures tend to have smaller molecular size compared to linear polymers with the same molecular weight. Therefore, the molecular weight of a polymer with a branched structure tends to be underestimated in terms of polystyrene by gel permeation chromatography (GPC), which is a relative comparison method with a standard polystyrene sample that separates the polymer by molecular size. On the other hand, the absolute molecular weight measured by the GPC-light scattering method with a viscometer is not affected by the polymer structure or interactions with the column packing material, as compared to the polystyrene-equivalent molecular weight determined by gel permeation chromatography (GPC), because the molecular size is directly observed by the light scattering method and the molecular weight (absolute molecular weight) is measured. Therefore, the molecular weight can be accurately measured without being affected by the polymer structure, such as the branched structure of the conjugated diene polymer.

[0021] The absolute molecular weight of the conjugated diene polymer (A) is 40×10 4 or more, preferably 50×10 4 More preferably, it is 60×10 4 More preferably, it is 80×10 4 More preferably, it is 100×10 4 That's all. The absolute molecular weight of the conjugated diene polymer (A) is 5000×10 4 or less, preferably 4500×10 4 More preferably, it is 4000×10 or less. 4 or less, and more preferably 3500×10 4 and even more preferably 3000×10 4 The following is the result. The absolute molecular weight of the conjugated diene polymer (A) is 40×10 4 When the absolute molecular weight is 5000×10 or more, the abrasion resistance of the vulcanized product tends to be excellent. 4 When the rubber composition is 0.1 to 1.0 wt %, the rubber composition has excellent processability and dispersibility of the filler when being made into a vulcanizate, and has excellent wet grip performance. The absolute molecular weight of the conjugated diene polymer (A) can be measured by the method described in the examples below. The absolute molecular weight of the conjugated diene polymer (A) can be controlled within the above-mentioned range by adjusting the amount of polymerization initiator added, the number of functional groups of the branching agent, the amount of branching agent added, the timing of adding the branching agent, and the amounts of coupling agent and modifier added.

[0022] <Degree of branching of conjugated diene polymer (A)> The conjugated diene polymer (A) has a degree of branching (Bn) of 8 or more from the viewpoints of processability and wet grip performance. The degree of branching (Bn) of 8 or more means that the conjugated diene polymer (A) substantially has 8 or more side polymer chains relative to the longest polymer main chain. The branching degree (Bn) of the conjugated diene polymer (A) is defined as g'=6Bn / [(Bn+1)(Bn+2)], where g' is a shrinkage factor measured by a GPC-light scattering method with a viscosity detector.

[0023] In general, a polymer having branches tends to have a smaller molecular size when compared to a linear polymer having the same absolute molecular weight. The shrinkage factor (g') is a measure of the ratio of the molecular size to that of a linear polymer of the same assumed absolute molecular weight. In other words, the greater the degree of branching of a polymer, the smaller the shrinkage factor (g') tends to be. In this embodiment, the intrinsic viscosity is used as an index of molecular size for this shrinkage factor. For linear polymers, the intrinsic viscosity [η] is −3.883M 0.771 In the above formula, M is the absolute molecular weight. However, the shrinkage factor (g') represents the rate of decrease in molecular size and does not accurately represent the branched structure of the polymer. Therefore, the branching degree (Bn) of the conjugated diene polymer (A) is calculated using the value of the shrinkage factor (g') at each absolute molecular weight of the conjugated diene polymer (A). The calculated "branching degree (Bn)" accurately represents the number of polymers that are directly or indirectly bonded to each other with respect to the longest main chain structure.

[0024] The calculated branching degree (Bn) is an index that expresses the branching structure of the conjugated diene polymer (A). For example, in the case of a typical four-branched star polymer (four polymer chains connected to the center), two polymer chain arms are bonded to the longest highly branched main chain structure, and the branching degree (Bn) is evaluated as 2. In a typical eight-branched star polymer, six polymer chain arms are attached to the longest highly branched main chain structure, and the branching degree (Bn) is evaluated as six. The conjugated diene polymer (A) has a branching degree (Bn) of 8 or more, which means that the conjugated diene polymer has a star polymer structure having 10 branches similar to a star polymer structure. Here, "branch" refers to a structure formed by direct or indirect bonding of one polymer to another polymer, and "degree of branching (Bn)" refers to the number of polymers that are directly or indirectly bonded to each other in the longest main chain structure. When the conjugated diene polymer (A) has a branching degree (Bn) of 8 or more, the conjugated diene polymer (A) has excellent processability and wet grip performance when vulcanized. Generally, the increase in absolute molecular weight tends to deteriorate processability, and when the absolute molecular weight is increased in a linear polymer structure, the viscosity of the vulcanized product increases significantly, and processability is significantly deteriorated. Therefore, even if a large number of functional groups are introduced into the polymer to improve the affinity and / or reactivity with silica blended as a filler, the silica cannot be sufficiently dispersed in the polymer during the kneading process. As a result, the function of the introduced functional groups is not exerted, and the effect of improving wet grip performance by introducing functional groups, which should be expected, is not exerted. On the other hand, in the conjugated diene polymer composition of the present embodiment, the conjugated diene polymer (A) is specified to have a branching degree (Bn) of 8 or more, so that the increase in viscosity of the vulcanizate accompanying an increase in absolute molecular weight is significantly suppressed, and the conjugated diene polymer (A) is thoroughly mixed with silica in the kneading step, making it possible to disperse silica around the conjugated diene polymer (A). As a result, the abrasion resistance can be improved by setting the molecular weight of the conjugated diene polymer (A) to be large, and the silica can be dispersed around the conjugated diene polymer (A) by thorough kneading, allowing the functional groups to act and / or react, thereby making it possible to provide wet grip performance sufficient for practical use. The branching degree of the conjugated diene polymer (A) can be measured by the method described in the examples below.

[0025] The conjugated diene polymer (A) has a branching degree (Bn) of 8 or more, preferably 10 or more, more preferably 12 or more, and further preferably 15 or more. When the degree of branching (Bn) of the conjugated diene polymer (A) is within the above range, the processability when made into a vulcanizate tends to be excellent. The upper limit of the branching degree (Bn) is not particularly limited and may be equal to or higher than the detection limit, but is preferably 84 or less, more preferably 80 or less, even more preferably 64 or less, and even more preferably 57 or less. When the branching degree (Bn) is 84 or less, the abrasion resistance tends to be excellent when made into a vulcanizate. The degree of branching of the conjugated diene polymer (A) can be controlled to 8 or more by adjusting the amount of the branching agent and the amount of the terminal modifier in combination. Specifically, the degree of branching can be controlled by adjusting the number of functional groups of the branching agent, the amount of the branching agent, the timing of adding the branching agent, and the amount of the modifier and coupling agent. More specifically, this will be described later in (Production method of the conjugated diene polymer (A)).

[0026] <Modification rate of conjugated diene polymer (A)> From the viewpoint of improving fuel economy, the conjugated diene polymer (A) is preferably modified with a predetermined modifying agent, such as a nitrogen-containing modifying agent, and the modification rate is preferably 60 mass% or more based on the total amount of the conjugated diene polymer. In this specification, the "modification ratio" represents the mass ratio of a conjugated diene polymer having a functional group, for example a nitrogen-containing functional group, by a modifying agent to the total amount of the conjugated diene polymer. For example, when a nitrogen-containing modifier is reacted with a terminal end, the mass ratio of a conjugated diene polymer having a nitrogen-containing functional group by the nitrogen-containing modifier to the total amount of the conjugated diene polymer is represented as a modification rate. On the other hand, when a polymer is branched by a branching agent containing nitrogen, the resulting conjugated diene polymer has a nitrogen-containing functional group, and therefore, this branched polymer is also counted when calculating the modification rate. That is, in the present specification, when the conjugated diene-based polymer is particularly a modified "modified conjugated diene-based polymer", the modification rate is the total mass ratio of the modified polymer with a modifying agent having a nitrogen-containing functional group and / or the branched polymer with a branching agent having a nitrogen-containing functional group.

[0027] The modification rate of the conjugated diene polymer (A) is preferably 65% ​​by mass or more, more preferably 70% by mass or more, even more preferably 75% by mass or more, still more preferably 80% by mass or more, and even more preferably 82% by mass or more. By setting the modification rate to 60% by mass or more, the fuel economy performance tends to be more excellent when made into a vulcanizate. In this specification, unless otherwise specified, the term "conjugated diene polymer" also includes modified conjugated diene polymers that have been modified (containing functional groups).

[0028] The degree of modification can be measured by chromatography, which is capable of separating the functional group-containing modified and unmodified components. Examples of methods using chromatography include a method in which a gel permeation chromatography column is packed with a polar substance such as silica that adsorbs specific functional groups, and the non-adsorbed components are quantified using an internal standard for comparison. More specifically, the modification rate is obtained by measuring the amount of adsorption to the silica column from the difference between a chromatogram obtained by measuring a sample solution containing a sample and a low-molecular-weight internal standard polystyrene using a polystyrene-based gel column and a chromatogram obtained by measuring a sample solution using a silica-based column. More specifically, the modification rate can be measured by the method described in the Examples.

[0029] In the conjugated diene polymer (A), the modification rate can be controlled to 60 mass% or more by selecting a specific compound as a polymerization initiator, selecting a specific compound as a polymerization monomer, adjusting the amount of the modifier added, and adjusting the reaction method. For example, the above modification rate can be achieved by combining a method of polymerization using an organolithium compound having at least one nitrogen atom in the molecule described below as a polymerization initiator, a method of copolymerizing a monomer having at least one nitrogen atom in the molecule, and a method of using a modifying agent having a structural formula described below, and controlling the polymerization conditions.

[0030] <Structure of Conjugated Diene Polymer (A)> From the viewpoint of a balance between processability and abrasion resistance, the conjugated diene polymer (A) is preferably a conjugated diene polymer having a star polymer structure with three or more branches, at least one branched chain of the star structure having a moiety derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, and the polymer chain is further branched in the moiety derived from the vinyl monomer containing an alkoxysilyl group or a halosilyl group, i.e., a conjugated diene polymer having a main chain branched structure. As used herein, the term "star polymer structure" refers to a structure in which multiple polymer chains (arms) are bonded to one central branch point. In addition, one central branch point referred to here has a "substituent containing an atom derived from a coupling agent" or a "substituent containing a nitrogen atom derived from a modifier". The term "main chain branched structure" as used herein refers to a structure in which a polymer chain forms a branch point at a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, and the polymer chain (arm) extends from the branch point.

[0031] From the viewpoint of improving the branching degree Bn, the conjugated diene polymer (A) preferably has 4 or more main chain branching points constituted by moieties derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, and the branched structure derived from a star polymer structure formed by a modifying agent in the reaction step preferably has 3 or more branches, more preferably 4 or more branches, and even more preferably 8 or more branches. In addition, the degree of branching Bn increases when the polymer is modified with a coupling agent that forms a star structure, and when a branching agent is introduced into the polymer. However, branching the entire polymer chain with a coupling agent has a greater contribution to the degree of branching Bn. In designing a polymer, the degree of branching Bn can be controlled by selecting a coupling agent and selecting the type and amount of a branching agent, but it is easy to control the degree of branching Bn by taking into account the contribution rate.

[0032] <Main chain branching structure> The main chain branched structure is a branching point in a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, and has two or more branching points, preferably three or more branching points, and more preferably four or more branching points. In addition, the branching points forming the main chain branched structure preferably have at least two or more polymer chains, more preferably have three or more polymer chains that are not the main chain, and even more preferably have four or more polymer chains that are not the main chain. In particular, in the case of a main chain branched structure consisting of a vinyl monomer containing an alkoxysilyl group or a halosilyl group, 29When signal detection is performed by Si-NMR, peaks derived from the main chain branched structure are detected in the range of −45 ppm to −65 ppm, and more specifically, in the range of −50 ppm to −60 ppm.

[0033] <Star-shaped polymer structure> The conjugated diene polymer (A) preferably has a star-shaped polymer structure, and the number of branches derived from the star-shaped polymer structure is preferably 3 or more, more preferably 4 or more, even more preferably 6 or more, and even more preferably 8 or more.

[0034] Regarding a method for obtaining a conjugated diene-based polymerization as a conjugated diene-based polymer (A), which is a conjugated diene-based polymer having a star polymer structure with three or more branches, in which at least one branched chain of the star structure has a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, and in which the portion derived from the vinyl monomer containing an alkoxysilyl group or a halosilyl group has a further main chain branch structure, the "star polymer structure" can be formed by adjusting the number of functional groups of the modifying agent and the amount of the modifying agent added, and the "main chain branch structure" can be controlled by adjusting the number of functional groups of the branching agent, the amount of the branching agent added, and the timing of adding the branching agent.

[0035] In order to obtain a conjugated diene-based polymer having a star polymer structure with three or more branches, in which at least one branched chain of the star structure has a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, and in which the portion derived from the vinyl monomer containing an alkoxysilyl group or a halosilyl group has a further main chain branched structure, for example, a method can be mentioned in which polymerization is carried out using an organolithium compound as a polymerization initiator, a branching agent that gives a specific branch point is added during or after the polymerization, and the polymerization is continued and then modified with a modifying agent that gives a specific branching rate. Such means for controlling the polymerization conditions will be described in the production method in the examples given below.

[0036] <Details of main chain branch structure> The conjugated diene polymer (A) is preferably a conjugated diene polymer in which a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group is a monomer unit based on a compound represented by the following formula (1) or (2), has a polymer chain branching point due to the monomer unit based on the compound represented by the following formula (1) or (2), and at least one end of the conjugated diene polymer is coupled using a coupling agent, and more preferably has at least one end of the conjugated diene polymer modified with a nitrogen atom-containing group.

[0037] [ka]

[0038] [ka]

[0039] (In formula (1), R 1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. R 2 ~R 3 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. R when multiple exist 1 ~R 3 are each independent. X 1 represents an independent halogen atom. m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.) (In formula (2), R 2 ~R 5 Each of R independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may partially have a branched structure. 2 ~R 5 are each independent. X 2~X 3 represents an independent halogen atom. m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) means 3. a represents an integer of 0 to 2, b represents an integer of 0 to 3, and c represents an integer of 0 to 3. (m+n+l) represents an integer of 3.)

[0040] The conjugated diene polymer (A) is a polymer represented by the formula (1) R 1 is a hydrogen atom, and m=0. This improves the degree of branching, and provides the effects of improving the wear resistance and processability.

[0041] In addition, the conjugated diene polymer (A) preferably has a monomer unit based on the compound represented by the formula (2) in which m=0 and b=0. This provides the effect of improving the wear resistance and processability.

[0042] The conjugated diene polymer (A) is R 1 is a hydrogen atom, m=0, and l=0. This improves the degree of branching, and the effects of improving the wear resistance and processability are obtained.

[0043] In addition, the conjugated diene polymer (A) is preferably a conjugated diene polymer having a monomer unit based on a compound represented by the formula (2), in which m=0, l=0, a=0, and b=0. This provides the effects of improving wear resistance and processability.

[0044] The conjugated diene polymer (A) is represented by the formula (1), 1is a hydrogen atom, l=0, and n=3. This improves the modification rate and branching degree, resulting in improved fuel efficiency, wear resistance, and processability.

[0045] <Branching agent> When constructing a main chain branched structure in the conjugated diene polymer (A), it is preferable to use a branching agent represented by the following formula (1) or formula (2) as a branching agent.

[0046] [ka]

[0047] [ka]

[0048] (In formula (1), R 1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. R 2 ~R 3 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. R when multiple exist 1 ~R 3 are each independent. X 1 represents an independent halogen atom. m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) means 3. (In formula (2), R 2 ~R 5 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. R when multiple exist 2 ~R5 are each independent. X 2 ~X 3 represents an independent halogen atom. m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) means 3. a represents an integer of 0 to 2, b represents an integer of 0 to 3, and c represents an integer of 0 to 3. (m+n+l) represents 3.)

[0049] The branching agent used in constructing the main chain branched structure of the conjugated diene polymer (A) is, from the viewpoints of continuity of polymerization and improvement of the degree of branching, R 1 is a hydrogen atom and m=0.

[0050] Moreover, the branching agent used when constructing the main chain branched structure of the conjugated diene polymer (A) is preferably a compound in which m=0 and b=0 in formula (2), from the viewpoint of improving the degree of branching.

[0051] In addition, the branching agent used in constructing the main chain branched structure of the conjugated diene polymer (A) is, from the viewpoints of continuity of polymerization, improvement of the modification rate and the degree of branching, R 1 It is more preferable that the compound is a compound in which is a hydrogen atom, m=0, and l=0.

[0052] Moreover, the branching agent used for constructing the main chain branched structure of the conjugated diene polymer (A) is more preferably a compound represented by the formula (2) in which m=0, l=0, a=0, and b=0, from the viewpoint of improving the modification rate and the degree of branching.

[0053] In addition, the branching agent used in constructing the main chain branched structure of the conjugated diene polymer (A) is, from the viewpoints of continuity of polymerization, improvement of the modification rate and the degree of branching, R 1 is a hydrogen atom, l=0, and n=3.

[0054] Examples of the branching agent represented by the formula (1) include, but are not limited to, trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, tripropoxy(4-vinylphenyl)silane, tributoxy(4-vinylphenyl)silane, triisopropoxy(4-vinylphenyl)silane, trimethoxy(3-vinylphenyl)silane, triethoxy(3-vinylphenyl)silane, tripropoxy(3-vinylphenyl)silane, tributoxy(3-vinylphenyl)silane, triisopropoxy(3-vinylphenyl)silane, (2-vinylphenyl)silane, trimethoxy(2-vinylphenyl)silane, triethoxy(2-vinylphenyl)silane, tripropoxy(2-vinylphenyl)silane, tributoxy(2-vinylphenyl)silane, triisopropoxy(2-vinylphenyl)silane, dimethoxymethyl(4-vinylphenyl)silane, diethoxymethyl(4-vinylphenyl)silane, dipropoxymethyl(4-vinylphenyl)silane, dibutoxymethyl(4-vinylphenyl)silane, diisopropoxymethyl(4-vinylphenyl)silane, dimethoxymethyl methyl(3-vinylphenyl)silane, diethoxymethyl(3-vinylphenyl)silane, dipropoxymethyl(3-vinylphenyl)silane, dibutoxymethyl(3-vinylphenyl)silane, diisopropoxymethyl(3-vinylphenyl)silane, dimethoxymethyl(2-vinylphenyl)silane, diethoxymethyl(2-vinylphenyl)silane, dipropoxymethyl(2-vinylphenyl)silane, dibutoxymethyl(2-vinylphenyl)silane, diisopropoxymethyl(2-vinylphenyl)silane, dimethylmethoxy(4-vinylphenyl)silane, phenyl)silane, dimethylethoxy(4-vinylphenyl)silane, dimethylpropoxy(4-vinylphenyl)silane, dimethylbutoxy(4-vinylphenyl)silane, dimethylisopropoxy(4-vinylphenyl)silane, dimethylmethoxy(3-vinylphenyl)silane, dimethylethoxy(3-vinylphenyl)silane, dimethylpropoxy(3-vinylphenyl)silane, dimethylbutoxy(3-vinylphenyl)silane, dimethylisopropoxy(3-vinylphenyl)silane, dimethylmethoxy(2-vinylphenyl)silane,Examples of the silane include dimethylethoxy(2-vinylphenyl)silane, dimethylpropoxy(2-vinylphenyl)silane, dimethylbutoxy(2-vinylphenyl)silane, and dimethylisopropoxy(2-vinylphenyl)silane.

[0055] In addition, examples of the branching agent represented by (1) include trimethoxy(4-isopropenylphenyl)silane, triethoxy(4-isopropenylphenyl)silane, tripropoxy(4-isopropenylphenyl)silane, tributoxy(4-isopropenylphenyl)silane, triisopropoxy(4-isopropenylphenyl)silane, trimethoxy(3-isopropenylphenyl)silane, triethoxy(3-isopropenylphenyl)silane, tripropoxy(3-isopropenylphenyl)silane, and tributoxy(3-isopropenylphenyl). Silane, triisopropoxy(3-isopropenylphenyl)silane, trimethoxy(2-isopropenylphenyl)silane, triethoxy(2-isopropenylphenyl)silane, tripropoxy(2-isopropenylphenyl)silane, tributoxy(2-isopropenylphenyl)silane, triisopropoxy(2-isopropenylphenyl)silane, dimethoxymethyl(4-isopropenylphenyl)silane, diethoxymethyl(4-isopropenylphenyl)silane, dipropoxymethyl(4-isopropenylphenyl)silane, dibutoxy Methyl(4-isopropenylphenyl)silane, diisopropoxymethyl(4-isopropenylphenyl)silane, dimethoxymethyl(3-isopropenylphenyl)silane, diethoxymethyl(3-isopropenylphenyl)silane, dipropoxymethyl(3-isopropenylphenyl)silane, dibutoxymethyl(3-isopropenylphenyl)silane, diisopropoxymethyl(3-isopropenylphenyl)silane, dimethoxymethyl(2-isopropenylphenyl)silane, diethoxymethyl(2-isopropenylphenyl)silane, diprop dimethylmethoxy(4-isopropenylphenyl)silane, dimethylethoxy(4-isopropenylphenyl)silane, dimethylpropoxy(4-isopropenylphenyl)silane, dimethylbutoxy(4-isopropenylphenyl)silane, dimethylisopropoxy(4-isopropenylphenyl)silane, dimethylmethoxy(3-isopropenylphenyl)silane,Dimethylethoxy(3-isopropenylphenyl)silane, dimethylpropoxy(3-isopropenylphenyl)silane, dimethylbutoxy(3-isopropenylphenyl)silane, dimethylisopropoxy(3-isopropenylphenyl)silane, dimethylmethoxy(2-isopropenylphenyl)silane, dimethylethoxy(2-isopropenylphenyl)silane, dimethylpropoxy(2-isopropenylphenyl)silane, dimethylbutoxy(2-isopropenylphenyl)silane, dimethylisopropoxy(2-isopropenylphenyl)silane, trichloro(4-vinylphenyl)silane, trichloro(3-vinylphenyl)silane, trichloro(2-vinylphenyl)silane, tribromo(4-vinylphenyl)silane nylphenyl)silane, tribromo(3-vinylphenyl)silane, tribromo(2-vinylphenyl)silane, dichloromethyl(4-vinylphenyl)silane, dichloromethyl(3-vinylphenyl)silane, dichloromethyl(2-vinylphenyl)silane, dibromomethyl(4-vinylphenyl)silane, dibromomethyl(3-vinylphenyl)silane, dibromomethyl(2-vinylphenyl)silane, dimethylchloro(4-vinylphenyl)silane, dimethylchloro(3-vinylphenyl)silane, dimethylchloro(2-vinylphenyl)silane, dimethylbromo(4-vinylphenyl)silane, dimethylbromo(3-vinylphenyl)silane, and dimethylbromo(2-vinylphenyl)silane.

[0056] Among these, trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, tripropoxy(4-vinylphenyl)silane, tributoxy(4-vinylphenyl)silane, triisopropoxy(4-vinylphenyl)silane, trimethoxy(3-vinylphenyl)silane, triethoxy(3-vinylphenyl)silane, tripropoxy(3-vinylphenyl)silane, tributoxy(3-vinylphenyl)silane, triisopropoxy(3-vinylphenyl)silane, and trichloro(4-vinylphenyl)silane are preferred, and trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, tripropoxy(4-vinylphenyl)silane, tributoxy(4-vinylphenyl)silane, and triisopropoxy(4-vinylphenyl)silane are more preferred.

[0057] The branching agent represented by the formula (2) is not limited to the following, but examples thereof include 1,1-bis(4-trimethoxysilylphenyl)ethylene, 1,1-bis(4-triethoxysilylphenyl)ethylene, 1,1-bis(4-tripropoxysilylphenyl)ethylene, 1,1-bis(4-tripentoxysilylphenyl)ethylene, 1,1-bis(4-triisopropoxysilylphenyl)ethylene, 1,1-bis(3-trimethoxysilylphenyl)ethylene, 1,1-bis(3-triethoxysilylphenyl)ethylene, 1,1-bis(3-tripoxysilylphenyl)ethylene, 1,1-bis(3-tripentoxysilylphenyl)ethylene, 1,1-bis(3-triisopropoxysilylphenyl)ethylene, 1,1-bis(2 -trimethoxysilylphenyl)ethylene, 1,1-bis(2-triethoxysilylphenyl)ethylene, 1,1-bis(3-tripropoxysilylphenyl)ethylene, 1,1-bis(2-tripentoxysilylphenyl)ethylene, 1,1-bis(2-triisopropoxysilylphenyl)ethylene, 1,1-bis(4-(dimethylmethoxysilyl)phenyl)ethylene, 1,1-bis(4-(diethylmethoxysilyl)phenyl)ethylene, 1,1-bis(4-(dipropylmethoxysilyl)phenyl)ethylene, 1,1-bis(4-(dimethylethoxysilyl)phenyl)ethylene, 1,1-bis(4-(diethylethoxysilyl)phenyl)ethylene, and 1,1-bis(4-(dipropylethoxysilyl)phenyl)ethylene.

[0058] Among these, 1,1-bis(4-trimethoxysilylphenyl)ethylene, 1,1-bis(4-triethoxysilylphenyl)ethylene, 1,1-bis(4-tripropoxysilylphenyl)ethylene, 1,1-bis(4-tripentoxysilylphenyl)ethylene, and 1,1-bis(4-triisopropoxysilylphenyl)ethylene are preferred, with 1,1-bis(4-trimethoxysilylphenyl)ethylene being more preferred.

[0059] (Method for producing conjugated diene polymer (A)) The method for producing the conjugated diene polymer (A) includes the steps of: The method includes a polymerization / branching step of polymerizing at least a conjugated diene compound in the presence of an organolithium compound and obtaining a conjugated diene polymer having a main chain branched structure using at least one of the above-mentioned various branching agents, and a coupling step of coupling the conjugated diene polymer using a coupling agent and / or a reaction step of modifying the conjugated diene polymer with a modifying agent having a nitrogen atom-containing group. The conjugated diene polymer constituting the modified conjugated diene polymer may be any of a homopolymer of a single conjugated diene compound, a polymer or copolymer of different types of conjugated diene compounds, and a copolymer of a conjugated diene compound and an aromatic vinyl compound.

[0060] <Polymerization / branching process> In the polymerization / branching step in the production method of the conjugated diene polymer (A), an organolithium compound, for example, an organomonolithium compound is used as a polymerization initiator to polymerize at least a conjugated diene compound, and a branching agent is added to obtain a conjugated diene polymer having a main chain branched structure. In the polymerization step, it is preferable to carry out polymerization by a propagation reaction due to a living anionic polymerization reaction, and thus a conjugated diene-based polymer having an active terminal can be obtained. Then, in the branching step using a branching agent, the main chain branching can be appropriately controlled, and by continuing polymerization on the active terminal after the main chain branching, a modified conjugated diene-based polymer with a high modification rate tends to be obtained.

[0061] [Polymerization initiator] As the polymerization initiator, an organolithium compound is used, and it is preferable to use at least an organomonolithium compound. The organomonolithium compound is not limited to the following, but examples thereof include low molecular weight compounds and solubilized oligomeric organomonolithium compounds. In addition, examples of the organomonolithium compound include compounds having a carbon-lithium bond, a nitrogen-lithium bond, and a tin-lithium bond in terms of the bonding mode between the organic group and the lithium.

[0062] The amount of the organic monolithium compound used as the polymerization initiator is preferably determined depending on the targeted molecular weight of the conjugated diene polymer. The amount of a monomer such as a conjugated diene compound used relative to the amount of a polymerization initiator used relates to the degree of polymerization of a target conjugated diene polymer, i.e., tends to relate to the number average molecular weight and / or weight average molecular weight. Therefore, in order to increase the molecular weight of the conjugated diene polymer, the amount of the polymerization initiator should be adjusted to decrease, and in order to decrease the molecular weight, the amount of the polymerization initiator should be adjusted to increase.

[0063] From the viewpoint of using the organomonolithium compound as one method for introducing nitrogen atoms into the conjugated diene polymer, the organomonolithium compound is preferably an alkyllithium compound having a substituted amino group or a dialkylaminolithium. In this case, a conjugated diene polymer having a nitrogen atom consisting of an amino group at the polymerization initiation terminal is obtained.

[0064] The substituted amino group is an amino group that does not have an active hydrogen or has a structure in which the active hydrogen is protected. Examples of alkyllithium compounds having an amino group that does not have an active hydrogen include, but are not limited to, 3-dimethylaminopropyllithium, 3-diethylaminopropyllithium, 4-(methylpropylamino)butyllithium, and 4-hexamethyleneiminobutyllithium. Examples of alkyllithium compounds having an amino group with an active hydrogen protected structure include, but are not limited to, 3-bistrimethylsilylaminopropyllithium and 4-trimethylsilylmethylaminobutyllithium.

[0065] Examples of dialkylaminolithium include, but are not limited to, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium dibutylamide, lithium di-n-hexylamide, lithium diheptylamide, lithium diisopropylamide, lithium dioctylamide, lithium-di-2-ethylhexylamide, lithium didecylamide, lithium ethylpropylamide, lithium ethylbutylamide, lithium ethylbenzylamide, lithium methylphenethylamide, lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, lithium morpholide, 1-lithioazacyclooctane, 6-lithio-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane, and 1-lithio-1,2,3,6-tetrahydropyridine.

[0066] These organomonolithium compounds having a substituted amino group can also be used as oligomeric organomonolithium compounds solubilized in normal hexane or cyclohexane by reacting them with a small amount of a polymerizable monomer, such as 1,3-butadiene, isoprene, or styrene.

[0067] The organomonolithium compound is preferably an alkyllithium compound from the viewpoints of industrial availability and ease of control of the polymerization reaction, in which case a conjugated diene-based polymer having an alkyl group at the polymerization initiation terminal can be obtained. Examples of the alkyl lithium compound include, but are not limited to, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, n-hexyl lithium, benzyl lithium, phenyl lithium, and stilbene lithium. As the alkyllithium compound, n-butyllithium and sec-butyllithium are preferred from the viewpoints of industrial availability and ease of control of the polymerization reaction.

[0068] These organomonolithium compounds may be used alone or in combination of two or more, and may also be used in combination with other organometallic compounds. Examples of the other organometallic compounds include alkaline earth metal compounds, other alkali metal compounds, and other organometallic compounds. Alkaline earth metal compounds include, but are not limited to, organomagnesium compounds, organocalcium compounds, and organostrontium compounds, as well as alkaline earth metal alkoxides, sulfonates, carbonates, and amides. Examples of organomagnesium compounds include dibutylmagnesium and ethylbutylmagnesium. Other organometallic compounds include organoaluminum compounds.

[0069] In the polymerization step, the polymerization reaction mode is not limited to the following modes, but examples thereof include a batchwise mode (also called a "batch mode") and a continuous mode. In the continuous system, one or more connected reactors can be used. The continuous reactor is, for example, a tank type or a tube type equipped with an agitator. In the continuous system, preferably, the monomer, the inert solvent, and the polymerization initiator are continuously fed into the reactor, a polymer solution containing a polymer is obtained in the reactor, and the polymer solution is continuously discharged. The batch reactor may be, for example, a tank-type reactor equipped with a stirrer. In the batch reactor, preferably, a monomer, an inert solvent, and a polymerization initiator are fed, and if necessary, a monomer is added continuously or intermittently during polymerization to obtain a polymer solution in the reactor, and the polymer solution is discharged after the polymerization is completed. In the method for producing the conjugated diene polymer (A), in order to obtain a conjugated diene polymer having active ends at a high rate, a continuous method is preferred, which allows the polymer to be continuously discharged and subjected to the next reaction in a short time.

[0070] The polymerization step for the conjugated diene polymer is preferably carried out in an inert solvent. Examples of the inert solvent include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specific examples of the hydrocarbon solvent include, but are not limited to, aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene, and hydrocarbons consisting of mixtures thereof. By treating the impurities, that is, allenes and acetylenes, with an organometallic compound before subjecting the polymer to the polymerization reaction, a conjugated diene-based polymer having a high concentration of active ends tends to be obtained, which is preferable since a modified conjugated diene-based polymer having a high modification rate tends to be obtained.

[0071] In the polymerization step, a polar compound (sometimes referred to as a polar substance in this specification) may be added. This allows the aromatic vinyl compound to be randomly copolymerized with the conjugated diene compound, and the polar compound tends to be usable as a vinylating agent for controlling the microstructure of the conjugated diene portion. It also tends to be effective in promoting the polymerization reaction.

[0072] Examples of polar compounds that can be used include, but are not limited to, ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2,2-bis(2-oxolanyl)propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, and quinuclidine; alkali metal alkoxide compounds such as potassium tert-amylate, potassium tert-butylate, sodium tert-butylate, and sodium amylate; and phosphine compounds such as triphenylphosphine. These polar compounds may be used alone or in combination of two or more.

[0073] The amount of the polar compound used is not particularly limited and can be selected depending on the purpose, but is preferably 0.01 moles or more and 100 moles or less per mole of the polymerization initiator. Such polar compounds (vinylating agents) can be used in an appropriate amount according to the desired vinyl bond amount as regulators for the microstructure of the conjugated diene portion of the conjugated diene polymer. Many polar compounds also have an effective randomizing effect in the copolymerization of a conjugated diene compound and an aromatic vinyl compound, and tend to be usable as agents for adjusting the distribution of the aromatic vinyl compound or the amount of styrene blocks. As a method for randomizing the conjugated diene compound and the aromatic vinyl compound, for example, as described in JP-A-59-140211, a copolymerization reaction may be initiated with the total amount of styrene and a portion of 1,3-butadiene, and the remaining 1,3-butadiene may be intermittently added during the copolymerization reaction.

[0074] The polymerization temperature in the polymerization step is preferably a temperature at which living anionic polymerization proceeds, and from the viewpoint of productivity, is more preferably 0°C or higher, and even more preferably 120°C or lower. By being in such a range, there is a tendency that the amount of the modifying agent reacting with the active terminal after the polymerization is completed can be sufficiently ensured. Even more preferably, it is 50°C or higher and 100°C or lower.

[0075] In the method for producing the conjugated diene polymer (A), the amount of the branching agent added in the branching step for forming a main chain branched structure is not particularly limited and can be selected depending on the purpose, etc., but is preferably 0.03 mol or more and 0.5 mol or less, more preferably 0.05 mol or more and 0.4 mol or less, and even more preferably 0.01 mol or more and 0.25 mol or less, relative to 1 mol of the polymerization initiator. The amount of the branching agent can be selected depending on the number of branching points in the main chain branched structure of the conjugated diene portion of the intended conjugated diene polymer (A).

[0076] The timing of adding the branching agent in the branching step is not particularly limited and can be selected depending on the purpose, etc., but from the viewpoint of improving the absolute molecular weight and the modification rate of the conjugated diene polymer (A), the timing is preferably when the raw material conversion rate after addition of the polymerization initiator is 20% or more, more preferably 40% or more, even more preferably 50% or more, even more preferably 65% ​​or more, and even more preferably 75% or more. After the branching agent is added, the desired raw materials may be further added to continue the polymerization step after branching, or the above-described process may be repeated. The monomer to be added is not particularly limited, but from the viewpoint of improving the modification rate of the conjugated diene polymer, it is preferably 5% or more of the total amount of conjugated diene monomers used in the polymerization step, for example, the total amount of butadiene, more preferably 10% or more, even more preferably 15% or more, even more preferably 20% or more, and even more preferably 25% or more.

[0077] In the method for producing the conjugated diene polymer (A), the conjugated diene polymer obtained in the polymerization / branching step and before the modification reaction step has a Mooney viscosity measured at 110°C of preferably 10 or more and 150 or less, more preferably 15 or more and 140 or less, and even more preferably 20 or more and 130 or less. Within this range, the conjugated diene polymer composition of the present embodiment tends to have excellent processability and abrasion resistance.

[0078] The conjugated diene polymer (A) constituting the conjugated diene polymer composition of the present embodiment is a polymer containing a conjugated diene polymer, and may be a polymer with a conjugated diene monomer, an aromatic vinyl monomer, and a branching agent, or may be a copolymer with a conjugated diene monomer, an aromatic vinyl monomer, a branching agent, and a monomer other than these. For example, when the conjugated diene monomer is butadiene or isoprene and is polymerized with a branching agent containing an aromatic vinyl moiety, the polymer chain is a so-called polybutadiene or polyisoprene, and the branched portion contains a structure derived from aromatic vinyl. By having such a structure, it is possible to improve the linearity of each polymer chain and improve the crosslinking density after vulcanization, which has the effect of improving the abrasion resistance of the polymer. Therefore, it is suitable for applications such as tires, resin modification, interior and exterior parts of automobiles, anti-vibration rubber, and footwear. When the conjugated diene polymer is used for tire tread applications, a copolymer of a conjugated diene monomer, an aromatic vinyl monomer, and a branching agent is suitable, and in the copolymer for this application, the bound conjugated diene content is preferably 40% by mass or more and 100% by mass or less, and more preferably 55% by mass or more and 80% by mass or less. The amount of bound aromatic vinyl in the conjugated diene polymer (A) is not particularly limited, but is preferably from 0 to 60% by mass, and more preferably from 20 to 45% by mass. When the bound conjugated diene amount and bound aromatic vinyl amount are within the above ranges, the balance between low hysteresis loss and wet grip performance, abrasion resistance, and fracture properties tend to be excellent when made into a vulcanizate. The amount of bound aromatic vinyl can be measured by ultraviolet absorption of the phenyl group, and the amount of bound conjugated diene can also be calculated from the amount. Specifically, the amount is measured according to the method described in the examples below.

[0079] In the conjugated diene polymer (A), the amount of vinyl bonds in the conjugated diene monomer units derived from the conjugated diene compound is not particularly limited, but is preferably 10 mol % or more and 75 mol % or less, and more preferably 20 mol % or more and 65 mol % or less. If the amount of vinyl bonds is within the above range, the balance between low hysteresis loss and wet grip performance, abrasion resistance, and breaking strength tend to be excellent when made into a vulcanizate. Here, when the conjugated diene polymer (A) is a copolymer of butadiene and styrene, the vinyl bond amount (1,2-bond amount) in the butadiene bond unit can be determined by the Hampton method (RR Hampton, Analytical Chemistry, 21, 923 (1949)). Specifically, it is measured by the method described in the examples below.

[0080] Regarding the microstructure of the conjugated diene polymer (A), when the bond amounts in the conjugated diene polymer (A) are within the above-mentioned numerical ranges and the glass transition temperature of the conjugated diene polymer (A) is in the range of -20°C or higher, a vulcanizate having an even better balance between fuel economy and wet grip performance tends to be obtained. The glass transition temperature is measured by recording a DSC curve while increasing the temperature within a predetermined temperature range in accordance with ISO 22768:2006, and the peak top (inflection point) of the DSC differential curve is taken as the glass transition temperature. Specifically, it is measured by the method described in the examples below.

[0081] When the conjugated diene polymer (A) is a conjugated diene-aromatic vinyl copolymer, it is preferable that the number of blocks having 30 or more aromatic vinyl units linked together is small or that there is no such block. More specifically, when the conjugated diene polymer (A) is a butadiene-styrene copolymer, in a known method in which the copolymer is decomposed by the Kolthoff method (method described in I.M.Kolthoff, et al., J.Polym.Sci.1,429(1946)) and the amount of polystyrene insoluble in methanol is analyzed, the amount of blocks having 30 or more aromatic vinyl units linked together is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, based on the total amount of the conjugated diene polymer.

[0082] When the conjugated diene polymer (A) is a conjugated diene-aromatic vinyl copolymer, it is preferable that the proportion of aromatic vinyl units present independently is high from the viewpoint of improving fuel economy performance. Specifically, when the conjugated diene polymer (A) is a butadiene-styrene copolymer, when the conjugated diene polymer is decomposed by an ozonolysis method known as the Tanaka et al. method (Polymer, 22, 1721 (1981)) and the styrene chain distribution is analyzed by GPC, it is preferable that the amount of isolated styrene is 40 mass% or more relative to the total bound styrene amount, and the amount of chain styrene structures having 8 or more styrene chains is 5.0 mass% or less. In this case, the hysteresis loss in the resulting vulcanized rubber can be effectively reduced.

[0083] <Reaction process> In the method for producing the conjugated diene polymer (A), a step of coupling the active terminals of the conjugated diene polymer obtained through the above-mentioned polymerization and branching steps using a coupling agent, for example, a reactive compound having three or more functionalities, and / or a step of modifying the active terminals using a modifying agent having a nitrogen atom-containing group (preferably, a coupling agent having a nitrogen atom-containing group) are carried out. Hereinafter, the coupling step and / or the modification step will be referred to as a reaction step. In the reaction step, one of the active terminals of the conjugated diene polymer is reacted with a coupling agent or a modifying agent having a nitrogen atom-containing group to obtain a coupled or modified conjugated diene polymer.

[0084] [Coupling agent] The coupling agent used in the reaction step of the method for producing the conjugated diene polymer (A) may have any structure as long as it is a trifunctional or more reactive compound, but is preferably a trifunctional or more reactive compound having a silicon atom, and more preferably has at least four silicon-containing functional groups. More preferably, the coupling agent is a compound in which at least one silicon atom constitutes an alkoxysilyl group or a silanol group having 1 to 20 carbon atoms. Examples of such coupling agents include tetramethoxysilane and tetraethoxysilane.

[0085] [Denaturant] The modifying agent is not limited to the following, but examples thereof include tris(3-trimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-tripropoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1- sila-2-azacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-methyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine propyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis(3-trimethoxysilylpropyl)-1,6-hexamethylenediamine, pentakis(3-trimethoxysilylpropyl)-diethylenetriamine, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]- silane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]silane, 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-trimethoxysilylpropane, 1-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexane, 1-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexane, 3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexyl-[3 -(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]ether, (3-trimethoxysilylpropyl)phosphate, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]phosphate, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)phosphate, and tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]phosphate.

[0086] The modifying agent preferably contains a compound represented by any one of the following general formulas (A) to (C).

[0087] [ka]

[0088] (In formula (A), R 1 ~R 4 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms; R 5 represents an alkylene group having 1 to 10 carbon atoms; R 6 represents an alkylene group having 1 to 20 carbon atoms. m represents an integer of 1 or 2, n represents an integer of 2 or 3, and (m+n) represents an integer of 4 or more. 1 ~R 4 are independent of each other.)

[0089] [ka]

[0090] (In formula (B), R 1 ~R 6 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms; R 7 ~R 9 each independently represents an alkylene group having 1 to 20 carbon atoms. m, n, and l each independently represent an integer of 1 to 3, and (m+n+l) represents an integer of 4 or more. 1 ~R 6 are independent of each other.)

[0091] [ka]

[0092] (In formula (C), R 12 ~R 14 each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms; R 15 ~R 18 , and R 20 each independently represents an alkyl group having 1 to 20 carbon atoms; R 19 and R 22 each independently represents an alkylene group having 1 to 20 carbon atoms; R 21 represents an alkyl group having 1 to 20 carbon atoms or a trialkylsilyl group. m represents an integer of 1 to 3; p represents 1 or 2. R when there are multiple of each 12 ~R 22 , m, and p are each independent and may be the same or different. i represents an integer of 0 to 6, j represents an integer of 0 to 6, k represents an integer of 0 to 6, and (i+j+k) is an integer of 4 to 10. A represents a hydrocarbon group having 1 to 20 carbon atoms, or an organic group having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom, and a phosphorus atom and having no active hydrogen.

[0093] The modifying agent represented by the formula (A) is not limited to the following, but may be, for example, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(5-trimethoxysilylpentyl)-1-aza-2-silacycloheptane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacic acid, 2-methoxy,2-methyl-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-ethoxy,2-ethyl-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, and 2-ethoxy-2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silacyclopentane. Among these, from the viewpoints of reactivity and interaction between the functional group of the modifier and inorganic fillers such as silica, and processability, those in which m is 2 and n is 3 are preferred. Specifically, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane and 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane are preferred.

[0094] The reaction temperature, reaction time, etc., when reacting the modifying agent represented by the formula (A) with the active terminal of the polymer are not particularly limited, but it is preferable to react at 0°C or higher and 120°C or lower for 30 seconds or longer. The total number of moles of alkoxy groups bonded to silyl groups in the modifying agent compound represented by the formula (A) is preferably in the range of 0.6 to 3.0 times the number of moles of the alkali metal compound and / or alkaline earth metal compound added as the polymerization initiator, more preferably in the range of 0.8 to 2.5 times, and even more preferably in the range of 0.8 to 2.0 times. From the viewpoint of obtaining a sufficient modification rate, molecular weight, and branched structure for the modified conjugated diene polymer obtained, it is preferably 0.6 times or more, and from the viewpoint of obtaining a branched polymer component by coupling polymer terminals to improve processability and from the viewpoint of the cost of the modifying agent, it is preferably 3.0 times or less. More specifically, the number of moles of the polymerization initiator is preferably 3.0 times or more, more preferably 4.0 times or more, by mole relative to the number of moles of the modifying agent.

[0095] The modifying agent represented by the formula (B) includes, but is not limited to, tris(3-trimethoxysilylpropyl)amine, tris(3-methyldimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-methyldiethoxysilylpropyl)amine, tris(trimethoxysilylmethyl)amine, tris(2-trimethoxysilylethyl)amine, and tris(4-trimethoxysilylbutyl)amine. Among these, from the viewpoints of reactivity and interactivity between the functional group of the modifier and an inorganic filler such as silica, and from the viewpoint of processability, it is preferable that n, m, and l all represent 3. Preferable specific examples include tris(3-trimethoxysilylpropyl)amine and tris(3-triethoxysilylpropyl)amine.

[0096] The reaction temperature, reaction time, etc., when reacting the modifying agent represented by the formula (B) with the active terminal of the polymer are not particularly limited, but it is preferable to react at 0°C or higher and 120°C or lower for 30 seconds or longer. The total number of moles of alkoxy groups bonded to silyl groups in the compound of the modifying agent represented by the formula (B) is preferably in the range of 0.6 to 3.0 times the number of moles of lithium constituting the above-mentioned polymerization initiator, more preferably in the range of 0.8 to 2.5 times, and even more preferably in the range of 0.8 to 2.0 times. From the viewpoint of obtaining a sufficient modification rate, molecular weight, and branched structure in the modified conjugated diene polymer, it is preferably 0.6 times or more, and from the viewpoint of the cost of the modifying agent, it is preferable to couple the polymer terminals to each other to obtain a branched polymer component for improving processability, and it is preferably 3.0 times or less. More specifically, the number of moles of the polymerization initiator is preferably 4.0 times or more, more preferably 5.0 times or more, relative to the number of moles of the modifying agent.

[0097] In the above formula (C), A is preferably represented by any one of the following general formulae (II) to (V).

[0098] [ka]

[0099] (In formula (II), B 1 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. 1 are independent of each other.)

[0100] [ka]

[0101] (In formula (III), B 2 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms; B 3 represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. 2 and B. 3 are independent of each other.)

[0102] [ka]

[0103] (In formula (IV), B 4 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. 4 are independent of each other.)

[0104] [ka]

[0105] (In formula (V), B 5 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. 5 are independent of each other.)

[0106] In the formula (C), when A is represented by formula (II), the modifying agent is not limited to the following, but examples thereof include tris(3-trimethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)amine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tris(3-ethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-sila cyclopentane)propyl]amine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)amine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]amine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine.

[0107] In addition, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3 -Propanediamine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine Tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-triethoxysilylpropyl)-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[ Examples of the silylpropyl group include 3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, and tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-1,3-propanediamine.

[0108] In addition, tetrakis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propane Diamine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bis Aminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexa tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl] tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, and bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane.

[0109] In addition, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-1,3-propanediamine, tetrakis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bisaminomethylcyclohexane, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis(3-trimethoxysilylpropyl)-1,6-hexamethylenediamine, and pentakis(3-trimethoxysilylpropyl)-diethylenetriamine.

[0110] In the formula (C), when A is represented by formula (III), the modifying agent is not limited to the following, but examples thereof include tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, bis(2-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propanediamine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, and bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine. silylpropyl)-methyl-1,3-propanediamine, tris(3-triethoxysilylpropyl)-methyl-1,3-propanediamine, bis(2-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propanediamine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-methyl-1,3-propanediamine, N 1 ,N 1 '-(Propane-1,3-diyl)bis(N 1 -Methyl-N 3 ,N 3 -bis(3-(trimethoxysilyl)propyl)-1,3-propanediamine), and N 1 -(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N 1 -Methyl-N 3 -(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N 3 -(3-(trimethoxysilyl)propyl)-1,3-propanediamine.

[0111] In the formula (C), when A is represented by formula (IV), the modifying agent is not limited to the following, but may be, for example, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[ 3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, (3-trimethoxysilyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane yl]silane, bis[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2 -azacyclopentane)propyl]-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-bis(3-trimethoxysilylpropyl)silane, and bis(3-trimethoxysilylpropyl)-bis[3-(1-methoxy-2-methyl-1-sila-2-azacyclopentane)propyl]silane.

[0112] In the formula (C), when A is represented by formula (V), examples of the modifying agent include, but are not limited to, 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-(2,2-dimethoxy-1-aza-2-silacyclopentane)propane and 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-trimethoxysilylpropane.

[0113] In the formula (C), A is preferably represented by the formula (II) or the formula (III), and k is 0. Such a modifier tends to be easily available, and also tends to provide better abrasion resistance and low hysteresis loss performance when the conjugated diene polymer composition of the present embodiment containing the conjugated diene polymer (A) is vulcanized. Examples of such a modifying agent include, but are not limited to, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tris(3-trimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, and the like. tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, and bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trismethoxysilylpropyl)-methyl-1,3-propanediamine.

[0114] In the formula (C), A is more preferably represented by formula (II) or formula (III), k represents 0, and in formula (II) or formula (III), a represents an integer of 2 to 10. This tends to result in better abrasion resistance and low hysteresis loss performance when vulcanized. Examples of such modifiers include, but are not limited to, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, and N 1 -(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N 1 -Methyl-N 3 -(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N 3 -(3-(trimethoxysilyl)propyl)-1,3-propanediamine.

[0115] The amount of the compound represented by the formula (C) added as a modifier can be adjusted so that the modifier is reacted with the conjugated diene polymer in a desired stoichiometric ratio of the number of moles of the conjugated diene polymer to the number of moles of the modifier, which tends to achieve a desired highly branched star structure. Specifically, the number of moles of the conjugated diene polymer is preferably 5.0 times or more, more preferably 6.0 times or more, by mole relative to the number of moles of the modifying agent. In this case, the number of functional groups of the modifying agent in formula (C), ((m-1)xi+pxj+k), is preferably an integer of 5-10, and more preferably an integer of 6-10.

[0116] In the process for producing the conjugated diene polymer (A), a condensation reaction step in which a condensation reaction is carried out in the presence of a condensation promoter may be carried out after or before the above-mentioned reaction step.

[0117] The conjugated diene polymer (A) may be one in which the conjugated diene portion has been hydrogenated. The method for hydrogenating the conjugated diene portion of the conjugated diene polymer (A) is not particularly limited, and any known method can be used. A suitable hydrogenation method is to blow gaseous hydrogen into a polymer solution in the presence of a catalyst. Examples of the catalyst include heterogeneous catalysts such as catalysts in which a precious metal is supported on a porous inorganic material, catalysts in which a salt of nickel, cobalt, or the like is solubilized and reacted with an organoaluminum, etc., and homogeneous catalysts such as catalysts using metallocenes such as titanocene, etc. Among these, titanocene catalysts are preferred from the viewpoint of being able to select mild hydrogenation conditions. Hydrogenation of aromatic groups can also be carried out using supported noble metal catalysts.

[0118] Examples of the hydrogenation catalyst include, but are not limited to, (1) supported heterogeneous hydrogenation catalysts in which metals such as Ni, Pt, Pd, Ru, etc. are supported on carbon, silica, alumina, diatomaceous earth, etc., (2) so-called Ziegler-type hydrogenation catalysts using transition metal salts such as organic acid salts or acetylacetone salts of Ni, Co, Fe, Cr, etc. and reducing agents such as organoaluminum, and (3) so-called organometallic complexes such as organometallic compounds of Ti, Ru, Rh, Zr, etc. Further examples of the hydrogenation catalyst include known hydrogenation catalysts described in, for example, JP-B-42-8704, JP-B-43-6636, JP-B-63-4841, JP-B-1-37970, JP-B-1-53851, JP-B-2-9041, and JP-A-8-109219. Preferred hydrogenation catalysts include a reaction mixture of a titanocene compound and a reducing organometallic compound.

[0119] In the method for producing the conjugated diene polymer (A), after the reaction step, a deactivator, a neutralizing agent, etc. may be added to the polymer solution, if necessary. The quenching agent is not limited to the following, but examples thereof include water; alcohols such as methanol, ethanol, isopropanol, and the like; and the like. Examples of neutralizing agents include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and versatic acid (a highly branched carboxylic acid mixture having 9 to 11 carbon atoms, with the majority having 10 carbon atoms); aqueous solutions of inorganic acids, and carbon dioxide gas.

[0120] It is preferable to add a rubber stabilizer to the conjugated diene polymer (A) from the viewpoint of preventing gel formation after polymerization and improving stability during processing. The rubber stabilizer is not limited to the following ones, and known ones can be used. For example, antioxidants such as 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenol)propionate, and 2-methyl-4,6-bis[(octylthio)methyl]phenol are preferred.

[0121] <Extended conjugated diene polymer> The conjugated diene polymer (A) may be an extended conjugated diene polymer by adding at least one selected from the group consisting of an extending oil, a liquid rubber, and a resin to the conjugated diene polymer obtained by the above-mentioned production process. The extended conjugated diene polymer includes not only oil-extended conjugated diene polymers containing oil, but also those containing liquid polybutadiene and various resins other than oil. This can further improve the processability of the conjugated diene polymer. The method for adding the extender oil to the conjugated diene polymer is not limited to the following method, but a method in which the extender oil is added to a conjugated diene polymer solution, mixed, and the extended polymer solution is desolvated is preferred. Examples of extender oils include aromatic oils, naphthenic oils, and paraffinic oils. Among these, aromatic substitute oils having a polycyclic aromatic (PCA) content of 3% by mass or less according to the IP346 method are preferred from the viewpoints of environmental safety, oil bleed prevention, and wet performance. Examples of aromatic substitute oils include TDAE (Treated Distillate Aromatic Extracts), MES (Mild Extraction Solvate), and RAE (Residual Aromatic Extracts) shown in Kautschuk Gummi Kunststoffe 52(12)799(1999). Examples of liquid rubber include, but are not limited to, liquid polybutadiene and liquid styrene-butadiene rubber. Examples of resins include, but are not limited to, aromatic petroleum resins, coumarone-indene resins, terpene resins, rosin derivatives (including paulownia oil resins), tall oil, tall oil derivatives, rosin ester resins, natural and synthetic terpene resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, mixed aliphatic / aromatic hydrocarbon resins, coumarin-indene resins, phenolic resins, p-tert-butylphenol-acetylene resins, phenol-formaldehyde resins, xylene-formaldehyde resins, monoolefin oligomers, diolefin oligomers, hydrogenated aromatic hydrocarbon resins, cyclic aliphatic hydrocarbon resins, hydrogenated hydrocarbon resins, hydrocarbon resins, hydrogenated paulownia oil resins, hydrogenated oil resins, esters of hydrogenated oil resins with monofunctional or polyfunctional alcohols, and the like. These resins may be used alone or in combination of two or more. When hydrogenating, all of the unsaturated groups may be hydrogenated, or some of them may remain. The amount of at least one selected from the group consisting of extending oil, liquid rubber, and resin is not particularly limited, but is preferably 1 to 60 parts by mass, more preferably 5 to 60 parts by mass, and even more preferably 10 to 37.5 parts by mass, relative to 100 parts by mass of the conjugated diene polymer.

[0122] <Solvent removal process> The conjugated diene polymer (A) can be obtained from the polymer solution by a known method, for example, a method in which the solvent is separated by steam stripping or the like, the conjugated diene polymer is filtered, and then dehydrated and dried to obtain a conjugated diene polymer, a method in which the polymer is concentrated in a flashing tank and then devolatilized by a vent extruder or the like, or a method in which the polymer is directly devolatilized by a drum dryer or the like.

[0123] (Composition of Conjugated Diene Polymer Composition) The conjugated diene polymer composition of the present embodiment preferably contains 10 to 90 parts by mass of the above-mentioned conjugated diene polymer (A) having a glass transition temperature of -20°C or higher, and 10 to 90 parts by mass of a modified conjugated diene polymer (B) described below having a glass transition temperature of -25°C or lower, and further contains 0.5 to 30 parts by mass of a thermoplastic resin per 100 parts by mass of the total amount of the conjugated diene polymers (A) and (B).

[0124] (Conjugated diene polymer (B)) The conjugated diene polymer composition of the present embodiment contains 10 to 90 parts by mass of the above-mentioned conjugated diene polymer (A) and 10 to 90 parts by mass of a conjugated diene polymer (B) having a glass transition temperature of -25°C or lower. By containing the conjugated diene polymer (B), the abrasion resistance tends to be excellent when made into a vulcanizate. In the conjugated diene polymer composition of this embodiment, from the viewpoint of improving abrasion resistance, the glass transition temperature of the conjugated diene polymer (B) is preferably −35° C. or lower, more preferably −45° C. or lower, and even more preferably −55° C. or lower. The method for controlling the glass transition temperature of the conjugated diene polymer (B) is not particularly limited. For example, when the glass transition temperature is -35°C or lower, the amount of the aromatic vinyl compound is 5 to 30 mass% and the amount of the vinyl compound in the conjugated diene polymer is 10 to 70 mass%, thereby controlling the glass transition temperature within the above range. When the glass transition temperature is -55°C or lower, the amount of the aromatic vinyl compound is 5 to 20 mass% and the amount of the vinyl compound in the conjugated diene polymer is 10 to 40 mass%, thereby controlling the glass transition temperature within the above range. The glass transition temperature is measured by recording a DSC curve while increasing the temperature within a predetermined temperature range in accordance with ISO22768:2006, and the peak top (inflection point) of the DSC differential curve is determined as the glass transition temperature. Specifically, the glass transition temperature can be measured by the method described in the examples below. In addition, in the conjugated diene polymer composition of the present embodiment, the conjugated diene polymer (B) is preferably 20 parts by mass or more, and more preferably 30 parts by mass or more, from the viewpoint of reducing rolling resistance. Also, from the viewpoint of improving grip performance on wet road surfaces, the content is preferably not more than 80 parts by mass, and more preferably not more than 70 parts by mass.

[0125] The lower limit of the glass transition temperature of the conjugated diene polymer (B) is not particularly limited, but is preferably not less than −90° C. By adjusting the glass transition temperature to not less than −90° C., wet grip performance tends to be excellent.

[0126] The conjugated diene compound that is the raw material of the conjugated diene polymer (B) is not particularly limited as long as it is a polymerizable conjugated diene compound, and examples thereof include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-heptadiene, and 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

[0127] If the conjugated diene compound (B) contains allenes, acetylenes, etc. as impurities, the modification reaction of the polymer terminal may be inhibited. Therefore, the total content concentration (mass) of these impurities is preferably 300 ppm or less, more preferably 200 ppm or less, and even more preferably 100 ppm or less in some cases. Examples of the arenes include propadiene, 1,2-butadiene, etc. Examples of the acetylenes include ethyl acetylene, vinyl acetylene, etc.

[0128] The conjugated diene polymer (B) may be a copolymer of the above-mentioned conjugated diene compound and an aromatic vinyl compound. The aromatic vinyl compound may be any monomer that can be copolymerized with the conjugated diene compound, and is not particularly limited. Examples of the aromatic vinyl compound include styrene, m- or p-methylstyrene, α-methylstyrene, vinylxylene, vinylnaphthalene, diphenylethylene, and divinylbenzene. Among these, styrene is preferred from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

[0129] When the conjugated diene polymer (B) is a copolymer, it may be a random copolymer or a block copolymer. Examples of random copolymers include butadiene-isoprene random copolymers, butadiene-styrene random copolymers, isoprene-styrene random copolymers, and butadiene-isoprene-styrene random copolymers. The composition distribution of each monomer in the copolymer is not particularly limited, and examples include complete random copolymers that are close to a statistically random composition, and tapered (gradient) random copolymers with a gradient in composition distribution. The bond type of the conjugated diene, i.e., the composition of 1,4-bonds, 1,2-bonds, etc., may be uniform or different depending on the molecular chain.

[0130] Examples of block copolymers include type 2 block copolymers consisting of two blocks, type 3 block copolymers consisting of three blocks, and type 4 block copolymers consisting of four blocks. If a block consisting of an aromatic vinyl compound such as styrene is represented by S and a block consisting of a conjugated diene compound such as butadiene or isoprene and / or a block consisting of a copolymer of an aromatic vinyl compound and a conjugated diene compound is represented by B, then the block copolymers are represented as S-B2 type block copolymers, SB-S3 type block copolymers, SBS-B4 type block copolymers, etc.

[0131] In the above formula, the boundaries of each block do not necessarily need to be clearly distinguished. For example, when block B is a copolymer of an aromatic vinyl compound and a conjugated diene compound, the aromatic vinyl compound in block B may be distributed uniformly or in a tapered shape. In addition, block B may have a plurality of parts in which the aromatic vinyl compound is distributed uniformly and / or a plurality of parts in which the aromatic vinyl compound is distributed in a tapered shape. Furthermore, block B may have a plurality of segments with different aromatic vinyl compound contents. When a plurality of blocks S and blocks B are present in the copolymer, their structures such as molecular weight and composition may be the same or different.

[0132] The polymerization initiator used when polymerizing a conjugated diene compound or polymerizing a conjugated diene compound and an aromatic vinyl compound is not particularly limited as long as it is an anionic polymerization initiator. From the viewpoints of stability and ease of handling, however, alkyl compounds of metals such as aluminum, magnesium, lithium, sodium, and potassium are preferred, and among these, organolithium compounds are particularly preferred from the viewpoint of polymerization efficiency. The organolithium used as the polymerization initiator may be a low molecular weight compound or a solubilized oligomeric organolithium. In addition, the bonding mode between the organic group and lithium may be a compound containing a carbon-lithium bond, a compound containing a nitrogen-lithium bond, a compound containing a tin-lithium bond, or the like. Examples of organolithium compounds having a carbon-lithium bond include n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and stilbenelithium.

[0133] Examples of organolithium compounds containing a nitrogen-lithium bond include lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium di-n-hexylamide, lithium diisopropylamide, lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, and lithium morpholide.

[0134] As the organolithium, not only the above-mentioned monoorganolithium but also a polyfunctional organolithium can be used, or a monoorganolithium and a polyfunctional organolithium can be used in combination for polymerization. Examples of polyfunctional organolithium include 1,4-dilithiobutane, a reaction product of sec-butyllithium and diisopropenylbenzene, 1,3,5-trilithiobenzene, a reaction product of n-butyllithium and 1,3-butadiene and divinylbenzene, and a reaction product of n-butyllithium and a polyacetylene compound. Furthermore, organolithiums disclosed in U.S. Pat. No. 5,708,092, British Patent No. 2,241,239, U.S. Pat. No. 5,527,753, etc. can also be used. As the organolithium, n-butyllithium and sec-butyllithium are preferred from the viewpoints of industrial availability and ease of control of the polymerization reaction. The organolithium may be used alone or in combination of two or more.

[0135] When an organolithium is actually used as a polymerization initiator, it is preferable to use a solution obtained by diluting it in a hydrocarbon solvent in order to improve handling properties and dispersibility in the polymerization solution. Examples of the hydrocarbon solvent include C4-C8 hydrocarbon solvents, toluene, xylene, etc., which may be cyclic and may contain unsaturated bonds or branched structures. C5-C6 hydrocarbon solvents are preferred because their boiling points and vapor pressures make them easy to handle in the production process, and specifically, pentane, normal hexane, and cyclohexane are preferably used. The concentration of the organolithium diluted in the above-mentioned hydrocarbon solvent is preferably in the range of 0.01 to 1 mass %, more preferably 0.1 to 0.8 mass %, from the viewpoints of polymerization initiation efficiency and uniform mixing with the monomer.

[0136] The polymerization reaction of the conjugated diene compound is preferably carried out in a solvent. Examples of the solvent include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specific examples include acyclic aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; and hydrocarbons consisting of a mixture of two or more of these.

[0137] If the allenes and acetylenes, which are impurities in the conjugated diene compound, are treated with an organometallic compound before the polymerization reaction, a polymer having a high concentration of active ends tends to be obtained. Therefore, when a modification reaction is performed after the polymerization reaction, a high modification rate tends to be achieved, so it is preferable to perform the above-mentioned treatment.

[0138] In the polymerization reaction of the conjugated diene compound, a polar compound may be added. Polar compounds can be used to randomly copolymerize aromatic vinyl compounds with conjugated diene compounds, and can also be used as vinylating agents to control the microstructure of the conjugated diene moiety. The use of polar compounds is also effective in improving the polymerization rate. Examples of polar compounds that can be used include, but are not limited to, ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2,2-bis(2-oxolanyl)propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, and quinuclidine; alkali metal alkoxide compounds such as potassium t-amylate, potassium t-butylate, sodium t-butylate, and sodium amylate; and phosphine compounds such as triphenylphosphine. These polar compounds may be used alone or in combination of two or more.

[0139] The amount of the polar compound used is not particularly limited and can be selected depending on the purpose. Usually, it is preferably 0.01 to 100 moles per mole of the polymerization initiator. Such a polar compound (vinylating agent) can be used as a regulator of the microstructure of the conjugated diene portion of the conjugated diene polymer (B) in an appropriate amount depending on the desired vinyl bond amount.

[0140] Many polar compounds have an effective randomizing effect in the copolymerization of a conjugated diene compound and an aromatic vinyl compound, and can be used as an adjuster for the distribution of the aromatic vinyl compound and the amount of styrene blocks. As a method for randomizing the conjugated diene compound and the aromatic vinyl compound, for example, a method of intermittently adding a portion of 1,3-butadiene during copolymerization as described in JP-A-59-140211 may be used.

[0141] The polymerization temperature is not particularly limited as long as it is a temperature at which the polymerization proceeds, but from the viewpoint of productivity, it is preferably 0° C. or higher, and from the viewpoint of suppressing deactivation during polymerization, it is preferably 120° C. or lower.

[0142] From the viewpoint of preventing cold flow of the conjugated diene polymer (B), a polyfunctional aromatic vinyl compound such as divinylbenzene may be used to control branching.

[0143] From the viewpoint of vulcanization properties, the conjugated diene polymer (B) constituting the conjugated diene polymer composition of the present embodiment is preferably modified with a modifying agent such as a compound having a functional group that interacts with silica, such as a glycidyl group or an alkoxysilyl group. The modifier is not particularly limited, but preferably contains a compound represented by any one of the following general formulas (A) to (D).

[0144] [ka]

[0145] (In formula (A), R1 ~R 4 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms; R 5 represents an alkylene group having 1 to 10 carbon atoms; R 6 represents an alkylene group having 1 to 20 carbon atoms. m represents an integer of 1 or 2, n represents an integer of 2 or 3, and (m+n) represents an integer of 4 or more. 1 ~R 4 are independent of each other.)

[0146] [ka]

[0147] (In formula (B), R 1 ~R 6 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms; R 7 ~R 9 each independently represents an alkylene group having 1 to 20 carbon atoms. m, n, and l each independently represent an integer of 1 to 3, and (m+n+l) represents an integer of 4 or more. 1 ~R 6 are independent of each other.)

[0148] [ka]

[0149] (In formula (C), R 12 ~R 14 each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms; R 15 ~R 18 , and R 20 each independently represents an alkyl group having 1 to 20 carbon atoms; R 19 and R 22 each independently represents an alkylene group having 1 to 20 carbon atoms; R 21 represents an alkyl group having 1 to 20 carbon atoms or a trialkylsilyl group. m represents an integer of 1 to 3; p represents 1 or 2. R when there are multiple of each 12 ~R 22 , m, and p are each independent and may be the same or different. i represents an integer of 0 to 6, j represents an integer of 0 to 6, k represents an integer of 0 to 6, and (i+j+k) is an integer of 4 to 10. A represents a hydrocarbon group having 1 to 20 carbon atoms, or an organic group having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom, and a phosphorus atom and having no active hydrogen.

[0150] [ka]

[0151] (In formula (D), R 2 and R 3 are each independently a hydrocarbyl group having 1 to 20 carbon atoms; R 4 is an alkanediyl group having 1 to 20 carbon atoms, 2 is the group "*-C(R 1 )=N-" or the group "*-N=C(R 1 )-" (However, R 1 is a hydrogen atom or a hydrocarbyl group, and "*" is R 5 ) indicates that it is a bond that bonds to. R 5 is an m-valent hydrocarbyl group having 1 to 20 carbon atoms, or an m-valent group having 1 to 20 carbon atoms which has at least one atom selected from the group consisting of nitrogen atoms, oxygen atoms, and sulfur atoms and has no active hydrogen. n is an integer of 1 to 3, and m is an integer of 2 to 10. In formula (D), 2 , R 3 , R 4 , A 2 may be the same or different.)

[0152] The modifying agent represented by the formula (A) is not limited to the following, but may be, for example, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silacyclohexane, 2,2-dimethoxy-1-(5-trimethoxysilylpentyl)-1-aza-2-silacycloheptane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacic acid, 2-methoxy,2-methyl-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-ethoxy,2-ethyl-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-methoxy,2-methyl-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, and 2-ethoxy,2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silacyclopentane. Among these, from the viewpoints of reactivity and interaction between the functional group of the modifier and inorganic fillers such as silica, and processability, those in which m is 2 and n is 3 are preferred. Specifically, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane and 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane are preferred.

[0153] The reaction temperature, reaction time, etc., when reacting the modifying agent represented by the formula (A) with the active terminal of the polymer are not particularly limited, but it is preferable to react at 0°C or higher and 120°C or lower for 30 seconds or longer.

[0154] The total number of moles of alkoxy groups bonded to silyl groups in the compound of the modifying agent represented by the formula (A) is preferably in the range of 0.6 to 3.0 times, more preferably 0.8 to 2.5 times, and even more preferably 0.8 to 2.0 times, the number of moles of the alkali metal compound and / or alkaline earth metal compound added as the polymerization initiator. From the viewpoint of obtaining a sufficient modification rate, molecular weight, and branched structure of the resulting modified conjugated diene polymer (B), it is preferably 0.6 times or more, and from the viewpoint of obtaining a branched polymer component by coupling polymer terminals to improve processability and from the viewpoint of the cost of the modifying agent, it is preferably 3.0 times or less. More specifically, the number of moles of the polymerization initiator is preferably 3.0 times or more, more preferably 4.0 times or more, by mole relative to the number of moles of the modifying agent.

[0155] The modifying agent represented by the formula (B) includes, but is not limited to, tris(3-trimethoxysilylpropyl)amine, tris(3-methyldimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-methyldiethoxysilylpropyl)amine, tris(trimethoxysilylmethyl)amine, tris(2-trimethoxysilylethyl)amine, and tris(4-trimethoxysilylbutyl)amine. Among these, from the viewpoints of reactivity and interactivity between the functional group of the modifier and an inorganic filler such as silica, and from the viewpoint of processability, it is preferable that n, m, and l all represent 3. Preferable specific examples include tris(3-trimethoxysilylpropyl)amine and tris(3-triethoxysilylpropyl)amine.

[0156] The reaction temperature, reaction time, etc., when reacting the modifying agent represented by the formula (B) with the active terminal of the polymer are not particularly limited, but it is preferable to react at 0°C or higher and 120°C or lower for 30 seconds or longer.

[0157] The total number of moles of alkoxy groups bonded to silyl groups in the compound of the modifying agent represented by the formula (B) is preferably in the range of 0.6 to 3.0 times the number of moles of lithium constituting the above-mentioned polymerization initiator, more preferably in the range of 0.8 to 2.5 times, and even more preferably in the range of 0.8 to 2.0 times. In order to obtain a sufficient modification rate, molecular weight, and branched structure in the modified conjugated diene polymer (B), it is preferably 0.6 times or more, and in order to improve processability, it is preferable to couple polymer terminals to each other to obtain a branched polymer component, and in terms of the cost of the modifying agent, it is preferably 3.0 times or less. More specifically, the number of moles of the polymerization initiator is preferably 4.0 times or more, more preferably 5.0 times or more, relative to the number of moles of the modifying agent.

[0158] In the above formula (C), A is preferably represented by any one of the following general formulae (II) to (V).

[0159] [ka]

[0160] (In formula (II), B 1 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. 1 are independent of each other.)

[0161] [ka]

[0162] (In formula (III), B 2 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms; B 3 represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. 2 and B. 3 are independent of each other.)

[0163] [ka]

[0164] (In formula (IV), B 4 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. 4 are independent of each other.)

[0165] [ka]

[0166] (In formula (V), B 5 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 10. 5 are independent of each other.)

[0167] In the formula (C), when A is represented by formula (II), the modifying agent is not limited to the following, but examples thereof include tris(3-trimethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)amine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tris(3-ethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-sila cyclopentane)propyl]amine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)amine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]amine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine.

[0168] In addition, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3 -Propanediamine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine Tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-triethoxysilylpropyl)-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[ Examples of the silylpropyl group include 3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, and tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-1,3-propanediamine.

[0169] In addition, tetrakis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila -2-azacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, and bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane.

[0170] In addition, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, 1,3-bisaminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3 -trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis( Examples of the bis(3-triethoxysilylpropyl)-1,3-propanediamine include tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane and bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane.

[0171] In addition, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-1,3-propanediamine, tetrakis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bisaminomethylcyclohexane, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis(3-trimethoxysilylpropyl)-1,6-hexamethylenediamine, and pentakis(3-trimethoxysilylpropyl)-diethylenetriamine.

[0172] In the formula (C), when A is represented by formula (III), the modifying agent is not limited to the following, but examples thereof include tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, bis(2-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propanediamine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, and bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine. silylpropyl)-methyl-1,3-propanediamine, tris(3-triethoxysilylpropyl)-methyl-1,3-propanediamine, bis(2-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propanediamine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-methyl-1,3-propanediamine, N 1 ,N 1 '-(Propane-1,3-diyl)bis(N 1 -Methyl-N 3 ,N 3 -bis(3-(trimethoxysilyl)propyl)-1,3-propanediamine), and N 1 -(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N 1 -Methyl-N 3 -(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N 3 -(3-(trimethoxysilyl)propyl)-1,3-propanediamine.

[0173] In the formula (C), when A is represented by formula (IV), the modifying agent is not limited to the following, but may be, for example, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[ 3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, (3-trimethoxysilyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane yl]silane, bis[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2 -azacyclopentane)propyl]-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-bis(3-trimethoxysilylpropyl)silane, and bis(3-trimethoxysilylpropyl)-bis[3-(1-methoxy-2-methyl-1-sila-2-azacyclopentane)propyl]silane.

[0174] In the formula (C), when A is represented by formula (V), examples of the modifying agent include, but are not limited to, 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-(2,2-dimethoxy-1-aza-2-silacyclopentane)propane and 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-trimethoxysilylpropane. In the formula (C), A is preferably represented by formula (II) or formula (III), and k is 0.

[0175] The modifier represented by the above formula (C) tends to be easily available, and also tends to provide better abrasion resistance and low hysteresis loss performance when the conjugated diene polymer composition of the present embodiment containing the conjugated diene polymer (B) is vulcanized. Particularly preferred modifiers include, but are not limited to, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tris(3-trimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, and the like. tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, and bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trismethoxysilylpropyl)-methyl-1,3-propanediamine.

[0176] In the formula (C), A is more preferably represented by formula (II) or formula (III), k represents 0, and in formula (II) or formula (III), a represents an integer of 2 to 10. This tends to result in better abrasion resistance and low hysteresis loss performance when vulcanized. Examples of such modifiers include, but are not limited to, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, and N 1 -(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N 1 -Methyl-N 3 -(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N 3 -(3-(trimethoxysilyl)propyl)-1,3-propanediamine.

[0177] The amount of the compound represented by the formula (C) added as a modifying agent can be adjusted so that the modifier is reacted with the conjugated diene polymer so that the moles of the conjugated diene polymer before modification to the moles of the modifier are in a desired stoichiometric ratio, which tends to achieve a desired highly branched star structure.

[0178] Specifically, the number of moles of the conjugated diene polymer is preferably 5.0 times or more, more preferably 6.0 times or more, by mole relative to the number of moles of the modifying agent. In this case, the number of functional groups of the modifying agent in formula (C), ((m-1)xi+pxj+k), is preferably an integer of 5-10, and more preferably an integer of 6-10.

[0179] In the formula (D), R 2 , R 3Examples of the hydrocarbyl group include an alkyl group having 1 to 20 carbon atoms, an allyl group, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms. R 4 Examples of the hydrocarbylene group include an alkanediyl group having 1 to 20 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, and an arylene group having 6 to 20 carbon atoms. 4 is preferably linear. A 2 R has 1 With regard to n, the above explanation of the “specific imino group” applies. n is preferably 2 or 3, and more preferably 3, from the viewpoint of a high effect of improving silica dispersibility. R 5 Examples of the m-valent hydrocarbyl group include groups in which m hydrogen atoms have been removed from a chain hydrocarbon having 1 to 20 carbon atoms, an alicyclic hydrocarbon having 3 to 20 carbon atoms, or an aromatic hydrocarbon having 6 to 20 carbon atoms. From the viewpoint of a high effect of improving the abrasion resistance of the resulting vulcanized rubber, a group in which m hydrogen atoms have been removed from a ring portion of an aromatic hydrocarbon (aromatic ring group) is preferred. Examples of the aromatic hydrocarbon include a ring structure represented by the following formula (D-2) and a polycyclic structure (e.g., a biphenyl group) in which two or more of the ring structures are linked together.

[0180] [ka]

[0181] (In formula (D-2), r is an integer of 0 to 5.)

[0182] In the formula (D), R 5 When is an m-valent group having 1 to 20 carbon atoms having at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom and having no active hydrogen, preferred specific examples include an m-valent heterocyclic group, an m-valent group having a tertiary amine structure, and the like. The heterocyclic group is preferably a conjugated system, and examples thereof include a monocyclic or fused ring such as pyridine, pyrimidine, pyrazine, quinoline, naphthalidine, furan, or thiophene, or a group in which m hydrogen atoms have been removed from a ring portion of a structure in which a plurality of such monocyclic or fused rings are linked together. m is an integer from 2 to 10. m is preferably from 2 to 6 from the viewpoint of processability of the rubber composition. In this specification, the term "active hydrogen" refers to a hydrogen atom bonded to an atom other than a carbon atom, and preferably refers to one having a bond energy lower than that of the carbon-hydrogen bond of polymethylene.

[0183] The modifying agent represented by the formula (D) is not limited to the following, but examples thereof include compounds represented by the following formulae (M-1) to (M-23). These may be used alone or in combination of two or more. In addition, R in formula (M-11) 7 represents a hydrogen atom or an alkyl group. <Compound [M] used in the modification step: Formula (M-1) to Formula (M-23)>

[0184] [ka]

[0185] [ka]

[0186] [ka]

[0187] [ka]

[0188] In the formulas (M-1) to (M-23), Et is an ethyl group, and Me is a methyl group.

[0189] The conjugated diene polymer (B) used in the conjugated diene polymer composition of the present embodiment is not particularly limited, but is preferably a styrene-butadiene copolymer, and a commercially available product can also be used as necessary. Commercially available products are not particularly limited, but examples thereof include Asahi Kasei Corporation's trade name "Tufden 1834" (glass transition temperature -73°C), Asahi Kasei Corporation's trade name "Asaprene Y031" (glass transition temperature -25°C), Trinzeo Corporation's trade name "SLR3402" (glass transition temperature -60°C), Trinzeo Corporation's trade name "SLR4602" (glass transition temperature -30°C), JSR Corporation's trade name "HPR840" (glass transition temperature -60°C), JSR Corporation's trade name "HPR350" (glass transition temperature -34°C), JSR Corporation's trade name "HPR355" (glass transition temperature -25°C), JSR Corporation's trade name "HPR850" (glass transition temperature -25°C), ZS Elastomers' trade name "NS612" (glass transition temperature -60°C), and ZS Elastomers' trade name "NS616" (glass transition temperature -25°C). From the viewpoint of further improving wet grip performance, Asahi Kasei Corporation's product name "Asaprene Y031" (glass transition temperature -25°C) or JSR Corporation's product name "HPR350" (glass transition temperature -34°C) is preferred, and from the viewpoint of further improving abrasion resistance, Trinzeo Corporation's product name "SLR3402" (glass transition temperature -60°C) or JSR Corporation's product name "HPR840" (glass transition temperature -60°C) is preferred.

[0190] (thermoplastic resin) The conjugated diene polymer composition of the present embodiment preferably contains 0.5 parts by mass or more and 30 parts by mass or less of a thermoplastic resin per 100 parts by mass of the total amount of the above-mentioned conjugated diene polymers (A) and (B). By containing 0.5 parts by mass or more of thermoplastic resin, the tire has excellent grip performance on wet road surfaces. The thermoplastic resin used in the conjugated diene polymer composition of the present embodiment can be clearly distinguished from the above-mentioned conjugated diene polymers (A) and (B) in that it has a softening point and softens when heated. In addition, the thermoplastic resin generally has a glass transition temperature above room temperature and does not have a bonding property with silica, which is a filler, so that the abrasion resistance of the vulcanized product tends to be poor. From the viewpoint of excellent abrasion resistance, the content of the thermoplastic resin is preferably 10 parts by mass or less, more preferably 8 parts by mass or less.

[0191] The thermoplastic resin used in the conjugated diene polymer composition of the present embodiment is not particularly limited, and examples thereof include aromatic petroleum resins, coumarone-indene resins, terpene resins, rosin derivatives (including paulownia oil resins), tall oil, tall oil derivatives, rosin ester resins, natural and synthetic terpene resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, mixed aliphatic / aromatic hydrocarbon resins, coumarin-indene resins, phenol resins, p-tert-butylphenol-acetylene resins, phenol-formaldehyde resins, xylene-formaldehyde resins, monoolefin oligomers, diolefin oligomers, hydrogenated aromatic hydrocarbon resins, cyclic aliphatic hydrocarbon resins, hydrogenated hydrocarbon resins, hydrocarbon resins, hydrogenated paulownia oil resins, hydrogenated oil resins, and esters of hydrogenated oil resins with monofunctional or polyfunctional alcohols. These thermoplastic resins may be used alone or in combination of two or more. When hydrogenating, all of the unsaturated groups may be hydrogenated, or some of them may remain.

[0192] The conjugated diene polymer composition of the present embodiment preferably contains 0.5 to 30 parts by mass of a thermoplastic resin, 10 to 90 parts by mass of a conjugated diene polymer (A) having a glass transition temperature of not less than −20° C., and 10 to 90 parts by mass of a conjugated diene polymer (B) having a glass transition temperature of not more than −25° C. The conjugated diene polymer composition of the present embodiment having the above ratios is excellent in rolling resistance, grip performance on wet road surfaces, and abrasion resistance when made into a tire.

[0193] (Rubber-like polymers other than conjugated diene polymers (A) and (B)) The conjugated diene polymer composition of the present embodiment may contain a rubbery polymer (hereinafter simply referred to as a "rubbery polymer") other than the conjugated diene polymers (A) and (B). Examples of such rubbery polymers include, but are not limited to, a conjugated diene polymer or a hydrogenated product thereof, a random copolymer of a conjugated diene compound and a vinyl aromatic compound or a hydrogenated product thereof, a block copolymer of a conjugated diene compound and a vinyl aromatic compound or a hydrogenated product thereof, and others include a non-diene polymer and natural rubber. Examples of rubber-like polymers include, but are not limited to, styrene-based elastomers such as butadiene rubber or hydrogenated products thereof, isoprene rubber or hydrogenated products thereof, styrene-butadiene rubber or hydrogenated products thereof, styrene-butadiene block copolymer or hydrogenated products thereof, and styrene-isoprene block copolymer or hydrogenated products thereof, and acrylonitrile-butadiene rubber or hydrogenated products thereof.

[0194] Examples of non-diene polymers include, but are not limited to, olefin elastomers such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, and ethylene-octene rubber, butyl rubber, brominated butyl rubber, acrylic rubber, fluororubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α,β-unsaturated nitrile-acrylate-conjugated diene copolymer rubber, urethane rubber, and polysulfide rubber. Examples of natural rubber include, but are not limited to, smoked sheets such as RSS3 to 5, SMR, and epoxidized natural rubber. The above-mentioned various rubber-like polymers may be modified rubbers to which a polar functional group such as a hydroxyl group, an amino group, etc. When used for tires, butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber are preferably used. From the viewpoint of the balance between various performances and processing characteristics of the resin composition, the weight average molecular weight of the rubber-like polymer is preferably from 2000 to 2,000,000, and more preferably from 5000 to 1,500,000. Also, a low molecular weight rubber-like polymer, so-called liquid rubber, can be used. These rubber-like polymers may be used alone or in combination of two or more.

[0195] When the conjugated diene polymer composition of the present embodiment is a composition containing the rubber-like polymer, the content ratio (mass ratio) of the total of the conjugated diene polymers (A) and (B) to the rubber-like polymer (total of the modified conjugated diene polymers (A) and (B) / rubber-like polymer) is preferably 10 / 90 or more and 100 / 0 or less, more preferably 20 / 80 or more and 90 / 10 or less, and even more preferably 50 / 50 or more and 80 / 20 or less.

[0196] (Silica-based inorganic filler) The conjugated diene polymer composition of the present embodiment preferably contains a silica-based inorganic filler. From the viewpoint of exhibiting rolling resistance and of ensuring practically sufficient processability, cut resistance, and fatigue resistance, the amount of the silica-based inorganic filler is preferably 0.5 to 300 parts by mass, more preferably 5 to 200 parts by mass, and even more preferably 20 to 100 parts by mass, relative to 100 parts by mass of the total amount of the conjugated diene polymer (A), the conjugated diene polymer (B), and the rubber-like polymer.

[0197] The silica-based inorganic filler is not particularly limited, and for example, a known silica-based inorganic filler can be used. Specifically, the silica-based inorganic filler is preferably a solid particle containing SiO2 or Si3Al as a constituent unit, and more preferably contains SiO2 or Si3Al as the main constituent unit. Here, "containing SiO2 or Si3Al as the main constituent" means that the silica-based inorganic filler contains 50% by mass or more of the target component. The silica-based inorganic filler preferably contains 70% by mass or more, more preferably 80% by mass or more of SiO2 or Si3Al. More specifically, examples of the silica-based inorganic filler include silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and inorganic fibrous materials such as glass fiber. Also usable are silica-based inorganic fillers whose surfaces have been made hydrophobic, and mixtures of silica-based inorganic fillers and non-silica-based inorganic fillers. Among these, silica and glass fiber are preferred, and silica is more preferred, from the viewpoints of strength, abrasion resistance, etc. Examples of silica include dry silica, wet silica, and synthetic silicate silica. Among these, wet silica is preferred. The above-mentioned dry silica can be obtained, for example, by reacting purified silicon tetrachloride in a high-temperature flame, and compared to the wet type, the dry silica has a higher purity, finer particles, and an extremely low moisture content. In general, the dry silica is widely used as a filler for silicone rubber, a thickener or reinforcing agent for resins, or a fluidizing agent for powders, and a raw material for ceramics. The above-mentioned wet silica can be exemplified by the fact that an aqueous solution of sodium silicate made from silica sand is neutralized to precipitate silica, which is then filtered and dried. The resulting powder has a fluffy, light white appearance and is generally used as a reinforcing filler for synthetic rubber, for powdering and preventing caking of liquids such as agricultural chemicals, for preventing print ink from striking through to the back of lightweight paper, for thickening and preventing dripping of paints and inks, as a heat insulating material, and as an abrasive.

[0198] In the conjugated diene polymer composition of the present embodiment, from the viewpoint of obtaining better rolling resistance characteristics, the nitrogen adsorption specific surface area of ​​the silica-based inorganic filler determined by the BET adsorption method is 100 to 300 m 2 / g, and 170 to 250m 2 It is more preferable that the molecular weight is / g.

[0199] (Carbon Black) The conjugated diene polymer composition of the present embodiment preferably further contains 0.5 to 100 parts by mass of carbon black in addition to the silica-based inorganic filler, based on 100 parts by mass of the total amount of the conjugated diene polymer (A), the conjugated diene polymer (B), and the rubber-like polymer, from the viewpoint of reinforcement of tensile properties, etc. The carbon black is not particularly limited, and for example, carbon black of each class such as SRF, FEF, HAF, ISAF, SAF, etc. can be used. Among these, from the viewpoint of extrusion moldability and rolling resistance characteristics, carbon black having a nitrogen adsorption specific surface area of ​​50 m 2 / g or more, and a dibutyl phthalate (DBP) oil absorption of 80 mL / 100 g or more is preferred. From the viewpoint of a balance between rolling resistance characteristics, extrusion processability, and cut resistance, the amount of carbon black to be blended is more preferably 3 to 100 parts by mass, and even more preferably 5 to 50 parts by mass, based on 100 parts by mass of the total amount of the conjugated diene polymer (A), the conjugated diene polymer (B), and the rubber-like polymer.

[0200] (Metal oxides, metal hydroxides) The conjugated diene polymer composition of the present embodiment may contain a metal oxide or a metal hydroxide in addition to the silica-based inorganic filler and carbon black. Metal oxide refers to solid particles whose main component is a chemical formula MxOy (M represents a metal atom, and x and y each independently represent an integer of 1 to 6), and examples thereof include alumina, titanium oxide, magnesium oxide, and zinc oxide. A mixture of a metal oxide and an inorganic filler other than a metal oxide can also be used. The metal hydroxide is not particularly limited, and examples thereof include aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

[0201] The method for identifying the type and content ratio of the rubber component contained in the conjugated diene polymer composition of the present embodiment is not particularly limited, but can be identified by using NMR. For example, as previously reported (JSR TECHNICAL REVIEW No. 126 / 2019), the ratios of styrene units, 1,2-vinyl, 1,4-vinyl, 1,4-cis bonds, and isoprene units contained in a conjugated diene polymer composition can be quantitatively calculated using solid-state 13C-NMR.

[0202] (Silane coupling agent) The conjugated diene polymer composition of the present embodiment may contain a silane coupling agent. The silane coupling agent has a group having affinity or binding properties for each of the rubber component, the rubber-like polymer, and the silica-based inorganic filler, and has the function of strengthening the interaction between them. In general, a compound having a sulfur bond portion, an alkoxysilyl group, and a silanol group portion in one molecule is used.

[0203] Examples of the silane coupling agent include, but are not limited to, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, ethoxy(3-mercaptopropyl)bis(3,6,9,12,15-pentaoxaoctacosan-1-yloxy)silane [Evonik Silane coupling agents containing mercapto groups, such as Degussa's Si363, Momentive's NXT-Z30, NXT-Z45, NXTZ60, and NXT silane, bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide, bis(3-triethoxysilylpropyl)trisulfide, bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyl ... trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropyl benzothiazolyl tetrasulfide, 3-triethoxysilylpropyl benzolyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis(3-diethoxymethylsilylpropyl)tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, dimethoxymethylsilylpropyl benzothiazolyl tetrasulfide, and the like.Among them, from the viewpoint of high reinforcing effect, silane coupling agents containing a mercapto group, such as bis-[3-(triethoxysilyl)-propyl]-disulfide, ethoxy(3-mercaptopropyl)bis(3,6,9,12,15-pentaoxaoctacosan-1-yloxy)silane [Si363 manufactured by Evonik Degussa], and NXT-Z30, NXT-Z45, NXTZ60, and NXT silane manufactured by Momentive, and bis-[3-(triethoxysilyl)-propyl]-tetrasulfide are preferred. These silane coupling agents can be used alone or in combination of two or more.

[0204] From the viewpoint of making the effect of intensifying the interaction between the rubber component and the silica-based inorganic filler more pronounced, the amount of the silane coupling agent blended is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and even more preferably 1 to 15 parts by mass, relative to 100 parts by mass of the total amount of the conjugated diene polymer (A), the conjugated diene polymer (B), and the rubber-like polymer.

[0205] (rubber softener) The conjugated diene polymer composition of the present embodiment may contain a rubber softener in order to improve processability. Suitable rubber softeners include, for example, mineral oil-based rubber softeners and liquid or low molecular weight synthetic softeners. The mineral oil-based rubber softener is also called process oil or extender oil, and is used to soften rubber, increase its volume, and improve its processability. The mineral oil-based rubber softener is a mixture of aromatic rings, naphthene rings, and paraffin chains, and those in which the carbon number of the paraffin chain is 50% or more of the total carbon are called paraffin-based, those in which the carbon number of the naphthene ring is 30-45% are called naphthene-based, and those in which the aromatic carbon number is more than 30% are called aromatic. As a rubber softener to be used together with the modified conjugated diene-aromatic vinyl copolymer, those having a moderate aromatic content are preferred because they tend to have good affinity with the copolymer. The amount of the rubber softener is preferably 0 to 100 parts by mass, more preferably 10 to 90 parts by mass, and even more preferably 30 to 90 parts by mass, per 100 parts by mass of the total amount of the conjugated diene polymer (A), the conjugated diene polymer (B), and the rubber-like polymer. By setting the blending amount of the rubber softener within the above numerical range, the occurrence of bleed-out can be suppressed, and the occurrence of stickiness on the surface of the conjugated diene polymer composition can be prevented.

[0206] [Method for producing conjugated diene polymer composition] The conjugated diene polymer composition of the present embodiment can be obtained by mixing the above-mentioned conjugated diene polymers (A) and (B), and, if necessary, the above-mentioned thermoplastic resin, other rubber-like polymers, silica-based inorganic fillers, carbon black and other fillers, and additives such as silane coupling agents and rubber softeners. The mixing method is not limited to the following, but examples thereof include a melt-kneading method using a general mixer such as an open roll, a Banbury mixer, a kneader, a single-screw extruder, a twin-screw extruder, or a multi-screw extruder, and a method in which the components are dissolved and mixed and then the solvent is removed by heating. Among these, the melt kneading method using a roll, a Banbury mixer, a kneader, or an extruder is preferred from the viewpoints of productivity and good kneading properties. In addition, it is possible to use either a method in which the constituent materials of the conjugated diene polymer composition of the present embodiment are kneaded at once or a method in which the materials are mixed in separate batches.

[0207] The conjugated diene polymer composition of the present embodiment may be vulcanized with a vulcanizing agent to form a vulcanized composition. Examples of the vulcanizing agent include, but are not limited to, radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur compounds. The sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, polymeric polysulfur compounds, and the like. The content of the vulcanizing agent is preferably 0.01 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the total amount of the conjugated diene polymer (A), the conjugated diene polymer (B), and the rubber-like polymer. As the vulcanization method, a conventionally known method can be applied, and the vulcanization temperature is preferably 120°C or more and 200°C or less, and more preferably 140°C or more and 180°C or less.

[0208] In vulcanization, a vulcanization accelerator and a vulcanization aid may be used, if necessary. As the vulcanization accelerator, a conventionally known material can be used, and examples thereof include, but are not limited to, sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, thiourea-based, and dithiocarbamate-based vulcanization accelerators. Furthermore, the vulcanization aid may include, but is not limited to, zinc oxide and stearic acid. The content of the vulcanization accelerator is preferably 0.01 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 15 parts by mass or less, per 100 parts by mass of the total amount of the conjugated diene polymer (A), the conjugated diene polymer (B) and the rubber-like polymer.

[0209] In the conjugated diene polymer composition of the present embodiment, various additives such as softeners, fillers, heat stabilizers, antistatic agents, weather stabilizers, antioxidants, colorants, and lubricants other than those described above may be used within the scope of the present embodiment without impairing the object of the present embodiment. As the other softening agents, known softening agents can be used. Specific examples of other fillers include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. As the heat resistance stabilizer, antistatic agent, weather resistance stabilizer, antioxidant, colorant, and lubricant, known materials can be used.

[0210] 〔tire〕 The conjugated diene polymer composition of the present embodiment is suitably used as a rubber composition for tires. That is, the tire of the present embodiment is formed using the conjugated diene polymer composition of the present embodiment.

[0211] The conjugated diene polymer composition of the present embodiment can be used in various tire parts such as treads, carcasses, sidewalls, and beads of various tires, including fuel-efficient tires, all-season tires, high-performance tires, and studless tires, although the use is not limited thereto. In particular, the conjugated diene polymer composition of the present embodiment has a balance between low hysteresis loss and wet performance, and is excellent in abrasion resistance, when vulcanized, and is therefore more suitably used for the treads of fuel-saving tires and high-performance tires. EXAMPLES

[0212] Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples, but the present embodiment is not limited in any way to the following examples and comparative examples. Various physical properties in the examples and comparative examples were measured by the methods shown below. In the following Examples and Comparative Examples, the modified conjugated diene polymer is referred to as a "modified conjugated diene polymer." When it is unmodified, it is described as an "unmodified conjugated diene polymer". Furthermore, modified and unmodified ones may be collectively referred to as "conjugated diene polymers."

[0213] (Physical property 1) Bound styrene content The modified conjugated diene polymer or unmodified conjugated diene polymer (sample 19) was used as a sample, and 100 mg of the sample was made into 100 mL of chloroform and dissolved to prepare a measurement sample. The amount of bound styrene (mass%) relative to 100 mass% of the modified conjugated diene polymer or unmodified conjugated diene polymer (sample 19) was measured based on the amount of absorption of ultraviolet light by the phenyl group of styrene (near 254 nm) (Shimadzu Corporation spectrophotometer "UV-2450").

[0214] (Physical property 2) Microstructure of butadiene part (1,2-vinyl bond amount) The modified conjugated diene polymer or the unmodified conjugated diene polymer (sample 19) was used as a sample, and 50 mg of the sample was dissolved in 10 mL of carbon disulfide to prepare a measurement sample. Using a solution cell, infrared spectra are recorded from 600 to 1000 cm -1 The absorbance at a predetermined wave number was measured in the range of 100 nm to 150 nm, and the microstructure of the butadiene portion, i.e., the amount of 1,2-vinyl bonds (mol%) was calculated according to the formula of Hampton's method (method described in R.R. Hampton, Analytical Chemistry 21, 923 (1949)) (Fourier transform infrared spectrophotometer "FT-IR230" manufactured by JASCO Corporation).

[0215] (Physical properties 3) Molecular weight Measurement condition 1: An unmodified conjugated diene polymer or a modified conjugated diene polymer was used as a sample, and a chromatogram was measured using a GPC measurement device (manufactured by Tosoh Corporation under the trade name "HLC-8320GPC") in which three columns packed with polystyrene gel were connected, and an RI detector (manufactured by Tosoh Corporation under the trade name "HLC8020") was used. Based on a calibration curve obtained using standard polystyrene, the weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) were determined. The eluent used was tetrahydrofuran (THF) containing 5 mmol / L triethylamine. Three columns, Tosoh Corporation's "TSKgel SuperMultiporeHZ-H" (trade name), were connected, and a Tosoh Corporation's "TSKguardcolumn SuperMP(HZ)-H" (trade name) was connected in front of them as a guard column. 10 mg of the measurement sample was dissolved in 10 mL of THF to prepare a measurement solution, and 10 μL of the measurement solution was injected into a GPC measurement device and measured under conditions of an oven temperature of 40° C. and a THF flow rate of 0.35 mL / min. Among the various samples measured under the above measurement condition 1, samples whose molecular weight distribution (Mw / Mn) was less than 1.6 were measured again under the following measurement condition 2. For samples whose molecular weight distribution was 1.6 or more when measured under measurement condition 1, the results of measurement under measurement condition 1 are shown in Tables 1 to 3. Measurement condition 2: An unmodified conjugated diene polymer or a modified conjugated diene polymer was used as a sample, and a chromatogram was measured using a GPC measurement device having three columns connected together, each column using a polystyrene gel as a packing material, and the weight average molecular weight (Mw) and number average molecular weight (Mn) were calculated based on a calibration curve using standard polystyrene. The eluent used was THF containing 5 mmol / L triethylamine. The columns used were the following: guard column: Tosoh Corporation's product name "TSKguardcolumn SuperH-H"; columns: Tosoh Corporation's product names "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000". An RI detector (manufactured by Tosoh Corporation under the trade name "HLC8020") was used under the conditions of an oven temperature of 40° C. and a THF flow rate of 0.6 mL / min. 10 mg of a sample to be measured was dissolved in 20 mL of THF to prepare a measurement solution, and 20 μL of the measurement solution was injected into a GPC measurement device for measurement. For samples that were measured under measurement condition 1 and had a molecular weight distribution value of less than 1.6, the results of measurement under measurement condition 2 are shown in Tables 1 to 3.

[0216] (Physical Property 4) Contraction factor (g') A modified conjugated diene polymer or an unmodified conjugated diene polymer (sample 19) was used as a sample, and a GPC measuring device (trade name "GPCmax VE-2001" manufactured by Malvern) with three columns packed with polystyrene gel was used. Measurements were performed using three detectors connected in this order: a light scattering detector, an RI detector, and a viscosity detector (trade name "TDA305" manufactured by Malvern). Based on standard polystyrene, the absolute molecular weight was determined from the measurement results of the light scattering detector and the RI detector, and the intrinsic viscosity was determined from the measurement results of the RI detector and the viscosity detector. Linear polymer has an intrinsic viscosity [η] = -3.883M0.771 was used to calculate the shrinkage factor (g') as the ratio of the intrinsic viscosity corresponding to each molecular weight, where M is the absolute molecular weight. The eluent used was THF containing 5 mmol / L triethylamine. The columns used were "TSKgel G4000HXL", "TSKgel G5000HXL", and "TSKgel G6000HXL" manufactured by Tosoh Corporation. 20 mg of the measurement sample was dissolved in 10 mL of THF to prepare a measurement solution, and 100 μL of the measurement solution was injected into a GPC measurement device and measured under conditions of an oven temperature of 40° C. and a THF flow rate of 1 mL / min.

[0217] (Physical Property 5) Polymer Mooney Viscosity The Mooney viscosity of the unmodified conjugated diene polymer or modified conjugated diene polymer sample was measured using a Mooney viscometer (manufactured by Ueshima Seisakusho Co., Ltd., product name "VR1132") with an L-shaped rotor in accordance with JIS K6300. The measurement temperature was 110° C. when an unmodified conjugated diene polymer was used as the sample, and 100° C. when a modified conjugated diene polymer was used as the sample. First, the sample was preheated at the test temperature for 1 minute, and then the rotor was rotated at 2 rpm. The torque was measured after 4 minutes to determine the Mooney viscosity (ML (1+4) ) was decided.

[0218] (Physical property 6) Glass transition temperature (Tg) The modified conjugated diene polymer or the unmodified conjugated diene polymer (sample 19) was used as a sample, and a DSC curve was recorded in accordance with ISO 22768:2006 using a differential scanning calorimeter "DSC3200S" manufactured by Mac Science, Inc., while heating from -100°C at 20°C / min under a helium flow of 50 mL / min, and the peak top (inflection point) of the DSC differential curve was determined as the glass transition temperature.

[0219] (Physical property 7) Modification rate The modified conjugated diene polymer was used as a sample, and the measurement was carried out by utilizing the adsorption property of the modified basic polymer component in a GPC column packed with silica gel. The amount of a sample solution containing a sample and low molecular weight internal standard polystyrene was adsorbed onto the silica-based column by measuring the difference between the chromatogram measured using a polystyrene-based column and the chromatogram measured using a silica-based column, and the modification rate was calculated. Specifically, it is as follows: Furthermore, for samples that were measured under the above (Physical Property 3) Measurement Condition 1 and had a molecular weight distribution value of 1.6 or more, they were measured under the following Measurement Condition 3, and the measured value was adopted. For samples that were measured under the above (Physical Property 3) Measurement Condition 1 and had a molecular weight distribution value of less than 1.6, they were measured under the following Measurement Condition 4, and the measured value was adopted. The measurement results are shown in Tables 1 to 3.

[0220] Preparation of sample solution: 10 mg of sample and 5 mg of standard polystyrene were dissolved in 20 mL of THF to prepare a sample solution. Measurement condition 3: GPC measurement conditions using a polystyrene column: A Tosoh Corporation product name "HLC-8320GPC" was used, and 10 μL of the sample solution was injected into the device using THF containing 5 mmol / L triethylamine as the eluent. A chromatogram was obtained using an RI detector under the following conditions: column oven temperature 40°C, THF flow rate 0.35 mL / min. The columns used were three Tosoh Corporation products (TSKgel SuperMultiporeHZ-H) connected together, with a Tosoh Corporation product (TSKguardcolumn SuperMP(HZ)-H) connected in front of them as a guard column.

[0221] Measurement condition 4: GPC measurement conditions using a polystyrene column: A Tosoh Corporation product "HLC-8320GPC" was used, and 20 μL of the sample solution was injected into the device and measured using THF containing 5 mmol / L triethylamine as the eluent. The columns used were the guard column "TSKguardcolumn SuperH-H" manufactured by Tosoh Corporation, and the columns "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000" manufactured by Tosoh Corporation. The chromatogram was obtained by measurement using an RI detector (HLC8020 manufactured by Tosoh Corporation) under the conditions of a column oven temperature of 40°C and a THF flow rate of 0.6 mL / min.

[0222] GPC measurement conditions using a silica column: A Tosoh Corporation product name "HLC-8320GPC" was used, THF was used as the eluent, 50 μL of the sample solution was injected into the device, and a chromatogram was obtained using an RI detector under the conditions of a column oven temperature of 40°C and a THF flow rate of 0.5 ml / min. The columns used were Zorbax PSM-1000S, PSM-300S, and PSM-60S, and a guard column "DIOL 4.6 × 12.5 mm 5 micron" was connected to the front of the columns.

[0223] Calculation method of modification rate: The total peak area of ​​the chromatogram using a polystyrene-based column was set as 100, the peak area of ​​the sample was set as P1, the peak area of ​​the standard polystyrene was set as P2, the total peak area of ​​the chromatogram using a silica-based column was set as 100, the peak area of ​​the sample was set as P3, and the peak area of ​​the standard polystyrene was set as P4, and the modification rate (%) was calculated from the following formula. Denaturation rate (%) = [1-(P2 x P3) / (P1 x P4)] x 100 (where P1+P2=P3+P4=100)

[0224] (Physical Property 8) Branching Degree (Bn) A modified conjugated diene polymer or an unmodified conjugated diene polymer (sample 19) was used as a sample, and a GPC measuring device (trade name "GPCmax VE-2001" manufactured by Malvern) with three columns packed with polystyrene gel was used. Measurements were performed using three detectors connected in this order: a light scattering detector, an RI detector, and a viscosity detector (trade name "TDA305" manufactured by Malvern). Based on standard polystyrene, the absolute molecular weight M was calculated from the results of the light scattering detector and the RI detector, and the intrinsic viscosity [η] was calculated from the results of the RI detector and the viscosity detector. Linear polymer has an intrinsic viscosity [η] = -3.883M 0.771 was used to calculate the shrinkage factor (g') as the ratio of the intrinsic viscosity corresponding to each molecular weight. The obtained shrinkage factor (g') was then used to calculate the branching degree (Bn), defined as g' = 6Bn / [(Bn+1)(Bn+2)]. The eluent used was THF containing 5 mmol / L triethylamine. The columns used were "TSKgel G4000HXL", "TSKgel G5000HXL", and "TSKgel G6000HXL" manufactured by Tosoh Corporation. 20 mg of the measurement sample was dissolved in 10 mL of THF to prepare a measurement solution, and 100 μL of the measurement solution was injected into a GPC measurement device and measured under conditions of an oven temperature of 40° C. and a THF flow rate of 1 mL / min.

[0225] (Physical Properties 9) Molecular weight (absolute molecular weight) measured by GPC-light scattering method The modified conjugated diene polymer or the unmodified conjugated diene polymer (sample 19) was used as a sample, and a chromatogram was measured using a GPC-light scattering measurement device in which three columns packed with polystyrene gel were connected, and the weight average molecular weight (Mw-i) was calculated based on the solution viscosity and the light scattering method (also referred to as the "absolute molecular weight"). The eluent used was a mixed solution of tetrahydrofuran and triethylamine (THF in TEA: prepared by mixing 5 mL of triethylamine in 1 L of tetrahydrofuran). The columns used were a guard column (manufactured by Tosoh Corporation under the trade name "TSKguardcolumn HHR-H") and columns (manufactured by Tosoh Corporation under the trade names "TSKgel G6000HHR", "TSKgel G5000HHR", and "TSKgel G4000HHR"). A GPC-light scattering measuring device (trade name "Viscotek TDAmax" manufactured by Malvern Instruments) was used under conditions of an oven temperature of 40° C. and a THF flow rate of 1.0 mL / min. 10 mg of the sample to be measured was dissolved in 20 mL of THF to prepare a measurement solution, and 200 μL of the measurement solution was injected into the GPC measurement device and measured.

[0226] [Conjugated diene polymer] (Modified conjugated diene polymer (sample 1)) Two tank-type pressure vessels having an internal volume of 10 L, an internal height (L) to diameter (D) ratio (L / D) of 4.0, an inlet at the bottom and an outlet at the top, and an agitator as a tank-type reactor and a jacket for temperature control were connected together as polymerization reactors. 1,3-butadiene, which had been previously dehydrated, was mixed at 17.0 g / min, styrene at 11.4 g / min, and n-hexane at 175.2 g / min. This mixed solution was mixed with n-butyllithium for inactivating remaining impurities at 0.103 mmol / min in a static mixer installed in the middle of the piping supplying the inlet of the reactor, and then continuously supplied to the bottom of the reactor. Furthermore, 2,2-bis(2-oxolanyl)propane as a polar substance was supplied at a rate of 0.075 mmol / min, and n-butyllithium as a polymerization initiator was supplied at a rate of 0.143 mmol / min to the bottom of the first reactor, which was vigorously mixed with a stirrer, and the temperature inside the reactor was maintained at 67°C. The polymer solution was continuously withdrawn from the top of the first reactor and continuously fed to the bottom of the second reactor to continue the reaction at 70°C, and further fed to a static mixer from the top of the second reactor. When the polymerization was sufficiently stabilized, trimethoxy(4-vinylphenyl)silane (abbreviated as "BS-1" in the table) was added as a branching agent from the bottom of the second reactor at a rate of 0.0190mmol / min, and when the polymerization reaction and branching reaction were further stabilized, a small amount of the conjugated diene polymer solution before the addition of the modifier was withdrawn, an antioxidant (BHT: dibutylhydroxytoluene) was added so that it was 0.2g per 100g of polymer, and the solvent was then removed, and the Mooney viscosity at 110°C and various molecular weights were measured. Other physical properties are also shown in Table 1.

[0227] Next, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (abbreviated as "A" in the table) was continuously added as a modifier to the polymer solution flowing out from the outlet of the reactor at a rate of 0.0360 mmol / min, and the mixture was mixed using a static mixer to carry out a modification reaction. At this time, the time until the modifier was added to the polymer solution flowing out from the outlet of the reactor was 4.8 minutes, the temperature was 68°C, and the difference between the temperature in the polymerization process and the temperature before the modifier was added was 2°C. An antioxidant (BHT) was continuously added to the modified polymer solution at 0.055 g / min (n-hexane solution) so that the amount was 0.2 g per 100 g of polymer, and the modification reaction was terminated. Simultaneously with the antioxidant, oil (JOMO Process NC140 manufactured by JX Nippon Oil & Energy Corporation) was continuously added so that the amount was 37.5 g per 100 g of polymer, and the mixture was mixed using a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene-based polymer (Sample 1). The physical properties of Sample 1 are shown in Table 1.

[0228] (Modified conjugated diene polymer (sample 2)) A modified conjugated diene polymer (sample 2) was obtained in the same manner as (sample 1), except that the modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table) and the amount added was changed to 0.0250 mmol / min. The physical properties of sample 2 are shown in Table 1.

[0229] (Modified conjugated diene polymer (sample 3)) A modified conjugated diene polymer (sample 3) was obtained in the same manner as in (sample 1), except that the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table) and the amount of the modifying agent was changed to 0.0190 mmol / min. The physical properties of sample 3 are shown in Table 1.

[0230] (Modified conjugated diene polymer (sample 4)) A modified conjugated diene polymer (sample 5) was obtained in the same manner as in (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to dimethylmethoxy(4-vinylphenyl)silane (abbreviated as "BS-2" in the table) and the amount of the branching agent was changed to 0.0350 mmol / min. The physical properties of sample 4 are shown in Table 1.

[0231] (Modified conjugated diene polymer (sample 5)) A modified conjugated diene polymer (sample 5) was obtained in the same manner as (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to dimethylmethoxy(4-vinylphenyl)silane (abbreviated as "BS-2" in the table), and the amount added was changed to 0.0350 mmol / min, and the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table), and the amount added was changed to 0.0250 mmol / min. The physical properties of sample 5 are shown in Table 1.

[0232] (Modified conjugated diene polymer (sample 6)) A modified conjugated diene polymer (sample 6) was obtained in the same manner as (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to dimethylmethoxy(4-vinylphenyl)silane (abbreviated as "BS-2" in the table), and the amount added was changed to 0.0350 mmol / min, and the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table), and the amount added was changed to 0.0160 mmol / min. The physical properties of sample 6 are shown in Table 1.

[0233] (Modified conjugated diene polymer (sample 7)) A modified conjugated diene polymer (sample 7) was obtained in the same manner as in (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-(dimethylmethoxysilyl)phenyl)ethylene (abbreviated as "BS-3" in the table) and the amount added was changed to 0.0120 mmol / min. The physical properties of sample 7 are shown in Table 1.

[0234] (Modified conjugated diene polymer (sample 8)) A modified conjugated diene polymer (sample 8) was obtained in the same manner as (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-(dimethylmethoxysilyl)phenyl)ethylene (abbreviated as "BS-3" in the table) and the amount added was changed to 0.0120 mmol / min, and the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table) and the amount added was changed to 0.0250 mmol / min. The physical properties of sample 8 are shown in Table 1.

[0235] (Modified conjugated diene polymer (sample 9)) A modified conjugated diene polymer (sample 9) was obtained in the same manner as (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-(dimethylmethoxysilyl)phenyl)ethylene (abbreviated as "BS-3" in the table) and the amount added was changed to 0.0120 mmol / min, and the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table) and the amount added was changed to 0.0160 mmol / min. The physical properties of sample 9 are shown in Table 1.

[0236] (Modified conjugated diene polymer (sample 10)) A modified conjugated diene polymer (sample 10) was obtained in the same manner as in sample 1, except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-trimethoxysilylphenyl)ethylene (abbreviated as "BS-4" in the table) and the amount of the branching agent was changed to 0.0210 mmol / min. The physical properties of sample 10 are shown in Table 2.

[0237] (Modified conjugated diene polymer (sample 11)) A modified conjugated diene polymer (sample 11) was obtained in the same manner as (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-trimethoxysilylphenyl)ethylene (abbreviated as "BS-4" in the table), and the amount added was changed to 0.0210mmol / min, and the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table), and the amount added was changed to 0.0250mmol / min. The physical properties of sample 11 are shown in Table 2.

[0238] (Modified conjugated diene polymer (sample 12)) A modified conjugated diene polymer (sample 12) was obtained in the same manner as (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to 1,1-bis(4-trimethoxysilylphenyl)ethylene (abbreviated as "BS-4" in the table), and the amount added was changed to 0.0210mmol / min, and the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table), and the amount added was changed to 0.0160mmol / min. The physical properties of sample 12 are shown in Table 2.

[0239] (Modified conjugated diene polymer (sample 13)) A modified conjugated diene polymer (sample 13) was obtained in the same manner as in sample 1, except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to trichloro(4-vinylphenyl)silane (abbreviated as "BS-5" in the table). The physical properties of sample 13 are shown in Table 2.

[0240] (Modified conjugated diene polymer (sample 14)) A modified conjugated diene polymer (sample 14) was obtained in the same manner as (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to trichloro(4-vinylphenyl)silane (abbreviated as "BS-5" in the table), the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table), and the amount of the modified agent was changed to 0.0250 mmol / min. The physical properties of sample 14 are shown in Table 2.

[0241] (Modified conjugated diene polymer (sample 15)) A modified conjugated diene polymer (sample 15) was obtained in the same manner as (sample 1), except that the branching agent was changed from trimethoxy(4-vinylphenyl)silane to trichloro(4-vinylphenyl)silane (abbreviated as "BS-5" in the table), the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table), and the amount of the modified agent was changed to 0.0190 mmol / min. The physical properties of sample 15 are shown in Table 2.

[0242] (Modified conjugated diene polymer (sample 16)) A modified conjugated diene polymer (sample 16) was obtained in the same manner as (sample 1), except that the amount of branching agent added was changed to 0.025 mmol / min, the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table), and the amount added was changed to 0.0160 mmol / min. The physical properties of sample 16 are shown in Table 2.

[0243] (Modified conjugated diene polymer (sample 17)) A modified conjugated diene polymer (sample 17) was obtained in the same manner as in (sample 1), except that the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table) and the amount of the modifying agent was changed to 0.0110 mmol / min. The physical properties of sample 17 are shown in Table 2.

[0244] (Conjugated diene polymer (sample 18)) A conjugated diene polymer (sample 18) was obtained in the same manner as in (sample 1), except that the modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetraethoxysilane (abbreviated as "D" in the table) as a coupling agent and the amount of the modifier added was changed to 0.0250 mmol / min. The physical properties of sample 18 are shown in Table 2.

[0245] (Conjugated diene polymer (sample 19)) Except for not adding a modifying agent, an unmodified conjugated diene-based polymer (Sample 19) was obtained in the same manner as in Sample 1. The physical properties of Sample 19 are shown in Table 2. In Table 2, the bound styrene amount, vinyl bond amount, glass transition temperature, degree of branching, and absolute molecular weight are shown in the column for modified conjugated diene polymer.

[0246] (Modified conjugated diene polymer (sample 20)) Two tank-type pressure vessels having an internal volume of 10 L, an internal height (L) to diameter (D) ratio (L / D) of 4.0, an inlet at the bottom and an outlet at the top, and an agitator as a tank-type reactor and a jacket for temperature control were connected together as polymerization reactors. 1,3-butadiene, which had been previously dehydrated, was mixed at 18.6 g / min, styrene at 10.0 g / min, and n-hexane at 175.2 g / min. In a static mixer installed in the middle of the pipe supplying this mixed solution to the inlet of the reactor, n-butyllithium for inactivating remaining impurities was added at 0.103 mmol / min, mixed, and then continuously supplied to the bottom of the reactor. Furthermore, 2,2-bis(2-oxolanyl)propane as a polar substance was supplied at a rate of 0.081 mmol / min, and n-butyllithium as a polymerization initiator was supplied at a rate of 0.143 mmol / min to the bottom of the first reactor, which was vigorously mixed with a stirrer, and the temperature inside the reactor was maintained at 67°C. The polymer solution was continuously withdrawn from the top of the first reactor and continuously fed to the bottom of the second reactor to continue the reaction at 70°C, and then fed to the static mixer from the top of the second reactor. When the polymerization was sufficiently stabilized, a small amount of the polymer solution before the addition of the modifier was withdrawn, and an antioxidant (BHT) was added so that the amount was 0.2 g per 100 g of polymer, after which the solvent was removed and the Mooney viscosity at 110°C and various molecular weights were measured. Other physical properties are also shown in Table 3.

[0247] Next, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (abbreviated as "A" in the table) was continuously added as a modifier to the polymer solution flowing out from the outlet of the reactor at a rate of 0.0360 mmol / min, and the mixture was mixed using a static mixer to carry out a modification reaction. At this time, the time until the modifier was added to the polymer solution flowing out from the outlet of the reactor was 4.8 minutes, the temperature was 68°C, and the difference between the temperature in the polymerization process and the temperature before the modifier was added was 2°C. An antioxidant (BHT) was continuously added to the modified polymer solution at 0.055 g / min (n-hexane solution) so that the amount was 0.2 g per 100 g of polymer, and the modification reaction was terminated. Simultaneously with the antioxidant, oil (JOMO Process NC140 manufactured by JX Nippon Oil & Energy Corporation) was continuously added so that the amount was 37.5 g per 100 g of polymer, and the mixture was mixed using a static mixer. The solvent was removed by steam stripping to obtain a modified conjugated diene-based polymer (Sample 20). The physical properties of Sample 20 are shown in Table 3.

[0248] (Modified conjugated diene polymer (sample 21)) A modified conjugated diene polymer (sample 21) was obtained in the same manner as (sample 20), except that the modifier was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tris(3-trimethoxysilylpropyl)amine (abbreviated as "B" in the table) and the amount of the modifier was changed to 0.0250 mmol / min. The physical properties of sample 21 are shown in Table 3.

[0249] (Modified conjugated diene polymer (sample 22)) A modified conjugated diene polymer (sample 22) was obtained in the same manner as (sample 20), except that the modifying agent was changed from 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane to tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (abbreviated as "C" in the table) and the amount of the modifying agent was changed to 0.0190 mmol / min. The physical properties of sample 22 are shown in Table 3.

[0250] (Modified conjugated diene polymer (sample 23)) A modified conjugated diene polymer (sample 23) was obtained in the same manner as (sample 1), except that the amount of 2,2-bis(2-oxolanyl)propane added as a polar substance was changed to a rate of 0.098mmol / min, the amount of n-butyllithium added as a polymerization initiator was changed to a rate of 0.188mmol / min, the amount of trimethoxy(4-vinylphenyl)silane (abbreviated as "BS-1" in the table) added as a branching agent was changed to 0.0350mmol / min, and the amount of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane added as a modifier was changed to 0.0510mmol / min. The physical properties of sample 23 are shown in Table 3.

[0251] (Modified conjugated diene polymer (sample 24)) A modified conjugated diene polymer (sample 24) was obtained in the same manner as in (sample 1), except that the amount of 1,3-butadiene added was changed to 18.6 g / min and the amount of styrene added was changed to 10.0 g / min. The physical properties of sample 24 are shown in Table 3.

[0252] (Modified conjugated diene polymer (sample 25)) A 10L autoclave with a stirrer and a jacket was washed and dried, and the inside of the autoclave was replaced with nitrogen. Then, 720g of 1,3-butadiene, from which impurities such as moisture had been removed, 80g of styrene, and 5kg of cyclohexane were added. Then, 1.90mmol of 2,2-bis(2-oxolanyl)propane was added as a polar substance, and 2.5mmol of n-butyllithium was added to initiate polymerization at 52°C. The polymerization was carried out by adiabatic polymerization, and the maximum temperature reached 70°C. After polymerization was continued for another 5 minutes from the time when the maximum temperature was reached, the obtained reaction solution, i.e., a polymer solution containing a conjugated diene-based polymer consisting of a conjugated diene compound and an aromatic vinyl compound, was sampled, the solvent was removed, and analysis was performed. Next, a cyclohexane solution containing 1.3 mmol of compound M-1 (the compound shown as (M-1) in the above <Compounds used in the modification step>) as a modifier was added to the polymerization solution after sampling, and the reaction was carried out for 15 minutes. Then, 2 g of an antioxidant (BHT) was added to the resulting polymer solution, and the solvent was then removed to obtain a modified conjugated diene-based polymer (Sample 25). The bound styrene content of sample 25 was 10 mass %, the bound vinyl content was 30 mol %, and the glass transition temperature was -60°C.

[0253] [Table 1]

[0254] [Table 2]

[0255] [Table 3]

[0256] [Examples 1 to 19] and [Comparative Examples 1 to 5] According to the formulation shown below, conjugated diene polymer compositions containing the respective raw rubbers were obtained. Raw rubber: 100 parts by mass (50 parts by mass of conjugated diene polymers (samples 1 to 24) shown in Tables 1 to 3 above and 50 parts by mass of modified conjugated diene polymers (Trinzeo Corporation's product name "SLR3402", glass transition temperature: -60°C)) Silica (product name "Ultrasil 7000GR" manufactured by Evonik Degussa, nitrogen adsorption specific surface area 170 m2 / g): 50.0 parts by mass Carbon black (product name "Seast KH (N339)" manufactured by Tokai Carbon Co., Ltd.): 5.0 parts by mass Silane coupling agent (product name "Si75" manufactured by Evonik Degussa, bis(triethoxysilylpropyl)disulfide): 6.0 parts by mass S-RAE oil (product name "Process NC140" manufactured by JX Nippon Oil & Energy Corporation): 36 parts by mass Thermoplastic resin (product name "Neopolymer 120" manufactured by JXTG Corporation): 8 parts by mass Zinc white: 2.5 parts by mass Stearic acid: 1.0 parts by weight Antiaging agent (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine): 2.0 parts by mass Sulfur: 2.2 parts by mass Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazylsulfinamide): 1.7 parts by mass Vulcanization accelerator 2 (diphenyl guanidine): 2.0 parts by mass

[0257] Example 20 A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (sample 1): 50 parts by mass Modified conjugated diene polymer (sample 25, glass transition temperature: -60°C): 50 parts by mass

[0258] Example 21 A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (sample 1): 20 parts by mass Modified conjugated diene polymer (Trinzeo Corporation's product name "SLR3402", glass transition temperature: -60°C): 80 parts by mass

[0259] Example 22 A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (sample 1): 80 parts by mass Modified conjugated diene polymer (Trinzeo Corporation's product name "SLR3402", glass transition temperature: -60°C): 20 parts by mass

[0260] Example 23 A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the thermoplastic resin and oil were changed to the following composition. Thermoplastic resin (product name "Neopolymer 120" manufactured by JXTG Corporation): 15 parts by mass S-RAE oil (product name "Process NC140" manufactured by JX Nippon Oil & Energy Corporation): 27 parts by mass

[0261] Example 24 A conjugated diene-based polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (sample 1): 50 parts by mass Conjugated diene polymer (trade name "Tufden 1834" manufactured by Asahi Kasei Corporation, glass transition temperature: -73°C): 50 parts by mass

[0262] Example 25 A conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Conjugated diene polymer (sample 19): 50 parts by mass Conjugated diene polymer (trade name "Tufden 1834" manufactured by Asahi Kasei Corporation, glass transition temperature: -73°C): 50 parts by mass

[0263] Comparative Example 6 A modified conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (sample 1): 5 parts by mass Modified conjugated diene polymer (Trinzeo Corporation's product name "SLR3402", glass transition temperature: -60°C): 95 parts by mass

[0264] Comparative Example 7 A modified conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (sample 1): 95 parts by weight Modified conjugated diene polymer (Trinzeo Corporation's product name "SLR3402", glass transition temperature: -60°C): 5 parts by mass

[0265] Comparative Example 8 A modified conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (Trinzeo Corporation's product name "SLR3402", glass transition temperature: -60°C): 100 parts by mass

[0266] Comparative Example 9 A modified conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (sample 1): 100 parts by mass

[0267] Example 26 A modified conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the thermoplastic resin and oil were changed to the following composition. Thermoplastic resin (product name "Neopolymer 120" manufactured by JXTG Corporation): 35 parts by mass S-RAE oil (product name "Process NC140" manufactured by JX Nippon Oil & Energy Corporation): 7 parts by mass

[0268] Example 27 A modified conjugated diene polymer composition was obtained in the same manner as in Example 1, except that no thermoplastic resin was added and the oil was changed to the composition shown below. S-RAE oil (product name "Process NC140" manufactured by JX Nippon Oil & Energy Corporation): 42 parts by mass

[0269] Example 28 A modified conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (sample 1): 80 parts by mass Modified conjugated diene polymer (JSR Corporation's product name "HPR350", glass transition temperature: -34°C): 20 parts by mass

[0270] Example 29 A modified conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (sample 1): 20 parts by mass Modified conjugated diene polymer (product name "HPR350" manufactured by JSR Corporation, glass transition temperature: -34°C): 30 parts by mass

[0271] Comparative Example 10 A modified conjugated diene polymer composition was obtained in the same manner as in Example 1, except that the raw rubber was changed to the composition shown below. Modified conjugated diene polymer (product name "HPR350" manufactured by JSR Corporation, glass transition temperature: -34°C): 30 parts by mass

[0272] The above materials were kneaded by the following method to obtain rubber compositions. Using an internal mixer (capacity 0.3 L) equipped with a temperature control device, the raw rubber, fillers (silica 1, silica 2, carbon black), silane coupling agent, process oil, zinc oxide, and stearic acid were kneaded in the first stage under conditions of a filling rate of 65% and a rotor rotation speed of 30 to 50 rpm. At this time, the temperature of the internal mixer was controlled, and each rubber composition (compound) was obtained at a discharge temperature of 155 to 160°C. Next, as the second stage of kneading, the compound obtained above was cooled to room temperature, and then an antioxidant was added and kneaded again to improve the dispersion of silica. In this case, the discharge temperature of the compound was adjusted to 155 to 160°C by controlling the temperature of the kneader. After cooling, as the third stage of kneading, sulfur and vulcanization accelerators 1 and 2 were added and kneaded with an open roll set at 70°C. Then, the product was molded and vulcanized at 160°C for 20 minutes in a vulcanization press. The properties of the rubber composition before vulcanization and the rubber composition after vulcanization were evaluated. Specifically, the evaluation was performed by the following method. The results are shown in Tables 4 to 8.

[0273] [Evaluation of characteristics] (Evaluation 1) Compound Mooney Viscosity The mixture obtained above after the second mixing and before the third mixing was used as a sample, and the viscosity was measured using a Mooney viscometer in accordance with JIS K6300-1 after preheating at 130°C for 1 minute and rotating the rotor at 2 rotations per minute for 4 minutes. The result of Comparative Example 1 was set to 100 and indexed. The smaller the index, the better the processability.

[0274] (Evaluation 2) Viscoelastic parameters Viscoelastic parameters were measured in torsion mode using a viscoelasticity tester "ARES" manufactured by Rheometrics Scientific Corp. Each measured value was indexed with the result for the rubber composition of Comparative Example 1 set at 100. Tan δ measured at 0°C, a frequency of 10 Hz, and a strain of 1% was used as an index of wet performance. The higher the index, the better the wet performance. Tan δ measured at 50°C, a frequency of 10 Hz, and a strain of 3% was used as an index of fuel economy. The smaller the index, the better the fuel economy and the more excellent the rolling resistance.

[0275] (Rating 3) Tensile strength The tensile strength was measured according to the tensile testing method of JIS K6251, and indexed with the result of Comparative Example 1 being set at 100. A larger index indicates better tensile strength and superior breaking strength.

[0276] (Rating 4) Abrasion resistance Using an Acron abrasion tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.), the amount of wear was measured at a load of 44.4 N and 1000 revolutions in accordance with JIS K6264-2, and indexed based on the result of Comparative Example 1 being 100. A higher index indicates better abrasion resistance.

[0277] [Table 4]

[0278] [Table 5]

[0279] [Table 6]

[0280] [Table 7]

[0281] [Table 8]

[0282] As shown in Tables 4 to 8, it was confirmed that, compared with Comparative Examples 1 to 10, Examples 1 to 29 had low compound Mooney viscosity when vulcanized, exhibited good processability, and were excellent in rolling resistance characteristics, grip performance on wet road surfaces, and abrasion resistance when vulcanized. [Industrial Applicability]

[0283] The conjugated diene polymer composition according to the present invention has industrial applicability in the fields of tire treads, interior and exterior parts of automobiles, anti-vibration rubber, belts, footwear, foams, various industrial products, and the like.

Claims

1. 10 to 90 parts by mass of a conjugated diene polymer (A) having a glass transition temperature of −20° C. or higher; 10 to 90 parts by mass of a conjugated diene polymer (B) having a glass transition temperature of −25° C. or lower; Contains The conjugated diene polymer (A) has an absolute molecular weight of 40×10 as measured by a GPC-light scattering method with a viscosity detector. 4 Above 5000 x 10 4 or less, and the branching degree (Bn) measured by the viscosity detector-equipped GPC-light scattering method is 8 or more, the conjugated diene polymer (A) is a conjugated diene polymer having a star-shaped polymer structure with three or more branches, at least one branched chain of the star-shaped structure has a moiety derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group, and the polymer chain is branched at the moiety derived from the vinyl-based monomer containing an alkoxysilyl group or a halosilyl group; Conjugated diene polymer composition.

2. The glass transition temperature of the conjugated diene polymer (B) is −55° C. or lower. The conjugated diene polymer composition according to claim 1 .

3. The thermoplastic resin is contained in an amount of 0.5 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the total amount of the conjugated diene polymers (A) and (B). The conjugated diene polymer composition according to claim 1 or 2.

4. The conjugated diene polymer (A) and / or the conjugated diene polymer (B) are modified. The conjugated diene polymer composition according to any one of claims 1 to 3.

5. The modification rate of the conjugated diene polymer (A) is 60% by mass or more. The conjugated diene polymer composition according to claim 4.

6. the content of the thermoplastic resin is 0.5 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the total amount of the conjugated diene-based polymers (A) and (B); The conjugated diene polymer composition according to any one of claims 3 to 5.

7. The portion of the conjugated diene polymer (A) derived from the vinyl monomer containing an alkoxysilyl group or a halosilyl group is a monomer unit based on a compound represented by the following formula (1) or (2), and has a branch point of a polymer chain due to the monomer unit based on a compound represented by the following formula (1) or (2): At least one end of the conjugated diene polymer (A) is coupled with a coupling agent. The conjugated diene polymer composition according to any one of claims 1 to 6. 【Chemistry 1】 【Chemistry 2】 (In formula (1), R 1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. R 2 ~R 3 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. R when there are multiple 1 ~R 3 are each independent. X 1 represents an independent halogen atom. m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3. (In formula (2), R 2 ~R 5 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, which may partially have a branched structure. 2 ~R 5 are each independent. X 2 ~X 3 represents an independent halogen atom. m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3. a represents an integer from 0 to 2, b represents an integer from 0 to 3, and c represents an integer from 0 to 3. (m+n+l) represents 3.

8. In the formula (1), R 1 is a hydrogen atom, and m=0. The conjugated diene polymer composition according to claim 7.

9. The present invention includes a conjugated diene polymer (A) having a monomer unit based on a compound represented by the formula (2), in which m=0 and b=0 in the formula (2), The conjugated diene polymer composition according to claim 7.

10. In the formula (1), R 1 is a hydrogen atom, m = 0, and l = 0, The conjugated diene polymer composition according to claim 7 or 8.

11. The present invention includes a conjugated diene polymer (A) having a monomer unit based on a compound represented by formula (2), in which m = 0, l = 0, a = 0, and b = 0. The conjugated diene polymer composition according to claim 7 or 9.

12. In the formula (1), R 1 is a hydrogen atom, l=0, and n=3, The conjugated diene polymer composition according to any one of claims 7, 8 and 10.

13. A tire comprising the conjugated diene-based polymer composition according to any one of claims 1 to 12.

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